Photoconductor unit, cartridge, electrophotographic image forming apparatus

Abstract

Develop the photoreceptor unit. [Solution] A photoreceptor unit that can be attached to the main body of an image forming apparatus having a first main body side bevel gear section and a second main body side bevel gear section that rotate coaxially, comprising: a photoreceptor rotatable about a rotation axis; a first unit side bevel gear section for meshing with the first main body side bevel gear section; and a second unit side bevel gear section for meshing with the second main body side bevel gear section, wherein the twist direction of the teeth of the second unit side bevel gear section is the same as the twist direction of the teeth of the first unit side bevel gear section, and the twist angle of the teeth of the second unit side bevel gear section is greater than the twist angle of the teeth of the first unit side bevel gear section, and the first unit side bevel gear section and the second unit side bevel gear section rotate while the first unit side bevel gear section meshes with the first main body side bevel gear section and the second unit side bevel gear section meshes with the second main body side bevel gear section.

Description

Technical Field

[0001] The present invention relates to a cartridge detachable from an electrophotographic image forming apparatus and an electrophotographic image forming apparatus using the same.

[0002] An electrophotographic image forming apparatus forms an image on a recording medium using the electrophotographic image forming method. Examples of electrophotographic image forming apparatuses include, for example, electrophotographic copiers, electrophotographic printers (LED printers, laser beam printers, etc.), facsimile apparatuses, and word processors.

Background Art

[0003] In an electrophotographic image forming apparatus (hereinafter, also simply referred to as "image forming apparatus"), a toner image is formed on an electrophotographic photoreceptor (photosensitive drum or drum), and the toner image is transferred directly or indirectly onto a recording medium to form an image on the recording material.

[0004] Generally, in such an image forming apparatus, replenishment of toner (developer) and maintenance of various members are required. Therefore, there is a cartridge-type image forming apparatus configured such that a cartridge is detachable from the image forming apparatus, and by replacing the cartridge, replenishment of toner and maintenance can be performed.

[0005] A cartridge has at least one of a drum or process means and is detachably attached to the main body (apparatus main body) of the image forming apparatus. The process means is a means for forming an image, and examples of those acting on the drum mainly include developing means, charging means, transfer means, discharging means, cleaning means, etc. Examples of cartridges include process cartridges having a drum and at least one process means, which are integrally detachably attached to the apparatus main body, drum cartridges having a drum, developing cartridges having developing means, etc. According to such a cartridge system, it becomes possible to easily perform toner replenishment and maintenance of the image forming apparatus.

[0006] Configurations for transmitting driving force from the main body of the device to the cartridge included those using gears, as shown in Patent Document 1, and those using couplings, as shown in Patent Document 2. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 63-4252 [Patent Document 2] Japanese Patent Publication No. Hei 8-328449 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] The present invention (this disclosure) aims to develop a photoreceptor unit, cartridge, or electrophotographic image forming apparatus. [Means for solving the problem]

[0009] The present invention (this disclosure) discloses a photoreceptor unit that is detachable from the apparatus body of an image forming apparatus having at least a first body-side bevel gear portion and a second body-side bevel gear portion that rotate coaxially, the photoreceptor unit comprising a photoreceptor rotatable about a rotation axis, a first unit-side bevel gear portion for meshing with the first body-side bevel gear portion, and a second unit-side bevel gear portion for meshing with the second body-side bevel gear portion, wherein the twist direction of the teeth of the second unit-side bevel gear portion is the same as the twist direction of the teeth of the first unit-side bevel gear portion, the twist angle of the teeth of the second unit-side bevel gear portion is greater than the twist angle of the teeth of the first unit-side bevel gear portion, and the first unit-side bevel gear portion and the second unit-side bevel gear portion rotate while the first unit-side bevel gear portion is meshing with the first body-side bevel gear portion and the second unit-side bevel gear portion is meshing with the second body-side bevel gear portion. [Effects of the Invention]

[0010] According to the present invention (the present disclosure), a photoreceptor unit, a cartridge, or an electrophotographic image forming apparatus can be developed.

Brief Description of the Drawings

[0011] [Figure 1] Perspective view of the portion for driving transmission from the apparatus main body to the drum unit [Figure 2] Schematic cross-sectional view of the apparatus main body and the cartridge [Figure 3] Cross-sectional view of the cartridge [Figure 4] Exploded perspective view of the cartridge [Figure 5] Exploded perspective view of the cartridge [Figure 6] Exploded perspective view of the cleaning unit [Figure 7] Cross-sectional view of the driving portion from the apparatus main body to the cartridge [Figure 8] Cross-sectional view of the apparatus main body [Figure 9] Cross-sectional view of the apparatus main body [Figure 10] Cross-sectional view of the apparatus main body [Figure 11] Exploded perspective view of the apparatus main body [Figure 12] Perspective view of the driving transmission portion of the apparatus main body [Figure 13] Schematic diagram of the driving transmission gear of the apparatus main body [Figure 14] Schematic diagram of the driving transmission configuration from the driving transmission gear to the driving side flange [Figure 15] Diagram showing the driving transmission configuration from the driving side flange to the developing roller [Figure 16] Schematic diagram of the driving transmission gear and the driving side flange, cross-sectional view of the driving transmission gear [Figure 17] Cross-sectional view of the driving transmission gear and the driving side flange [Figure 18] Cross-sectional view of the driving transmission gear and the driving side flange [Figure 19] Side view of the driving transmission gear and the driving side flange [Figure 20] Side view of the driving transmission gear and the driving side flange [Figure 21]Figure showing the drive transmission gear and the drive-side flange [Figure 22] Figure showing the drive transmission gear and the drive-side flange [Figure 23] Cross-sectional view of the cartridge [Figure 24] Schematic diagram of the drive transmission configuration [Figure 25] Figure showing the drive transmission configuration [Figure 26] Cross-sectional view of the drive transmission section [Figure 27] Graph showing the deformation amounts of the coupling drive and the drive transmission gear [Figure 28] Figure showing the retraction mechanism [Figure 29] Schematic diagram showing the engagement of the drive-side flange and the developing roller gear [Figure 30] Perspective view of the cartridge [Figure 31] Cross-sectional view of the drive transmission gear and the drive-side flange [Figure 32] Figure showing the drive-side flange [Figure 33] Cross-sectional view of the drive-side flange and the drive transmission gear, graph showing the change in the number of teeth of the meshing gears [Figure 34] Cross-sectional view of the drive-side flange and the drive transmission gear, graph showing the change in the number of teeth of the meshing gears [Figure 35] Perspective view of the drive-side flange [Figure 36] Schematic diagram showing the engagement of the drive transmission gear and the drive-side flange [Figure 37] Perspective view of the image forming apparatus [Figure 38] Schematic diagram showing the engagement of the drive transmission gear and the drive-side flange [Figure 39] Cross-sectional view of the drive transmission gear and the drive-side flange [Figure 40] Cross-sectional view of the drive transmission gear and the drive-side flange [Figure 41] Cross-sectional view of the drive transmission gear and the drive-side flange [Figure 42] Perspective view of the drive-side flange, cross-sectional view of the drive transmission gear and the drive-side flange [Figure 43]Cross-sectional view of the drive-side flange, cross-sectional view of the drive transmission gear and the drive-side flange. [Figure 44] Partial perspective view of the cartridge [Figure 45] A cross-sectional view of the area near the drum of the cartridge, showing the drum and developing roller. [Figure 46] Cross-sectional view of the drive transmission gear and drive-side flange [Figure 47] Schematic diagram of the drive transmission gear and drive-side flange. [Figure 48] Cross-sectional view of the drive-side flange, cross-sectional view of the drive transmission gear and the drive-side flange. [Figure 49] Graph showing drive transmission error when alignment is misaligned. [Figure 50] Schematic cross-sectional view of the device body and cartridge [Figure 51] Disassembled perspective view of the cleaning unit [Figure 52] Perspective view of the drum bearing member, cross-sectional view of the drive-side flange and drum bearing member, partial cross-sectional view of the cartridge [Figure 53] Exploded perspective view of the main unit of the device. [Figure 54] Schematic cross-sectional view of the gear section of the drive transmission gear, schematic cross-sectional view of the gear section of the drive-side flange, schematic cross-sectional view of the gear section of the drive transmission gear and the gear section of the drive-side drum flange. [Figure 55] schematic cross-sectional view of the gear section of the drive transmission gear and the gear section of the drive-side drum flange. [Figure 56] Perspective view of the drive train that drives the developing roller, partial perspective view of the developing unit, perspective view of the cartridge. [Figure 57] Partial perspective view of the main body of the device [Figure 58] Cross-sectional view of the cleaning unit and drive transmission gear. [Figure 59] Partial perspective view of the cartridge [Figure 60] Cross-section of the drum unit [Figure 61] Partial perspective view of the drum unit [Figure 62] Cross-sectional view of the second gear section and the second main gear section. [Figure 63]Partial perspective view of the drum unit [Figure 64] Side view of the cleaning unit [Figure 65] Disassembled perspective view of the cleaning unit [Figure 66] Partial cross-sectional view of the cleaning unit [Figure 67] Partial cross-sectional view of the cleaning unit [Figure 68] Cross-sectional view showing the engagement state between the drum unit and the drive transmission gear. [Figure 69] Cross-sectional view showing the engagement state between the drum unit and the drive transmission gear. [Figure 70] Disassembled perspective view of the cleaning unit [Figure 71] Cross-sectional view showing the engagement state between the drum unit and the drive transmission gear. [Figure 72] Partial perspective view of the drum unit [Figure 73] Disassembled perspective view of the cleaning unit [Figure 74] Diagram showing the drum unit meshing with the drive transmission gear. [Figure 75] Cross-sectional view showing the engagement state between the drum unit and the drive transmission gear. [Figure 76] Partial perspective view of the drum unit [Figure 77] Disassembled perspective view of the cleaning unit and drum unit. [Figure 78] Cross-sectional view of the cleaning unit [Figure 79] Cross-sectional view showing the engagement state between the drum unit and the drive transmission gear. [Figure 80] Cross-sectional view showing the engagement state between the drum unit and the drive transmission gear. [Figure 81] Partial perspective view of the drum unit [Figure 82] Partial perspective view of the drum unit [Figure 83] Partial perspective view of the drum unit [Figure 84] Cross-section of the drum unit [Figure 85] Diagram showing the drum unit assembled into the cleaning unit. [Figure 86] Cross-sectional view of the drive side flange and drive transmission gear [Figure 87] Cross-sectional view of the drive side flange and drive transmission gear [Figure 88] Partial perspective view of the drum unit [Figure 89] Cross-sectional view of the drive-side flange [Figure 90] Diagram showing the drum unit assembled into the cleaning unit. [Figure 91] Cross-sectional view of the drive side flange and drive transmission gear [Figure 92] Side view of the cleaning unit [Figure 93] Exploded perspective view of the cleaning unit and drive-side drum flange. [Figure 94] Exploded perspective view of the drum bearing unit [Figure 95] Partial cross-sectional view of the cleaning unit [Figure 96] Diagram showing the cleaning unit [Figure 97] Partial cross-sectional view of the cleaning unit [Figure 98] Diagram showing the cartridge and the main unit of the device. [Figure 99] Diagram showing the drive-side drum flange 2463 that engages with the drive transmission gear. [Figure 100] A schematic cross-sectional view of the meshing portion between the drive-side drum flange and the drive transmission gear. [Figure 101] Diagram showing the cleaning unit [Figure 102] Disassembled perspective view of the cleaning unit and drum unit. [Figure 103] Partial cross-sectional view of the cleaning unit [Figure 104] Perspective view showing the cleaning unit and drive transmission gear. [Figure 105] A schematic cross-sectional view of the meshing portion between the drive gear, idler gear, and drive transmission gear. [Figure 106] A schematic cross-sectional view of the meshing portion between the drive gear, idler gear, and drive transmission gear. [Figure 107] A schematic cross-sectional view of the meshing portion between the drive gear, idler gear, and drive transmission gear. [Figure 108] Disassembled perspective view of the cleaning unit and drum unit. [Figure 109] Diagram showing the engagement state between the cleaning unit and the drive transmission gear. [Figure 110] A view of the cartridge along the direction of the drum's rotation axis. [Figure 111] Perspective view of the cartridge drive transmission mechanism [Figure 112] Perspective view of an alternative configuration of the drive transmission gear. [Figure 113] Diagram showing the cartridge [Figure 114] Diagram showing the cartridge [Modes for carrying out the invention]

[0012] [Example 1] <Overall configuration of the image forming apparatus> Figure 2 is a cross-sectional view of the electrophotographic image forming apparatus (image forming apparatus) 100, the cross-section being perpendicular to the rotation axis L1 of the photosensitive drum 62, which will be described later. The image forming apparatus 100 is a laser beam printer utilizing electrophotographic technology, and a cartridge B containing the photosensitive drum 62 is detachably mounted on the apparatus body A. In other words, the part of the image forming apparatus 100 excluding cartridge B is the apparatus body A. When cartridge B is mounted on the apparatus body A, it is possible to form an image on a recording medium (sheet material) PA such as paper.

[0013] <Configuration of the main device> The main body A of the apparatus includes an exposure device (laser scanner unit) 3 and a sheet tray 4 for storing the sheet material PA. Furthermore, the main body A includes a pickup roller 5a, a pair of transport rollers 5b, a transfer guide 6, a transfer roller 7, a transport guide 8, a fixing device 9, a pair of discharge rollers 10, and a discharge tray 11 along the transport direction D of the sheet material PA. The fixing device 9 is equipped with a heating roller 9a and a pressure roller 9b.

[0014] <Cartridge Configuration> Next, the overall configuration of cartridge B will be explained using Figures 3, 4, 5, 6, and 7. Figure 3 is a cross-sectional view of cartridge B, and its cross-section is perpendicular to the rotation axis L1 of the photosensitive drum 62, which will be described later. Figures 4 and 5 are exploded perspective views illustrating the configuration of cartridge B. Figure 6(a) is an exploded perspective view illustrating the configuration of the drum unit 69. Figure 6(b) is an exploded perspective view illustrating the configuration of the cleaning unit. Figure 7 is a cross-sectional view of the drive unit that transmits power from the image forming apparatus A to cartridge B. In this embodiment, screws and the like used to connect the various parts will be omitted from the explanation.

[0015] Cartridge B is a process cartridge and mainly comprises an electrophotographic photoreceptor and process means that act upon it. The process means are a charging means, a developing means, and a cleaning means, which will be described later. Cartridge B mainly has a structure comprising a cleaning unit (drum unit) 60 and a developing unit 20, and the electrophotographic photoreceptor and process means are provided in either the cleaning unit 60 or the developing unit 20.

[0016] The longitudinal direction of the drum 62 is parallel to the direction of the rotation axis L1 of the drum 62 (the rotation axis direction). Of the drum 62, the side to which the driving force is transmitted from the device body A in the direction of its rotation axis is called the driving side, and the opposite side is called the non-driving side. Furthermore, the direction from the non-driving side to the driving side along the rotation axis L1 of the drum 62 (parallel to the rotation axis L1) is called the J direction, and the direction from the driving side to the non-driving side is called the H direction. When defining the J direction and H direction in the device body A, they are defined to coincide with the J direction and H direction defined when the cartridge B is installed in the device body A.

[0017] <Cleaning Unit (Drum Unit)> As shown in Figure 3, the cleaning unit (drum unit) 60 includes a photosensitive drum 62, a charging roller 66, a cleaning member 77, and a cleaning frame (drum frame) 60a that supports them. The cleaning frame (drum frame) 60a includes a frame member 71 and a drum bearing member 73.

[0018] As shown in Figure 6(a), the rotating photosensitive drum (drum) 62 is a cylindrical electrophotographic photoreceptor, which is an aluminum cylinder with a photosensitive layer coated on its outer surface. A drive-side flange (driving force receiving member) 63 is crimped to the drive-side end (one end) of the drum 62, and a non-drive-side flange 64 is crimped to the non-drive-side end (the other end). The drum 62, drive-side flange 63, and non-drive-side flange 64 are integrated in this way (i.e., a unit that can rotate integrally with the drum 62), and this unit is called a drum unit 69.

[0019] In general, the cleaning unit 60 is sometimes referred to as the drum unit. However, in this case, the entire cleaning unit 60 is recognized as a unit having a drum 62, paired with the developing unit 20 which has a developing mechanism, when broadly recognizing the contents of cartridge B. Therefore, the term "drum unit" as a whole name for the cleaning unit 60 is a different concept from the drum unit 69 (a unit that can rotate integrally with the drum 62) in this embodiment. In the following explanation, "drum unit" refers to the unit that can rotate integrally with the drum 62.

[0020] The drum 62, the drive-side flange 63, and the non-drive-side flange 64 rotate integrally around the drum's axis of rotation L1. In other words, the axis of rotation of the drive-side flange 63, the non-drive-side flange 64, and the drum unit 69 are all coaxial with the drum 62's axis of rotation L1. For this reason, from now on, the axis of rotation of the drum 62, drive-side flange 63, non-drive-side flange 64, and the drum unit 69 in the assembled drum unit 69 will all be referred to as the axis of rotation L1.

[0021] Furthermore, the drive-side flange 63 and the non-drive-side flange 64 are integrally fixed with respect to the direction of the rotation axis L1. The drive-side flange 63 and the non-drive-side flange 64 are made of resin. The drive-side flange 63 includes a first gear section 63c and a second gear section 63d, which will be described in detail later.

[0022] As shown in Figure 6(b), the drum unit 69 is rotatably supported about the rotation axis L1 by the drum frame 60a (frame member 71 and drum bearing member 73). Specifically, the drive-side flange 63 has a hole 63g coaxial with the rotation axis L1, and a shaft member 86, which is press-fitted into the drum bearing member 73, is inserted into the hole 63g, thereby rotatably supporting the drive-side flange 63. The non-drive-side flange 64 has a hole (not shown) coaxial with the rotation axis L1, and a shaft member 78, which is press-fitted into a hole 71c of the frame member 71, is inserted into this hole, thereby rotatably supporting the drive-side flange 64. Thus, the non-drive-side flange 64 and the drive-side flange 63 are bearing-supported parts rotatably supported by the shaft members 86 and 78.

[0023] Furthermore, as shown in Figure 7, the second gear portion 63d of the drive-side flange 63 has a projection 63d1 protruding in the H direction on the downstream end face in the H direction, and a projection 63f protruding in the J direction on the upstream end face in the H direction (downstream end face in the J direction). The frame member 71 has a rib 71p and a side wall 71m that are provided to extend in a direction perpendicular to the rotation axis L1. The projection 63d1 can contact the side surface of the rib 71p, and the projection 63f can contact the side surface of the side wall 71m. The drive-side flange 63 is slidably fitted between the rib 71p and the side wall 71m in a clearance fit. For this reason, there may be cases where the projection 63d1 contacts the side surface of the rib 71p, and cases where the projection 63f contacts the side surface of the side wall 71m, but the fitting play (gap) is set to be extremely small (maximum of about 150 μm), and it can be said that in both cases the projection is positioned in substantially the same position. Thus, the drum unit 69, including the drive flange 63, is positioned relative to the drum frame 60a in the direction of the rotation axis L1 by the rib 71p or the side wall 71m.

[0024] In this embodiment, the longitudinal directions of the cartridge B, the drum frame 60a, and the frame member 71 are parallel to the direction of the rotation axis L1 of the drum 62.

[0025] Furthermore, as shown in Figure 3, in the cleaning unit 60, the charging roller (charging member) 66 as a charging means and the cleaning member 77 as a cleaning means are each positioned in contact with the outer circumferential surface of the drum 62. The cleaning member 77 comprises a rubber blade 77a, which is a blade-shaped elastic member made of rubber as an elastic material, and a support member 77b that supports the rubber blade 77a. The rubber blade 77a abuts against the drum 62 in a counter-direction with respect to the rotational direction of the drum 62. That is, the tip of the rubber blade 77a abuts against the drum 62 such that it faces upstream in the rotational direction of the drum 62. The waste toner removed from the surface of the drum 62 by the cleaning member 77 is contained (accumulated) in the waste toner chamber 71b formed by the frame member 71 and the cleaning member 77. A sheet 65 is attached to the edge of the frame member 71 so as to abut the drum 62, in order to prevent waste toner from leaking from the gap between the frame member 71 and the drum 62.

[0026] The charging roller 66 is rotatably supported at both ends in the direction of its rotation axis by charging roller bearings 67 supported by the frame member 71. The rotation axis of the charging roller 66 is approximately parallel to the rotation axis L1 of the drum 62. The charging roller 66 is pressed against the drum 62 by the charging roller bearings 67 being pressurized toward the drum 62 by a biasing member 68. The charging roller 66 rotates in accordance with the rotation of the drum 62.

[0027] <Developing Unit> As shown in Figure 3, the developing unit 20 includes a developing roller 32, a magnetic roller 34, a developing blade 42, a transport member 43, and a developing frame 20a that supports these. The developing frame 20a includes a developing container 23, a bottom member 22, a bearing member 24 (see Figure 5), a bearing member 37 (see Figure 4), a developing side cover 26 (see Figure 4), and a developing side cover 27 (see Figure 5). Inside the developing unit 20, the developing container 23 and the bottom member 22 form a toner supply chamber 28 and a toner chamber 29.

[0028] As shown in Figures 4 and 5, within the toner supply chamber 28, the developing roller 32 is rotatably supported at both ends in the direction of its rotation axis by bearing members 24 and 37. The bearing members 24 and 37 are attached to the developing container 23. The developing roller (developing member) 32, which acts as a developing means, is a cylindrical member, and a magnetic roller 34 is arranged inside it. A developing blade 42 that defines (regulates) the thickness of the toner (toner layer) carried on the surface of the developing roller 32 is arranged therein.

[0029] The developing roller 32 has spacing members 38 attached to both ends in the direction of its rotation axis. The spacing members 38 contact the surface of the drum 62, thereby determining the distance between the surface of the developing roller 32 and the surface of the drum 62. Specifically, the distance is determined so that a minute gap is formed between the surface of the developing roller 32 and the surface of the drum 62.

[0030] Furthermore, as shown in Figure 3, a sheet 33 is attached to the edge of the bottom member 22 so as to contact the developing roller 32, in order to prevent toner from leaking from the gap between the developing frame 20a and the developing roller 32. In addition, a transport member (agitation member) 43 is rotatably provided inside the toner chamber 29. By rotating, the transport member 43 agitates the toner contained in the toner chamber 29 and transports the toner from the toner chamber 29 to the toner supply chamber 28.

[0031] <Combining the cleaning unit and the developing unit> Cartridge B is assembled by combining the cleaning unit 60 and the developing unit 20. As shown in Figures 4 and 5, first, the center of the first development support boss 26a of the developing container 23 is aligned with the first suspension hole 71i on the drive side of the frame member 71, and the center of the second development support boss 27a is aligned with the second suspension hole 71j on the non-drive side. Then, by moving the developing unit 20 in the direction of arrow G, the first development support boss 26a and the second development support boss 27a are fitted into the first suspension hole 71i and the second suspension hole 71j. After that, the drum bearing member 73 is assembled to the cleaning unit 60, which restricts the developing unit 20 from detaching from the cleaning unit 60. This makes the developing unit 20 movably connected to the cleaning unit 60. Specifically, the developing unit 20 is rotatably connected to the cleaning unit 60 around the first development support boss 26a and the second development support boss 27a.

[0032] Furthermore, as shown in Figure 4, the first end 46Rb of the drive-side spring (biasing member) 46R is fixed to the surface 26b of the developing side cover 26, and the second end 46Ra abuts against the surface 71k of the frame member 71 of the cleaning unit 60. In addition, as shown in Figure 5, the first end 46Lb of the non-drive-side spring (biasing member) 46L is fixed to the surface 27b of the developing side cover 27, and the second end 46La abuts against the surface 71l of the frame member 71. The non-drive-side spring 46L and the drive-side spring 46R are compression springs. The biasing force of these springs generates a biasing force between the developing frame 20a and the cleaning frame 60a so as to press the developing roller 32 toward the drum 62. As a result, as described above, the spacing member 38 is pressed against the surface of the drum 62 and held in a state in which a predetermined gap is formed between the surface of the developing roller 32 and the surface of the drum 62.

[0033] <Image Formation Process> Next, the image formation process will be explained. The image formation process begins when a control unit (not shown) receives a print command signal from a host computer or the like, and generates a print start signal based on that signal.

[0034] When the image formation process begins, the drum 62 is first rotated at a predetermined peripheral speed (process speed) in the direction of arrow R (see Figures 2 and 3). A charging bias voltage is applied to the charging roller 66, and the surface (outer surface) of the drum 62 is charged substantially uniformly. Furthermore, as shown in Figure 2, the exposure apparatus (exposure means) 3 emits laser light L corresponding to the image information to be printed. This laser light L passes through the laser aperture 71h provided in the frame member 71 of the cartridge B and is irradiated onto the surface of the drum 62 that has been charged by the charging roller 66, scanning the surface of the drum 62 with the laser light L. As a result, an electrostatic latent image corresponding to the image information is formed on the photosensitive layer on the surface of the drum 62.

[0035] On the other hand, as shown in Figure 3, in the developing unit 20, the toner (developer) T in the toner chamber 29 is agitated and conveyed by the rotation of the transport member 43 and sent to the toner supply chamber 28. The toner T is supported on the surface of the developing roller 32 by the magnetic force of the magnetic roller (fixed magnet) 34. The developing roller 32 is a developer carrier that supports the toner T on its surface and visualizes (develops) the electrostatic latent image formed on the drum 62 with toner. The toner T is triboelectrically charged by the developing blade 42, and furthermore, the developing blade 42 regulates the thickness of the toner T layer on the circumferential surface of the developing roller 32 to a desired thickness. The toner T supported on the surface of the developing roller 32 is then supplied to and adheres to the region of the drum 62 corresponding to the electrostatic latent image. As a result, the electrostatic latent image on the drum 62 is made visible (developed) as a toner image. The drum 62 can be said to be an image carrier that supports the electrostatic latent image and the toner image (developer image) on its surface.

[0036] Furthermore, as shown in Figure 2, in synchronization with the output timing of the laser beam L, the sheet material PA stored in the sheet tray 4 at the bottom of the main body A is fed into the transport path within the main body A by the pickup roller 5a and the transport roller pair 5b. Subsequently, the sheet material PA is guided by the transfer guide 6 and transported to the transfer nip between the drum 62 and the transfer roller (transfer means) 7. At this transfer nip, the toner image formed on the drum 62 is transferred onto the sheet material PA.

[0037] The sheet material PA, on which the toner image has been transferred after passing through the transfer nip, is guided by the transport guide 8 and transported to the fixing device (fixing means) 9. The sheet material PA then passes through the fixing nip between the heating roller 9a and the pressure roller 9b of the fixing device 9. In this fixing nip, the sheet material PA is pressurized and heated, fusing and fixing the toner image to the sheet material PA. After passing through the fixing nip, the sheet material PA is transported to the discharge roller pair 10 and discharged onto the discharge tray 11.

[0038] On the other hand, as shown in Figure 3, the surface of the drum 62 after passing through the transfer nip comes into contact with the cleaning blade 77, and the toner remaining on the surface of the drum 62 is removed, making it usable again for the image forming process described above. The toner removed from the drum 62 by the cleaning blade 77 is stored as waste toner in the waste toner chamber 71b of the cleaning unit 60.

[0039] In this embodiment, at least the charging roller 66, exposure apparatus 3, developing roller 32, transfer roller 7, and cleaning blade 77 are process means that act on the drum 62.

[0040] <Cartridge installation and removal> Next, the installation of cartridge B into the device body A will be explained in detail using Figures 8, 9, and 10. Figure 8(a) is a cross-sectional view of the drive side of the device body A with the door 13 open, and Figure 8(b) is a cross-sectional view of the non-drive side of the device body A with the door 13 open. The cross-sections shown in Figures 8(a) and 8(b) are cross-sections perpendicular to the rotation axis L1. Figure 9 is a diagram for explaining the positioning of cartridge B in the longitudinal direction (direction of the rotation axis L1), and is a cross-sectional view obtained by cutting the fitting portion 15j of the device body A with a horizontal plane parallel to the rotation axis L1 (a plane parallel to the installation surface of the device body A). Figure 9(a) shows the state just before cartridge B is fitted into the fitting portion 15j, and Figure 9(b) shows the state after cartridge B has been fitted into the fitting portion 15j. Figure 10(a) is a cross-sectional view of the drive side of the device body A with the door 13 closed, and Figure 10(b) is a cross-sectional view of the non-drive side of the device body A with the door 13 closed. The cross-sections shown in Figures 10(a) and 10(b) are perpendicular to the rotation axis L1.

[0041] First, the installation of cartridge B into the device body A will be explained. The device body A is provided with a first drive-side plate 15 and a non-drive-side plate 16 so as to sandwich cartridge B, which is installed in the device body A, with respect to the direction of the rotation axis L1. The device body A is also rotatably fitted with a door 13 for opening and closing the insertion opening 17. The first drive-side plate 15 has an upper guide rail 15g and a lower guide rail 15h that guide cartridge B when it is installed and removed. The non-drive-side plate 16 has an upper guide rail 16d and a lower guide rail 16e that guide cartridge B when it is installed and removed. Furthermore, the drum bearing member 73 of cartridge B is provided with a guided portion 73g and a rotation-stopping portion 73c, and the frame member 71 has a positioning portion 71d and a rotation-stopping portion 71g. Therefore, the guided portion 73g and the rotation-stopping portion 73c are located on the drive side of cartridge B, while the guided portion 73g and the rotation-stopping portion 73c are located on the non-drive side of cartridge B.

[0042] When the door 13 of the device body A is opened, and the insertion opening 17 formed between the first drive-side plate 15 and the non-drive-side plate 16 is open, cartridge B can be inserted into or removed from the device body A through the insertion opening 17. At this time, cartridge B can be inserted into and mounted in the device body A, and removed from the device body A, by moving cartridge B in a direction substantially perpendicular to the rotation axis L1 of the drum 62. In other words, the mounting direction M of cartridge B to the device body A (see Figure 9(a)) and the removal direction from the device body A (the opposite direction of mounting direction M) are substantially perpendicular to the rotation axis L1. Since the rotation axis L1 of cartridge B mounted in the device body A is parallel to the rotation axis L2 of the drive transmission gear 81, it can also be said that the mounting direction M of cartridge B to the device body A and the removal direction from the device body A are substantially perpendicular to the rotation axis L2. Furthermore, when cartridge B is attached to and removed from the device body A, the drum unit 69 moves integrally with cartridge B relative to the device body A, and is attached to and removed from the device body A. Therefore, the direction in which the drum unit 69 is attached to and removed from the device body A is the same as the direction M in which cartridge B is attached to and removed from the device body A, respectively.

[0043] <Cartridge installation and positioning> As cartridge B is inserted into the device body A through the cartridge insertion opening 17, the guided portion 73g and the rotation-preventing portion 73c on the drive side of cartridge B are guided by the upper guide rail 15g and the guide rail 15h, respectively. The positioning portion 71d and the rotation-preventing portion 71g on the non-drive side of cartridge B are guided by the upper guide rail 16d and the lower guide rail 16e. As cartridge B is guided and inserted into the device body A in this manner, the mounting of cartridge B into the device body A is finally completed.

[0044] As shown in Figures 9(a) and 9(b), the drum bearing member 73 has a fitted portion 73h as a positioned portion (axially positioned portion) that is positioned relative to the device body A with respect to the direction of the rotation axis L1. The fitted portion 73h has a concave shape (or groove shape or slit shape) that is recessed in the mounting direction M (direction perpendicular to the rotation axis L1). On the other hand, the first drive side plate 15 of the device body A has a fitted portion 15j that can be fitted with the fitted portion 73h. The fitted portion 15j has a convex shape that protrudes in the opposite direction to the mounting direction MD.

[0045] During the process of inserting cartridge B into the device body A, as shown in Figure 9(b), the position of cartridge B in the direction of its rotation axis L1 (the longitudinal direction of cartridge B) is determined when the mating portion 73h engages with the mating portion 15j. Although the mating of the mating portion 73h and the mating portion 15j is a clearance fit, the play (gap) is set to be extremely small (maximum of about 150 μm). Therefore, regardless of whether the mating portion 73h abuts against the mating portion 15j in the H direction or the J direction, cartridge B is positioned in substantially the same position with respect to the direction of its rotation axis L1.

[0046] Furthermore, as shown in Figures 8(a), 8(b), 10(a), and 10(b), the first drive-side plate 15 has a positioning portion 15a, a positioning portion 15b, and a rotation-stopping portion 15c, while the non-drive-side plate 16 has a positioning portion 16a, a positioning portion 16b, and a rotation-stopping portion 16c. Cartridge pressing members 1 and 2 are attached to both ends of the door 13 in the direction of the rotation axis of the door 13 so as to be movable (rotatable) relative to the door 13. In addition, pressing springs 19 and 21 are attached to the first drive-side plate 15 and the non-drive-side plate 16, respectively.

[0047] Furthermore, as shown in Figure 3, the drum bearing member 73 of cartridge B has a pressed portion (biasing force receiving portion) 73e, and the frame member 71 has a pressed portion (biasing force receiving portion) 71n. The pressed portions 73e and 71n are provided in concave-shaped portions located on the drive side and non-drive side of cartridge B, respectively.

[0048] As shown in Figures 10(a) and 10(b), when the door 13 is closed, the cartridge pressing members 1 and 2 are biased toward cartridge B by the pressing springs 19 and 21. The cartridge pressing members 1 and 2 then come into contact with the parts to be pressed 73e and 71n, and the biasing force of the pressing springs 19 and 21 presses the parts to be pressed 73e and 71n.

[0049] As a result, on the drive side, the positioned portion 73g of cartridge B contacts the positioning portions 15a and 15b of the device body A, and the rotation-stopping portion 73c contacts the rotation-stopping portion 15c of the device body A. This positions the drive-side portion of the drum frame 60a of cartridge B in a direction perpendicular to the rotation axis L1, and restricts rotation around an axis parallel to the rotation axis L1. On the non-drive side, the positioned portion 71d of cartridge B contacts the positioning portions 16a and 16b of the device body A, and the rotation-stopping portion 71g contacts the rotation-stopping portion 16c of the device body A. This positions the non-drive-side portion of the drum frame 60a of cartridge B in a direction perpendicular to the rotation axis L1, and restricts rotation around an axis parallel to the rotation axis L1.

[0050] By positioning the drum frame 60a of cartridge B relative to the main body A in this way, the drum unit 69, which is positioned relative to the drum frame 60a, is also indirectly positioned relative to the main body A.

[0051] <Drive transmission to the drum unit> Next, the configuration for transmitting drive from the main body A to the drum unit 69 and drum 62 will be described. Figure 1 is a perspective view of the part that transmits drive from the main body A to the drum unit 69. Figure 11 is an exploded perspective view showing the support configuration of the drive transmission gear 81 of the main body A. Figure 12 is a perspective view showing the drive transmission section of the main body A. Figure 13(a) is a schematic diagram showing the drive transmission gear 81 of the main body A. Figure 13(b) is a schematic diagram showing the drive-side flange 63 of the cartridge B. Note that in Figures 13(a) and 13(b), the teeth of the gear are shown as the ridges of the tooth tips. Figure 14 is a schematic diagram showing the drive transmission configuration from the drive transmission gear 81 of the main body A to the drive-side flange 63 of the cartridge B.

[0052] <Drive configuration on the main device side> As shown in Figure 11, the device body A includes a motor (not shown), an idler gear 80, a drive transmission gear 81, a second drive-side plate 83, a main frame 84, a drive shaft 82, and a compression spring 85. The driving force from the motor is transmitted from the idler gear 80 to the drive transmission gear 81. The idler gear 80 and the drive transmission gear 81 are supported by the drive shaft 82 so that they can rotate coaxially with each other and move in the direction of their rotational axis. One end 82a of the drive shaft 82 is fixed to a hole 83a in the second drive-side plate 83, and the other end 82b is supported by a hole 84a in the main frame 84. The drive shaft 82 is positioned so that the rotational axis of the drive transmission gear 81 is parallel to the rotational axis L1 of the drum 62 when the cartridge B is mounted on the device body A.

[0053] Furthermore, a compression spring 85 is provided between the other end 80b of the idler gear 80 and the second drive-side plate 83, biasing the idler gear 80 in the H direction in the direction of the rotation axis. As mentioned above, the J and H directions in the device body A are defined to coincide with the J and H directions of the cartridge B mounted on the device body A. As a result, as shown in Figure 11, the J direction is the direction from the idler gear 80 towards the second drive-side plate 83 along the rotation axis of the idler gear 80, and the H direction is the opposite direction.

[0054] One end 80a of the idler gear 80 is provided with a recess 80a1 that is recessed in the direction of the rotation axis. On the other hand, one end 81a of the drive transmission gear 81 is provided with a projection 81a1 that protrudes in the direction of the rotation axis at a location opposite to the recess 80a1 of the idler gear 80. When the recess 80a1 of the idler gear 80 and the projection 81a of the drive transmission gear 81 engage, driving force is transmitted from the idler gear 80 to the drive transmission gear 81, causing them to rotate as a single unit. Note that the relationship between the recess 80a1 and the projection 81a1 may be reversed.

[0055] As will be described later, the drive transmission gear 81 meshes with the drive-side flange 63 of cartridge B and transmits driving force. As shown in Figure 1, during the image forming process described above, the initial operation after cartridge B is installed, and the preparation operation for the image forming process (collectively referred to as "driving"), the drive transmission gear 81 rotates in direction I, and the drive-side flange 63 rotates in direction K. In other words, the driving direction (rotation direction) of the drive transmission gear 81 during driving is direction I, and the driving direction (rotation direction) of the drive-side flange 63 during driving is direction K. Note that when viewing the drive transmission gear 81 and the drive-side flange 63 along direction H from the drive side to the non-drive side, direction I is clockwise and direction K is counterclockwise.

[0056] <Drive transmission gear 81> As shown in Figures 1, 12, and 13(a), the drive transmission gear 81 comprises a first main body gear section (first main body side gear section, first main body side helical gear section) 81c and a second main body gear section (second main body side gear section, second main body side helical gear section) 81d coaxially as helical gear sections. The first main body gear section 81c is positioned downstream in the H direction (upstream in the J direction) of the second main body gear section 81d. The first main body gear section 81c includes a plurality of first main body helical teeth 81ct, and the second main body gear section 81d includes a plurality of second main body helical teeth 81dt. Both the first main body helical teeth 81ct and the second main body helical teeth 81dt are involute teeth. The first main body gear section 81c and the second main body gear section 81d are integrally molded in resin and rotate as a single unit. Furthermore, the twisting directions of the first main gear section 81c and the second main gear section 81d are the same, and the twisting direction is such that the tooth surfaces shift toward the I direction as they move toward the J direction. Also, as shown in Figure 13(a), the twist angle α2 of the second main gear section 81d is greater than the twist angle α1 of the first main gear section 81c (i.e., α1 < α2). In addition, the number of teeth of the first main gear section 81c and the second main gear section 81d are the same.

[0057] <Drive side flange 63> On the other hand, as shown in Figures 1, 6(b), and 13(b), the drive-side flange 63 coaxially comprises a first gear section (first unit-side gear section, first unit-side helical gear section, first helical gear section) 63c and a second gear section (second unit-side gear section, second unit-side helical gear section, second helical gear section) 63d, which are helical gear sections. The first gear section 63c is positioned downstream of the second gear section 63d in the H direction (upstream in the J direction). In other words, with respect to the direction of the rotation axis L1, the first gear section 63c is positioned between the second gear section 63d and the drum 62. The first gear section 63c includes a plurality of first helical teeth (first projections) 63ct arranged at different positions in the circumferential direction around the rotation axis L1, and the second gear section 63d includes a plurality of second helical teeth (second projections) 63dt arranged at different positions in the circumferential direction around the rotation axis L1. The first oblique tooth 63ct and the second oblique tooth 63dt are both involute teeth, and are projections that protrude radially around the rotation axis L1. The first gear section 63c and the second gear section 63d are integrally molded in resin and rotate together; therefore, the first gear section 63c and the second gear section 63d can be viewed as a first rotating section and a second rotating section that rotate integrally with each other. The first gear section 63c meshes with the first main gear section 81c of the drive transmission gear 81, and the second gear section 63d meshes with the second main gear section 81d of the drive transmission gear 81.

[0058] As shown in Figure 1, the torsional directions of the first gear portion 63c and the second gear portion 63d of the drive-side flange 63 are the same, and the torsional direction is such that the tooth surfaces shift toward the K direction as they move toward the J direction. Note that the torsional directions of the first gear portion 63c and the second gear portion 63d are opposite to the torsional directions of the first main gear portion 81c and the second main gear portion 81d of the drive transmission gear 81. Also, as shown in Figure 13(b), the torsional angle α2 of the second gear portion 63d is greater than the torsional angle α1 of the first gear portion 63c (i.e., α1 < α2). Note that the torsional angle α1 of the first gear portion 63c is the same as the torsional angle α1 of the first main gear portion 81c, and the torsional angle α2 of the second gear portion 63d is the same as the torsional angle α2 of the second main gear portion 81d. Furthermore, the number of teeth in the first gear section 63c and the second gear section 63d of the drive-side flange 63 is the same. Also, the width (tooth width) W63c(Wc, Wc1) of the first helical tooth (first projection) 63ct in the direction of the rotation axis L1 is greater than the width (tooth width) W63d(Wd) of the second helical tooth (second projection) 63dt in the direction of the rotation axis L1. In other words, each of the first gear section 63c and the second gear section 63d has at least one tooth such that the tooth width Wc of the first helical tooth (tooth, first projection) 63ct and the tooth width Wd of the second helical tooth (tooth, second projection) 63dt in the direction of the rotation axis L1 satisfy the following equation A1. Wc>Wd···(Equation A1)

[0059] In other words, when the width (tooth width) of the first helical tooth 63ct, which has the widest width (tooth width) in the direction of the rotation axis L1 of the first gear portion 63c, is defined as Wc1, the second gear portion 63d has a second helical tooth (second projection) 63dt whose width (tooth width) in the direction of the rotation axis L1 is smaller than Wc1.

[0060] As will be explained in detail later, while the drive-side flange 1763 is being driven by the drive transmission gear 1781 in a balanced state, the driving force FD received by the first gear section 1763c is greater than the restricting force FB received by the second gear section 1763d, so this relationship is preferable.

[0061] Furthermore, the wider the width of the rotation axis L1 of the portion of the first gear section 63c that meshes (contacts) with the first main gear section 81c (measuring width), and the wider the meshing width of the second helical gear section 63c with the second main gear section 81d, the better the drive transmission accuracy. However, if the meshing width is set to be larger than necessary, the width of the first gear section 63c and the second gear section 63c in the direction of the rotation axis L1 will increase, causing the drive-side flange 63, drum unit 69, cartridge B, and ultimately the main body A to become larger. Therefore, it is preferable that the tooth width Wc1 of the first helical tooth 63ct, which has the widest tooth width among the first gear section 63c, and the tooth width Wd1 of the second helical tooth 63dt, which has the widest tooth width among the second gear section 63d, satisfy the following formula A2, more preferably formula A3. Wd1≦(4 / 5)·Wc1···(Formula A2) Wd1≦(3 / 4)·Wc1···(Formula A3)

[0062] Furthermore, from the standpoint of the strength of the second helical tooth 63dt of the second gear portion 63d, it is preferable that the second helical tooth 63dt has a tooth width of a certain degree or more, and it is preferable that the tooth width Wc1 and tooth width Wd1 satisfy the following formula A4. Wd1≧(1 / 10)·Wc1···(Formula A4)

[0063] Furthermore, as shown in Figure 14, the meshing pitch circle diameters D63c and D63d of the first gear portion 63c and the second gear portion 63d in the meshing between the drive-side flange 63 and the drive transmission gear 81 are set to be approximately the same. Similarly, the tooth tip circle diameters Dt63c and Dt63d of the first gear portion 63c and the second gear portion 63d are set to be approximately the same. Likewise, the meshing pitch circle diameters D81c and D81d of the first main body gear portion 81c and the second main body gear portion 81d are set to be approximately the same. As a result, the meshing between the first gear portion 63c and the first main body gear portion 81c, and the meshing between the second gear portion 63d and the second main body gear portion 81d, can be properly engaged without tooth tip contact.

[0064] In order to set the meshing pitch circle diameters D63c and D63d of the first gear section 63c and the second gear section 63d to be approximately the same, it is preferable to determine the shapes of the first gear section 63c and the second gear section 63d as follows.

[0065] Specifically, it is preferable to set the size of the tip circle diameter Dt63c of the first gear portion 63c to a value greater than the root circle diameter Db63d of the second gear portion 63d, or to a value greater than 0.8 times (more preferably 0.9 times) the tip circle diameter Dt63d of the second gear portion 63d. Furthermore, it is preferable to set the size of the tip circle diameter Dt63c of the first gear portion 63c to a value less than 1.1 times the tip circle diameter Dt63d of the second gear portion 63d.

[0066] Furthermore, it is preferable to set the root circle diameter Db63c of the first gear portion 63c to a value smaller than the tip circle diameter Dt63d of the second gear portion 63d. Also, it is preferable to set the root circle diameter Db63c of the first gear portion 63c to a value larger than 0.9 times the root circle diameter Db63d of the second gear portion 63d.

[0067] Furthermore, it is preferable to set the size of the tip circle diameter Dt63d of the second gear portion 63d to a value greater than the root circle diameter Db63c of the first gear portion 63c, or to a value greater than 0.8 times (more preferably 0.9 times) the tip circle diameter Dt63c of the first gear portion 63c. Also, it is preferable to set the size of the tip circle diameter Dt63d of the second gear portion 63d to a value less than 1.1 times the tip circle diameter Dt63c of the first gear portion 63c.

[0068] Furthermore, it is preferable to set the root circle diameter Db63d of the second gear portion 63d to a value smaller than the tip circle diameter Dt63c of the first gear portion 63c. Also, it is preferable to set the root circle diameter Db63d of the second gear portion 63d to a value greater than 0.9 times the root circle diameter Db63c of the first gear portion 63c.

[0069] Here, the relationship between these dimensions is shown using the diameters of the first gear section 63c and the second gear section 63d, but it is self-evident that the same relationship exists even if the diameter is replaced with the radius. Furthermore, in the embodiments described later, examples are shown in which the teeth of the first gear section 63c and the second gear section 63d are replaced with multiple protrusions of various shapes. In this case, the tip circle is the circle traced as the rotational trajectory when the tip (point) of the multiple protrusions that is furthest from the rotation axis L1 rotates, and the diameter / radius of this circle is defined as the tip circle diameter / tip circle radius.

[0070] In order to make the meshing pitch circle diameters D63c and D63d the same while making the helix angles of the first gear section 63c and the second gear section 63d different, the modules are made different or the amount of transfer is changed between the first gear section 63c and the second gear section 63d. Similarly, for the drive transmission gear 81, the modules are made different or the amount of transfer is changed between the first main gear section 81c and the second main gear section 81d.

[0071] Furthermore, the drive-side flange 63 includes a cylindrical portion (intermediate portion, small diameter portion, shaft portion) 63e between the first gear portion 63c and the second gear portion 63d with respect to the direction of the rotation axis L1. The maximum diameter D63e of the cylindrical portion 63e centered on the rotation axis L1 is smaller than the tip circle diameter Dt63c of the first gear portion 63c and the tip circle diameter Dt63d of the second gear portion 63d. Moreover, in this embodiment, the maximum diameter D63e of the cylindrical portion 63e centered on the rotation axis L1 is smaller than the root circle diameter Db63c of the first gear portion 63c and the root circle diameter Db63d of the second gear portion 63d. However, the maximum diameter D63e of the cylindrical portion 63e centered on the rotation axis L1 is not limited to the drive-side flange 63 unless it is in contact with the drive transmission gear 81 while the drive-side flange 63 is being driven by the drive transmission gear 81. Furthermore, as will be described later in Examples 22 and 23, the drive flange 63 and the drive transmission gear 81 may mesh together to transmit driving force, and the distance (radius) R63e from the rotation axis L1 to the outer diameter of the cylindrical portion 63e may be configured such that it is at least temporarily smaller than the tip circle radius Rt63ct of the first gear portion 63c or the tip circle radius Rt63d of the second gear portion 63d.

[0072] Here, the relationship between these dimensions is shown using the diameters of the first gear section 63c, the second gear section 63d, and the cylindrical section 63e, but it is self-evident that the same relationship exists even if the diameter is replaced with the radius. Note that the shape of the cylindrical section 63e does not have to be a cylindrical shape centered on the rotation axis L1. For example, it can be a polygonal prism or a shape that is not symmetrical with respect to the rotation axis L1, among other shapes. In this case, when the drive-side flange 63 rotates, the diameter of the circle traced by the point of the intermediate section 63e furthest from the rotation axis L1 as the rotation trajectory is the maximum diameter D63e mentioned above, and the radius of that circle is the maximum value of the radius R63e.

[0073] By providing the cylindrical portion 63e, the second gear portion 63d can be positioned away from the drum 62 (further downstream in the J direction) so as not to come into contact with the first gear portion 81c. Similarly, the first gear portion 63c can be positioned closer to the drum 62 (further downstream in the H direction) so as not to come into contact with the second main body gear portion 81d. In other words, by providing the cylindrical portion 63e, a gap g is formed between the first gear portion 81c and the second gear portion 63d in the direction of the rotation axis L1. This prevents the first gear portion 63c from coming into contact with the second main body gear portion 81d, and prevents the second gear portion 63d from coming into contact with the first main body gear portion 81c, in the direction of the rotation axis L1 when the cartridge B is mounted on the device body A. Furthermore, when the drive transmission gear 81 is driven and moves to the equilibrium position, it is possible to prevent the first main body gear portion 81c from coming into contact with the second gear portion 63d, and the second main body gear portion 81d from coming into contact with the first gear portion 63c. The width of the cylindrical portion 63e in the direction of the rotation axis L1 will be described in detail below.

[0074] <Drive transmission to the developing roller> Figure 15 shows the drive transmission configuration from the drive-side flange 63 to the developing roller 32. The developing roller 32 is fixed to the developing roller shaft 31, and a developing roller gear 30 is provided at one end of the developing roller shaft 31 on the drive side so as to be movable in the direction of the rotation axis of the developing roller shaft 31. The developing roller gear 30 is rotatable integrally with the developing roller shaft 31 and the developing roller 32. In other words, the developing roller gear 30 is provided so as to be able to transmit drive to the developing roller shaft 31 and the developing roller 32. The developing roller gear 30 meshes with the first gear portion 63c of the drive-side flange 63 to transmit driving force.

[0075] The developing roller gear 30 may be configured to mesh with the second gear section 63d to transmit driving force. However, by configuring the developing roller gear 30 to mesh with the first gear section 63c, the length of the developing roller shaft 31 in the direction of the rotation axis can be shortened compared to the configuration in which the developing roller gear 30 meshes with the second gear section 63d.

[0076] <Drive transmission operation> Next, the meshing operation between the drive transmission gear 81 and the drive-side flange 63 will be explained sequentially using Figures 16, 17, 19, 20, and 21, starting from the installation of cartridge B.

[0077] Figure 16(a) is a schematic diagram of the drive transmission gear 81 and drive-side flange 63 viewed along their rotational axis. Figure 16(b) is a cross-sectional view of the drive transmission gear 81 along the cutting line AF-AF. In Figures 16(b) and subsequent figures, the hatched areas represent the cross-sections of the gear's peaks, and the areas between the hatched areas correspond to the valleys of the gear. Figure 16(c) is a cross-sectional view of the drive-side flange 63 along the cutting line AF-AF. Figure 16(d) is a cross-sectional view of the drive transmission gear 81 along the cutting line AF-AF before cartridge installation. Figure 16(e) is a cross-sectional view of the drive transmission gear 81 and drive-side flange 63 along the cutting line AF-AF after cartridge B is installed and before drive is started.

[0078] Figure 17 is a cross-sectional view of the drive transmission gear 81 and the drive-side flange 63 immediately after the start of driving, at the cross-sectional plane AF-AF tangent to the meshing pitch circle, and shows the state as time progresses in the order of Figure 17(a), Figure 17(b), Figure 17(c), and Figure 17(d).

[0079] Figures 19(a), 19(b), and 19(c) show the drive transmission gear 81 and the drive-side flange 63 viewed along the H direction.

[0080] Figure 21(a) is a view of the drive transmission gear 81 and the drive-side flange 63 along a direction perpendicular to the rotation axis. Figure 21(b) is a cross-sectional view of the first main body gear section 81c during operation along the cutting line AD-AD. Figure 21(c) is a cross-sectional view of the second main body gear section 81d during operation along the cutting line AD-AD.

[0081] <Fitting when cartridge B is installed> As shown in Figure 16(d), before the cartridge B is installed, the drive transmission gear 81 is held in place by the biasing force F1 of the compression spring 85, with its other end 81e abutting against the abutment surface 84b of the main frame 84. By configuring the drive transmission gear 81 to abut against the abutment surface 84b in this way, the initial position of the drive transmission gear 81 in the direction of its rotation axis can be kept constant, and the meshing with the drive-side flange 63 can be stabilized.

[0082] As cartridge B is mounted to the device body A along the mounting direction M (M direction), the drive-side flange 63 engages with the drive transmission gear 81, as shown in Figure 19(a). Here, the force required to rotate the drive-side flange 63 is greater than the force required to rotate the drive transmission gear 81. Therefore, the movement of the drive-side flange 63 in the M direction causes the drive transmission gear 81 to rotate in the I direction (clockwise). At this time, as shown in Figure 16(e), the first main body gear portion 81c or the second main body gear portion 81d of the drive transmission gear 81 comes into contact with the first gear portion 63c or the second gear portion 63d of the drive-side flange 63 and is pressed in the M direction. A thrust force F3 in the H direction acts on the drive transmission gear 81. However, the other end 81e of the drive transmission gear 81 abuts against the abutment surface 84b of the main frame 84 and receives a reaction force F4, so the drive transmission gear 81 cannot move in the H direction.

[0083] <Operation after starting the drive> Next, we will explain the case where the drive-side flange 63 is driven to perform initial operations and preparatory operations for image formation. As shown in Figure 19(b), the drive transmission gear 81 is rotated in the I direction by a motor (not shown) of the main body A of the device. As a result, the drive-side flange 63 rotates in the K direction. Immediately after the drive transmission gear 81 starts rotating in the I direction, as shown in Figure 17(a), the second main body gear portion 81d of the drive transmission gear 81 first meshes with the second gear portion 63d of the drive-side flange 63 and transmits the driving force. Then, the second main body gear portion 81d generates a thrust force in the H direction on the second gear portion 63d. However, the drive-side flange 63 is restricted from moving in the H direction by the rib 71p and receives a reaction force in the J direction corresponding to the thrust force in the H direction. For this reason, the second main body gear portion 81d receives a thrust force F5 in the J direction due to the reaction force received from the second gear portion 63d. This thrust force F5 causes the drive transmission gear 81 to move in the J direction.

[0084] As the drive transmission gear 81 continues to rotate and moves in the J direction, as shown in Figure 17(b), the first gear section 63c also meshes with the first main gear section 81c, generating a thrust force F6 on the first main gear section 81c. This thrust force F6 is the same thrust force in the J direction as the thrust force F7 that the second main gear section 81d receives when it meshes with the second gear section 63d. As a result, the drive transmission gear 81 moves further in the J direction.

[0085] As the drive transmission gear 81 rotates further and moves in the J direction, eventually the second main gear portion 81d will no longer mesh with the second gear portion 63d, as shown in Figure 17(c). On the other hand, the meshing between the first gear portion 81c and the first gear portion 63c is maintained, and a thrust force F8 acts on the first gear portion 81c in the J direction. At this time, the drive transmission gear 81 rotates the drive-side flange 63 solely by the meshing between the first main gear portion 81c and the first gear portion 63c. In other words, the tooth surface 81c1 on the downstream side in the I direction of the first main gear portion 81c and the tooth surface 63c1 on the upstream side in the I direction of the first gear portion 63c are in contact.

[0086] This is because the twist angle α2 of the second main body gear portion 81d of the drive transmission gear 81 is larger than the twist angle α1 of the first main body gear portion 81c (α2 > α1). Specifically, it will be described below with reference to FIGS. 21(b) and 21(c). Assume that the drive transmission gear 81 moves a displacement amount LL in the J direction by receiving a thrust force through engagement with the drive-side flange 63. In FIGS. 21(b) and 21(c), the first main body gear portion 81c and the second main body gear portion 81d are shown with solid lines before movement and dashed lines after movement. The displacement amounts in the rotational direction of the first main body gear portion 81c and the second main body gear portion 81d associated with this movement can be expressed as LL / tanα1 and LL / tanα2, respectively. Based on the relationship between the twist angles α1 and α2, the displacement amount LL / tanα2 in the rotational direction of the second main body gear portion 81d is larger than the displacement amount LL / tanα1 in the rotational direction of the first main body gear portion 81c (LL / tanα1 < LL / tanα2). Thus, the displacement amount in the rotational direction corresponding to the displacement amount LL in the J direction is larger for the second main body gear portion 81d than for the first main body gear portion 81c. Therefore, even if the first main body gear portion 81c and the first gear portion 63c are engaged, the second main body gear portion 81d will separate from the second gear portion 63d.

[0087] When the rotation continues and the drive transmission gear 81 moves further in the drive direction J, as shown in FIG. 17(d), finally, the tooth surface 81d2 on the upstream side of the second main body gear portion 81d in the I direction contacts the tooth surface (contact portion) 63d2 on the downstream side of the second gear portion 63d in the I direction. Note that the surface 81c1 of the first main body gear portion 81c and the surface 63c1 of the first gear portion 63c maintain contact. That is, in this state, the first main body gear portion 81c of the drive transmission gear 81 presses the tooth surface (contact portion) 63c1 with the tooth surface 81c1 to rotate the drive-side flange 63, and the tooth surface 81d2 of the second main body gear portion 81d of the drive transmission gear 81 abuts against the tooth surface 63d2 and is sandwiched by the drive-side flange 63. Then, the movement in the direction of the rotation axis L1 of the drive transmission gear 81 stops. The position in the direction of the rotation axis L1 at this time is defined as the equilibrium position. A state where the drive transmission gear 81 rotates at the equilibrium position and transmits drive to the drive-side flange 63 will be described.

[0088] In the equilibrium state, the drive transmission gear 81 is subjected to the following forces F9, F10, and F1 with respect to the direction of the rotation axis L1. Force F9 is a thrust force in the J direction received by the first main gear section 81c due to the meshing force with the first gear section 63c, force F1 is a thrust force in the H direction received by the second main gear section 81d due to the meshing force with the second gear section 63d, and force F1 is the biasing force of the compression spring 85. In addition, the drive-side flange 63 receives a force from the drive transmission gear 81 and is positioned with respect to the direction of the rotation axis L1 by the side wall 71m or rib 71p, generating a reaction force F11 that balances the force received from the drive transmission gear 81. Figure 17(d) shows the case where the drive transmission gear 81 is positioned in contact with the side wall 71m. In the equilibrium state, neglecting friction, forces F9, F10, F1, and F11 are balanced, and the drive transmission gear 81 and the drive-side flange 63 are positioned in the direction of the rotation axis L1.

[0089] Furthermore, the drive-side flange 63 is sandwiched (in contact with) the first main gear portion 81c and the second main gear portion 81d of the drive transmission gear 81 in the K direction (rotation direction) and is subjected to the following forces. That is, the tooth surface (contact portion) 63c1 of the first gear portion 63c contacts the first main gear portion 81c, which is located upstream in the K direction (first circumferential direction), and receives a driving force FD as a force component that rotates the drive-side flange 63 in the K direction (predetermined direction). At the same time, the tooth surface (contact portion) 63d2 of the second gear portion 63d contacts the second main gear portion 81d, which is located downstream in the K direction (first circumferential direction), and receives a restricting force (braking force) FB as a force component that suppresses (restricts) the rotation of the drive-side flange 63 in the K direction. For this reason, the first gear portion 63c can be said to be a driving force receiving portion that receives the driving force FD, and the second gear portion 63d can be said to be a restricting force receiving portion that receives the restricting force FB. Furthermore, the driving force FD is greater than the restricting force FB.

[0090] Here, the second gear section 63d is integrally provided with respect to the first gear section 63c in terms of the direction of rotation, so it is configured not to rotate relative to the first gear section 63c in the opposite direction to the K direction. More precisely, because the drive-side flange 63 is made of resin and deformation of the teeth and other components occurs, the second gear section 63d, upon receiving the restricting force FB, rotates slightly in the opposite (reverse) direction to the K direction relative to the first gear section 63c, and then stops rotating and becomes fixed. For this reason, the restricting force FB received by the second gear section 63d acts (is transmitted) to the first gear section 63c. By a similar principle, the driving force FD received by the first gear section 63d acts (is transmitted) to the second gear section 63d.

[0091] Thus, when the first gear section 63c receives the driving force FD and the second gear section 63d receives the restricting force FB, there is no play (backlash) in the rotational direction (direction I) between the drive-side flange 63 and the drive transmission gear 81, i.e., it is a backlash-free state. In this way, the drive-side flange 63 is rotated in the direction K while maintaining the backlash-free state. As long as the gears are meshed and transmitting power in a backlash-free state, it is possible to transmit power with high rotational accuracy.

[0092] Furthermore, the width (tooth width) W63c of the first helical tooth (first projection) 63ct in the direction of the rotation axis L1 is greater than the width (tooth width) W63d of the second helical tooth (second projection) 63dt in the direction of the rotation axis L1. In other words, the second gear section 63d has a second helical tooth (second projection) 63dt that is narrower than the first helical tooth 63ct of the first gear section 63c, which has the widest width (tooth width) in the direction of the rotation axis L1.

[0093] Furthermore, if the second main body gear section 81d and the second gear section 63d do not come into contact at the start of driving, but the first main body gear section 81c and the first gear section 63c come into contact, driving will start from the state shown in Figure 17(c) without going through the states shown in Figures 17(a) and 17(b) described above. Then, by the same principle as described above, the equilibrium state shown in Figure 17(d) will be reached. That is, from the state shown in Figure 17(c), the drive transmission gear 81 moves in the J direction due to the thrust force F8, and transitions to the equilibrium state shown in Figure 17(d).

[0094] <Disengaging the lock when removing cartridge B> Next, the disengagement operation between the drive transmission gear 81 and the drive-side flange 63 when removing cartridge B after the end of the drive will be explained using Figures 18, 19, and 20. Figure 18 is a cross-sectional view of the drive transmission gear 81 and the drive-side flange 63 at the cross-section AF-AF tangent to the meshing pitch circle when removing cartridge B after the end of the drive, and shows the state as time progresses in the order of Figure 18(a) and Figure 18(b). Figure 20 is a schematic diagram of the drive transmission gear 81 and the drive-side flange 63 viewed along the H direction.

[0095] As shown in Figure 19(c), cartridge B is removed from the device body A by moving it in the removal direction N (N direction). The N direction is the opposite direction to the M direction. As mentioned earlier, the force required to rotate the drive-side flange 63 is greater than the force required to rotate the drive transmission gear 81. Therefore, the movement of the drive-side flange 63 in the N direction causes the drive transmission gear 81 to rotate in the K direction (counterclockwise). At this time, as shown in Figure 18(a), when the drive-side flange 63 moves in the N direction, the first gear portion 63c presses against the first main body gear portion 81c. Also, Figure 20 shows the positional relationship between the drive-side flange 63 and the drive transmission gear 81 moving in the N direction, with a solid line indicating the position before movement in the N direction and a dashed line indicating the position after movement. The distance between the rotation center (rotation axis) L1 of the drive-side flange 63 and the rotation center (rotation axis) L2 of the drive transmission gear 81 changes from distance LA to distance LB as the drive-side flange 63 moves in the N direction (LA <LB)。

[0096] As a result, the meshing position of the teeth of the first gear portion 63c and the first main gear portion 81c gradually shifts to the tooth tips. Therefore, as shown in Figure 18(b), the backlash of the teeth in the rotational direction increases, and the gap AL between the surface 63d2 of the second gear portion 63d and the tooth surface 81d2 of the second main gear portion 81d increases. When a gap AL occurs between the tooth surfaces, no force from the second gear portion 63d acts on the drive transmission gear 81, and a thrust force F16 in the J direction acts due to the meshing between the first main gear portion 81c and the first gear portion 63c. As a result, when cartridge B is removed, the drive transmission gear 81 rotates in the K direction while gradually moving in the J direction, and eventually the meshing between the first gear portion 63c and the first main gear portion 81c is lost. This releases the meshing between the drive-side flange 63 and the drive transmission gear 81.

[0097] <Setting the twist angle> Next, preferred twist angles of the first gear section 63c and the second gear section 63d will be explained using Figure 46. Figures 46(a) and 46(b) are cross-sectional views taken at the cross-section AF-AF tangent to the meshing pitch circle of the drive transmission gear 81 and drive-side flange 63 of the second gear section 63d and the second main body gear section 81d.

[0098] As described above, the setting of the helix angle α1 of the first gear section 63c and the helix angle α2 of the second gear section 63d, where the first gear section 63c is the gear section that receives the driving force FD and the second gear section 63d is the gear section that receives the restricting force FB, will be explained. First, as a premise, since the first gear section 63c is the gear section that receives the driving force FD and the second gear section 63d is the gear section that receives the restricting force FB, the helix angle α2 is larger than the helix angle α1 (α2 > α1). If the helix angle α2 is smaller than the helix angle α1, it is not possible to transmit power in a backlash-free state. That is, the thrust force that the first gear section 63c applies to the first main gear section 81c and the thrust force that the second gear section 63d applies to the second main gear section 81d are not balanced, and the position of the drive transmission gear 81 in the direction of the rotation axis L1 cannot be determined at the equilibrium position.

[0099] The helix angle α1 of the first gear portion 63c of the drive-side flange 63 is preferably 10° or more (α1≧10°), more preferably 15° or more (α1≧15°), and even more preferably 20° or more (α1≧20°). The reason is that, generally, if the tooth width (the width of the gear teeth in the direction of the rotation axis L1) is the same, a larger helix angle results in a larger meshing ratio and improved rotational accuracy. Furthermore, the helix angle α1 is preferably 40° or less (α1≦40°), and more preferably 35° or less (α1≦35°). The reason is that, generally, a larger helix angle worsens the moldability by the mold.

[0100] On the other hand, the helix angle α2 of the second gear portion 63d of the drum gear 63 is preferably 40° or less (α2≦40°), and more preferably 35° or less (α2≦35°). The reason is that, generally, a larger helix angle worsens the moldability by the mold. Furthermore, the helix angle α2 of the second gear portion 63d of the drum gear is preferably 20° or more (α2≧20°), and more preferably 25° or more (α2≧25°). The reason is that, as shown in Figures 46(a) and 46(b), the larger the helix angle α2, the larger the width E in the rotational direction (K direction) of the contact surface with the second main body gear portion 81d. In this embodiment, the helix angle α2 is set to 35°.

[0101] If the width E is small, when the second gear section 63d receives the thrust force F9 (see Figure 17(d)) ​​received by the first gear section 63c, the tooth surface of the second gear section 63d deforms, causing the second main gear section 81d to bite in like a wedge and move, resulting in unstable positioning in the direction of the rotation axis L1. For this reason, it is necessary to secure a certain width E in order to reliably receive the thrust force F9 and position the drive transmission gear 81 in the direction of the rotation axis L1.

[0102] In summary, the twist angle α1 is preferably between 10° and 40° (15°≦α1≦40°), more preferably between 15° and 40° (15°≦α1≦40°), and even more preferably between 20° and 35° (20°≦α1≦35°). Furthermore, the twist angle α2 is preferably between 20° and 40° (20°≦α2≦40°), and more preferably between 25° and 35° (25°≦α2≦35°). In this embodiment, the twist angle α1 is set to 20° and the twist angle α2 is set to 35°, satisfying the above conditions.

[0103] <Width of cylindrical section 63e> Next, the width (length) of the cylindrical portion 63e in the direction of the rotation axis L1 will be explained. Figure 47(a) is a schematic diagram of the drive-side flange 63 and drive transmission gear 81 when cartridge B is installed, viewed from a direction perpendicular to the rotation axis L1. Figure 47(b) is a schematic diagram of the drive-side flange 63 and drive transmission gear 81 during operation, viewed from a direction perpendicular to the rotation axis L1.

[0104] As mentioned above, by providing the cylindrical portion 63e, it is possible to prevent the first gear portion 63c from contacting the second main gear portion 81d, and the second gear portion 63d from contacting the first main gear portion 81c, in the direction of the rotation axis L1. Furthermore, by providing the cylindrical portion 63e, it is possible to prevent the first main gear portion 81c from contacting the second gear portion 63d, and the second main gear portion 81d from contacting the first gear portion 63c, when the drive transmission gear 81 is driven and moves to the equilibrium position. In other words, by providing the cylindrical portion 63e, a gap g is formed between the first gear portion 81c and the second gear portion 63d, in the direction of the rotation axis L1. For this reason, in the following explanation, the width (length) of the cylindrical portion 63e in the direction of the rotation axis L1 is synonymous with the width (length) of the gap g in the direction of the rotation axis L1.

[0105] The aforementioned contact can occur in the following two situations. The first is when cartridge B is mounted on the device body A, as shown in Figure 47(a), and the other end 81e of the drive transmission gear 81 is abutting against the abutment surface 84b of the main frame 84 and is held in place. The second is when the drive transmission gear 81 is driven and moving toward the equilibrium position, as shown in Figure 47(b).

[0106] The positions of the first gear portion 63c and the second gear portion 63d of the drive-side flange 63, the positions of the first main body gear portion 81c and the second main body gear portion 81d of the drive transmission gear 81, and the equilibrium position may vary due to the influence of the following factors: Specifically, (1) tolerances in the direction of the rotation axis L1 of the drive-side flange 63, the drive transmission gear 81, and related parts such as the cleaning frame (drum frame) 60a, (2) tolerances related to the distance between the rotation axis L1 of the drive-side flange 63 and the rotation axis L2 of the drive transmission gear 81, (3) tolerances in the rotational phase of the teeth of the first gear portion 63c and the second gear portion 63d of the drive-side flange 63, (4) tolerances in the rotational phase of the teeth of the first main body gear portion 81c and the second main body gear portion 81d of the drive transmission gear 81, and (5) deformation of the teeth due to the maximum drive load, and thermal expansion and contraction of the drive-side flange 63 and the drive transmission gear 81. Taking these factors into consideration, the width (length) We of the cylindrical portion 63e (or gap g) in the direction of the rotation axis L1 is set.

[0107] Specifically, the width We is preferably set such that it satisfies the following equation B1, with Wc being the width (tooth width, length) of the teeth of the first gear section 63c in the direction of the rotation axis L1. We≧Wc / 5...(Formula B1)

[0108] Furthermore, as the width We increases, the width in the direction of the rotation axis L1 of cartridge B also increases. Therefore, in order to miniaturize cartridge B and the device body A, the width We should not be set to be unnecessarily large. With this in mind, it is more preferable to set the width We so as to satisfy the following equation B2. We≦Wc...(Formula B2)

[0109] In this embodiment, Wc = 8.6 mm and We = 2.3 mm are set, satisfying equations B1 and B2 above. If the tooth width Wc of the first gear section 63c is not constant, the tooth width Wc1 of the widest tooth is considered to be the tooth width Wc.

[0110] Furthermore, as is clear from Figures 13(b), 14, and 47, the width We is preferably set such that it satisfies the following equation B3, with Wd being the width (tooth width, length) of the teeth of the second gear section 63c in the direction of the rotation axis L1. We ≤ Wd ···(Equation B3)

[0111] <Regarding rotational accuracy> The reason why rotational accuracy improves in the backlash-free state is explained below using Figures 22 and 49. Figure 22(a) is a view of the drive transmission gear 81 and the drive-side flange 63 along a direction perpendicular to the rotation axis. Figure 22(b) is a partial cross-sectional view of the meshing portion of a typical helical gear 51 and 53 as a comparative example. Figure 22(c) is a partial cross-sectional view of the AD-AD cross-section tangent to the meshing pitch circle of the drive transmission gear 81 and the drive-side flange 63. Figure 22(d) is a partial perspective view of the helical gear 51. Figure 22(e) is a partial perspective view of the drive transmission gear 81. Figure 49 is a graph comparing the drive transmission error when the alignment of the drive-side flange 63 and the helical gear 53 is misaligned.

[0112] As shown in Figure 22(b), in gear drives, due to molding accuracy and play or deformation of the shaft, the tooth surfaces of the drive-side and driven-side helical gears may not mesh parallel to each other in the tooth trace direction. This condition is generally called misalignment. In typical helical gears, the drive-side helical gear 51 and the driven-side helical gear 53 will mesh only at one end of their tooth surfaces in the axial direction, and the meshing ratio will be significantly reduced compared to the state where the alignment is not misaligned. As a result, the rotational accuracy during drive transmission will be extremely poor. Figure 22(d) shows the region of the tooth surface of helical gear 51 that meshes with helical gear 53 when the alignment is misaligned, and the width of this region is denoted as width LP.

[0113] On the other hand, as shown in Figure 22(c), the drive-side flange 63 rotates by clamping the first main body gear portion 81c and the second main body gear portion 81d of the drive transmission gear 81 with the first gear portion 63c and the second gear portion 63d of the drive-side flange 63. This generates a clamping force FC (i.e., a rotational drive brake) acting on the second main body gear portion 81d. The reaction force of this clamping force FC is added to the force applied to the tooth surface of the first main body gear portion 81c that presses the first gear portion 63c in the I direction, resulting in a force FB. On the other hand, when the same load torque is driven, no excess load FA is generated on the tooth surface of the conventionally used helical gear 51. For this reason, the force FB applied to the tooth surface of the first main body gear portion 81c in this embodiment is greater than the force FA applied to the tooth surface of the helical gear 51. Figure 22(e) shows the region where the tooth surface of the first main gear portion 81c of the drive transmission gear 81 meshes with the first gear portion 63 of the drive-side flange 63 when the alignment is misaligned, and the width of this region is denoted as width LQ. Since force FB is greater than force FA, comparing width LP in Figure 22(d) with width LQ in Figure 22(e), width LQ is greater than width LP. Therefore, the decrease in the overlap meshing ratio of the first main gear portion 81c and the first gear portion 63c when the alignment is misaligned is smaller compared to the helical gears 51 and 53.

[0114] Figure 49 is a graph showing the measurement results of the drive transmission error of the driven helical gear 53 and drive-side flange 63 with respect to the amount of alignment misalignment, when using general helical gears 51 and 53 and when using the drive transmission gear 81 and drive-side flange 63 of this embodiment. The helical gears 51 and 53 and the drive transmission gear 81 and drive-side flange 63 were treated as having the same gear specifications, such as the number of teeth and backlash in the axial direction of 0.15 mm, as well as the same conditions such as load torque of 0.25 N·m and rotational speed of 270 rpm, with no play between the shaft and gear. Here, the drive transmission error (%) represents the percentage deviation of the experimentally measured rotational pitch from the ideal rotational pitch during the gear meshing period. For example, if the ideal rotational pitch is 0.7258 mm and the experimental deviation from the ideal rotational pitch is 0.00036 mm, then the error is 0.05% (= 0.00036 / 0.7258 × 100). Furthermore, the alignment misalignment (°) is defined as the angle between the axes when the driven gear's axis is tilted such that the angle β in the tooth trace direction of the teeth (see Figures 22(b) and 22(c)) is misaligned, with 0° representing the state where the axes of the meshing gears are parallel. As shown in this graph, the deterioration of the rotational accuracy of the drive-side flange 63 in this embodiment is suppressed more than that of a typical helical gear 53 when there is alignment misalignment. Therefore, the drive transmission configuration using the drive transmission gear 81 and drive-side flange 63 in this embodiment is more resistant to alignment misalignment than a drive transmission configuration using a typical helical gear.

[0115] <Regarding wear on drive transmission gears> Next, the wear of the drive transmission gear 81 and the helical gear 101 will be explained below using Figure 24. Figure 24(a) is a schematic diagram of a conventional drive transmission configuration using a helical gear. Figure 24(b) is a schematic diagram of the drive transmission configuration of this embodiment. As shown in Figure 24(a), when rotational drive is performed by the helical gear 101, the helical gear 101 receives a thrust force (axial force) FD due to the meshing force. As a result, the helical gear 101 moves in the H direction toward the non-driven side, and the end face 101a of the helical gear 101 and the abutment surface 184b of the main frame 84 come into contact and slide against each other, causing wear. In contrast, as shown in Figure 24(b), in this embodiment, the drive transmission gear 81 is positioned in the direction of the rotation axis L1 by the drive-side flange 63 and spring 85 (not shown) during operation. As a result, a gap AA is formed between the H-direction end face 81e and the J-direction end face 81f of the drive transmission gear 81 and the main frame 84 and the second drive-side plate 83, preventing sliding. Therefore, wear on the two end faces 81e and 81f of the drive transmission gear 81, as well as the main frame 84 and the second drive-side plate 83, is suppressed, and durability can be increased.

[0116] <Comparison with conventional coupling drives> Next, a comparison with a conventional coupling-driven drum configuration will be explained using Figures 26 and 27. Figure 26(a) is a cross-sectional view of the drive transmission section of a conventional coupling drive, and the cross-section includes the rotation axis of the coupling. Figure 26(b) is a cross-sectional view of the drive transmission section of this embodiment, and the cross-section includes the rotation axis (L1) of the drive-side flange 63 and the rotation axis of the drive transmission gear 81. Figure 27 is a graph showing the deformation amounts of the coupling drive and the drive transmission gear.

[0117] As shown in Figure 26(a), in a conventional coupling drive, a drive-side flange 263 equipped with a convex-shaped coupling 263a, which is a twisted polygonal prism shape, is attached to the end of the drum 62 of the cartridge. The drum flange 263 has a support portion 263b, which is a cylindrical portion with a diameter smaller than the diameter of the drum 62. The device body has a drive transmission gear 281 equipped with a concave-shaped coupling 281a into which the coupling 263a is inserted and engages.

[0118] The coupling 263a is provided at the end of the drive-side flange 263 in the direction of the rotation axis. Therefore, the amount of twist of the drive-side flange 263 during driving in coupling drive is greater than the amount of twist of the drive-side flange 63 in gear drive in this embodiment shown in Figure 26(b). As shown in Figure 27, the simulation results of the deformation amount of the drive members (drum flange 263, drive-side flange 63) in the rotation direction show that the deformation amount is smaller in gear drive (driving with the drive-side flange 63) than in coupling drive (driving with the drum flange 263). Now, the deformation amount of the drive members in the rotation direction will be explained. This deformation amount is the rotational displacement of the drive transmission point to the drum 62 when the drum 62 side of the drum coupling 263 and drive-side flange 63 is fixed and the same static load torque of 0.25 N·m is applied to the engagement part with the drive input member 281 or the meshing part with the drive transmission gear 81. The drive transmission point is a point fixed to the drum 62. The displacement is then converted into a positional displacement amount compared to the case where there is no twisting at a predetermined point on the surface of the drum 62. Due to this difference in the amount of deformation of the drive member, when the load torque of cartridge B fluctuates, the fluctuation in the amount of deformation of the drive member is smaller with gear drive compared with coupling drive, and the fluctuation in the rotational speed of drum 62 due to the fluctuation in the amount of deformation is reduced. In other words, when the load torque of cartridge B fluctuates, the density unevenness of the image in the rotational direction of drum 62 on the image (which occurs due to variations in the pitch in the sub-scanning direction between scan lines formed when scanning the surface of drum 62 with laser light L (pitch unevenness)) can be kept low. Thus, with the drive transmission configuration of the drive-side flange 63 and drive transmission gear 81 of the embodiment described above, the decrease in the rotational accuracy of drum 62 in response to load torque fluctuations can be suppressed compared to the conventional coupling drive configuration.

[0119] Furthermore, comparing it to conventional coupling drives from a different perspective, in the case of conventional coupling drives, a retraction mechanism is required to move the coupling 263a on the main body side forward and backward in the direction of the rotation axis in order to attach and detach cartridge B.

[0120] Next, the retraction mechanism will be explained using Figure 28. Figure 28(a) is a cross-sectional view of the retraction mechanism including the rotation axis of the drum 62. Figure 28(b) is a schematic cross-sectional view of an image forming apparatus equipped with the retraction mechanism. Figures 28(c) and 28(d) are cross-sectional views of the drive transmission gear 281 and the retraction mechanism, and the cross-section includes the rotation axis of the drive transmission gear 281.

[0121] The main body of the coupling-driven image forming apparatus is equipped with a retraction mechanism consisting of a link 210, a cylindrical cam 212, and a compression spring 214. One end of the link 210 is connected to the opening / closing door 211 of the apparatus body A. The other end of the link 210 is connected to the cylindrical cam 212, which is rotatably mounted coaxially with the drive input member 281 and between the drive input member 281 and the side wall 213. As shown in Figure 28(a), the cylindrical cam 212 has a slope 212d, a convex surface 212c, and a concave surface 212e on one end face in the axial direction, with a difference in height in the rotational direction. Furthermore, the side wall 213 has a slope 213e, a convex surface 213f, and a concave surface 213g at locations opposite to the slope 212d, convex surface 212c, and concave surface 212e, respectively. Also, as shown in Figure 28(d), the drive transmission gear 281 is biased in the H direction by the compression spring 214.

[0122] As shown in Figure 28(b), the opening of the door 211 rotates the cylindrical cam 212 in the I direction via the link 210, causing the cylindrical cam 212 to come into contact with the convex surfaces 212c and 213f on the side wall 213, and moving the cylindrical cam 212 in the J direction. This movement of the cylindrical cam 212 in the J direction causes the cylindrical cam 212 to move the drive input member 281 in the J direction against the biasing force of the compression spring 214, as shown in Figure 28(c). As a result, the drive input member 281 moves away from the drum flange 263 (see Figure 26(a)), disengaging the coupling 281a and the coupling 263a (see Figure 26(a)). Consequently, the cartridge B can be removed.

[0123] Furthermore, as shown in Figure 28(b), when the door 211 is closed, the cylindrical cam 212 rotates in the opposite direction to the I direction via the link 210, with the cylindrical cam 212 and the inclined surfaces 212d and 213e provided on the side wall 213 in contact with each other. During this rotation, the cylindrical cam 212, the side wall 213, and the drive input member 281 cease to be in contact in the direction of the rotation axis, and as shown in Figure 28(d), the biasing force of the compression spring 214 allows the drive input member 281 to move in the H direction. As a result, the drive input member 281 moves in a direction toward the drum flange 263 (see Figure 26(a)), allowing the coupling 281a and coupling 263a (see Figure 26(a)) to engage.

[0124] Thus, in the case of conventional coupling drives, a retraction mechanism is required as explained above, which may increase the size or cost of the device itself. However, in the case of a gear drive as in this embodiment, cartridge B can be attached and detached without providing such a retraction mechanism.

[0125] <Example 1> Next, let's describe the first modified example. In the embodiment described above, the number of teeth of the first main gear portion 81c and the second main gear portion 81d of the drive transmission gear 81 were assumed to be the same, but this is not necessarily required. However, the reduction ratio between the first main gear portion 81c of the drive transmission gear 81 and the first gear portion 63c of the drive-side flange 63 must be the same as the reduction ratio between the second main gear portion 81d of the drive transmission gear 81 and the second gear portion 63d of the drive-side flange 63. For example, if the number of teeth of the first gear portion 81d of the drive transmission gear is 20 and the number of teeth of the first gear portion of the drum gear is 30, resulting in a reduction ratio of 2:3, then if the number of teeth of the second main gear portion 81d of the drive transmission gear is 40 and the number of teeth of the second gear portion 63d of the drive-side flange 63 is 60, the reduction ratio will be the same 2:3. In this case as well, since the gear of the drive transmission gear 81 can be sandwiched between the first gear portion 63c and the second gear portion 63d of the drive-side flange 63, it is possible to achieve a backlash-free state in the rotational direction.

[0126] <Modification 2> Next, we will describe Modification 2. In this modification, the first gear portion 181c and the second gear portion 181d of the drive transmission gear 181 have different numbers of teeth, and the number of teeth of one is not an integer multiple of the number of teeth of the other. Similarly, the first gear portion 163c and the second gear portion 163d of the drive-side flange 163 have different numbers of teeth, and the number of teeth of one is not an integer multiple of the number of teeth of the other. These are the differences between this modification and the previously described embodiment. Aside from these differences and the associated configurations, the configuration of this modification and the previously described embodiment are the same, and therefore, no further explanation is provided.

[0127] In this modified example, as in the previously described embodiment, it is possible to achieve a backlash-free state in the rotational direction. However, due to the setting of the number of teeth as described above, this modified example has a configuration in which the meshing phase of the drive-side flange 163 with respect to the drive transmission gear 181 is not unique. In a configuration in which the meshing phase is not unique, the position in which the drive transmission gear 181 is positioned in the axial direction (equilibrium position) will be explained using Figure 25. Figure 25(a) is a schematic diagram of the drive transmission configuration using the drive transmission gear 81 of the previously described embodiment. Figure 25(b) is an explanatory diagram of the drive transmission section using the modified drive transmission gear 181 and drive-side flange 163. Figures 25(c) and 25(d) show the state in which the drive transmission gear 181 is in the equilibrium position after being driven.

[0128] Comparing Figure 25(c) and Figure 25(d), both show the drive transmission gear 181 and the drive-side flange 163 meshing, but the way they mesh at the meshing portion is different. Specifically, in Figure 25(c), at the meshing portion between the drive-side flange 163 and the drive transmission gear 181, the phases of the teeth of the first gear portion 181c and the second gear portion 181d of the drive transmission gear 181 are aligned, while the phases of the teeth of the first gear portion 163c and the second gear portion 163d of the drive-side flange 163 are aligned. In Figure 25(d), at the meshing portion, the phases of the teeth of the first gear portion 181c and the second gear portion 181d of the drive transmission gear 181 are aligned, while the phases of the teeth of the first gear portion 163c and the second gear portion 163d of the drive-side flange 163 are aligned.

[0129] If the number of teeth of the first gear portion 181c and the second gear portion 181d of the drive transmission gear 181 are different, the phase of the peaks of the teeth of the first gear portion 181c and the second gear portion 181d will differ depending on the phase in the direction of gear rotation. For example, depending on the phase in the direction of gear rotation, if there is a position Q1 where the phase of the peak 181cs of the first gear portion and the phase of the peak 181ds of the second gear portion match, there is also a position Q2 where the phase of the peak 181cs of the first gear portion and the phase of the trough 181dv of the second gear portion match. The same applies to the relationship between the first gear portion 163c and the second gear portion 163d of the drum gear 163. As a result, as shown in Figures 25(c) and 25(d), the axial equilibrium position of the drive transmission gear 181 relative to the drive side flange 163 differs depending on the initial (pre-drive) phase of meshing between the drive transmission gear 181 and the drive side flange 163 in the direction of rotation. Figure 25(c) shows the case where the equilibrium position of the drive transmission gear 181 is furthest downstream in the H direction, and Figure 25(d) shows the case where the equilibrium position of the drive transmission gear 181 is furthest downstream in the J direction. The change in equilibrium position can be expressed, for example, as the amount of displacement of the boundary line between the first gear portion 181c and the second gear portion 181d of the drive transmission gear 181, with reference to the midpoint line between the first gear portion 163c and the second gear portion 163d of the drive-side flange 163. In other words, in the state shown in Figure 25(c), the displacement is LD in the J direction, and in the state shown in Figure 25(d), the displacement is LE in the H direction. Therefore, the sum of the displacement LD and the displacement LE (LD+LE) is the change in equilibrium position in this modified example.

[0130] If the first gear portion 181c comes into contact with the second gear portion 163d, or the second gear portion 181d comes into contact with the main frame 184, or if the second gear portion 181d comes into contact with the first gear portion 163c, before the drive transmission gear 181 reaches the equilibrium position, then the drive cannot be driven into a backlash-free state. Therefore, in this modified example, the distance LF (width of the cylindrical portion 163e) between the first gear portion 163c and the second gear portion 163d of the drive-side flange 163 and the gap LG between the drive transmission gear 181 and the main frame 184 are set considering the amount of change in the equilibrium position (LD+LE).

[0131] On the other hand, in the configuration of the embodiment described above, as shown in Figure 25(a), the number of teeth of the first main body gear section 81c and the second main body gear section 81d are the same, and the positional relationship between the peaks 81cs and 81ds of the first main body gear section 81c and the second main body gear section 81d does not change with respect to the rotational phase. Therefore, the equilibrium position in which the drive transmission gear 81 is positioned axially with respect to the drive-side flange 63 does not change. In other words, the amount of change in equilibrium position (LD+LE), which had to be considered in the modified example, does not need to be considered. For this reason, in this embodiment, compared to the modified example, the gap between the first gear section 63c and the second gear section 63d of the drive-side flange 63 (width of the cylindrical section 63e) can be designed to be smaller, and the cartridge B can be miniaturized. In addition, in this embodiment, the gap between the drive transmission gear 81 and the main frame 84 of the device body A can be designed to be smaller compared to the modified example. As a result, the cartridge B and / or the device body A can be miniaturized.

[0132] <Other variations> Next, we will describe a modified example where the main changes lie in parts other than the drive transmission configuration itself, specifically the drive-side flange 63 and the drive transmission gear 81.

[0133] <Application to cleanerless configurations> In the previously described embodiment, cartridge B was described in which toner that remains on the drum 62 without being transferred is scraped off by bringing the rubber blade 77a into contact with the drum 62 and collected in the waste toner chamber 71b (see Figure 3). However, cartridge B may also have a cleanerless configuration. In other words, the drive transmission configuration of the drive-side flange 63 and drive transmission gear 81 of the previously described embodiment may be applied to a cleanerless cartridge.

[0134] Figure 23 is a cross-sectional view of cartridge B with a cleanerless configuration. Cartridge B with a cleanerless configuration is configured and controlled so that residual toner on the drum 62 can be recovered by the developing roller 32. For this reason, cartridge B does not have a rubber blade that contacts the drum 62. Therefore, compared to a configuration in which the rubber blade 77a contacts the drum 62, cartridge B with a cleanerless configuration requires less torque to drive the drum 62 because there is no rubber blade 77a which acted as resistance when rotating the drum 62. As a result, the rotational speed of the drum 62 is more susceptible to fluctuations due to the impact of the sheet material PA being transported. In other words, the rotational accuracy of the drum 62 may decrease. By applying the drive transmission configuration of the drive-side flange 63 and drive transmission gear 81 of the embodiment described above, the drum 62 can be driven in a backlash-free state between the drive-side flange 63 and the drive transmission gear 81. Therefore, compared to a configuration in which there is backlash or rotational play between the drive-side flange and the drive member on the main body side that transmits the drive to it, it is possible to suppress the decrease in rotational accuracy of the drum 62 caused by the absence of rubber blades.

[0135] <Application to configurations without magnetic roller 34> Furthermore, although the above-described embodiment described a developer carrier in which a magnetic roller 34 is provided inside the developing roller 32, an elastic roller without a magnetic roller inside may also be used.

[0136] <Application to a configuration in which the developing roller gear 30 engages with the second gear section 63d> Furthermore, in the embodiment described above, a configuration was explained in which the developing roller gear 30 meshes with the first gear portion 63c of the drive-side flange 63. However, a configuration in which the developing roller gear 30 meshes with the second gear portion 63d is also possible. This case will be explained using Figure 29. Figure 29 is a schematic diagram showing the meshing between the drive-side flange 63 and the developing roller gear 30. The developing roller gear 130, which is fixed to the end of the developing roller shaft 31, meshes with the second gear portion 63d. Since the second gear portion 63d has a larger twist angle than the first gear portion 63c, the meshing ratio is also larger. For this reason, the developing roller gear 130 that meshes with the second gear portion 63d can have a smaller tooth width compared to the developing roller gear 30 that meshes with the first gear portion 63d.

[0137] <Application to a drive transmission configuration from the drive-side flange to the developing roller gear> Furthermore, a configuration similar to the drive force transmission configuration from the drive transmission gear 81 to the drive-side flange 63 may be further applied to the drive force transmission configuration from the drive-side flange 63 to the developing roller gear 230. This case will be explained below with reference to Figure 30. Figure 30 is a perspective view of cartridge B. The developing roller gear 230 is provided with a first developing gear section 230c and a second developing gear section 230d that mesh with the first gear section 63c and the second gear section 63d of the drive-side flange 63, respectively. When the drive-side flange 63 is driven, the developing roller gear 230 moves in the direction of the rotation axis L1 and reaches the equilibrium position by the same principle as the drive transmission gear 81 moving in the direction of the rotation axis L1 to reach the equilibrium position in the above embodiment. When the developing roller gear 230 is in the equilibrium position, the developing roller gear 230 is driven in a backlash-free state relative to the drive-side flange 63, so that alignment deviations and deterioration of the rotation accuracy of the developing roller 32 during load fluctuations can be suppressed.

[0138] <Application to a configuration that drives the developing roller gear without using a drive-side flange> Alternatively, the driving force may be transmitted to the developing roller 532 without going through the drive-side flange 63. Figure 44 is a partial perspective view of cartridge B showing the drive train to the developing roller 532. Note that for illustrative purposes, a portion of the frame of cartridge B is not shown.

[0139] As shown in Figure 44, the developing roller 532 is not configured to receive driving force from the drive-side flange 63, but rather to receive driving force through another path. Specifically, cartridge B has a developing coupling member 89 that can engage with a coupling member (not shown) for driving the developing roller of the device body A. Furthermore, cartridge B is provided with idler gears 90 and 91 that mesh with the gear portion 89a of the developing coupling member 89, and has a developing roller gear 530 at one end of the shaft of the developing roller 532 that meshes with the idler gear 91. In this configuration, the developing roller 530 is driven by the driving force received by the developing coupling member 89, transmitted via the idler gears 90 and 91 and the developing roller gear 530. Therefore, it is possible to control the driving of the developing coupling member 89 separately from the driving of the drive-side flange 63, for example, by driving the developing coupling member 89 while the drive-side flange 63 is stopped.

[0140] <Application to drive transmission configurations for rotating bodies other than drums> The drive-side flange 63 was attached to the end of the drum 62, but it is also possible to apply a configuration in which the developing roller gear 30 is provided with a first gear section 63c, a second gear section 63d, and a cylindrical section 63e, and the drive transmission gear 81 drives the developing roller 30. Furthermore, the object driven by the drive transmission gear 81 is not limited to the developer carrier that holds toner (developer), such as the drum 62 or the developing roller 30. The object driven by the drive transmission gear 81 may be, for example, a transport member (or agitator) 43 that transports (or agitates) the toner, a charging roller 66, or a supply member that supplies toner to the developing roller 30. Also, if the object driven by the drive transmission gear 81 is a component other than the drum 62 of cartridge B, cartridge B may be a cartridge that does not have a photoreceptor such as a drum 62.

[0141] [Example 2] Next, Example 2 will be described below with reference to Figure 31. This example differs from Example 1 in the configuration of the first gear section and the second gear section provided on the drive-side flange. Other aspects are the same as in Example 1, so the explanation will be omitted.

[0142] Figure 31 is a cross-sectional view of the meshing portion between the drive transmission gear 81 and the drive-side flange 263, the cross-section being the surface tangent to the meshing pitch circle. The drive-side flange 263 has a first gear portion (first unit side gear portion) 263c and a second gear portion (second unit side gear portion) 263d. The first gear portion 263c includes a plurality of first spur teeth (first projections) 263ct with a tooth width that can fit between the teeth of the first main gear portion 81c. The second gear portion 263d includes a plurality of second spur teeth (second projections) 263dt with a tooth width that can fit between the teeth of the second main gear portion 81d. Furthermore, the width (tooth width) of the first spur teeth 263ct in the direction of the rotation axis L1 is greater than the width (tooth width) of the second spur teeth 263dt in the direction of the rotation axis L1. Multiple first spur teeth and multiple second spur teeth are projections that protrude radially around the rotation axis L1 and are positioned at offset locations in the circumferential direction around the rotation axis L1.

[0143] Even when such a drive-side flange 263 is used, the drive transmission gear 81 rotates in the I direction, causing the drive transmission gear 81 to move to the equilibrium position and become backlash-free, similar to Embodiment 1. That is, the first main body gear portion 81c meshes with the first gear portion 263c and receives a reaction force of the driving force FD and a thrust force F209 in the J direction from the contact point (contact portion) CP1 of the first gear portion 263c. The second main body gear portion 81d meshes with the second gear portion 263d and receives a reaction force of the restricting force FB and a thrust force F210 in the H direction from the contact point (contact portion) CP2 of the second gear portion 263d. In this way as well, the drive transmission gear 81 is sandwiched between the first gear portion 263c and the second gear portion 263d of the drive-side flange 263 with respect to the axial rotation direction, so it becomes backlash-free, similar to Embodiment 1.

[0144] [Example 3] Next, Embodiment 3 will be described below with reference to Figure 32. This embodiment differs from Embodiment 1 in the configuration of the first gear section and the second gear section provided on the drive-side flange. Other aspects are the same as in Embodiment 1, so the explanation will be omitted.

[0145] Figure 32 shows the drive-side flange 363. The drive-side flange 363 has a first gear section 363c and a second gear 363d1. The first gear section (first unit side gear section) 363c includes a plurality of first helical gears (first projections) 363ct, which are divided into multiple sections in the direction of the rotation axis L1. Although the plurality of first helical gears (projections) 363ct are divided in the direction of the rotation axis L1, they function substantially as a single helical tooth extending in the direction of the rotation axis L1 with respect to the first main gear section 81c. Furthermore, the tooth surfaces of the plurality of first helical gears (projections) 363ct are a plurality of force-receiving sections that receive force from the first main gear section 81c. For this reason, it can be said that the plurality of force-receiving sections that receive force from the first main gear section 81c are provided across the plurality of first helical gears (first projections) 363ct. Furthermore, the tooth surfaces of the multiple first helical gears (projections) 363ct can be said to constitute helical tooth surfaces divided into multiple sections in the direction of the rotation axis L1, or helical tooth surfaces divided into multiple sections in the circumferential direction centered on the rotation axis L1 of the drive-side flange 363. In this way, the multiple helical tooth-shaped projections 363ct constitute one tooth of the helical gear corresponding to one tooth of the first main gear section 81c.

[0146] The tooth surfaces of the multiple second helical gears (projections) 363dt are multiple force-receiving parts that receive force from the second main gear section 81d. Therefore, it can be said that the multiple force-receiving parts that receive force from the second main gear section 81d are provided across the multiple second helical gears (second projections) 363dt. The second gear section (second unit side gear section) 363d includes multiple second helical gears (projections) 363dt which are divided into multiple parts in the direction of the rotation axis L1. Although the multiple second helical gears (second projections) 363dt are divided in the direction of the rotation axis L1, they function substantially as a single helical tooth extending in the direction of the rotation axis L1 with respect to the second main gear section 81d. Furthermore, the tooth surfaces of the multiple second helical gears (projections) 363dt can be said to constitute helical tooth surfaces divided into multiple sections in the direction of the rotation axis L1, or to constitute helical tooth surfaces divided into multiple sections in the circumferential direction centered on the rotation axis L1 of the drive-side flange 363. In this way, the multiple helical tooth-shaped projections 363dt constitute one tooth of the helical gear corresponding to one tooth of the second main gear section 81d.

[0147] Therefore, even when such a drive-side flange 363 is used, the drive transmission gear 81 rotates in direction I, causing the drive transmission gear 81 to move to the equilibrium position, resulting in a backlash-free state similar to that of Embodiment 1.

[0148] [Example 4] Next, Embodiment 4 will be described below with reference to Figure 33. This embodiment differs from Embodiment 1 in the configuration of the first gear section and the second gear section provided on the drive-side flange. Other aspects are the same as in Embodiment 1, so the explanation will be omitted.

[0149] The drive-side flange 463 has two gear sections (first unit side gear section and second unit side gear section), similar to the first gear section 63c and second gear section 63d of the drive-side flange 63 in Embodiment 1. At least one of the two gear sections has missing teeth (apparently, a portion where the teeth of the gear are thinned out) 463L. Figure 33(a) is a view of the drive-side flange 463 and drive transmission gear 81 meshing with each other, in a cross section perpendicular to the rotation axis L1. Figure 33(b) is a graph showing the change in the number of teeth of the meshing gears. If the meshing ratio between each gear section of the drive-side flange 463 and each gear section of the drive transmission gear 81 is N teeth (rounded down to the nearest whole number), then each gear section of the drive-side flange 463 may have missing teeth 463L at intervals of up to N-1 teeth. By satisfying this condition, even if there is a missing tooth portion 463L, there will be at least one tooth that meshes with the drive transmission gear 81 (the meshing ratio will be 1 or more). With this configuration, as the drive transmission gear 81 rotates in direction I, the drive transmission gear 81 moves to the equilibrium position and becomes backlash-free, similar to Embodiment 1. As shown in Figure 33(b), the number of teeth on the gear of the drive-side flange 463 that meshes with each gear portion of the drive transmission gear 81 changes during operation.

[0150] [Example 5] Next, Example 5 will be described below with reference to Figure 34. This example differs from Example 1 in the configuration of the first gear section and the second gear section provided on the drive-side flange. Other aspects are the same as in Example 1, so the explanation will be omitted.

[0151] The drive-side flange 563 has two gear sections (first unit side gear section and second unit side gear section), similar to the first gear section 63c and second gear section 63d of the drive-side flange 63 in Embodiment 1. At least one of the two gear sections has a missing tooth section 563L. Figure 34(a) is a view of the drive-side flange 563 and drive transmission gear 81 meshing with each other, in a cross section perpendicular to the rotation axis L1. Figure 34(b) is a diagram showing the change in the number of teeth of the meshing gears. As shown in Figure 34(a), unlike the drive-side flange 463 in Embodiment 4, the teeth of the drive-side flange 563 are not arranged at equal pitches in the circumferential direction. In other words, the size of the multiple missing tooth sections 563 is not constant in the circumferential direction, or the apparent amount of tooth reduction of all missing tooth sections 563 is not the same. To put it another way, they only need to be arranged in the rotation direction at intervals LI, LJ that are natural numbers (1, 2, ...) times the minimum pitch LH between adjacent teeth. Even if such missing teeth 563 are present, it is sufficient that at least one tooth is present to mesh with them (the meshing ratio is 1 or more). With this configuration, as the drive transmission gear 81 rotates in direction I, the drive transmission gear 81 moves to the equilibrium position, resulting in a backlash-free state similar to Embodiment 1. Note that, as shown in Figure 34(b), the number of teeth on the gear of the drive-side flange 463 that meshes with each gear portion of the drive transmission gear 81 changes.

[0152] [Example 6] Next, Example 6 will be described below with reference to Figure 35. This example differs from Example 1 in the configuration of the first gear section and the second gear section provided on the drive-side flange. Specifically, while the first gear section 63c and the second gear section 63d in Example 1 were equipped with involute tooth profiles, this example differs in that they are involute tooth profiles. Other points are the same as in Example 1, so the explanation will be omitted.

[0153] Figure 35 is a perspective view of the drive-side flange 763. The drive-side flange 763 has a first gear section (first unit-side gear section) 763c and a second gear section (second unit-side gear section) 763d. The first gear section 763c includes a plurality of first protrusions 763ct, and the second gear section 763d includes a plurality of second protrusions 763dt. The first protrusions 763ct and the second protrusions 763dt are projections that project radially around the rotation axis L1, and their cross-sectional shape in a section perpendicular to the rotation axis L1 is a trapezoid that narrows towards the tip. Furthermore, the first protrusions 763ct and the second protrusions 763dt are helical teeth that are twisted with respect to the rotation axis L1. Even with this configuration, when meshing with the drive transmission gear 81, the first gear section 763c and the second gear section 763d function as helical gears. Therefore, as the drive transmission gear 81 rotates in direction I, the drive transmission gear 81 moves to the equilibrium position, resulting in a backlash-free state, similar to Embodiment 1.

[0154] Furthermore, the cross-sectional shape of the first projection 763ct and the second projection 763dt is not limited to a trapezoid; it may also be a rectangle, a triangle, a mountain shape composed of curves, or a shape with chamfered corners.

[0155] [Example 7] Next, Example 7 will be described below with reference to Figure 36. This example differs from Example 1 in the configuration of the first gear section and the second gear section provided on the drive-side flange. Specifically, the twist direction is reversed compared to the first gear section 63c and the second gear section 63d of Example 1. Accordingly, the twist direction of the first main gear section and the second main gear section of the drive transmission gear is also reversed compared to Example 1. Other points are the same as in Example 1, so the explanation will be omitted.

[0156] Figure 36 is a schematic diagram showing the meshing between the drive transmission gear 881 and the drive-side flange 863. As shown in Figure 36, the twisting direction of the first gear portion (first unit side gear portion) 863c and the second gear portion (second unit side gear portion) 863d of the drive-side flange 863 is such that as you move toward the J direction, the tooth surfaces shift toward the I direction. The twisting direction of the first gear portion 881c and the second gear portion 881d of the drive transmission gear 881 is such that as you move toward the J direction, the tooth surfaces shift toward the K direction.

[0157] Since the torsional direction is reversed compared to Embodiment 1, the direction of the thrust force F21 due to the meshing acting on the drive transmission gear 881 while it is being driven is also reversed compared to Embodiment 1. Therefore, when moving to the axial equilibrium position, a space with a width LK is required for the drive transmission gear 881 to move in the H direction. For this reason, a compression spring 185 is provided to bias the drive transmission gear 881 in the J direction, and the drive transmission gear 881 is positioned to abut against the positioning portion 83b of the second drive side plate 83 before the cartridge B is installed.

[0158] Even with this configuration, as the drive transmission gear 881 rotates in direction I, the drive transmission gear 881 moves to the equilibrium position, resulting in a backlash-free state similar to that of Embodiment 1.

[0159] [Example 8] Next, Example 8 will be described using Figure 37. This example differs from Example 1 in that the cartridge B is attached to the main body of the device. Other aspects are the same as in Example 1, so their explanation will be omitted.

[0160] Figure 37 is a perspective view of the image forming apparatus 800. In this image forming apparatus 800, the insertion direction of the cartridge B into the apparatus body A is parallel or nearly parallel to the rotation axis L1 of the drum 62. Even after the cartridge B has been inserted in the direction parallel to the rotation axis L1, there is a distance between the drive-side flange 63 and the drive transmission gear (not shown) of the apparatus body A in a direction perpendicular to the rotation axis L1, so they cannot engage. Subsequently, by closing the door 211, the lift-up mechanism (not shown) of the apparatus body A connected to the door 211 displaces the cartridge B at least in a direction VD perpendicular to the rotation axis L1, causing the drive-side flange 63 to engage with the drive transmission gear (not shown) of the apparatus body A.

[0161] The drive operation after the drive-side flange 63 and the drive transmission gear (not shown) engage is the same as in Embodiment 1, and the drive transmission gear moves to the balanced position, resulting in a backlash-free state, similar to Embodiment 1.

[0162] Furthermore, when the lift-up mechanism displaces cartridge B in a direction VD perpendicular to the rotation axis L1, cartridge B may be displaced not only in a direction perpendicular to the rotation axis L1, but also in the direction of the rotation axis L1. Alternatively, the lift-up mechanism may be configured to rotate cartridge B around an axis perpendicular to the rotation axis L1, and displace the drive-side flange 63 in a direction VD perpendicular to the rotation axis L1.

[0163] Alternatively, instead of closing the door 211 and activating the lift-up mechanism after inserting cartridge B into the device body A, cartridge B may be displaced in a direction VD at least perpendicular to the rotation axis L1 during the insertion process into the device body A. Specifically, in the initial stage of the insertion process of cartridge B into the device body A, cartridge B is guided by a guide (not shown) to move in a direction parallel to the rotation axis L1. Then, in the final stage of the insertion process, cartridge B is guided by a guide (not shown) to displace cartridge B in a direction VD at least perpendicular to the rotation axis L1. Thus, the direction of movement (mounting direction) of cartridge B may be configured to change during the insertion process.

[0164] [Example 9] Next, Embodiment 9 will be described below with reference to Figure 38. Compared to Embodiment 1, this embodiment differs in the configuration of the first gear section and the second gear section provided on the drive-side flange. Specifically, in this embodiment, the arrangement of the first gear section 963c and the second gear section 963d with respect to the direction of the rotation axis L1 is reversed compared to the first gear section 63c and the second gear section 63d in Embodiment 1. Accordingly, the positions of the first main gear section and the second main gear section of the drive transmission gear with respect to the direction of the rotation axis L1 are also reversed compared to Embodiment 1. Other points are the same as in Embodiment 1, so the explanation will be omitted.

[0165] Figure 38 is a schematic diagram showing the meshing between the drive transmission gear 981 and the drive-side flange 963. The drive-side flange 963 has a first gear portion (first unit side gear portion) 963c and a second gear portion (second unit side gear portion) 963d. The twist angle of the second gear portion 963d is greater than that of the first gear portion 963c. The first gear portion 963c is positioned downstream in the J direction (drive side) of the second gear portion 963d. In other words, with respect to the direction of the rotation axis L1, the second gear portion 963d is positioned between the first gear portion 963c and the drum 62. Similarly, the drive transmission gear 981 is provided with a first gear portion 981c that meshes with the first gear portion 963c and a second gear portion 981d that meshes with the second gear portion 963d. The positions of these also have the opposite relationship with respect to the direction of the rotation axis L1 compared to Embodiment 1.

[0166] Even with this configuration, when the drive transmission gear 981 is driven, the drive transmission gear 981 moves to the equilibrium position. During subsequent driving, as in Embodiment 1, the first gear section 963c receives the driving force FD (see Figure 17(d)) ​​and the second gear section 963d receives the regulating force FB (see Figure 17(d)), resulting in a backlash-free state.

[0167] Here, the drive-side (downstream in the J direction) end of the drum unit 969, in which the drive-side flange 963 and drum 62 are integrated, is rotatably supported by a shaft member 86 (see also Figure 4). Furthermore, the first gear portion 963c is positioned closer to the root of the shaft member 86 than the second gear portion 963d. Moreover, the force acting on the tooth surface of the drive-side flange 963 is greater for the first gear portion 963c, which receives the driving force FD, than for the second gear portion 963d, which receives the restricting force FB. As a result, the driving force FD may act to tilt the rotation axis L1 of the drum unit 969, causing the drum 62 to tilt relative to the ideal rotation axis L1. However, as in this embodiment, by positioning the first gear portion 963c, which receives the driving force FD, closer to the root of the shaft member 86 than the second gear portion 963d, the tilting of the rotation axis L1 of the drum unit 969 caused by receiving the driving force FD can be suppressed.

[0168] [Example 10] Next, Example 10 will be described below with reference to Figure 39. This example differs from Example 1 in the configuration of the first gear section and the second gear section provided on the drive-side flange. Specifically, in Example 1, the position and width of the teeth of the first gear section 63c and the second gear section 63d in the direction of the rotation axis L1 were the same, but in this example, the position and width of the teeth in the direction of the rotation axis L1 are not aligned. Other points are the same as in Example 1, so the explanation will be omitted.

[0169] Figure 39 is a cross-sectional view of the meshing portion between the drive transmission gear 81 and the drive-side flange 1063, and the cross-section is the surface tangent to these meshing pitch circles. The drive-side flange 1063 is provided with a first gear portion (first unit side gear portion) 1063c and a second gear portion (second unit side gear portion) 1063d. The first gear portion 1063c includes a plurality of first helical teeth (first projections) 1063ct that differ in width and position with respect to the direction of the rotation axis L1. The second gear portion 1063d includes a plurality of second helical teeth (second projections) 1063dt that differ in width and position with respect to the direction of the rotation axis L1.

[0170] In this configuration, although the meshing ratio differs from that of the drive-side flange 63 in Embodiment 1, the first gear section 1063c and the second gear section 1063d function as helical gears similar to the first gear section 63c and the second gear section 63d, respectively. Therefore, as the drive transmission gear 81 rotates in the I direction, the drive transmission gear 81 moves to the equilibrium position, resulting in a backlash-free state similar to Embodiment 1.

[0171] [Example 11] Next, Example 11 will be described below with reference to Figure 40. This example differs from Example 1 in the configuration of the second gear section provided on the drive-side flange. Specifically, the second gear section 63d in Example 1 was a helical gear, while in this example it is a spur gear. Other aspects are the same as in Example 1, so the explanation will be omitted.

[0172] Figure 40 is a cross-sectional view of the meshing portion between the drive transmission gear 81 and the drive-side flange 1163, and the cross-section is the surface tangent to these meshing pitch circles. The drive-side flange 1163 is provided with a first gear portion (first unit side gear portion) 1163c and a second gear portion (second unit side gear portion) 1163d. The first gear portion 1163c is the same as the first gear portion 63c in Embodiment 1. The second gear portion 1163d includes a plurality of second spur teeth (teeth, second projections) 1163dt. The plurality of second spur teeth 1163dt are spur teeth with tooth width and tooth thickness that can be inserted between the teeth (grooves) of the second main gear portion 81d of the drive transmission gear 81. For this reason, the width (tooth width) of the second spur teeth (second projections) 1163dt in the direction of the rotation axis L1 is smaller than the width (tooth width) of the first gear portion 1163c in the direction of the rotation axis L1. In other words, the second gear portion 1163d has a second flat tooth (second projection) 1163dt that is narrower than the first helical tooth of the first gear portion 1163c, which has the widest width (tooth width) in the direction of the rotation axis L1.

[0173] Furthermore, the width (length) of the second projection 1163dt in the rotational direction (direction I) or circumferential direction is smaller than the width (length) of one tooth of the first gear portion 1163c in the rotational direction (direction I) or circumferential direction. In other words, the second gear portion 1163dt has a second projection 1163dt that is narrower in the rotational direction (direction I) or circumferential direction compared to the first oblique tooth of the first gear portion 1163c, which has the widest width (length) in the rotational direction (direction I) or circumferential direction.

[0174] Furthermore, the second projection 1163dt has a contact portion CP2 that contacts the second main gear portion 81d. As shown in Figure 40, the contact portion CP2 is provided at the corner of the second projection 1163dt. The corner (contact point CP2) is provided such that it contacts one tooth of the second main gear portion 81d at only one point in the direction of the rotation axis L1. The radius of curvature of this corner can be set to a desired value, and by making the radius of curvature smaller, a sharper corner shape can be made, or by making the radius of curvature larger, a gentler corner can be made, as in the second projection 1363dt shown in Embodiment 13 described later.

[0175] When the drive transmission gear 81 is driven, it receives a thrust force F1109 in the J direction and moves in the J direction, similar to Embodiment 1. Then, the upstream surface 81d2 of the second main gear portion 81d in the I direction comes into contact with the contact portion CP2 of the second spur tooth 1163dt of the second gear 1163d, receiving a thrust force F1110 in the H direction. As a result, the drive transmission gear 81 is positioned at the equilibrium position and becomes backlash-free, based on the same principle as Embodiment 1. Furthermore, in the backlash-free state, with respect to rotational driving, the first gear portion 1163c receives a driving force FD, and the second gear portion 1163d receives a restricting force FB at the contact portion CP2 of the second spur tooth 1163dt.

[0176] [Example 12] Next, Example 12 will be described below with reference to Figure 41. This example differs from Example 1 in the configuration of the second gear section provided on the drive-side flange. Specifically, in Example 1, the twist angle of the second gear section 63d was larger than that of the first gear section 63c, but in this example, the twist angle of the second gear section 1263d is not. Other aspects are the same as in Example 1, so the explanation will be omitted.

[0177] Figure 41 is a cross-sectional view of the meshing portion between the drive transmission gear 81 and the drive-side flange 1263, and the cross-section is the surface tangent to these meshing pitch circles. The drive-side flange 1263 is provided with a first gear portion (first unit side gear portion) 1263c and a second gear portion (second unit side gear portion) 1263d. The first gear portion 1263c is the same as the first gear portion 63c in Embodiment 1. The second gear portion 1263d includes a plurality of second helical teeth (teeth, second projections) 1263dt. The helix angle of the plurality of second helical teeth 1263dt is the same as the helix angle of the helical teeth of the first gear portion 1263c. Also, similar to the plurality of second helical teeth 1163dt in Embodiment 11, the plurality of second helical teeth 1263dt are helical teeth with tooth width and tooth thickness that can be inserted between the teeth (grooves) of the second main gear portion 81d of the drive transmission gear 81. Therefore, the width (tooth width) of the second helical tooth (second projection) 1263dt in the direction of the rotation axis L1 is smaller than the width (tooth width) of the first gear section 1263c in the direction of the rotation axis L1. In other words, the second gear section 1263d has a second helical tooth (second projection) 1263dt that is narrower than the first helical tooth of the first gear section 1263c, which has the widest width (tooth width) in the direction of the rotation axis L1.

[0178] Furthermore, the width (length) of the second projection 1263dt in the rotational direction (direction I) or circumferential direction is smaller than the width (length) of one tooth of the first gear portion 1263c in the rotational direction (direction I) or circumferential direction. In other words, the second gear portion 1263dt has a second projection 1263dt that is narrower in the rotational direction (direction I) or circumferential direction compared to the first helical tooth of the first gear portion 1263c, which has the widest width (length) in the rotational direction (direction I) or circumferential direction.

[0179] Furthermore, the second projection 1263dt has a contact portion CP2 that contacts the second main gear portion 81d. As shown in Figure 40, the contact portion CP2 is provided at the corner of the second projection 1263dt. The corner (contact point CP2) is provided such that it contacts one tooth of the second main gear portion 81d at only one point in the direction of the rotation axis L1. The radius of curvature of this corner can be set to a desired value, and by making the radius of curvature smaller, a sharper corner shape can be made, or by making the radius of curvature larger, a gentler corner can be made, as shown in the second projection 1363dt in Embodiment 13 described later.

[0180] When the drive transmission gear 81 is driven, it receives a thrust force F1209 in the J direction and moves in the J direction, similar to Embodiment 1. Then, the upstream surface 81d2 of the second main gear portion 81d in the I direction contacts the contact portion CP2 of the second helical tooth 1163dt of the second gear portion 1263d and receives a thrust force F1210 in the H direction. As a result, the drive transmission gear 81 is positioned at the equilibrium position using the same principle as Embodiment 1, and becomes backlash-free. Furthermore, in the backlash-free state, with respect to rotational driving, the first gear portion 1263c receives a driving force FD, and the second gear portion 1263d receives a restricting force FB at the contact portion CP2 of the second helical tooth 1263dt.

[0181] [Example 13] Next, Example 13 will be described below with reference to Figure 42. This example differs from Example 1 in the configuration of the part corresponding to the second gear section provided on the drive-side flange. Specifically, while the second gear section 63d in Example 1 was an inclined gear, in this example it is composed of multiple cylindrical protrusions. Other aspects are the same as in Example 1, so their explanation will be omitted.

[0182] Figure 42(a) is a perspective view of the drive-side flange 1363. Figure 42(b) is a cross-sectional view of the meshing portion between the drive transmission gear 81 and the drive-side flange 1363, where the cross-section is the surface tangent to the meshing pitch circle.

[0183] The drive-side flange 1363 is provided with a first gear section (first unit side gear section) 1363c and a second gear section (second unit side gear section) 1363d. The first gear section 1363c is the same as the first gear section 63c in Embodiment 1.

[0184] The second gear section 1363d includes a plurality of cylindrical second projections (teeth) 1363dt that project radially from a tooth root cylindrical section (base cylindrical section) 1363Bd extending along the rotation axis L1, with respect to the rotation axis L1. The second gear section 1363d is a rotating part that rotates integrally with the first gear section 1363c. The plurality of second projections 1363dt are arranged at the same position (on the same plane perpendicular to the rotation axis L1) with respect to the direction of the rotation axis L1.

[0185] Furthermore, the tips S of the multiple second projections 1363dt are arranged on a predetermined circumference centered on the rotation axis L1 when viewed along the rotation axis L1, and are also equally spaced in the circumferential direction. The tooth tip circle of the second gear section 1363d is the circle traced as a rotational trajectory by the tip S of the multiple second projections 1363dt that is furthest from the rotation axis (rotation axis L1) of the second gear section 1363d when the drive-side flange 1363 rotates. In this embodiment, since all the second projections 1363dt have the same shape, the distance from the rotation axis L1 to the tip S of all the second projections 1363dt is the same, so all the tip S trace the same rotational trajectory. The diameter / radius of this rotational trajectory circle is defined as the tooth tip circle diameter / tooth tip circle radius of the second gear section 1363d.

[0186] The multiple second projections 1363dt are projections with a width in the direction of the rotation axis L1 and the rotational direction (I direction) that are large enough to be inserted between the teeth (grooves) of the second main gear portion 81d of the drive transmission gear 81. Therefore, the width of the second projections 1363dt in the direction of the rotation axis L1 is smaller than the width (tooth width) of the first gear portion 1363c in the direction of the rotation axis L1. In other words, the second gear portion 1363d has second projections 1363dt that are narrower in the direction of the rotation axis L1 compared to the first helical tooth of the first gear portion 1363c, which has the widest width (tooth width) in the direction of the rotation axis L1. Also, the width (length) of the second projections 1363dt in the rotational direction (I direction) or circumferential direction is smaller than the width (length) of one tooth of the first gear portion 1363c in the rotational direction (I direction) or circumferential direction. In other words, the second gear portion 1363d has a second projection 1363dt that is narrower in the rotational direction (direction I) or circumferential direction compared to the first helical tooth of the first gear portion 1363c, which has the widest width (length) in the rotational direction (direction I) or circumferential direction.

[0187] Furthermore, the second projection 1363dt has a contact portion CP2 that contacts the second main gear portion 81d. As shown in Figure 42(b), the contact portion CP2 is provided on a curved portion of the surface of the second projection 1363dt. This curved portion of the surface of the second projection 1363dt can be called a corner. The corner (contact point CP2) is provided such that it contacts one tooth of the second main gear portion 81d at only one point in the direction of the rotation axis L1. The radius of curvature of this corner can be set to a desired value; by making the radius of curvature smaller, a sharper corner shape can be made, or by making the radius of curvature larger, a gentler corner can be made.

[0188] When the drive transmission gear 81 is driven, it receives a thrust force in the J direction and moves in the J direction, similar to Embodiment 1. Then, the upstream surface 81d2 of the second main gear portion 81d in the I direction comes into contact with the contact portion CP2 of the second projection 1363dt of the second gear portion 1163d, and receives a thrust force F1310 in the H direction. As a result, the drive transmission gear 81 is positioned at the equilibrium position using the same principle as in Embodiment 1, resulting in a backlash-free state. Furthermore, in the backlash-free state, with respect to rotational driving, the first gear portion 1363c receives a driving force FD, and the second gear portion 1363d receives a restricting force FB at the contact portion CP2 of the second projection 1363dt.

[0189] Furthermore, the second gear section 1363d can mesh with other gears such as the second main gear section 81d using multiple second protrusions 1363dt, and is capable of receiving rotational driving force and / or thrust force; therefore, in this respect, it can be considered a type of gear.

[0190] Furthermore, the multiple second protrusions 1363dt are not limited to a cylindrical shape, but may be any shape that protrudes in the radial direction at least with respect to the axis of rotation L1, such as a polygonal prism shape. Also, not all of the multiple second protrusions 1363dt have to be the same shape.

[0191] [Example 14] Next, Example 14 will be described below with reference to Figure 43. This example differs from Example 1 in the configuration of the part corresponding to the second gear section provided on the drive-side flange. Specifically, while the second gear section 63d in Example 1 was a helical gear, in this example it is composed of multiple cylindrical protrusions. Other aspects are the same as in Example 1, so the explanation will be omitted. In addition, the only difference between this example and Example 13 is the arrangement of the multiple cylindrical protrusions.

[0192] Figure 43(a) is a cross-sectional view of the teeth and projections of the drive-side flange 1463, and its cross-section is the surface tangent to the circle centered on the axis of rotation L1. Figure 43(b) is a cross-sectional view of the meshing portion between the drive transmission gear 81 and the drive-side flange 1463, and its cross-section is the surface tangent to the meshing pitch circle.

[0193] The drive-side flange 1463 is provided with a first gear section (first unit side gear section) 1463c and a second gear section (second unit side gear section) 1463d. The first gear 1463c is the same as the first gear section 63c in Embodiment 1.

[0194] The second gear 1463d includes a plurality of cylindrical second projections 1463dt that project radially around the rotation axis L1. The second gear portion 1463d is a rotating portion that rotates integrally with the first gear portion 1463c. The plurality of second projections 1463dt are arranged at positions offset with respect to the direction of the rotation axis L1.

[0195] Furthermore, the tips S of the multiple second projections 1463dt (see Figure 42(a)) are arranged on a predetermined circumference centered on the rotation axis L1 when viewed along the rotation axis L1. The multiple second projections 1463dt are projections with widths in the direction of the rotation axis L1 and the rotation direction (direction I) that are large enough to be inserted between the teeth (valley portions) of the second main gear portion 81d of the drive transmission gear 81. In addition, the multiple second projections 1463dt are positioned so as to be inserted between the teeth (valley portions) of the second main gear portion 81d of the drive transmission gear 81 and to receive a regulating force FB from the second main gear portion 81d in a backlash-free state. Specifically, as shown in Figure 43(a), multiple virtual helical lines (spiral lines) L9 are drawn at a predetermined pitch P9 on a cylindrical surface centered on the rotation axis L1, twisted at the same angle as the helix angle α2 of the second main gear portion 81d. This pitch P9 is the same as the pitch in the direction perpendicular to the tooth surfaces of the multiple second helical teeth 81dt of the second main gear portion 81d of the drive transmission gear 81. The multiple second projections 1463dt are arranged in relation to the multiple helical lines L9 to satisfy the following condition. The condition is that the multiple helical lines L9 can be arranged such that some of the multiple helical lines L9 are in contact with some of the multiple second projections 1463dt, and none of the multiple helical lines L9 pass through the cross-section of the multiple second projections 1463dt. By arranging the multiple second projections 1463dt to satisfy this condition, the multiple second projections 1463dt can perform the same function as the multiple second projections 1363dt in Embodiment 13, receiving a regulating force FB from the second main gear portion 81d in a backlash-free state. Furthermore, similar to Example 13, the corner (contact point CP2) of the second projection 1463dt is positioned such that it contacts one tooth of the second main body gear portion 81d at only one point in the direction of the rotation axis L1.

[0196] When the drive transmission gear 81 is driven, as shown in Fig. 43(b), the drive transmission gear 81, similar to that in the first embodiment, receives the thrust force F1409 and moves in the J direction. Then, the surface 81d2 on the upstream side in the I direction of the second main body gear portion 81d contacts the contact portion CP of the second protrusion 1463dt of the second gear portion 1463d and receives the thrust force F1410 in the H direction. For this reason, the drive transmission gear 81 is positioned at the equilibrium position and becomes backlash-free in the same principle as in the first embodiment. Also, in the backlash-free state, regarding the drive in the rotational direction, the first gear portion 1463c receives the driving force FD, and the second gear portion 1463d receives the regulating force FB at the contact portion CP2 of the second protrusion 1463dt.

[0197] Note that the second gear portion 1463d can mesh with other gears such as the second main body gear portion 81d using a plurality of second protrusions 1463dt and receive a rotational driving force and / or a thrust force. Therefore, in this regard, it can be regarded as a kind of gear.

[0198] Also, the plurality of second protrusions 1463dt are not limited to a cylindrical shape, and it is only necessary that they protrude at least in the radial direction centered on the rotation axis L1, and not all of the plurality of second protrusions 1463dt need to have the same shape.

[0199] [Embodiment 15] Next, Embodiment 15 will be described with reference to Fig. 45. The drive transmission configuration in the cartridge B is different from that in the first embodiment. Fig. 45(a) is a partial cross-sectional view of a cross-section including the rotation axis L1 in the vicinity of the drum 62 of the cartridge B. Fig. 45(b) is a view of the drum 62 and the developing roller 632 of the cartridge B as seen in a direction orthogonal to the rotation axis L1.

[0200] The gear that meshes with the drive transmission gear 81 does not necessarily need to be integrally fixed to the end of the drum 62. As shown in Fig. 45(a), the driven gear 1563 that meshes with the drive transmission gear 81 is rotatably supported at both ends by a shaft 1578 fixed to one end of the cleaning frame 1571. That is, the shaft 1578 supports the driven gear 1563 in a state of passing through the driven gear 1563. The driven gear 1563 has a first gear portion (first unit side gear portion) 1563c that is a helical gear with a twist angle α1 and a second gear portion (second unit side gear portion) 1563d that is a helical gear with a twist angle α2, similar to the first gear portion 63c and the second gear portion 63d provided on the drive side flange 63 of the first embodiment. Also, at one end of the developing roller 632, a developing roller gear 630 that meshes with the second gear portion 1563d of the driven gear 1563 is integrally provided with the developing roller 632, and at the other end, a drum drive gear 92 is integrally provided with the developing roller 632. Further, at one end of the drum 62, a drum gear 93 that meshes with the drum drive gear 92 is integrally attached by caulking or the like and is rotatably supported by a drum shaft. Also, at the other end of the drum, a drum flange 1564 is attached by caulking or the like and is rotatably supported by the shaft 1578. With such a configuration, the driving force received by the driven gear 1563 from the drive transmission gear 81 is transmitted to the drum 62 in the order of the developing roller gear 630, the developing roller 632, the drum drive gear 92, and the drum gear 93.

[0201] [Example 16] Next, Example 15 will be described below with reference to Fig. 48. This example is different in the configuration of the portions corresponding to the first gear portion and the second gear portion provided on the drive side flange compared to Example 1. Specifically, the first gear portion 63c and the second gear portion 63d of Example 1 were helical gears, but in this example, the difference is that each gear portion is formed by a plurality of protrusions (each tooth of the gear portion is constituted by a plurality of protrusions). Since the other points are the same as those in Example 1, the description thereof will be omitted.

[0202] Figure 48(a) is a cross-sectional view of the teeth and projections of the drive-side flange 1663, and its cross-section is the surface tangent to the circle centered on the axis of rotation L1. Figure 48(b) is a cross-sectional view of the meshing portion between the drive transmission gear 81 and the drive-side flange 1663, and its cross-section is the surface tangent to the meshing pitch circle.

[0203] The first gear section (first unit side gear section, first unit side inclined gear section) 1663c includes a plurality of cylindrical first projections 1663ct that protrude radially from a tooth root cylindrical section (base cylindrical section) extending along the rotation axis L1, with respect to the rotation axis L1. The plurality of first projections 1663ct are arranged at the same position and offset positions with respect to the direction of the rotation axis L1.

[0204] Furthermore, the tips S of the multiple first projections 1663ct (see Figure 42(a)) are arranged on a predetermined circumference centered on the rotation axis L1 when viewed along the rotation axis L1. The multiple first projections 1663ct are projections with a width in the direction of the rotation axis L1 and the rotation direction (direction I) that are large enough to be inserted between the teeth (valley portions) of the first main gear portion 81c of the drive transmission gear 81. In addition, the multiple first projections 1663dt are positioned so as to be inserted between the teeth (valley portions) of the first main gear portion 81c of the drive transmission gear 81 and to receive the driving force FD from the first main gear portion 81c in a backlash-free state. Specifically, as shown in Figure 48(a), multiple virtual helical lines (spiral lines) L15 are drawn at a predetermined pitch P11 on a cylindrical surface centered on the rotation axis L1, twisted at the same angle as the helix angle α1 of the first main gear portion 81c. This pitch P11 is the same as the pitch in the direction perpendicular to the tooth surfaces of the multiple first helical teeth 81ct of the first main gear portion 81c of the drive transmission gear 81. The multiple first projections 1663dt are arranged in relation to the multiple helical lines L5 to satisfy the following condition. This condition is that the multiple helical lines L11 can be arranged such that some of the multiple helical lines L15 are in contact with some of the multiple first projections 1663ct, and none of the multiple helical lines L11 pass through the cross-section of the multiple first projections 1663ct. By arranging the multiple first projections 1663ct to satisfy this condition, the multiple first projections 1663dt can mesh with the first main gear portion 81c in a backlash-free state, rotate, and perform the function of receiving the driving force FB.

[0205] The second gear section (second unit side gear section, second unit side helical gear section) 1663d includes a plurality of cylindrical second protrusions 1663dt that project radially around the rotation axis L1. The second gear section 1663d is a rotating part that rotates integrally with the first gear section 1663c. The plurality of second protrusions 1663dt are arranged at positions offset with respect to the direction of the rotation axis L1.

[0206] Furthermore, the tips S of the multiple second projections 1663dt (see Figure 42(a)) are arranged on a predetermined circumference centered on the rotation axis L1 when viewed along the rotation axis L1. The multiple second projections 1663dt are projections with widths in the direction of the rotation axis L1 and the rotation direction (direction I) that are large enough to be inserted between the teeth (valley portions) of the second main gear portion 81d of the drive transmission gear 81. In addition, the multiple second projections 1663dt are positioned so as to be inserted between the teeth (valley portions) of the second main gear portion 81d of the drive transmission gear 81 and to receive a regulating force FB from the second main gear portion 81d in a backlash-free state. Specifically, as shown in Figure 48(a), multiple virtual helical lines (spiral lines) L14 are drawn at a predetermined pitch P10 on a cylindrical surface centered on the rotation axis L1, twisted at the same angle as the helix angle α2 of the second main gear portion 81d. This pitch P10 is the same as the pitch in the direction perpendicular to the tooth surfaces of the multiple second helical teeth 81dt of the second main gear portion 81d of the drive transmission gear 81. The multiple second projections 1663dt are arranged in relation to the multiple helical lines L14 to satisfy the following condition. The condition is that the multiple helical lines L14 can be arranged such that some of the multiple helical lines L14 are in contact with some of the multiple second projections 1663dt, and none of the multiple helical lines L14 pass through the cross-section of the multiple second projections 1663dt. By arranging the multiple second projections 1663dt to satisfy this condition, the multiple second projections 1663dt can perform the same function as the multiple second projections 1363dt in Embodiment 13, which is to mesh with the second main gear portion 81d in a backlash-free state, rotate, and receive a regulating force FB.

[0207] As shown in Figure 48(b), when the drive transmission gear 81 is driven, the drive transmission gear 81 moves in the J direction, similar to Embodiment 1. This is because the first main body gear portion 81c contacts the multiple first protrusions 1663ct and receives a thrust force in the J direction. As the drive transmission gear 81 moves in the J direction, the upstream surface 81d2 of the second main body gear portion 81d in the I direction contacts the contact portion CP2 of the second protrusion 1663dt of the second gear portion 1663d, and receives a thrust force F1610 in the H direction. Also, the downstream surface 81c1 of the first main body gear portion 81c in the I direction contacts the contact portion CP1 of the first protrusion 1663ct of the first gear portion 1663c, and receives a thrust force F1609 in the J direction. Therefore, the drive transmission gear 81 is positioned at the equilibrium position using the same principle as in Embodiment 1, resulting in a backlash-free state. Furthermore, in the backlash-free state, with respect to rotational drive, the first gear section 1663c receives a driving force FD, and the second gear section 1663d receives a restricting force FB at the contact point CP of the second projection 1463dt.

[0208] Furthermore, the first gear portion 1663c can mesh with other gears such as the first main gear portion 81d using multiple first protrusions 1663ct to receive rotational driving force and / or thrust force, and in this respect it can be considered a type of gear (inclined gear). In other words, the surfaces of the multiple first protrusions 1663ct (multiple contact portions CP1) constitute an inclined tooth surface divided into multiple sections in the direction of the rotation axis L1, or an inclined tooth surface divided into multiple sections in the circumferential direction centered on the rotation axis L1 of the drive-side flange 1663.

[0209] Therefore, by connecting multiple contact points CP1, a helix line L15 can be defined. The multiple first projections 1663ct are arranged so that they can each contact one tooth of the first main gear section 81c at multiple points separated in the direction of the rotation axis L1. It can also be said that multiple contact points CP1 that can simultaneously contact one tooth of the first main gear section 81c are provided at positions separated in the direction of the rotation axis L1. In this way, the multiple first projections 1663ct, which are separated in the direction of the rotation axis L1, can be said to constitute one tooth (inclined tooth) that meshes with one tooth of the first main gear section 81c. Therefore, the multiple first projections 1663ct function as an inclined gear, and the first gear section 1663c is the first inclined gear section.

[0210] Furthermore, the circle traced as a rotational trajectory by the tip (point) of the multiple first projections 1663ct that is furthest from the rotation axis L1 is defined as the tooth tip circle of the first gear section 1663c, and the diameter of that circle is defined as the tooth tip circle diameter.

[0211] Similarly, the second gear portion 1663d can mesh with other gears such as the second main gear portion 81d using multiple second protrusions 1663dt and receive rotational driving force and / or thrust force, so in this respect it can be considered a type of gear. In other words, the surfaces of the multiple second protrusions 1663dt (multiple contact portions CP2) can be said to constitute multiple inclined tooth surfaces divided in the direction of the rotation axis L1, or to constitute multiple inclined tooth surfaces divided in the circumferential direction centered on the rotation axis L1 of the drive-side flange 1663.

[0212] Therefore, by connecting multiple contact points CP2, a helix line L14 can be defined. The multiple second projections 1663dt are arranged so that they can each contact one tooth of the second main gear section 81d at multiple points separated in the direction of the rotation axis L1. It can also be said that multiple contact points CP2 that can simultaneously contact one tooth of the second main gear section 81d are provided at positions separated in the direction of the rotation axis L1. In this way, the multiple second projections 1663dt, which are separated in the direction of the rotation axis L1, can be said to constitute one tooth (inclined tooth) that meshes with one tooth of the second main gear section 81d. Therefore, the multiple second projections 1663dt function as an inclined gear, and the second gear section 1663d is the second inclined gear section.

[0213] Furthermore, the circle traced as a rotational trajectory by the tip (point) of the multiple second projections 1663dt that is furthest from the rotation axis L1 is defined as the tooth tip circle of the second gear section 1663d, and the diameter of that circle is defined as the tooth tip circle diameter.

[0214] Furthermore, each of the multiple first projections 1663ct and the multiple second projections 1663dt is not limited to a cylindrical shape, but may have a shape that protrudes at least in the radial direction centered on the axis of rotation L1. Also, the multiple first projections 1663ct do not have to be multiple projections that are completely separate, even if they have multiple contact parts CP1. For example, they may have a shape in which parts are connected, such that the cross-sectional shape in the tangential direction perpendicular to the radial direction centered on the axis of rotation L1 is like a staircase. The same applies to the multiple second projections 1663dt. Also, not all of the multiple first projections 1663ct have to be the same shape, and not all of the multiple second projections 1663dt have to be the same shape.

[0215] [Example 17] Example 17 differs from Example 1 in the following ways. First, the layout of each component within the device body A that houses cartridge B is different. As a result, the orientation of cartridge B within the device body A is different. Also, the support configuration of the drive-side flange 1763 and the engagement configuration between the drive transmission gear 1781 and the idler gear 1780 are different. Furthermore, the drive transmission configuration to the developing roller 1732 is the same as in the <Other Modifications> of Example 1. Also, the axial positional relationship between the first gear section that receives the driving force FD and the second gear section that receives the regulating force FB is the same as in Example 9. All other points are the same as in Example 1, and a detailed explanation is omitted. In addition, for each element in this embodiment, elements that correspond to elements in Example 1 (e.g., drum 62) (e.g., drum 1762) are given reference numerals that correspond to the corresponding elements in Example 1 (e.g., "1762" corresponding to "62"). Unless otherwise specified, these elements are the same as the corresponding elements in Example 1.

[0216] <Configuration of the main device> Figure 50 is a cross-sectional view of the main body A of the apparatus with cartridge B installed (the cross-section is perpendicular to the rotation axis L1). The main body A of the image forming apparatus 17100 has an exposure device (laser scanner unit) 1703 and a sheet tray 1704 for storing the sheet material PA. Furthermore, the main body A has a pickup roller (not shown), a pair of transport rollers 1705b, a transfer guide 1706, a transfer roller 1707, a transport guide 1708, a fixing device 1709, a pair of discharge rollers 1710, and a discharge tray 1711 along the transport path of the sheet material PA.

[0217] <Position of Cartridge B within Device Body A> As shown in Figure 50, cartridge B is positioned within the main body A of the apparatus with the cleaning unit 1760 and the developing unit 1720 aligned almost horizontally. At this time, the transfer roller 1707 is positioned below the drum 1762.

[0218] <Support configuration of drum unit 1769 by cleaning unit 1760> Next, the support structure of the drum unit 1769 by the cleaning unit 1760 will be described using FIGS. 51(a), 51(b), 52(a), 52(b), 52(c), 58, and 59.

[0219] FIG. 51(a) is an exploded perspective view of the cleaning unit 1760, showing a state where the inside of the drum bearing member 1773 can be seen from the developing unit side of the cleaning unit 1760. FIG. 51(b) is an exploded perspective view of the cleaning unit 1760, showing a state where the outside of the drum bearing member 1773 can be seen from the developing unit side of the cleaning unit 1760. FIG. 52(a) is a perspective view of the drum bearing member 1773 seen from the inside. FIG. 52(b) is a cross-sectional view obtained by cutting the guided portion 1773g of the drum bearing member 1773 that supports the drive-side flange 1763 along a cross-section perpendicular to the rotation axis L1. However, this cross-sectional view shows a state where the cross-section is seen from the inside of the drum bearing member 1773. FIG. 52(c) is a cross-sectional view obtained by cutting a portion near the drive-side flange 1763 of the cartridge B attached to the apparatus main body A along a cross-section that includes the rotation axis L1 and is perpendicular to the mounting direction M (see FIG. 57) of the cartridge B to the apparatus main body A. FIG. 58 is a view showing a cross-sectional state of the cleaning unit 1760 and the drive transmission gear 1781 seen from the outside of the drum bearing member 1773, and the cross-section passes through the hole 1773d of the drum bearing member 1773 that supports the drive-side flange 1763 and is perpendicular to the rotation axis L1. FIG. 59 is a partial perspective view of a portion near the drive-side flange 1763 of the cartridge B.

[0220] As shown in Figures 51(a) and 51(b), the cleaning unit 1760 has a frame member 1771 and a drum bearing member 1773 fixed thereto, which together form a drum frame that supports the drum 1762. The drive-side flange 1763 is provided with a cylindrical projection (supported portion) 1763g centered on the rotation axis L1, which is provided so as to protrude downstream in the J direction from the end of the drive-side flange 1763, outward from the end face of the first gear portion 1763c with respect to the rotation axis L1 (downstream in the J direction). The drum bearing member 1773 is provided with a hole 1773d recessed in the direction of the rotation axis L1 (J direction) for supporting the projection 1763g. As shown in Figures 52(a) and 52(b), the inner surface of the hole 1773d has two planes 1773e and 1773f and two circumferential surfaces 1773h and 1773i, each parallel to the axis of rotation L1. Furthermore, the two planes 1773e and 1773f are not parallel to each other and are arranged to form a roughly V-shaped concave shape when viewed from the direction of the axis of rotation L1. Planes 1773e and 1773f are support surfaces (support parts) that have support points that contact and support the projection 1763g. As shown in Figure 58, the roughly V-shaped concave shape formed by the two planes 1773e and 1773f is provided in a direction opposite to the force FH which is parallel to the force FG originating from the axis of rotation L1, so that it can receive the meshing force FG between the tooth surfaces of the gears when the driving force is transmitted from the drive transmission gear 1781 to the drive-side flange 1763. Specifically, the angle bisector of the angle formed by the extensions of plane 1773e and plane 1773f, viewed along the axis of rotation L1, is set to be substantially parallel to the force FH. However, the orientation of the two planes 1773e and 1773f is not limited to this, and may be set by comprehensively considering the various forces that apply load to the drive-side flange 1763.

[0221] After the drum unit 1769 is assembled inside the frame member 1771, the drum bearing member 1773 is attached and fixed to the frame member 1771, so that the projection 1763g of the drive-side flange 1763 fits inside the hole 1773d of the drum bearing member 1773. As a result, the drum unit 1769 is rotatably supported by the frame member 1771 and the drum bearing member 1773. Also, as shown in Figures 59 and 114(b), in the completed state as cartridge B, a part of the drive-side flange 1763 (a part of the first gear section 1363c and a part of the second gear section 1363d) and a part of the drum 1762 are not covered by the drum frame (drum bearing member 1773 and frame member 1771) and are exposed to the outside of cartridge B. In other words, the drum frame has an opening to expose a part of the drive-side flange 1763 (such as a part of the first gear section 1363c and a part of the second gear section 1363d) and a part of the drum 1762 to the outside.

[0222] As shown in Figure 52(c), when cartridge B is mounted on the device body A, the arcuate surface of the guided portion 1773g contacts the two positioning portions 1715a of the first drive-side plate 1715 of the device body A, and the position of the rotation axis L1 of cartridge B relative to the device body A is determined in two directions perpendicular to the rotation axis L1 (mounting direction M and orthogonal direction MP perpendicular to the mounting direction M) (see Figure 57). The guided portion 1773g is a projection that protrudes outward (direction J) in the direction of the rotation axis L1, and the aforementioned hole 1773d is provided on its inner side. The device body A is also provided with a pressing member (not shown) that presses cartridge B so as to press the guided portion 1773g toward the two positioning portions 1715a. Furthermore, the meshing force FG between the gear teeth during the transmission of driving force from the drive transmission gear 1781 to the drive-side flange 1763 also acts to press the guided portion 1773g toward the two positioning portions 1715a. In addition, the force exerted by the transfer roller 1707 (see Figure 50) pressing against the drum 1762 also acts to press the guided portion 1773g toward the positioning portion 1715a in the orthogonal direction MP.

[0223] At least a portion of the guided portion 1773g, at least a portion of the two planar portions 1773f and 1773e, and at least a portion of the projection 1763g are arranged in the same position in the direction of the rotation axis L1. In other words, at least a portion of the guided portion 1773g, at least a portion of the two planar portions 1773f and 1773e, and at least a portion of the projection 1763g are arranged on a single plane perpendicular to the rotation axis L1. This arrangement suppresses deformation that would cause the drum bearing 1773 to tilt relative to the rotation axis L1, and suppresses tilting (tilting) of the drive-side flange 1763 relative to the rotation axis L1. As a result, deterioration of the meshing accuracy between the drive-side flange 1763 and the drive transmission gear 1781 can be suppressed. Furthermore, by abutting the projection 1763g against the two flat surfaces 1773f and 1773e, the play in the fitting can be reduced to one direction (along the angle bisector of the angle formed by the extension of the plane 1773e and the extension of the plane 1773f when viewed along the axis of rotation L1), improving the positional accuracy of the drive-side flange 1763 in the direction perpendicular to the axis of rotation L1, and suppressing deterioration of the meshing accuracy with the drive transmission gear 1781.

[0224] In this embodiment, the projection 1763g is formed integrally with the drive-side flange 1763, but the projection 1763g may also be made of a separate part such as metal and press-fitted into the drive-side flange 1763.

[0225] Next, the axial positioning of the drive-side flange 1763 will be described. As shown in Figures 51(a) and 51(b), the first gear portion 1763c of the drive-side flange 1763 has a projection 1763c1 that protrudes slightly in the H direction on the downstream end face in the H direction, and a projection 1763f that protrudes slightly in the J direction on the downstream end face in the J direction (upstream end face in the H direction). The frame member 1771 also has a rib 1771p and a side wall 1771m that are provided to extend in a direction perpendicular to the rotation axis L1. The projection 1763c1 can contact the side surface of the rib 1771p, and the projection 1763f can contact the side surface of the side wall 1771m. The drive-side flange 1763 is fitted and held between the rib 1771p and the side wall 1771m in a gap fit so as to be slidable in the direction of the rotation axis L1. As a result, the drive-side flange 1763 is positioned relative to the frame member 1771 with respect to the direction of the rotation axis L1, and consequently the position of the drum unit 1769 within the frame member 1771 is determined.

[0226] <Attaching, detaching, and positioning of Cartridge B within Device Body A> Figure 113(a) shows cartridge B mounted on the device body A, which is installed on a horizontal mounting surface, viewed in the direction along the rotation axis L1 (direction K), where the horizontal direction is denoted as HD and the vertical direction as VD. The plane perpendicular to the rotation axis L1 is parallel to the vertical direction VD. Figure 113(b) shows cartridge B viewed along the HD1 direction, which is parallel to the horizontal direction HD shown in Figure 113(a). Figure 114(a) shows cartridge B viewed along the VD1 direction, which is parallel to the vertical direction VD shown in Figure 113(a). Figure 114(b) shows cartridge B viewed along the VD2 direction, which is parallel to the vertical direction VD shown in Figure 113(a). When viewed along the direction of the rotation axis L1, as can be seen from Figure 50, the line connecting the rotation center of the developing roller 1732 and the rotation center of the photosensitive drum 1762 (rotation axis L1) is approximately parallel to the mounting direction M. Therefore, the mounting direction M in the following description can be interpreted as a direction perpendicular to the rotation axis L1 and parallel to the straight line connecting the rotation center of the developing roller 1732 and the rotation center of the photosensitive drum 1762 (rotation axis L1).

[0227] Similar to Example 1, the mounting direction M of cartridge B to the device body A, and the removal direction (the opposite direction of mounting direction M) from the device body A, are substantially perpendicular to the rotation axis L1. Also, the mounting direction M of drum unit 69 to the device body A and the removal direction from the device body A are the same as the mounting direction M of cartridge B to the device body A and the removal direction from the device body A, respectively.

[0228] As shown in Figure 113(a), the drum bearing member 1773 is provided with guided portions 1773s1, 1773s2, and 1773s3 in addition to the guided portion 1773g described earlier. These guided portions are projections that protrude from the main body of the drum bearing member 1773 in the direction of the rotation axis L1. When the cartridge B is installed in the device body A and when it is removed from the device body A, it contacts and is guided by a guide portion (not shown) provided on the device body A. Note that, as shown in other figures, the guided portion 1773s1 can be omitted. The guided portion 1773s3 can also be omitted depending on the necessity. However, providing the guided portions 1773s1 and 1773s3 makes the installation and removal of the cartridge B more stable. Furthermore, the guided portion 1773s1 is a long projection in the mounting direction M (or, a long projection perpendicular to the rotation axis L1 and parallel to the straight line connecting the rotation center of the developing roller 1732 and the rotation center of the photosensitive drum 1762 (rotation axis L1)). Making the guided portion 1773s1 a long projection in this way increases the rigidity of the drum bearing member 1773. In addition, the guided portion 1773s1 and the guided portion 1773g are provided as a single connected projection, but they may also be provided as separate projections. However, providing them as a single connected projection increases the rigidity of the drum bearing member 1773.

[0229] Furthermore, as mentioned above, when cartridge B is mounted on the device body A, the guided portion 1773g contacts the two positioning portions 1715a of the device body A, determining the position of the rotation axis L1 of cartridge B relative to the device body A in two directions perpendicular to the rotation axis L1 (mounting direction M and perpendicular direction MP) (see Figures 52(c) and 57). In addition, when the guided portion 1773s2 contacts a positioning portion of the device body A (not shown), the position (orientation) of cartridge B relative to the device body A is determined in the rotation direction around the rotation axis L1.

[0230] Furthermore, the positioning of the cartridge B relative to the device body A in relation to the direction of the rotation axis L1 is the same as in Embodiment 1. Specifically, as shown in Figures 113(b) and 114(a), the drum bearing member 1773 has a recessed fitting portion 1773h that is recessed along the mounting direction M, and a convex fitting portion of the device body A that protrudes along the mounting direction M (not shown) fits into this, determining the position of the cartridge B relative to the device body A in relation to the direction of the rotation axis L1.

[0231] Furthermore, as shown in Figure 113(a), the drum bearing member 1773 has a substantially cylindrical developing unit support portion 1773b that extends in the direction of the rotation axis L1. The developing unit support portion 1773b supports the cylindrical portion 1721a, which is arranged to surround the developing coupling member 1789 and coupling portion 1789a of the frame 1721 of the developing unit 1720, so that it can rotate (oscillate) around the rotation axis DA. The rotation axis DA is coaxial with the rotation axis of the developing coupling member 1789 and is parallel to the rotation axis L1. The developing unit 1720 receives force from a force-applying portion (not shown) of the main body A at the force-receiving portion 1721b of the frame 1721 of the developing unit 1720, so that it can rotate (oscillate) in the DS direction around the rotation axis DA relative to the cleaning unit 1760. This rotation makes it possible to separate the developing roller 1732 from the drum 1762.

[0232] Furthermore, as shown in Figure 113(a), when viewing cartridge B from the direction of the rotation axis L1, the guided portion 1773s2 is positioned on a straight line LT passing through the rotation axis L1 and the pivot axis DA. In the direction parallel to the straight line LT, the developing unit support portion 1773b and the pivot axis DA are positioned between the rotation axis L1 and the guided portion 1773s2. Therefore, the cleaning unit 1760 can firmly support the relatively heavy developing unit 1760. Thus, in any of the directions—mounting direction M (or the longitudinal direction of the guided portion 1773s1), the orthogonal direction MP perpendicular to the mounting direction M (or the direction perpendicular to the longitudinal direction of the guided portion 1773s1), the horizontal direction HD, and the vertical direction VD—the developing unit support portion 1773b and the pivot axis DA are positioned between the rotation axis L1 and the guided portion 1773s2.

[0233] Furthermore, when viewing cartridge B from the direction of the rotation axis L1, if the region is divided by a straight line LT, the guided portion 1773s1 is located in one region and the guided portion 1773s3 is located in the other region, so the orientation of cartridge B is stable during installation and removal.

[0234] Furthermore, as shown in Figures 113(b), 114(a), and 114(b), the drum frame of the cleaning unit 1760 has, in addition to the drum bearing member (first bearing member) 1773 and frame member 1711 mentioned above, a non-driven side drum bearing member (second bearing member) 1712 attached to the frame member 1711. As mentioned above, the drive-side flange 1763 (first flange member) of the drum unit 1769 is rotatably supported by the drum bearing member 1773. On the other hand, the non-driven side flange (second flange member) 1764 of the drum unit 1769 is rotatably supported by the non-driven side drum bearing member 1712. The non-driven side flange 1764 is a member fixed to the downstream end in the H direction of the drum 1762. In other words, the drum bearing member (first bearing member) 1773 is positioned at the first end of the drum frame in the direction of the rotation axis L1, and the non-drive side drum bearing member (second bearing member) 1712 is positioned at the second end of the frame opposite to the first end. Of the two ends of the drum 62 in the direction of the rotation axis L1, the first photoreceptor end is positioned closer to the first end of the frame than the second end of the frame, and the second photoreceptor end opposite the first end is positioned closer to the second end of the frame than the first end of the frame. As can be seen from Figures 114(a) and (b), the non-drive side drum bearing member 1712 has a protruding portion 1712a that protrudes downstream with respect to the mounting direction M. Here, as can be seen from Figure 50, when viewed along the direction of the rotation axis L1, the line connecting the rotation center of the developing roller 1732 and the rotation center of the photosensitive drum 1762 (rotation axis L1) is approximately parallel to the mounting direction M. Therefore, the protruding portion 1712a is perpendicular to the rotation axis L1 and protrudes downstream of the drum bearing member 1773 or the drum 1762 with respect to the direction from the rotation center of the developing roller 1732 toward the rotation center of the photosensitive drum 1762 (a direction approximately parallel to the mounting direction M). A memory substrate 1740 on which a non-volatile memory chip is mounted is attached to the protruding portion 1712a. The memory substrate 1740 has an electrode portion (electrode surface) 1740a which is electrically connected to the non-volatile memory chip and is a surface that can contact and electrically connect to an electrode portion on the main body side of the device body A (not shown).The electrode portion 1740a is positioned close to the end (first frame end) on the opposite side (non-drive side) of the end (second frame end) where the drum bearing member 1773 and drive-side flange 1763 are located (drive side) with respect to the direction of the rotation axis L1. More specifically, with respect to the direction of the rotation axis L1, the region where the electrode portion 1740a is located includes the position of the downstream end (second photoreceptor end) in the H direction of the drum 1762. However, with respect to the direction of the rotation axis L1, the region where the electrode portion 1740a is located may be positioned closer to the outside of the drum frame (or outside of cartridge B) than the position of the downstream end (second photoreceptor end) of the drum 1762 in the H direction (downstream position in the H direction). Also, with respect to the direction of the rotation axis L1, the region where the electrode portion 1740a is located and the region where the non-drive-side flange 1764 is located are at least partially in the same position (at least partially overlapping). However, with respect to the direction of the rotation axis L1, the area where the electrode portion 1740a is located may be positioned closer to the outside of the drum frame (or outside of cartridge B) than the area where the non-drive side flange 1764 is located (downstream in the H direction). Also, the electrode portion 1740a is positioned downstream of the rotation axis L1 and the photosensitive drum 1762 with respect to the mounting direction M. Furthermore, the electrode portion 1740 is positioned downstream of the rotation axis L1 or the photosensitive drum 1762 with respect to the direction perpendicular to the rotation axis L1 and toward the rotation center of the developing roller 1732 toward the rotation center of the photosensitive drum 1762 (a direction approximately parallel to the mounting direction M). In addition, the memory substrate 1740 is supported by the cleaning unit 1760 in a position where the electrode portion (electrode surface) 1740a is oriented perpendicular to the mounting direction M.

[0235] <Drive side flange 1763> Next, the drive-side flange 1763 will be described using Figures 54(b) and 60. Figure 54(b) is a schematic cross-sectional view of the gear portion of the drive-side flange 1763. The cross-section is tangent to the meshing pitch circle when meshing with the drive transmission gear 1781. Figures 60(a) and (b) are cross-sectional views of the drum unit 1769 near the drive-side flange 1763, and the cross-section includes the rotation axis L1.

[0236] The drive-side flange 1763 coaxially comprises a first gear section (first unit side gear section, first unit side helical gear section) 1763c and a second gear section (second unit side gear section, second unit side helical gear section) 1763d, which are helical gear sections. The first gear section 1763c is positioned upstream of the second gear section 1763d in the H direction (downstream in the J direction). In other words, with respect to the direction of the rotation axis L1, the second gear section 1763d is positioned between the first gear section 1763c and the drum 1762. The first gear section 1763c includes a plurality of first helical teeth (teeth, first projections) 1763ct arranged at different positions in the circumferential direction around the rotation axis L1, and the second gear section 1763d includes a plurality of second helical teeth (teeth, second projections) 1763dt arranged at different positions in the circumferential direction around the rotation axis L1. The first oblique tooth 1763ct and the second oblique tooth 1763dt are both involute teeth, projections that protrude radially around the rotation axis L1. The first gear section 1763c and the second gear section 1763d are integrally molded in resin and rotate together; therefore, the first gear section 1763c and the second gear section 1763d can be viewed as a first rotating section and a second rotating section that rotate integrally with each other. The first gear section 1763c meshes with the first main gear section 1781c of the drive transmission gear 1781, and the second gear section 1763d meshes with the second main gear section 1781d of the drive transmission gear 1781.

[0237] The torsional directions of the first gear portion 1763c and the second gear portion 1763d of the drive-side flange 1763 are the same, and the torsional direction is such that the tooth surfaces shift toward the K direction as they move toward the J direction. The torsional directions of the first gear portion 1763c and the second gear portion 1763d are opposite to the torsional directions of the first main gear portion 1781c and the second main gear portion 1781d of the drive transmission gear 1781. Also, similar to Embodiment 1, the torsional angle of the second gear portion 1763d is larger than the torsional angle of the first gear portion 1763c. The torsional angle of the first gear portion 1763c is the same as the torsional angle of the first main gear portion 1781c, which will be described later, and the torsional angle of the second gear portion 1763d is the same as the torsional angle of the second main gear portion 1781d, which will be described later. Furthermore, the number of teeth on the first gear section 1763c and the second gear section 1763d of the drive-side flange 1763 are the same.

[0238] Furthermore, as shown in Figure 60(a), the width (tooth width) Wc of the first helical tooth (tooth, first projection) 1763ct in the direction of the rotation axis L1 is greater than the width (tooth width) Wd of the second helical tooth (tooth, second projection) 1763dt in the direction of the rotation axis L1. In other words, each of the first gear section 1763c and the second gear section 1763d has at least one tooth such that the tooth width Wc of the first helical tooth (tooth, first projection) 1763ct and the tooth width Wd of the second helical tooth (tooth, second projection) 1763dt satisfy the following equation A1 in the direction of the rotation axis L1. Wc>Wd···(Equation A1)

[0239] In a balanced state, while the drive-side flange 1763 is driven by the drive transmission gear 1781, the driving force FD received by the first gear portion 1763c is greater than the restricting force FB received by the second gear portion 1763d, so this relationship is preferable.

[0240] Furthermore, the wider the width of the rotation axis L1 of the portion where the first gear section 1763c meshes (contacts) with the first main gear section 1781c (measuring width), and the wider the meshing width of the second helical gear section 1763c with the second main gear section 1781d, the better the drive transmission accuracy. However, if the meshing width is set to be larger than necessary, the width in the direction of the rotation axis L1 of the first gear section 1763c and the second gear section 1763c will increase, causing the drive-side flange 1763, drum unit 1769, cartridge B, and ultimately the main body A to become larger. Therefore, it is preferable that the tooth width Wc1 of the first helical tooth 1763ct, which has the widest tooth width among the first gear section 1763c, and the tooth width Wd1 of the second helical tooth 1763dt, which has the widest tooth width among the second gear section 1763d, satisfy the following formula A2, more preferably formula A3. Wd1≦(4 / 5)·Wc1···(Formula A2) Wd1≦(3 / 4)·Wc1···(Formula A3)

[0241] Furthermore, from the standpoint of the strength of the second helical tooth 1763dt of the second gear portion 1763d, it is preferable that the second helical tooth 1763dt has a tooth width of a certain degree or more, and it is preferable that the tooth width Wc1 and tooth width Wd1 satisfy the following formula A4. Wd1≧(1 / 10)·Wc1···(Formula A4)

[0242] Furthermore, the width (length) We of the cylindrical portion 1763e (or gap g) in the direction of the rotation axis L1 is set to satisfy the following equations B1, B2, and B3, similar to Example 1, when the widths Wc and Wd are used as references.

[0243] If the tooth width Wc of the first gear section 1763c is not constant, the tooth width Wc1 of the widest tooth is considered to be the tooth width Wc. We≧Wc / 5...(Formula B1) We≦Wc...(Formula B2) We ≤ Wd ···(Equation B3)

[0244] In this embodiment, the tooth width of each tooth in the first gear section 1763c is the same, and the tooth width of each tooth in the second gear section 1763c is also the same, with the tooth width Wc set to 8.2 mm and the tooth width Wd set to 5.2 mm. The width We is set to 3.1 mm.

[0245] Furthermore, as shown in Figure 60(b), the meshing pitch circle diameters D63c and D63d of the first gear portion 1763c and the second gear portion 1763d in the meshing between the drive-side flange 1763 and the drive transmission gear 1781 are set to be approximately the same. Similarly, the meshing pitch circle diameters of the first main body gear portion 1781c and the second main body gear portion 1781d are set to be approximately the same. As a result, the meshing between the first gear portion 1763c and the first main body gear portion 1781c, and the meshing between the second gear portion 1763d and the second main body gear portion 1781d, can be properly engaged without tooth tip contact.

[0246] Furthermore, similar to Embodiment 1, the tooth tip diameter Dt63c of the first gear portion 1763c and the tooth root diameter Db63d of the second gear portion 1763d are set to be approximately the same so that the meshing between the first main gear portion 1781c and the second main gear portion 1781d is appropriate and does not result in tooth tip contact.

[0247] Specifically, it is preferable to set the size of the tip circle diameter Dt63c of the first gear portion 1763c to a value greater than the root circle diameter Db63d of the second gear portion 1763d, or to a value greater than 0.8 times (more preferably 0.9 times) the tip circle diameter Dt63d of the second gear portion 1763d. Furthermore, it is preferable to set the size of the tip circle diameter Dt63c of the first gear portion 1763c to a value less than 1.1 times the tip circle diameter Dt63d of the second gear portion 1763d.

[0248] Furthermore, it is preferable to set the root circle diameter Db63c of the first gear portion 1763c to a value smaller than the tip circle diameter Dt63d of the second gear portion 1763d. Also, it is preferable to set the root circle diameter Db63c of the first gear portion 1763c to a value greater than 0.9 times the root circle diameter Db63d of the second gear portion 1763d.

[0249] Furthermore, it is preferable to set the size of the tip circle diameter Dt63d of the second gear portion 1763d to a value greater than the root circle diameter Db63c of the first gear portion 1763c, or to a value greater than 0.8 times (more preferably 0.9 times) the tip circle diameter Dt63c of the first gear portion 1763c. Also, it is preferable to set the size of the tip circle diameter Dt63d of the second gear portion 1763d to a value less than 1.1 times the tip circle diameter Dt63c of the first gear portion 1763c.

[0250] Furthermore, it is preferable to set the root circle diameter Db63d of the second gear portion 1763d to a value smaller than the tip circle diameter Dt63c of the first gear portion 1763c. Also, it is preferable to set the root circle diameter Db63d of the second gear portion 1763d to a value greater than 0.9 times the root circle diameter Db63c of the first gear portion 1763c.

[0251] In this embodiment, the tip circle diameter Dt63c, pitch circle diameter D63c, and root circle diameter Db63c of the first gear section 1763c were set to 22.3 mm, 21.1 mm, and 19.6 mm, respectively. The tip circle diameter Dt63d, pitch circle diameter D63d, and root circle diameter Db63d of the second gear section 1763d were set to 22.1 mm, 21.1 mm, and 19.8 mm, respectively. The diameter of the cylindrical section 1763e was set to 17.5 mm.

[0252] Furthermore, the modules of the first gear section 1763c and the second gear section 1763d are made different, or the amount of displacement is changed, so that the meshing pitch circle diameters D63c and D63d are the same, while the helix angles of the first gear section 1763c and the second gear section 1763d are made different. Similarly, for the drive transmission gear 1781, the modules of the first main gear section 1781c and the second main gear section 1781d are made different, or the amount of displacement is changed.

[0253] Furthermore, the drive-side flange 1763 includes a cylindrical portion (intermediate portion, small diameter portion, shaft portion) 1763e between the first gear portion 1763c and the second gear portion 63d with respect to the direction of the rotation axis L1. The maximum diameter D63e of the cylindrical portion 1763e centered on the rotation axis L1 is smaller than the tip circle diameter Dt63c of the first gear portion 1763c and the tip circle diameter Dt63d of the second gear portion 1763d. Moreover, in this embodiment, the maximum diameter D63e of the cylindrical portion 1763e centered on the rotation axis L1 is smaller than the root circle diameter Db63c of the first gear portion 1763c and the root circle diameter Db63d of the second gear portion 1763d. However, the maximum diameter D63e of the cylindrical portion 1763e centered on the rotation axis L1 is not subject to the above unless it is in contact with the drive transmission gear 1781 while the drive-side flange 1763 is being driven by the drive transmission gear 1781. Furthermore, as will be explained later in Examples 22 and 23, the distance (radius) R63e from the rotation axis L1 to the outer diameter of the cylindrical portion 1763e may be configured such that it is at least temporarily smaller than the tip circle radius Rt63ct of the first gear portion 1763c or the tip circle radius Rt63d of the second gear portion 1763d, so that the drive-side flange 1763 and the drive transmission gear 1781 mesh and transmit driving force.

[0254] The section showing the dimensional relationships using the various diameters of the first gear section 1763c, the second gear section 1763d, and the cylindrical section 1763e will, of course, maintain the same relationship even if the diameters are replaced with radii.

[0255] <Drive transmission gear 1781> Next, the drive transmission gear 1781 of the device body A that meshes with the drive-side flange 1763 will be explained using Figures 53 and 54(a). Figures 53(a) and (b) are exploded perspective views of the area around the drive transmission gear 1781 of the device body A, with (a) showing the view from the second drive-side plate 1783 side and (b) showing the view from the main frame 1784 side. Figure 54(a) is a schematic cross-sectional view of the gear portion of the drive transmission gear 1781. The cross-section is tangent to the meshing pitch circle when meshing with the drive-side flange 1763.

[0256] The drive transmission gear 1781 comprises a first main gear section (first main helical gear section) 1781c and a second main gear section (second main helical gear section) 1781d, arranged coaxially as helical gear sections. The first main gear section 1781c is positioned upstream in the H direction (downstream in the J direction) of the second main gear section 1781d. The first main gear section 1781c includes a plurality of first main helical teeth 1781ct, and the second main gear section 1781d includes a plurality of second main helical teeth 1781dt. Both the first main helical teeth 1781ct and the second main helical teeth 1781dt are involute teeth. The first main gear section 1781c and the second main gear section 1781d are integrally molded from resin and rotate as a single unit. Furthermore, the twisting directions of the first main gear section 81c and the second main gear section 81d are the same, and the twisting direction is such that the tooth surfaces shift toward the I direction as they move toward the J direction. Also, similar to Embodiment 1, the twist angle of the second main gear section 1781d is larger than the twist angle of the first main gear section 1781c. In addition, the number of teeth of the first main gear section 81c and the second main gear section 81d are the same. With cartridge B mounted on the device body A, the first gear section 1763c meshes with the first main gear section 1781c, and the second gear section 1763c meshes with the second main gear section 1781d.

[0257] Figure 112 is a perspective view of another configuration example of the drive transmission gear 1781. As shown in Figure 112, a rib-shaped portion (projection, radial projection main portion) 1781p may be provided between the first main gear portion 1781c and the second main gear portion 1781d with respect to the direction of the rotation axis L2, projecting radially around the rotation axis L2. Depending on the manufacturing method of the drive transmission gear 1781, providing the rib-shaped portion 1781p may improve or suppress deterioration of molding accuracy, or reduce manufacturing costs. The diameter of the rib-shaped portion 1781p is approximately the same as the tip circle diameter of the first main gear portion 1781c and the tip circle diameter of the second main gear portion 1781d. The rib-shaped portion 1781p may be provided around the entire circumference with respect to the circumferential direction with respect to the rotation axis L2, or it may be provided only on a part of it. Here, the drive-side flange 1763 is provided with a cylindrical portion 1763e, which creates a gap g (see Figure 60, etc.) between the first gear portion 1763c and the second gear portion 1763d in the direction of the rotation axis L1. Because of this gap g, even if the drive transmission gear 1781 has a rib-shaped portion 1781p, contact between the rib-shaped portion 1781p and the drive-side flange 1763 is avoided, and the gear portions of the drive transmission gear 1781 and the drive-side flange 1763 can mesh properly. At this time, the rib-shaped portion 1781p is inserted into (entered into) the gap g between the first gear portion 1763c and the second gear portion 1763d.

[0258] As shown in Figures 53(a) and (b), the main body A of the device includes a motor (not shown), an idler gear 1780, a drive transmission gear 1781, a second drive side plate 1783, a main frame 1784, a drive shaft 1782, a reinforcing member 1798, and a compression spring 1785. The second drive side plate 1783 is a member corresponding to the second drive side plate 83 of Embodiment 1. The driving force from the motor is transmitted to the drive transmission gear 1781 via the idler gear 1780. The idler gear 1780, the drive transmission gear 1781, and the reinforcing member 1798 are supported by the fixed shaft, the drive shaft 1782, so that they can rotate coaxially with respect to the rotation axis L2 and move in the direction of the rotation axis L2. The drive shaft 1782 has one end fixed to the second drive side plate 1783, and the other end 1782b is fitted into and supported by a hole 1784a in the main frame 1784. The drive shaft 1782 is positioned such that the rotation axis L2 of the drive transmission gear 1781 is parallel to the rotation axis L1 of the drum 62 when the cartridge B is mounted on the device body A.

[0259] A compression spring 1785 is provided between the other end 1780b of the idler gear 1780 and the second drive-side plate 1783, biasing the idler gear 1780 toward the main frame 1784 (direction H) with respect to the direction of the rotation axis L2. A recess 1780a is provided at the end of the idler gear 1780 facing the drive transmission gear 1781, recessed in the direction of the rotation axis L2, and a protrusion (drive force transmission part) 1780a1 is provided inside the recess 1780a.

[0260] The end of the drive transmission gear 1781 facing the idler gear 1780 is provided with a projection 1781a1 that protrudes in the direction of the rotation axis L2, opposite to the recess 1780a1 of the idler gear 1780. The projection 1781a1 has a surface 1781e at its upstream end in the rotation direction I and a slope 1781h at its downstream end. The surface 1781e is perpendicular to the plane perpendicular to the rotation axis L2, and the slope 1781h is inclined with respect to the plane perpendicular to the rotation axis L2. When the convex portion 1780a1 of the idler gear 1780 and the surface 1781e of the projection 1781a1 engage, driving force is transmitted from the idler gear 1780 to the drive transmission gear 1781, causing them to rotate integrally in the rotation direction I.

[0261] On the other hand, when the drive transmission gear 1781 rotates relative to the idler gear 1780 in the rotational direction I, the inclined surface 1781h of the projection 1781a1 of the drive transmission gear 1781 comes into contact with the protrusion 1780a1 of the idler gear 1780. As a result, a force acts on the idler gear 1780 and the drive transmission gear 1781 that moves them apart in the direction of the rotation axis L2. The idler gear 1780 moves in the J direction against the spring force of the compression spring 1785, causing the protrusion 1780a1 to move over the projection 1781a1, and thus preventing the transmission of the driving force in the rotational direction I from the drive transmission gear 1781 to the idler gear 1780. During the process of mounting cartridge B onto the device body A, the drive transmission gear 1781 may engage with the drive-side flange 1763 and be rotated in the rotational direction I. However, due to the above-described configuration, the driving force in the rotational direction I is not transmitted from the drive transmission gear 1781 to the idler gear 1780. Therefore, when the user mounts cartridge B, they do not need to rotate the motor that drives the idler gear 1780 or the photosensitive drum 1762, thus reducing the load when mounting cartridge B onto the device body A.

[0262] Furthermore, the drive transmission gear 1781 has a hole 1781f, and an engaging portion 1781g, which is composed of multiple recesses and protrusions, is provided on its inner circumference. The reinforcing member 1798 has an engaging portion 1798b, which is composed of multiple recesses and protrusions, on its outer circumference, and is inserted into the hole 1781f. The engaging portion 1781g of the drive transmission gear 1781 and the engaging portion 1798b of the reinforcing member 1798 are engaged. The reinforcing member 1798 is in contact with the drive shaft 1782 and directly supported by the drive shaft 1782, while the drive transmission gear 1781 is indirectly supported by the drive shaft 1782 via the reinforcing member 1798. However, the drive transmission gear 1781 may also be configured to be directly supported by the drive shaft 1782.

[0263] However, when manufacturing a relatively large-diameter drive transmission gear 1781 by resin molding, as in this embodiment, it is advantageous in terms of achieving both molding accuracy and strength of the gear to support it on the drive shaft 1782 via the reinforcing member 1798. This is because, when constructing a gear with a relatively large radial thickness (the radial distance from the inner circumferential surface of the hole through which the shaft passes to the root circle of the gear teeth) from a single resin-molded member, it is necessary to provide a weight-reducing shape to avoid deterioration of the gear's molding accuracy due to shrinkage of the resin, etc. And providing a weight-reducing shape may reduce the strength of the gear. Therefore, as in this embodiment, by not directly supporting the drive transmission gear 1781 on the drive shaft 1782, but instead providing a separately molded resin reinforcing member 1798, it is possible to suppress deterioration of the molding accuracy of the resin-molded drive transmission gear 1781 while also suppressing a decrease in strength.

[0264] <Drive transmission operation> Next, the meshing operation between the drive transmission gear 1781 and the drive-side flange 1763 will be explained using Figures 54 and 55. Figures 54(c), 54(d), 55(a), 55(b), and 55(c) are schematic cross-sectional views of the meshing portion between the gear portion of the drive transmission gear 1781 and the gear portion of the drive-side drum flange 1763. The cross-section is tangent to the meshing pitch circle between the drive transmission gear 1781 and the drive-side flange 1763. Figures 54(c), 54(d), 55(a), 55(b), and 55(c) all show the state after the drive transmission gear 1781 has started to operate, in this order in chronological order.

[0265] First, when cartridge B is not attached to main body A, as shown in Figure 54(a), the drive transmission gear 1781 is biased in the H direction by the compression spring 1785 and abuts against the main frame 1784.

[0266] <Operation after starting the drive> After cartridge B is mounted on main body A, the drive transmission gear 1781 is driven by the motor (not shown) of the device body A via idler gear 1780 (see Figure 53) and rotates in direction I. The drive-side flange 1763 receives driving force from the drive transmission gear 1781 rotating in direction I and rotates in direction K.

[0267] Immediately after the drive transmission gear 1781 begins rotating in direction I, as shown in Figure 54(c), we will describe the case where the second main gear portion 1781d of the drive transmission gear 1781 first meshes with the second gear portion 1763d of the drive-side flange 1763 and transmits the driving force FD. The second main gear portion 1781d generates a thrust force that presses the second gear portion 1763d in direction H. However, the drive-side flange 1763 is restricted from moving in direction H by the rib 1771p (see Figure 51(a)) and receives a reaction force in direction J corresponding to the thrust force in direction H. Therefore, the second main gear portion 1781d receives a thrust force F5 in direction J due to the reaction force received from the second gear portion 1763d. This thrust force F5 causes the drive transmission gear 1781 to move in direction J.

[0268] As the drive transmission gear 1781 continues to rotate and moves in the J direction, as shown in Figure 54(d), the first gear section 1763c also meshes with the first main gear section 1781c, transmitting the drive force FD and generating a thrust force F6 on the first main gear section 1781c. The thrust force F6 is the same thrust force in the J direction as the thrust force F5 that the second main gear section 1781d receives when it meshes with the second gear section 1763d. As a result, the drive transmission gear 1781 moves further in the J direction.

[0269] As the drive transmission gear 1781 rotates further and moves in the J direction, eventually the second main gear portion 1781d will no longer mesh with the second gear portion 1763d, as shown in Figure 55(a). On the other hand, the meshing between the first gear portion 1781c and the first gear portion 1763c is maintained, and a thrust force F8 acts on the first gear portion 1781c in the J direction. At this time, the drive transmission gear 81 transmits the driving force FD solely through the meshing between the first main gear portion 1781c and the first gear portion 1763c, causing the drive-side flange 1763 to rotate.

[0270] As the rotation continues and the drive transmission gear 1781 moves in the J direction, as shown in Figures 55(b) and (c), eventually the second main gear portion 1781d comes into contact with the tooth surface (contact portion) 1763d2 of the second gear portion 1763d on the downstream side in the I direction. Note that the surface 1781c1 of the first main gear portion 1781c and the surface 1763c1 of the first gear portion 1763c maintain contact. In other words, the teeth of the first gear portion 1763c are in contact with the first main gear portion 1781c located on the upstream side in the I direction, and the teeth of the second gear portion 1763d are in contact with the second main gear portion 1781d located on the downstream side in the I direction. Furthermore, since the first gear section 1763c and the second gear section 1763d are integrally molded from resin, the teeth of the first gear section 1763c are fixed so that they cannot move (rotate) in the I direction relative to the teeth of the second gear section 1763d, and the teeth of the second gear section 1763d are fixed so that they cannot move (rotate) in the opposite direction to the I direction relative to the teeth of the first gear section 1763c. Therefore, in this state, the first main gear section 1781c of the drive transmission gear 1781 presses the tooth surface (contact portion) 1763c1 with its tooth surface 1781c1, causing the drive-side flange 1763 to rotate, and the tooth surface 1781d2 of the second main gear section 1781d of the drive transmission gear 1781 comes into contact with the tooth surface 1763d2, causing it to be sandwiched by the drive-side flange 1763. Then, the movement of the drive transmission gear 1781 in the direction of the rotation axis L1 stops. The position of the drive transmission gear 1781 in the direction of its rotation axis L1 at this time is defined as the equilibrium position.

[0271] In the equilibrium state, as shown in Figure 55(b), the drive transmission gear 1781 is subjected to forces F9, F10, and F1 in the direction of the rotation axis L1. Force F9 is a thrust force in the J direction received by the first main body gear section 1781c due to the meshing force with the first gear section 1763c, force F10 is a thrust force in the H direction received by the second main body gear section 1781d due to the meshing force with the second gear section 6173d, and force F1 is the biasing force of the compression spring 1785 received via the idler gear 1780. In addition, the drive-side flange 1763 receives a force from the drive transmission gear 1781 and is positioned in the direction of the rotation axis L1 by contacting the rib 1771p or the side wall 1771m, generating a reaction force F11 in the direction of the rotation axis L1 that balances the thrust force received from the drive transmission gear 1781. Figure 55(b) shows the case where the drive-side flange 1763 is in contact with the rib 1771p and positioned. In the equilibrium state, neglecting friction with respect to the direction of the rotation axis L1, forces F9, F10, F1, and F11 are balanced, and the drive transmission gear 1781 and the drive-side flange 1763 are positioned in the direction of the rotation axis L1.

[0272] Furthermore, in the equilibrium state, as shown in Figure 55(c), the drive-side flange 1763 is sandwiched (in contact with) the first main gear portion 1781c and the second main gear portion 1781d of the drive transmission gear 1781 in the K direction (direction of rotation) and is subjected to the following forces. That is, the tooth surface (contact portion) 1763c1 of the first gear portion 1763c contacts the first main gear portion 1781c, which is located upstream in the K direction (first rotation direction), and receives a driving force FD as a force component that rotates the drive-side flange 1763 in the K direction (predetermined direction). At the same time, the tooth surface (contact portion) 1763d2 of the second gear portion 1763d contacts the second main gear portion 1781d, which is located downstream in the K direction (first rotation direction), and receives a restricting force (braking force) FB as a force component that suppresses (restricts) the rotation of the drive-side flange 1763 in the K direction. Therefore, it can be said that the first gear section 1763c is a driving force receiving section that receives the driving force FD, and the second gear section 1763d is a restricting force receiving section that receives the restricting force FB. Figure 55(b) shows the reaction force FF of the driving force FD received by the first main body gear section 1781c, and the reaction force FE of the restricting force FB received by the second main body gear section 1781d.

[0273] Furthermore, immediately after the drive transmission gear 1781 begins to rotate in direction I, if the first main gear portion 1781c of the drive transmission gear 1781 first meshes with the first gear portion 1763c of the drive-side flange 1763 and transmits the driving force FD, the state shown in Figure 54(d) or Figure 55(a) will be reached. Thereafter, as described above, the drive transmission gear 1781 moves toward the drive side in direction J while transmitting the driving force FD to the first gear portion 1763c, and transitions to the balanced state shown in Figures 55(b) and 55(c).

[0274] Thus, in this embodiment as well, when the first gear section 1763c receives the driving force FD and the second gear section 1763d receives the restricting force FB, there is no play (backlash) in the rotational direction (direction I) between the drive-side flange 1763 and the drive transmission gear 1781, i.e., it is a backlash-free state. In this way, the drive-side flange 1763 is rotated in the direction K while maintaining the backlash-free state. As long as the gears are meshed and transmitting power in a backlash-free state, it is possible to transmit power with high rotational accuracy.

[0275] Furthermore, with respect to the direction of the rotation axis L1, the first gear portion 1763c is positioned closer to the projection 1763g, which is a supported part supported by planes 1773e and 1773f, than the second gear portion 1763d. The force acting on the tooth surface of the drive-side flange 1763 is greater on the first gear portion 1763c, which receives the driving force FD, than on the second gear portion 1763d, which receives the regulating force FB. As a result, the driving force FD may act to tilt the rotation axis L1 of the drum unit 1769, causing the drum 1762 to tilt relative to the ideal rotation axis L1. However, as in this embodiment, by positioning the first gear portion 1763c, which receives the driving force FD, closer to the projection 1763g, which is a supported part, than the second gear portion 1763d, the tilting of the rotation axis L1 of the drum unit 1769 caused by receiving the driving force FD can be suppressed.

[0276] <Drive transmission configuration to developing roller 1732> Furthermore, the configuration for transmitting driving force to the developing roller 1732 in this embodiment is the same as the configuration in which driving force is transmitted to the developing roller 532 via a developing coupling member 89 that engages with the coupling member of the device body A and receives driving force, as explained with reference to Figure 44 in the <Other Modifications> of Embodiment 1.

[0277] The specific configuration will be explained using Figures 56 and 57. Figure 56(a) is a perspective view of the drive train that drives the developing roller 1732 of the developing unit 1720. Figure 56(b) is a partial perspective view of the vicinity of the coupling member 1789 of the developing unit 1720. Figure 56(c) is a perspective view of cartridge B. Figure 57 is a partial perspective view of the vicinity of the main body coupling member 1799 of the device body A.

[0278] The developing unit 1720 comprises a developing coupling member 1789 having a coupling portion 1789a and a gear portion 1789b, which constitute a developing drive row that drives the developing roller 1732; an idler gear 1790 that meshes with the gear portion 1789b; an idler gear 1791 that meshes with the idler gear 1790; and a developing roller gear 1730 fixed to one end of the shaft portion of the developing roller 1732 and meshing with the idler gear 1791.

[0279] The main body A has a main body-side coupling member 1799, driven by a motor (not shown), supported on a first drive-side plate 1715. The main body-side coupling member 1799 is provided to be movable in the direction of the rotation axis. When the coupling portion 1789a of the main body-side coupling member 1799 and the developing coupling member 1789 are engaged and they rotate together, driving force is transmitted from the main body-side coupling member 1799 to the developing coupling member 1789. Then, the driving force is transmitted from the developing coupling member 1789 to the developing roller 1732 in the order of idler gears 1790, 1791, and developing roller gear 1730.

[0280] Furthermore, the developing unit 1720 is equipped with a toner moving member (stirring member) (not shown) that stirs or transports the toner in the toner storage container. The driving force received by the developing coupling member 1789 is transmitted to this toner moving member via another gear, thereby driving the toner moving member.

[0281] Furthermore, the member driven by the driving force from the developing coupling member 89 is not limited to the developing roller 1732 or the toner moving member (not shown) described above, but may be any other member of the cartridge B other than the drum unit 1769 (for example, a charging member, a sealing member, a cleaning member, etc.). Thus, the member to which the driving force is transmitted from the developing coupling member 1789 (a member connected to the developing coupling member 1789 in a manner that allows for the transmission of driving force) is not limited to the developing roller 1732.

[0282] Thus, the main unit A is equipped with two drive force output means for outputting drive force to cartridge B: a drive transmission gear 1781 and a main unit-side coupling member 1799. This makes it possible to control the drive transmission gear 1781 and the main unit-side coupling member 1799, for example, by driving one while stopping the other. For example, it becomes possible to drive the developing roller 1732 while the drum 1762 is stopped.

[0283] Furthermore, in cartridge B, the drive-side flange 1763 is not included in the components that are connected to the developing drive train or developing coupling member 1789 that drives the developing roller 1732 in a manner that enables the transmission of driving force. Therefore, even if the user rotates the drum 1762 when cartridge B is removed from the main body A, the driving of components connected to the developing roller 1732 or developing coupling member 1789 in a manner that enables the transmission of driving force in accordance with the rotation of the drum 1762 is suppressed. As a result, the possibility of toner leakage etc. occurring due to unnecessary driving of components connected to the developing roller 1732 or developing coupling member 1789 in a manner that enables the transmission of driving force can be reduced.

[0284] Thus, in this embodiment, the developing roller 1732 is driven by the driving force input to the developing coupling member 1789. However, similar to Embodiment 1, the developing roller 1732 may also be driven by transmitting the driving force from the drive-side flange 1763 to the developing roller gear 1730.

[0285] As described above, the same effects as in Example 1 can be obtained with this embodiment. Furthermore, the elements of each of the embodiments described above can be applied to the configuration of this embodiment. In particular, the configuration of the first helical tooth (first projection) 1763ct of the first gear portion 1763c of the drive-side flange 1763 and the second helical tooth (second projection) 1763dt of the second gear portion 1763d may be changed to helical teeth, spur teeth, projections, etc. as shown in Examples 2, 3, 4, 5, 6, 10, 11, 12, 13, 14, and 16.

[0286] [Example 18] This embodiment differs from Embodiment 17 in that a ring-shaped elastic member is provided to cover the drive-side flange 1763. Other aspects are the same as Embodiment 17, and a detailed explanation is omitted. Furthermore, for elements in this embodiment that correspond to elements in Embodiment 1, reference numerals are assigned in association with the corresponding elements in Embodiment 1. Unless otherwise specified, these elements are the same as the corresponding elements in Embodiment 1.

[0287] Figure 61 is a partial perspective view of the vicinity of the drive-side flange 1863 of the drum unit 1869. Figure 62 is a cross-sectional view of the second gear section 1863d and the second main body gear section 1881d, the cross-section being perpendicular to the rotation axis L1.

[0288] The drive-side flange 1863 has the same shape as the drive-side flange 1763 in Embodiment 17. In this embodiment, an elastic ring 1801, which is an elastically deformable ring-shaped elastic member, is provided so as to cover all or part of the outer circumference of the second gear portion (second unit side gear portion) 1863d.

[0289] The elastic ring 1801 is a thin film of rubber or sponge, and its thickness is preferably about 0.01 to 1 mm if it is rubber such as nitrile rubber, or about 1 to 6 mm if it is sponge. Furthermore, the inner diameter of the elastic ring before it is attached to the drive-side flange 1863 is preferably about 0.5 to 0.9 times the outer diameter of the second gear section 1863d. In this embodiment, the outer diameter of the second gear section 1863d is Φ20 mm, and the inner diameter of the elastic ring 1801 is Φ14 mm. When the outer diameter of the second gear section 1863d is Φ20 mm, it is preferable to appropriately select the inner diameter of the elastic ring 1801 in the range of Φ10 mm to 18 mm, which is slightly smaller than Φ20 mm. If it is larger than Φ18 mm, it may come off the second gear section 1863d, and if it is smaller than Φ10 mm, the tightening force on the second gear section 1863d will be too strong, which may cause the second gear section 1863d to deform.

[0290] As shown in Figure 62, when cartridge B is attached to the main body A of the device, the elastic ring 1801 elastically deforms to conform to the shape of the second helical teeth 1863dt of the second gear section 1863d and the second helical teeth 1781dt of the drive transmission gear 81, and the second gear section 1863d and the second main body gear section 1781d mesh with each other via the elastic ring 1801. In addition, the first gear section (first unit side gear section) 1863c meshes with the first main body gear section 1781c.

[0291] When the drive transmission gear 1781 rotates in the direction of arrow I, force is transmitted to the second gear section 1863d from the second main gear section 1781d via the elastic ring 1801. Therefore, the second gear section 1863d performs the same function as the second gear section 1763d of Embodiment 17. As a result, when the drive transmission gear 1781 rotates in the direction of arrow I, there is no play (backlash) in the rotational direction (direction I) between the drive-side flange 1863 and the drive transmission gear 1781, i.e., there is no backlash, just as in Embodiment 17.

[0292] Furthermore, the elastic ring 1801 may have a shape having multiple protrusions on its inner circumference that project toward the rotation axis L1 of the drive-side flange 1863, so as to fill the multiple gaps 1863ds between the multiple second helical teeth 1863dt of the second gear portion 1863d when it is not in contact with the drive transmission gear 1781, such as before the cartridge B is mounted on the device body A.

[0293] Furthermore, in this embodiment, the elastic ring 1801 is provided on the outer circumference of the second gear portion 1863d, but the elastic ring 1801 may be provided on the entire or a part of the outer circumference of the first gear portion 1863c, or on the entire or a part of the outer circumference of both the second gear portion 1863d and the first gear portion 1863c. In these cases as well, force is transmitted between the tooth surfaces of each gear via the elastic ring 1801. Therefore, the first gear portion 1863c and the second gear portion 1863d perform the same functions as the first gear portion 1763c and the second gear portion 1763d in Embodiment 17. As a result, when the drive transmission gear 1781 rotates in the direction of arrow I, there is no play (backlash) in the rotational direction (direction I) between the drive-side flange 1863 and the drive transmission gear 1781, i.e., a backlash-free state.

[0294] Furthermore, although the drive-side flange 1863 has the same shape as the drive-side flange 1763 of Embodiment 17, the gear tooth shape and gear size may be appropriately changed considering the thickness of the elastic ring 1801, etc.

[0295] As described above, this embodiment provides the same effects as in Embodiment 17. Furthermore, the elements of each embodiment described above can be applied to the configuration of this embodiment. In particular, the configuration of the first helical tooth (first projection) 1863ct of the first gear portion 1863c of the drive-side flange 1863 and the second helical tooth (second projection) 1863dt of the second gear portion 1863d may be changed to helical teeth, spur teeth, projections, etc., as shown in Embodiments 2, 3, 4, 5, 6, 10, 11, 12, 13, 14, and 16.

[0296] [Example 19] This embodiment differs from Embodiment 17 in that the rotation axis (L19, etc.) of the first gear section (external gear section 1902b, etc.) that receives the driving force FD and the rotation axis (L1) of the second gear section (1963d) that receives the regulating force FB are parallel rather than coaxial. Other aspects are the same as in Embodiment 17, and a detailed explanation is omitted. Furthermore, for elements in this embodiment that correspond to elements in Embodiment 1, reference numerals are used to indicate their relationship to the corresponding elements in Embodiment 1. Unless otherwise specified, these elements are the same as the corresponding elements in Embodiment 1.

[0297] <Drum Unit 1969> Figure 63 is a partial perspective view of the drum unit 1969. As shown in Figure 63, the drive-side flange 1963 of the drum unit 1969 comprises an internal gear section 1963f, a second gear section 1963d, a projection 1963g, a small diameter section 1963e, and a flange section 1963h, centered on the drum rotation axis L1. The internal gear section 1963f is a spur gear. The drum unit 1969 further comprises a gear 1902, which will be described in detail later (see Figure 65, etc.). The gear 1902 comprises an external gear section 1902b as a first gear section and an internal gear section 1902a that meshes with the internal gear section 1963f.

[0298] The projection 1963g is substantially cylindrical in shape and protrudes along the drum rotation axis L1 from the internal gear portion 1963f in the opposite direction to the drum 1962 side (downstream in the J direction). The small diameter portion (cylindrical portion) 1963e is substantially cylindrical in shape and protrudes along the drum rotation axis L1 from the internal gear portion 1963f towards the drum 1962 side (downstream in the H direction). The second gear portion 1963d is helical teeth with a helix angle α2, similar to Embodiment 17, and is provided on the drum 1962 side (downstream in the H direction) of the small diameter portion 1963e. The flange portion 1963h is a thin disc shape with a diameter equal to or greater than the diameter of the drum 1962, and is provided on the drum 1962 side (downstream in the H direction) of the second gear portion 1963d.

[0299] <Support configuration of the 1969 drum unit> Next, the configuration supporting the drum unit 1969 will be explained using Figures 64, 65, 66, and 67.

[0300] Figure 64 is a side view (viewed from a direction perpendicular to the rotation axis L1) of the cleaning unit 1960 with the drum unit 1969 attached. Figure 65 is an exploded perspective view of the drive side portion of the cleaning unit 1960. Figure 66 is a partial cross-sectional view of the cleaning unit 1960 near the drive side flange 1963, and the cross-section includes the rotation axis L1. Figure 67 is a partial cross-sectional view of the cleaning unit 1960, and is a cross-sectional view taken along the J direction, perpendicular to the rotation axis L1 and passing through the internal gear portion 1963f.

[0301] As shown in Figure 64, the cleaning frame 1960a of the cleaning unit 1960 supports the drum unit 1969. The cleaning frame 1960a of the cleaning unit 1960 is composed of a frame member 1971 and a drum bearing member 1973. The cleaning frame 1971 is provided with a drum sliding portion 1971g.

[0302] The drive-side flange 1963 is rotatably supported on the drum bearing 1973 in the same manner as in Embodiment 17. As described in Embodiment 17, after the drive-side flange 1963 of the drum unit 1969 engages with the drive transmission gear 1781, when the drive transmission gear 1781 rotates in a predetermined direction, the drive-side flange 1963 rotates in conjunction with the drive transmission gear 1781, while, as previously mentioned, a thrust force in the H direction is generated in the drum unit 1969. This thrust force causes the non-drive-side flange 1964 and the drum sliding portion 1971g to come into contact, restricting the movement of the drum unit 1969 in the H direction.

[0303] As shown in Figure 65, the bearing member 1973 is supported by the frame member 1971. The frame member 1971 has a cylindrical portion 19710b, which is a positioning portion for the bearing member 1973, protruding toward the drum unit 1969. The bearing member 1973 has a cylindrical portion 19730r, which is a positioning portion for the frame member 1971, protruding toward the drum unit 1969.

[0304] The inner circumferential surface 19710d of the cylindrical portion 19710b is formed in an arc shape, and the center of the arc is positioned to coincide with the drum rotation axis L1. Similarly, the outer circumferential surface 19730b of the cylindrical portion 19730r is formed in an arc shape, and the center of the arc is positioned to coincide with the drum rotation axis L1. On the other hand, the outer circumferential surface 19710c of the cylindrical portion 19710b is formed in an arc shape, but the central axis L19 of the arc (coaxial with the rotation axis L19 of the gear 1902) is positioned parallel to the drum rotation axis L1 but not coaxial. In other words, the outer circumferential surface 19710c of the cylindrical portion 19710b is positioned eccentrically with respect to the inner circumferential surface 19710d.

[0305] The outer circumferential surface 19710c of the cylindrical portion 19710b supports the gear 1902 so that it can rotate around the rotation axis L19. The gear 1902 is substantially cylindrical in shape, with an internal gear portion 1902a on the inner circumference and an external gear portion 1902b, which serves as the first gear portion (first unit side gear portion), on the outer circumference, centered on the rotation axis L19 of the cylinder. The internal gear portion 1902a has spur teeth, and the external gear portion 1902b has helical teeth with a helix angle α1, with the same number of teeth as the second gear portion (second unit side gear portion) 1963d of the drive side flange 1963. Furthermore, a support portion 1902c is provided on one end of the gear 1902, and a cylindrical portion 1902d is provided on the other end. The support portion 1902c is substantially cylindrical in shape and is provided projecting along the rotation axis L19 in the opposite direction from the drum 1962 (downstream with respect to the J direction) from the external gear portion 1902b and the internal gear portion 1902a. The cylindrical portion 1902d is substantially cylindrical in shape and is provided projecting along the rotation axis L19 toward the drum 1962 side (downstream with respect to the H direction) from the external gear portion 1902b and the internal gear portion 1902a.

[0306] As shown in Figure 66, the inner circumferential surface (supported portion) of the support portion 1902c engages with the outer circumferential surface 19710c of the cylindrical portion 19710b, and the gear 1902 is rotatably supported by the frame member 1971 around the rotation axis L19. Also, the outer circumferential surface 19730b of the cylindrical portion 19730r engages with the inner circumferential surface 19710d of the cylindrical portion 19710b, and the bearing member 1973 is positioned and supported by the frame member 1971. The drive-side flange 1963 is installed on the cleaning frame 1960a, passing through the inner circumferential portion of the gear 1902. Similar to Embodiment 17, the projection 1963g of the drive-side flange 1963 is rotatably supported by the bearing member 1973 around the rotation axis L1.

[0307] Furthermore, as shown in Figure 67, the internal gear portion 1963f of the drive-side flange 1963 has spur teeth, the same number as the number of teeth on the internal gear portion 1902a of gear 1902. Gear 1902 and the internal gear portion 1902a are installed so as to fit into the internal gear portion 1963f, and the tooth surfaces of the internal gear portion 1902a and the internal gear portion 1963f engage with each other in the rotational direction. In other words, the internal gear portion 1902a and the internal gear portion 1963f mesh in a way that allows rotational driving force to be transmitted.

[0308] As mentioned above, the outer circumferential surface 19710c of the cylindrical portion 19710b of the frame member 1971 is positioned eccentrically with respect to the inner circumferential surface 19710d. Therefore, the gear 1902 supported by the outer circumferential surface 19710c engages with the drive-side flange 1963, which is supported by the inner circumferential surface 19710d via the bearing member 1973, at an eccentric position. In other words, the gear 1902 and the drive-side flange 1963 are arranged to rotate with their respective rotation axes L19 and L1 parallel and non-coaxial, and can transmit rotational driving force to each other. In Figure 67, the positions of the rotation axes L19 and L1 are shown at the intersections of horizontal dashed lines extending left and right and vertical dashed lines extending up and down, respectively, and the misalignment between the horizontal dashed line corresponding to the rotation axis L19 and the horizontal dashed line corresponding to the rotation axis L1 can be seen. Furthermore, gear 1902 can also be referred to as a non-coaxial rotating member connected to the drive-side flange 1963 in a manner that enables the transmission of driving force.

[0309] <Transmission of driving force to drum unit 1969> Next, the transmission of driving force to the drum unit 1969 will be explained using Figures 68 and 69. Figure 68 is a cross-sectional view showing the engagement state between the drum unit 1969 and the drive transmission gear 1781, and this cross-section includes the rotation axis L1. Figure 69 is a cross-sectional view showing the engagement state between the drum unit 1969 and the drive transmission gear 1781, and is a cross-sectional view taken along the J direction, perpendicular to the rotation axis L1 and passing through the internal gear portion 1963f.

[0310] As shown in Figure 68, similar to Embodiment 17, the second main gear portion 81d of the drive transmission gear 1781 meshes with the second gear portion 1963d of the drive-side flange 1963. In addition, the first main gear portion 1781c of the drive transmission gear 1781 meshes with the external gear portion (first gear portion) 1902b of the gear 1902, and the internal gear portion 1902a of the gear 1902 meshes with the internal gear portion 1963f of the drive-side flange 1963.

[0311] As shown in Figure 69, when the drive transmission gear 1781 rotates in the direction of arrow I, the gear 1902 receives a driving force through the meshing of the external gear portion 1902b and the first main body gear portion 1781c, and rotates in the direction of arrow KW around the rotation axis L19. At this time, the internal gear portion 1902a engages with the internal gear portion 1963f of the drive-side flange 1963 in the rotational direction, and transmits the driving force to the drive-side flange 1963. As a result, the drive-side flange 1963 rotates in the direction of arrow K around the rotation axis L1.

[0312] As the drive transmission gear 1781 rotates in the direction of arrow I, the external gear portion 1902b receives a thrust force in the direction of arrow H (see Figure 68) due to its meshing with the first main gear portion 1781c. As a result, as shown in Figure 68, the gear 1902 moves in the direction of arrow H, and the cylindrical portion 1902d comes into contact with the end face of the second gear portion 1963d of the drive-side flange 1963, restricting (stopping) the movement of the gear 1902 in the direction of arrow H.

[0313] On the other hand, the drive transmission gear 1781 receives a thrust force due to its meshing with the external gear portion 1902b and moves in the direction of arrow J. Then, similar to Embodiment 17, the second main body gear portion 1781d moves to a balanced position where it engages with the second gear portion 1963d of the drive side flange 1963, and its movement in the direction of the rotation axis L1 stops.

[0314] In this equilibrium state, the external gear section (first gear section) 1902b receives a driving force FD from the first main gear section 1781c. Since gear 1902 can be considered a rigid body, this driving force FD is transmitted to the drive-side flange 1963 through the meshing (engagement) of the internal gear section 1902a and the internal gear section 1963f. That is, the drive-side flange 1963 receives the driving force FD via gear 1902. Furthermore, the drive-side flange 1963 has a second gear section 1963d that receives a regulating force (braking force) FB from the second main gear section 1781d. The teeth of the second gear section 1963d are fixed so that they cannot move (rotate) in the opposite direction to the I direction relative to the teeth of the first gear section 1902b. Therefore, the drum unit 1969 (drum 1962, drive-side flange 1963, and gear 1902) is driven in a backlash-free state. For this reason, the same effects as in Example 17 can be obtained even when using the configuration of this embodiment.

[0315] In addition, immediately after the start of rotation of the drive transmission gear 1781, the meshing of the second gear section 1963d and the second main body gear section 1781d may cause the drive-side flange 1963 to rotate in the K direction, and the meshing of the internal gear section 1902a and the internal gear section 1963f may cause the gear 1902 to rotate in the KW direction. In this case as well, as the drive transmission gear 1781 moves in the J direction, the first main body gear section 1781c meshes with the external gear section 1902b, and finally transitions to the equilibrium state described above.

[0316] Thus, in this embodiment, the rotation axis L19 of the external gear portion 1902b (first gear portion) and the rotation axis L1 of the second gear portion 1963d are parallel, not coaxial. In the equilibrium state, the gear 1902 has the following parts (i) to (iii): (i) Input portion: at least the portion of the external gear portion 1902b that meshes with the drive transmission gear 1781 (at least a part of the first gear portion), (ii) Transmission portion: the portion of the internal gear portion 1902a that meshes with the internal gear portion 1963f and transmits the driving force to the drive-side flange 1963, and (iii) Output portion: the portion between the input portion (i) and the output portion (ii). Since the parts (i) to (iii) of the gear 1902 are substantially rigid with respect to the K direction, they move together along the K direction. Therefore, in the balanced state, parts (i) to (iii) of gear 1902 and the second gear portion 1963d of the drive-side flange 1963 move integrally with respect to the K direction (rotational direction around the rotation axis L1). As a result, a force corresponding to the driving force FD and a regulating force FB act on the drive-side flange 1963, enabling backlash-free driving and obtaining the same effect as in driving embodiment 17. Furthermore, this indicates that it is sufficient for the first gear portion that receives the driving force FD and the second gear portion that receives the rotation axis and regulating force FB to be configured to move integrally in the K direction in the balanced state, and that it is not necessary for the first gear portion and the second gear portion to be permanently fixed integrally to the drive-side flange 1963, as in embodiments 1 to 18 described above.

[0317] Furthermore, this embodiment shows an example of a configuration in which the rotation axis of the first gear section that receives the driving force FD and the rotation axis of the second gear section that receives the restricting force FB are not coaxial. In other words, an example is shown in which the rotation axis of the second gear section (1963d) that receives the restricting force FB is coaxial with the rotation axis (L1) of the drive-side flange (1963), while the rotation axis of the first gear section (1902b) that receives the driving force FD is not coaxial with the rotation axis (L1) of the drive-side flange (1963). Specifically, the first gear section (1902b) is provided on a gear 1902, which is a non-coaxial rotating member connected to the drive-side flange 1963 in a manner that can transmit driving force. However, the configuration in which the rotation axis of the first gear section that receives the driving force FD and the rotation axis of the second gear section that receives the restricting force FB are not coaxial is not limited to this configuration.

[0318] For example, in another configuration, the rotation axis of the first gear section that receives the driving force FD may be coaxial with the rotation axis of the drive-side flange, while the rotation axis of the second gear section that receives the restricting force FB may not be coaxial with the rotation axis of the drive-side flange. Specifically, in this configuration, the first gear section is provided on the drive-side flange, and the second gear section is provided on a non-coaxial rotating member connected to the drive-side flange in a manner that can transmit driving force. As a more specific example of a configuration, in the drive-side flange 1763 of Embodiment 17, the first gear section 1763c may be left as is, and a gear 1902 with the second gear section in the position of the second gear section 1763d may be arranged in the same manner as in this embodiment.

[0319] As yet another example, the rotation axis of the first gear section that receives the driving force FD, the rotation axis of the second gear section that receives the regulating force FB, and the rotation axis of the drive-side flange may be configured not to be coaxial with each other. In this configuration, specifically, the first gear section is provided on the first non-coaxial rotating member that is connected to the drive-side flange in a manner that can transmit driving force, and the second gear section is provided on the second non-coaxial rotating member that is connected to the drive-side flange in a manner that can transmit driving force and rotates non-coaxially with the first non-coaxial rotating member. As a more specific example of a configuration, in the drive-side flange 1763 of Embodiment 17, a gear 1902 having the first gear section is arranged at the position of the first gear section 1763c in the same manner as in this embodiment, and a gear 1902 having the second gear section is arranged at the position of the second gear section 1763d in the same manner as in this embodiment.

[0320] Furthermore, the connection configuration that enables the transmission of driving force between the drive-side flange 1963 and the non-coaxial rotating member (gear 1902) is not limited to a meshing configuration of spur gears such as the internal gear portion 1902a and the internal gear portion 1963f. For example, a connection configuration that enables the transmission of driving force using helical gears or multiple projections arranged in the circumferential direction may also be used. In addition, a non-coaxial driving force transmission coupling such as an Oldham coupling (described in detail in Modification 2 of Example 19) may be used as the connection configuration that enables the transmission of driving force between the drive-side flange 1963 and the non-coaxial rotating member (gear 1902).

[0321] <Modification 1 of Example 19> In the above-described embodiment 19, the internal gear portion 1963f of the drive-side flange 1963 and the internal gear portion 1902a of the gear 1902 were described as having the same number of teeth and rotating as a single unit. However, in this modified example, a configuration in which the drive-side flange 1963 and the gear 1902 rotate at different speeds will be described. Figure 70 is an exploded perspective view of the drive-side portion of the cleaning unit 1960. Figure 71 is a cross-sectional view showing the engagement state of the drum unit 1969 and the drive transmission gear 1781, and is a cross-sectional view taken along the J direction, perpendicular to the rotation axis L1 and passing through the internal gear portion 1963f.

[0322] In the configuration described above, gear 1903 is installed as a non-coaxial rotating member instead of gear 1902, and drive-side flange 1963 is installed instead of drive-side flange 1963. Similar to the configuration described above, gear 1903 is rotatably supported on the outer circumferential surface 1971c of the cylindrical portion 1971b of the cleaning frame 1971, and drive-side flange 1963 is rotatably supported on the bearing member 1973, passing through gear 1903.

[0323] As shown in Figure 71, the internal gear portion 1903a of gear 1903 is significantly larger than the first gear portion 1963c of the drive-side flange 1963, and is even more eccentric than the previously described configuration. In Figure 71, the positions of the rotation axis L19 and rotation axis L1 are indicated by the intersections of the horizontal dashed lines extending from left to right and the vertical dashed lines extending from up to down, respectively.

[0324] In the balanced state, at least the portion of the gear 1903b that meshes with the drive transmission gear 1781 (at least a part of the first gear portion) and the second gear portion 1963d move integrally with respect to the rotational direction around the rotation axis L1. Therefore, the same effect as in the previously described embodiment 19 can be obtained.

[0325] In this embodiment, the first gear portion 1963c of the drive-side flange 1963 and the internal gear portion 1903a of the gear 1903 are composed of spur gears, but they may be composed of helical gears as long as the configuration allows for mutual eccentricity.

[0326] <Modification 2 of Example 19> A configuration using an Oldham coupling as the drive force transmission configuration between the non-coaxial rotating member and the drive-side flange 1963 will be described. Figure 72 is a partial perspective view of the drum unit 1969. As shown in Figure 72, the drive flange 1963 has a gear portion 1963d, a projection 1963g, a small diameter portion 1963e, and a flange portion 1963h, centered on the drum rotation axis L1.

[0327] The small-diameter portion 1963e is substantially cylindrical in shape and protrudes from the gear portion 1963c on the opposite side of the drum 1962 (downstream in the J direction) along the drum rotation axis L1. The small-diameter portion 1963e is provided with a recess 1963r that is recessed on the drum 1962 side (downstream in the H direction). The side portions 1963s of the recess 1963r have a planar shape parallel to the drum rotation axis L1 direction and are arranged at equally spaced positions on either side of the drum rotation axis L1. In addition, there are two recesses 1963r located symmetrically on either side of the small-diameter portion 1963g in a direction perpendicular to the drum rotation axis L1.

[0328] The projection 1963g is cylindrical in shape and is provided to protrude along the drum rotation axis L1 from the small diameter portion 1963e in the opposite direction to the drum 1962 (downstream with respect to the J direction).

[0329] The flange portion 1963h is a thin disc shape with a diameter equal to or greater than the diameter of the drum 1962, and is provided on the drum 1962 side (downstream side with respect to the H direction) of the gear portion 1963d. The gear portion 1963d has helical teeth with a helix angle α2, similar to Embodiment 17.

[0330] The drum unit 1969 also includes a gear 1904 with a gear section 1904c, which will be described in detail later, and a driven coupling 1905.

[0331] Next, the configuration of the cleaning unit will be explained using Figure 73. Figure 73 is an exploded perspective view of the drive side of the cleaning unit, where (a) is a view from the drive side toward the non-drive side, and (b) is a view from the non-drive side toward the drive side. As shown in Figures 73(a) and (b), the bearing member 1973 is supported by the frame member 1971. A hole 1971d, which is a positioning part for the bearing member 1973, is provided on the side surface of the frame member 1971. The hole 1971d is formed in an arc shape, and the center of the arc is located at a position that coincides with the drum rotation axis L1. In addition, a cylindrical portion 1971b is installed on the frame member 1971, protruding downstream in the H direction. The inner circumferential surface 1971c of the cylindrical portion 1971b is an arc shape, and the center line L19 of the arc is located at a position that is not coaxial with the drum rotation axis L1 but is parallel to it. In other words, the hole 1971d is positioned eccentrically with respect to the inner circumferential surface 1971c.

[0332] A gear 1904, acting as a non-coaxial rotating member, is rotatably supported on the inner circumferential surface 1971c of the cylindrical portion 1971b. The gear 1904 is substantially cylindrical in shape and has a through hole 1904a, a gear portion 1904c as the first gear portion on the outer circumference, and a cylindrical portion 1904d coaxially around the axis of the cylinder. The gear portion 1904c has helical teeth with a helix angle α1. A convex portion 1904b is positioned to protrude downstream in the H direction from the side of the gear 1904.

[0333] When the rotation axis of gear 1904 is defined as the gear rotation axis L19, the side portions 1904e and 1904f of the protrusion 1904b have a planar shape parallel to the gear rotation axis L19 direction and are arranged at equally spaced positions on either side of the gear rotation axis L19. Furthermore, the protrusion 1904b has an arc shape that does not protrude from the tooth root of the gear portion 1904c in the radial direction centered on the rotation axis L1. In addition, two protrusions 1904b are provided at symmetrical positions on either side of the through hole 1904a in a direction perpendicular to the gear rotation axis 1901. The cylindrical portion 1904d protrudes downstream in the J direction. The cylindrical portion 1904d fits into the inner circumferential surface 1971c of the cylindrical portion 1971b of the frame member 1971, thereby rotatably supporting the gear 1904 on the frame member 1971.

[0334] A driven coupling 1905 is installed downstream of gear 1904 in the H direction. The driven coupling 1905 is substantially cylindrical in shape, and has a through hole 1905a and a cylindrical portion 1905d coaxially with respect to the axis of the cylindrical shape. A convex portion 1905b is installed on the downstream side of the cylindrical portion 1905d in the H direction, protruding downstream in the H direction. In addition, a concave portion 1905c is installed on the downstream side of the cylindrical portion 1905d in the J direction, recessed downstream in the H direction. The convex portion 1905b has parallel surfaces that are equally spaced with the side surface portion 1963s of the concave portion 1963r, centered on the axis of the cylindrical shape, and the concave portion 1905c has parallel surfaces that are equally spaced with the side surface portions 1904e and 1904f of the convex portion 1904b, centered on the axis of the cylindrical shape, and the convex portion 1905b and the concave portion 1905c are arranged in a direction perpendicular to the axis of the cylindrical shape.

[0335] The protrusion 1904b of the gear 1904 fits into the recess 1905c of the driven coupling 1905 in the direction of the rotation axis L1 of the cylinder, and the protrusion 1904b is movable (slidable) in the 190Y direction (see Figure 73(b)) within the recess 1905c. The 190Y direction is parallel to the plane perpendicular to the rotation axis L1. In addition, the protrusion 1904b can transmit the driving force that rotates the driven coupling 1905 around the rotation axis L1 to the recess 1905c.

[0336] Furthermore, the projection 1963g of the drive flange 1963 passes through the through hole 1905a of the driven coupling 1905 and the through hole 1904a of the gear 1904. Here, the radial size of the through holes 1905a and 1904a is set to be sufficiently large compared to the outer diameter of the projection 1963g.

[0337] Furthermore, the protrusion 1905b of the driven coupling 1905 fits into the recess 1963r of the drive flange 1963 in the direction of the rotation axis L1, and the protrusion 1905b is movable (slidable) in the 190X direction within the recess 1963r. The 190X direction is parallel to the plane perpendicular to the rotation axis L1, and is perpendicular to the 190Y direction when viewed along the rotation axis L1. In addition, the protrusion 1905b can transmit the driving force that rotates the drive flange 1963 around the rotation axis L1 to the recess 1963r.

[0338] The tip of the projection 1963g is rotatably supported by the drum bearing member 1973, similar to Example 17.

[0339] As described above, the inner circumferential surface 1971c of the cylindrical portion 1971b of the frame member 1971 is positioned eccentrically with respect to the hole 1971d. Therefore, the gear 1904 supported by the inner circumferential surface 1971c and the drive-side flange 1963 supported coaxially with the hole 1971d are rotatably supported in eccentric positions.

[0340] Next, the engagement with the drive transmission gear 1781 will be explained using Figures 74 and 75. Figure 74 shows the drum unit 1969 meshing with the drive transmission gear 1781, and is viewed from a direction perpendicular to the rotation axis L1. Figures 75(a) to (e) are cross-sectional views showing the engagement state of the drum unit 1969 and the drive transmission gear 178, and are cross-sectional views taken along the H direction, perpendicular to the rotation axis L1 and passing through the protrusion 1904b of the gear 1904. In Figure 75, the position of the rotation axis L19 is shown at the intersection of the horizontal dashed line extending left and right and the vertical dashed line extending up and down, while the position of the rotation axis L1 is the center of the circular projection 1963g, and has therefore been omitted for the sake of simplifying the figure. The black circle shown on the driven coupling 1905 in Figure 75 is a mark indicating a specific part of the driven coupling 1905 and is included to make the rotation phase of the driven coupling 1905 easier to understand.

[0341] As shown in Figure 74, the second main gear 1781d of the drive transmission gear 1781 engages with the second gear portion 1963d of the drive-side flange 1963, and the first main gear portion 81c engages with the gear 1904 (first gear portion).

[0342] As shown in Figures 75(a) to (e), when the drive transmission gear 1781 rotates in direction I, driving force is transmitted from the drive transmission gear 1781 to the gear section 1904c (first gear section), causing the gear 1904 to rotate in the KW direction around the gear rotation axis L19. The driving force of the drive transmission gear 1781 is then transmitted to the drive flange 1963 via the driven coupling 1905 which engages with the gear 1904, causing the drive flange 1963 to rotate in the K direction (see Figure 72) around the rotation axis L1.

[0343] As the gear 1904 and drum unit 1969 rotate, the driven coupling 1905 moves in the 190X direction relative to the drive flange 1963 as the protrusion 1905b (see Figure 74) moves within the recess 1963r of the drive flange 1963. Furthermore, the gear 1904 moves in the 190Y direction relative to the driven coupling 1905 as the protrusion 1904b moves within the recess 1905c. As a result, the gear 1904 (rotation axis L19) and the drive flange 1963 (rotation axis L1) can transmit the driving force for rotation between the gear 1904 and the drive flange 1963 while maintaining an eccentric position (non-coaxial and parallel).

[0344] Then, through the same action as in Example 19, the drive transmission gear 1781 moves to the equilibrium position and enters an equilibrium state. In the equilibrium state, the drive transmission gear 1781 receives a regulating force FB at the second gear portion 1963d, and receives a force corresponding to the driving force FD received by the gear portion 1904c (first gear portion) of gear 1904 at the side portion 1963s via the driven coupling 1905. Furthermore, the teeth of the second gear portion 1963d are fixed so that they cannot move (rotate) in the opposite direction to the I direction relative to the teeth of the first gear portion 1904c. As a result, a backlash-free state is achieved, and the same effect as in Example 17 is obtained.

[0345] As described above, the same effects as in Example 17 can be obtained by Example 19, Modification 1 of Example 19, and Modification 2 of Example 19. Furthermore, it is possible to apply the elements of each of the aforementioned embodiments to the configuration of this embodiment. In particular, the configuration of the first helical teeth (first projection) of the first gear part and the second helical teeth (second projection) of the second gear part may be changed to helical teeth, spur teeth, projections, etc., as shown in Examples 2, 3, 4, 5, 6, 10, 11, 12, 13, 14, and 16.

[0346] [Example 20] Next, Example 20 will be described below with reference to Figures 76, 77, 78, and 79. This example differs from Example 17 in that the first gear section (external teeth section 2002b) that receives the driving force FD rotates coaxially with the rotation axis (L1) of the second gear section (2063d) that receives the regulating force FB, but only in a certain region. Alternatively, this example can be said to differ from Example 17 in that the movement of the first gear section (external teeth section 2002b) is not composed solely of rotation around a single rotation axis (L1). Other aspects are the same as in Example 17, and a detailed explanation will be omitted. In addition, for each element in this example, elements that correspond to elements in Example 1 are denoted by reference numerals associated with the corresponding elements in Example 1. Unless otherwise specified, these elements are the same as the corresponding elements in Example 1.

[0347] <Drum Unit 2069> Figure 76 is a partial perspective view of the drum unit 2069. Figure 77 is an exploded perspective view of the drive side of the cleaning unit 2060 and the drum unit 2069. Figure 78 is a cross-sectional view of the drive side flange 2063 of the cleaning unit 2060 at the position of the gear portion 2063f.

[0348] As shown in Figure 76, the drive-side flange 2063 has a gear section 2063f, a second gear section (second unit side gear section) 2063d, a projection 2063g, a small diameter section 2063e, and a flange section 2063h, centered on the drum rotation axis L1. The gear section 2063f has a pulley shape that corresponds to a toothed belt.

[0349] The projection 2063g is substantially cylindrical in shape and is provided projecting along the drum rotation axis L1 from the gear portion 2063f in the opposite direction to the drum 2062 side (downstream in the J direction). The small diameter portion 2063e is substantially cylindrical in shape with a diameter greater than or equal to the diameter of the gear portion 2063f and less than or equal to the diameter of the second gear portion 2063d, and is provided along the drum rotation axis L1 from the gear portion 2063f on the drum 2062 side (downstream in the H direction). The second gear portion 2063d is helical teeth with a helix angle α2, similar to Embodiment 17, and is provided on the drum 2062 side (downstream in the H direction) of the small diameter portion 2063e. The flange portion 2063h is a thin disc shape with a diameter equal to or greater than the diameter of the drum 2062, and is provided on the drum 2062 side (downstream in the H direction) of the second gear portion 2063d.

[0350] As shown in Figure 77, the drum unit 2069 further includes a belt 2002 (see Figure 77, etc.). The belt 2002 has an external tooth portion 2002b on its outer circumference as a first gear portion (first unit side gear portion) and an internal tooth portion 2002a on its inner circumference that meshes with the gear portion 2063f. The belt 2002 is an elastic belt-shaped member. The external tooth portion 2002b is an oblique tooth with a helix angle α1.

[0351] Next, the configuration of the drive-side cleaning unit 2060 will be described using Figures 77 and 78. As shown in Figure 77, the bearing member 2073 is supported by the frame member 2071. The frame member 2071 is provided with a substantially cylindrical hole 20710a. The bearing member 2073 is provided with a substantially cylindrical hole 20730a opposite to hole 20710a. A pulley 2001 is installed between holes 20710a and 20730a. The pulley 2001 has a substantially cylindrical shape extending in the direction of an axis parallel to the rotation axis L1. The pulley 2001 has supported portions 2001a and 2001b, which are substantially cylindrical protrusions, at both ends in the direction parallel to the rotation axis L1, and has a tooth portion 2001c on the circumferential surface of the central portion, which is a pulley shape corresponding to the internal teeth portion 2002a of the belt 2002. Furthermore, the pulley 2001 is provided with a flange portion 2001d, which has a larger diameter than the tooth portion 2001c, between the supported portion 2001a and the tooth portion 2001c. The supported portions 2001a and 2001b are rotatably supported in holes 20710a and 20730a, respectively, so that the pulley 2001 can rotate on a rotation axis parallel to the rotation axis L1.

[0352] <Support configuration of drum unit 2069> The support configuration of the drive-side flange 2062 and drum 2062 of the drum unit 2069, which is provided by the bearing member 2073 and the frame member 2071, is the same as in Example 19, so a description will be omitted. On the other hand, as shown in Figure 78, the belt 2002 of the drum unit 2069 has its internal teeth 2002a engaged with the gear portion 2063f of the drive-side flange 2063 and the teeth portion 2001c of the pulley 2001, and is supported by the pulley 2001 and the gear portion 2063f. The belt 2002 is supported by the drive-side flange 2063 and the pulley 2001 with appropriate tension so that the portion of the belt 2002 that is not in contact with either the drive-side flange 2063 or the pulley 2001 does not bend excessively. The belt 2002 can also circulate due to the rotation of the drive-side flange 2063 (gear portion 2063f) and the pulley 2001 (teeth portion 2001c).

[0353] <Transmission of driving force to drum unit 2069> Next, the engagement state with the drive transmission gear 1781 will be explained using Figures 79 and 80. Figure 79 is a cross-sectional view showing the engagement state between the drum unit 2069 and the drive transmission gear 1781, and is a cross-sectional view taken along the J direction, perpendicular to the rotation axis L1 and passing through the belt 2002. Figure 80 is a cross-sectional view showing the engagement state between the drum unit 2069 and the drive transmission gear 1781, and its cross-section includes the rotation axis L1.

[0354] As shown in Figure 79, when the drive transmission gear 1781 rotates in the direction of arrow I, the external teeth 2002b of the belt 2002 engage with the first main body gear 1781c and move in a circular motion in the direction of arrow KC, which is the direction of circular movement. As the belt 2002 moves in a circular motion, the gear portion 2063f of the drive-side flange 2063, which engages with the internal teeth 2002a of the belt 2002, rotates in the direction of arrow K. At this time, if the portion of the belt 2002 that is engaged with the internal teeth 2002a is called the rotating portion 2002R, then the rotating portion 2002R rotates in the direction K around the rotation axis L1. Therefore, the direction of circular movement KC of the rotating portion 2002R of the belt 2002 coincides with the direction K. Therefore, if the portion of the external teeth portion 2002b, which is the first gear portion, that is included in the rotating portion 2002R is designated as the rotating gear portion 2002bR, then the rotating gear portion 2002bR rotates integrally with the drive-side flange 2063 and the second gear portion 2063d around the rotation axis L1. In addition, as the belt 2002 circulates in the KC direction, the pulley 2001 rotates in the direction of arrow V20.

[0355] As the drive transmission gear 1781 rotates in the direction of arrow I, the external teeth portion 2002b receives a thrust force in the direction of arrow H due to meshing with the first main body gear portion 1781c, causing the belt 2002 to attempt to move in the direction of arrow H. However, as shown in Figure 80, since the diameter of the small diameter portion 2063e of the drive-side flange 2063 is larger than the diameter of the gear portion 2063f, the end face 2002E of the belt 2002 comes into contact with the end face 2063eE of the small diameter portion 2063e, restricting (stopping) the movement of the belt 2002 in the direction of arrow H.

[0356] On the other hand, the drive transmission gear 1781 receives a thrust force due to its meshing with the external teeth 2002b and moves in the direction of arrow J. Then, similar to Embodiment 17, it moves to a balanced position where the second main body gear portion 1781d engages with the second gear portion 2063d of the drive-side flange 1963, and its movement in the direction of the rotation axis L1 stops. The operation and function of the first gear portion (external teeth 2002b) and the second gear portion 2063d from the start of driving of the drive transmission gear 1781 until the drive transmission gear 1781 reaches the balanced position are the same as in Embodiment 19.

[0357] In this equilibrium state, the rotating gear portion 2002bR of the external gear portion (first gear portion) 2002b receives a driving force FD from the first main gear portion 1781c. Since the rotating portion 2002R of the belt 2002 can be considered a rigid body, this driving force FD is transmitted to the drive-side flange 2063 by the meshing (engagement) of the internal gear portion 2002a and the gear portion 2063f. That is, the drive-side flange 2063 receives the driving force FD via the rotating portion 2002R of the belt 2002. Furthermore, the drive-side flange 2063 has a second gear portion 2063d that receives a regulating force (braking force) FB from the second main gear portion 1781d. The teeth of the second gear portion 2063d are fixed so that they cannot move (rotate) in the opposite direction to the teeth of the first gear portion 2002b relative to the I direction. Therefore, the drum unit 2069 (drum 2062, drive-side flange 2063, and belt 2002) is driven in a backlash-free state. For this reason, the same effects as in Example 17 can be obtained even when using the configuration of this embodiment.

[0358] In this embodiment, the configuration is shown in which the first gear section that receives the driving force FD in the balanced state is provided on the belt 2002. However, the configuration may also be such that the second gear section that receives the regulating force FB in the balanced state is provided on a belt supported in the same way as the belt 2002. Alternatively, the configuration may be such that the first gear section that receives the driving force FD is provided on the belt 2002, while the second gear section that receives the regulating force FB is provided on a separate belt.

[0359] Furthermore, although this embodiment shows a configuration in which the belt 2002 has an internal tooth portion 2002a and an external tooth portion 2002b as a first gear portion, it is not limited to this. For example, the belt may be a belt that deforms to conform to the shape of the gear of the drive-side flange 2063 and the gear of the drive transmission gear 1781, such as the elastic ring 1801 shown in Embodiment 18. In this case, the gear portion 2063f of the drive-side flange 2063 is shaped to correspond to the first main gear portion 1781c of the drive transmission gear 1781, and the gear portion 2063f meshes with the first main gear portion 1781c via the belt. In this case, the gear portion 2063f can also be considered as a first gear portion that receives the driving force FD. If the belt covers the second gear portion 2063d of the drive-side flange 2063 and the belt is positioned to conform to the gear shape of the second gear portion 2063d, then the second gear portion 2063d can be considered as the second gear portion that receives the regulating force FD.

[0360] As described above, the same effects as in Example 17 can be obtained with this embodiment. Furthermore, the elements of each of the embodiments described above can be applied to the configuration of this embodiment. In particular, the configuration of the first helical teeth (first projection) of the first gear part and the second helical teeth (second projection) of the second gear part may be changed to helical teeth, spur teeth, projections, etc., as shown in Examples 2, 3, 4, 5, 6, 10, 11, 12, 13, 14, and 16.

[0361] [Example 21] Next, Example 21 will be described below with reference to Figures 81 and 82. This example differs from Example 17 in that the direction of tooth protrusion of the gear section is different. Specifically, in Example 17, the direction of tooth protrusion of each gear section (first gear section, second gear section) was radial around the rotation axis L1, but in this example, the direction of tooth protrusion has a component parallel to the rotation axis L1. Other aspects are the same as in Example 17, and a detailed explanation will be omitted. In addition, for each element in this example, elements that correspond to elements in Example 1 are denoted by reference numerals associated with the corresponding elements in Example 1. Unless otherwise specified, these elements are the same as the corresponding elements in Example 1.

[0362] <Drive side flange 2163> Figure 81 is a partial perspective view of the drive side portion of the drum unit 2169. Figure 82 is a partial perspective view of the drum unit 2169, with the drive side flange 2163 cut in a cross section perpendicular to the rotation axis L1 and passing through the projection 2163d. As shown in Figure 81, the drive side flange 2163 has a first gear portion (first unit side gear portion) 2163c, a projection 2163d as a second gear portion (second unit side gear portion), a projection (supported portion) 2163g, a small diameter portion 2163e, and a flange portion 2163h, centered on the rotation axis L1.

[0363] The first gear portion 2163c has helical teeth with a helix angle α1 and is substantially the same shape as the first gear portion 1763c of Embodiment 17. The projection (supported portion) 2163g is substantially cylindrical in shape with respect to the rotation axis L1 and is provided projecting along the rotation axis L1 from the first gear portion 2163c in the opposite direction to the drum 2162 (downstream with respect to the J direction). The projection 2163g is substantially the same shape as the projection 1763g of Embodiment 17.

[0364] The small-diameter portion 2163e is substantially cylindrical in shape and protrudes from the first gear portion 2163c toward the drum 2162 side (downstream in the H direction) along the rotation axis L1. The flange portion 2163h is a thin disc shape with a diameter equal to or greater than the diameter of the drum 2162 and is provided toward the drum 62 side (downstream in the H direction) of the small-diameter portion 2163e.

[0365] The projection 2163d, which serves as the second gear section, is composed of multiple projections (teeth) 2163dt. The number of projections 2163dt is the same as the number of teeth of the first gear section 2163c, and they are formed in a shape that can engage with the second main gear section 1781d of the drive transmission gear 1781. Furthermore, the multiple projections (teeth) 2163dt protrude from the flange section 2163h in the J direction, which is along the rotation axis L1 and away from the drum 2162, and are spiral projections twisted at a twist angle α2 so as they move in the J direction, they move downstream in the K direction (the rotation direction K of the drive-side flange 2163), which is the circumferential direction around the rotation axis L1. That is, the projection direction PD of the projection (teeth) 2163dt from the flange section 2163h has at least an H-direction component parallel to the rotation axis L1 and a K-direction component which is the circumferential direction around the rotation axis L1. The twist angle of the multiple protrusions 2163dt is the twist angle α2. Note that if the protrusions 2163dt are configured as flat teeth rather than oblique teeth, the protrusion direction PD has an H-direction component parallel to the rotation axis L1, but no circumferential (K-direction) component.

[0366] Furthermore, the multiple protrusions 2163dt are involute tooth profiles having involute surface portions on their sides, and have substantially the same shape as the second oblique teeth (second protrusions) 1763dt of the second gear portion 1763d in Embodiment 17. For this reason, the protrusions 2163d can mesh with the second main gear portion 1781d of the drive transmission gear 1781 and receive driving force and regulating force FB, and function as a second gear portion equivalent to the second gear portion 1763d in Embodiment 17.

[0367] Furthermore, as shown in Figure 82, the multiple protrusions 2163dt are arranged at equal intervals in the rotation direction K around the rotation axis L1. In addition, the multiple protrusions 2163dt are formed such that their tips are at the same distance from the rotation axis L1 in the radial direction around the rotation axis L1, and their rear ends are at a constant distance from the small diameter portion 2163e. Therefore, a space is formed between the rear ends of the multiple protrusions 2163dt and the outer circumferential surface of the small diameter portion 2163e in the radial direction around the rotation axis L1.

[0368] Even with such a drive-side flange 2163, the teeth (projections 2163dt) of the second gear portion 2163d are fixed so that they cannot move (rotate) in the opposite direction to the I direction relative to the teeth of the first gear portion 2163c. Therefore, it receives the driving force FD and the restricting force FB from the drive transmission gear 1781, and is rotationally driven in the K direction while maintaining a backlash-free state, making it possible to obtain the same effect as in Embodiment 17.

[0369] In this embodiment, the drive-side flange 2163 may be manufactured by molding multiple components and bonding them together. Alternatively, the drive-side flange 2163 may be molded using different materials such as resin or metal. In particular, since the projection 2163dt has a relatively thin shape, it may be preferable to use a metal material.

[0370] Furthermore, in this embodiment, the projection direction PD of the projection 2163dt, which is a tooth of the second gear portion (projection 2163d), from the flange portion 2163h is set to a direction having a J-direction component parallel to the rotation axis L1. However, the projection direction PD may also be set to a direction having an H-direction component parallel to the rotation axis L1. In that case, the flange portion 2163h is positioned at least upstream in the H-direction from the second gear portion (projection 2163d). Alternatively, the second gear portion may be composed of teeth with a shape that protrudes radially around the rotation axis L1, similar to the second gear portion 1763d of Embodiment 17, while the teeth of the first gear portion 2163c may be formed of projections that protrude in a projection direction having a component parallel to the rotation axis L1 (H-direction component or J-direction component). Alternatively, the teeth of the first gear portion 2163c and the teeth of the second gear portion (projection portion 2163d) may be formed as projections that protrude in a direction having a component parallel to the rotation axis L1 (H-direction component or J-direction component).

[0371] As described above, this embodiment provides the same effects as in Embodiment 17. Furthermore, the elements of each of the embodiments described above can be applied to the configuration of this embodiment. In particular, the configuration of the first gear portion of the drive-side flange may be changed to the helical teeth, spur teeth, projections, etc., as shown in Embodiments 2, 3, 4, 5, 6, 10, 11, 12, 13, 14, 16, etc.

[0372] [Example 22] Next, Example 22 will be described below with reference to Figures 83 to 87. This example differs from Example 17 in that it has a member that can fill the gap g between the first gear section and the second gear section. In all other respects, it is the same as Example 17, and a detailed explanation will be omitted. Also, among the elements in this example, those that correspond to the elements in Example 1 are given reference numerals that correspond to the elements in Example 1. Unless otherwise specified, these elements are the same as the elements in the corresponding Example 1.

[0373] <Drive side flange 2263> First, the configuration of the drive-side flange 2263 will be explained using Figures 83 and 84. Figure 83 is a partial perspective view of the drive side of the drum unit 2269. Figure 84 is a cross-sectional view of the drum unit 2269, the cross-section of which is perpendicular to the rotation axis L1 and passes through the eccentric ring 2201. The drive-side flange 2263 is centered on the rotation axis L1 and includes a first gear section (first unit side gear section) 2263c, a projection 2263d, a small diameter section 2263e, and a cylindrical support section 2263g. Furthermore, the eccentric ring 2201 is attached to the small diameter section 2263e.

[0374] The first gear section 2263c has helical teeth with a helix angle α1. The cylindrical support section (projection) 2263g is cylindrical in shape with respect to the rotation axis L1 and is provided projecting from the first gear section 2263c in the opposite direction to the drum 2262 (downstream with respect to the J direction) along the rotation axis L1. The small diameter section 2263e is substantially cylindrical and is provided projecting from the first gear section 2263c in the direction of the drum 2262 (downstream with respect to the H direction) along the rotation axis L1. The projection section (second gear section, second unit side gear section, second rotating section) 2263d is composed of multiple projections (second projections, teeth) 2263dt extending radially with respect to the rotation axis L1 and is provided on the small diameter section 2263e in the direction of the drum 2262 (downstream with respect to the H direction). The multiple protrusions 2263dt are formed in a shape that allows them to engage (mesh) with the second main gear portion 1781d of the drive transmission gear 1781 and transmit driving force. Specifically, the multiple protrusions 2263dt are projections that protrude radially from the rotation axis L1, and their tips are configured to be at approximately the same position as the tooth tip circle diameter of the first gear portion 2263c. Furthermore, the number of teeth of the multiple protrusions 2263dt is the same as that of the first gear portion 2263c, and they are arranged at equal intervals in the rotation direction K around the rotation axis L1. In this way, the multiple protrusions 2263dt can mesh with the second main gear portion 1781d and transmit rotational driving force, so in this respect, the multiple protrusions 2263dt can be called the second gear, and the protrusion portion 2263d can be called the second gear portion. Of course, the protrusion portion 2263d may be the gear portion shown in the second gear portion 1763d of Embodiment 17, etc.

[0375] As shown in Figure 84, the eccentric ring (intermediate member) 2201 is a cylindrical member composed of an inner diameter portion 2201a and an outer diameter portion 2201b, but the inner diameter portion 2201a and the outer diameter portion 2201b have different center positions. Furthermore, with the inner diameter portion 2201a as the center, the most protruding part of the outer diameter portion 2201b is designated as the thick-walled portion 2201c, and the closest part is designated as the thin-walled portion 2201d. In addition, the diameter of the inner diameter portion 2201a is approximately the same as the small diameter portion 2263e of the drive-side flange 2263. The radius of the eccentric ring 2201 from the rotation axis L1 is the maximum radius R2201max at the position of the thick-walled portion 2201c and the minimum radius R2201min at the thin-walled portion 2201d.

[0376] The inner diameter portion 2201a of the eccentric ring 2201 is rotatably supported by the smaller diameter portion 2263e of the drive-side flange 2263. The thick-walled portion 2201c of the eccentric ring 2201 protrudes radially beyond the first gear portion 2263c and projection portion 2263d of the drive-side flange 2263. That is, the radius R2201max is greater than the maximum radius R2263d of the projection portion 2263d and the radius of the tip circle of the first gear portion 2263c.

[0377] Furthermore, the thin-walled portion 2201d is recessed radially compared to the first gear portion 2263c and projection 2263d of the drive-side flange 2263. That is, the radius R2201min is smaller than the maximum radius R2263d of the projection 2263d and the radius of the tip circle of the first gear portion 2263c. In other words, by providing the thin-walled portion 2201d, a gap g is formed between the first gear portion 2263g and the projection 2263d with respect to the direction of the rotation axis L1. Moreover, the radius R2201min is set to a length such that the thin-walled portion 2201d does not penetrate the tip of the teeth of the drive transmission gear 1781 when the first gear portion 2263c and projection 2263d are engaged with the drive transmission gear 1781 (see Figure 86(b)).

[0378] Thus, the eccentric ring (intermediate member) 2201 has a thin-walled portion 2201d as the part that forms the gap g and a thick-walled portion 2201c as the part that fills the gap g. By rotating the eccentric ring (intermediate member) 2201 around the rotation axis L1, the thin-walled portion 2201d and the thick-walled portion 2201c are moved, making it possible to selectively form (or fill) the gap g. In this way, the eccentric ring (intermediate member) 2201 can move between the position that forms the gap g and the position that fills the gap g by rotating around the rotation axis L1.

[0379] Next, the state in which the drum unit 2269 is assembled to the cleaning unit 2260 will be explained using Figure 85. Figure 85 shows the state in which the drum unit 2269 is assembled to the cleaning unit 2260. The cleaning frame 2260a of the cleaning unit 2260 supports the drum unit 2269. The cleaning frame 2260a is composed of a frame member 2271 and a drum bearing member 73. The frame member 2271 is provided with a drum sliding po...

Claims

1. A photoreceptor unit that can be attached to and detached from the main body of an image forming apparatus, having a first main body-side bevel gear section and a second main body-side bevel gear section that rotate coaxially, A photoreceptor that can rotate around its axis of rotation, The first unit-side bevel gear portion engages with the first main body-side bevel gear portion, The second unit side bevel gear portion that meshes with the second main body side bevel gear portion, It has, The twisting direction of the teeth of the second unit's bevel gear portion is the same as the twisting direction of the teeth of the first unit's bevel gear portion. The helix angle of the teeth of the second unit's bevel gear portion is greater than the helix angle of the teeth of the first unit's bevel gear portion. A photoreceptor unit characterized in that the first unit-side bevel gear portion meshes with the first body-side bevel gear portion, and the second unit-side bevel gear portion meshes with the second body-side bevel gear portion, and the first unit-side bevel gear portion and the second unit-side bevel gear portion rotate together.

2. The photoreceptor unit according to claim 1, characterized in that, with respect to the direction of the rotation axis of the photoreceptor, the second unit-side bevel gear portion is arranged between the photoreceptor and the first unit-side bevel gear portion.

3. The photoreceptor unit according to claim 1 or 2, characterized in that a gap is formed between the first unit-side bevel gear portion and the second unit-side bevel gear portion with respect to the direction of the rotation axis of the photoreceptor.

4. The photoreceptor unit according to claim 3, characterized in that the main body of the image forming apparatus has a protrusion between the first main body side bevel gear portion and the second main body side bevel gear portion, and the protrusion is inserted into the gap when the first unit side bevel gear portion is engaged with the first main body side bevel gear portion and the second unit side bevel gear portion is engaged with the second main body side bevel gear portion.

5. The photoreceptor unit according to claim 3 or 4, characterized in that, with respect to the direction of the rotation axis of the photoreceptor, an intermediate member capable of filling the gap is provided between the first unit-side helical gear portion and the second unit-side helical gear portion.

6. The photoreceptor unit according to claim 5, characterized in that the intermediate member is movable between a position that forms the gap and a position that fills the gap by rotation.

7. The photoreceptor unit according to claim 5, characterized in that the intermediate member is movable between a position that forms the gap and a position that fills the gap by moving in a direction perpendicular to the rotation axis of the photoreceptor.

8. The photoreceptor unit according to claim 5, characterized in that the intermediate member is an elastic member and can take on a state of forming the gap and a state of filling the gap by elastic deformation.

9. With respect to the direction of the rotation axis of the photoreceptor, the tooth width Wc of the inclined gear portion on the first unit side and the gap width We are given by the following formula Wc>We≧Wc / 5 A photoreceptor unit according to any one of claims 3 to 8, characterized in that it satisfies the requirements.

10. With respect to the direction of the rotation axis of the photoreceptor, the gap width We and the tooth width Wd of the second unit side inclined gear portion are given by the following equation Wd > We The photoreceptor unit according to claim 9, characterized in that it satisfies the requirements.

11. The tooth width Wc of the first helical gear portion and the tooth width Wd of the second helical gear portion, respectively, with respect to the direction of the rotation axis of the photoreceptor, are given by the following equation Wc > Wd A photoreceptor unit according to any one of claims 1 to 10, characterized in that it is provided with at least one tooth that satisfies the following conditions.

12. The photoreceptor unit according to any one of claims 1 to 11, characterized in that the twist angle of the teeth of the first unit's side angled gear portion is 15° or more and 40° or less.

13. The photoreceptor unit according to any one of claims 1 to 11, characterized in that the twist angle of the teeth of the first unit's side angled gear portion is 20° or more and 35° or less.

14. The photoreceptor unit according to any one of claims 1 to 13, characterized in that the twist angle of the teeth of the second unit's side angled gear portion is 20° or more and 40° or less.

15. The photoreceptor unit according to claims 1 to 13, characterized in that the twist angle of the teeth of the second unit's side angled gear portion is 25° or more and 35° or less.

16. At least one of the multiple teeth of the first unit-side bevel gear portion is a tooth composed of a plurality of first protrusions arranged separately with respect to the direction of the rotation axis of the photoreceptor or the rotation direction of the first unit-side bevel gear portion. The photoreceptor unit according to any one of claims 1 to 15, characterized in that the plurality of first protrusions are arranged to be able to contact one tooth of the first main body side inclined gear portion at a plurality of locations separated in the direction of the rotation axis.

17. At least one of the multiple teeth of the second unit-side bevel gear portion is a tooth composed of multiple second protrusions arranged separately with respect to the direction of the rotation axis of the photoreceptor or the rotation direction of the second unit-side bevel gear portion. The photoreceptor unit according to any one of claims 1 to 16, characterized in that the plurality of second protrusions are arranged to be able to contact one tooth of the second main body side oblique gear portion at a plurality of locations separated in the direction of the rotation axis.

18. The photoreceptor unit according to any one of claims 1 to 17, characterized in that the number of teeth of the first unit's bevel gear portion and the number of teeth of the second unit's bevel gear portion are the same.

19. The photoreceptor unit according to any one of claims 1 to 17, characterized in that the first unit-side oblique gear portion is provided with a missing tooth portion.

20. The photoreceptor unit according to any one of claims 1 to 17, characterized in that the second unit-side oblique gear portion is provided with a missing tooth portion.

21. The photoreceptor unit according to claims 1 to 20, characterized in that the direction in which the teeth of the first unit-side bevel gear portion protrude, and / or the direction in which the teeth of the second unit-side bevel gear portion protrude, has a component parallel to the rotation axis of the photoreceptor drum.

22. The photoreceptor unit according to any one of claims 1 to 21, characterized in that it has an elastic member covering the first unit side bevel gear portion and / or the second unit side bevel gear portion.

23. The photoreceptor unit according to any one of claims 1 to 22, characterized in that, while the first unit-side bevel gear portion and the second unit-side bevel gear portion rotate in a predetermined direction due to the rotation of the first main body-side bevel gear portion and the second main body-side bevel gear portion, the teeth of the first unit-side bevel gear portion are in contact with the teeth of the first main body-side bevel gear portion located upstream in the predetermined direction, the teeth of the second unit-side bevel gear portion are in contact with the teeth of the second main body-side bevel gear portion located downstream in the predetermined direction, and the teeth of the second unit-side bevel gear portion are fixed in such a state that they cannot rotate relative to the teeth of the first unit-side bevel gear portion in the direction opposite to the predetermined direction.

24. The photoreceptor unit according to any one of claims 1 to 23, characterized in that the first unit-side bevel gear portion is capable of transmitting driving force to the second unit-side bevel gear portion.

25. The photoreceptor unit according to any one of claims 1 to 24, characterized in that the first unit-side beveled gear portion and the second unit-side beveled gear portion are rotatable coaxially.

26. The photoreceptor unit according to claim 25, characterized in that the rotation axis of the first unit's bevel gear portion and the rotation axis of the second unit's bevel gear portion are coaxial with the rotation axis of the photoreceptor.

27. The photoreceptor unit according to claim 25 or 26, characterized in that the first unit-side beveled gear portion and the second unit-side beveled gear portion are integrally molded.

28. The photoreceptor unit according to claim 27, characterized in that the first unit-side beveled gear portion and the second unit-side beveled gear portion are integrally molded from resin.

29. The photoreceptor unit according to any one of claims 25 to 28, characterized in that the tip circle diameter of the second unit-side helical gear portion is greater than 0.8 times the root circle diameter or tip circle diameter of the first unit-side helical gear portion, and less than 1.1 times the tip circle diameter of the first unit-side helical gear portion.

30. The photoreceptor unit according to any one of claims 1 to 24, characterized in that the rotation axis of the first unit's bevel gear portion and the rotation axis of the second unit's bevel gear portion are not coaxial.

31. The photoreceptor unit according to claim 30, characterized in that the rotation axis of the first unit's bevel gear portion or the rotation axis of the second unit's bevel gear portion is coaxial with the rotation axis of the photoreceptor.

32. The photoreceptor unit according to claim 30 or 31, characterized in that the rotation axis of the first unit's bevel gear portion and the rotation axis of the second unit's bevel gear portion are parallel.

33. The photoreceptor unit according to any one of claims 1 to 24, characterized in that the first unit-side beveled gear portion and / or the second unit-side beveled gear portion are provided on a belt-shaped member.

34. The photoreceptor unit according to any one of claims 1 to 23, characterized in that the first unit-side helical gear portion is connected to the second unit-side helical gear portion in a manner that can transmit driving force.

35. The photoreceptor unit according to claim 34, characterized in that the first unit-side inclined gear portion is connected to the second unit-side inclined gear portion in a manner that has play in the rotational direction.

36. The photoreceptor unit according to claim 34 or 35, characterized in that the first unit-side helical gear portion can be connected to the second unit-side helical gear portion in a connected state in which driving force can be transmitted, and a disconnected state in which driving force cannot be transmitted to the second unit-side helical gear portion.

37. The photoreceptor unit according to any one of claims 1 to 24, characterized in that the rotational driving force received by the first unit-side oblique gear portion is transmitted to the photoreceptor.

38. The photoreceptor unit according to any one of claims 1 to 24, characterized in that it has a flange attached to the end of the photoreceptor with respect to the rotation axis direction of the photoreceptor, and the first unit side helical gear portion and the second unit side helical gear portion are provided on the flange.

39. The photoreceptor unit according to any one of claims 1 to 36, characterized in that it has a drive force receiving portion that meshes with the first main body side bevel gear portion or the second main body side bevel gear portion and transmits a driving force to rotate the photoreceptor.

40. The photoreceptor unit according to any one of claims 1 to 36, characterized in that it has a drive force receiving portion that engages with a drive force applying portion provided in the main body of the image forming apparatus and receives a drive force for rotating the photoreceptor.

41. The tooth width Wc1 of the largest tooth in the first helical gear section with respect to the rotation axis direction of the photoreceptor and the tooth width Wd1 of the largest tooth in the second helical gear section with respect to the rotation axis direction of the photoreceptor are given by the following equation Wd1≦(4 / 5)・Wc1 The photoreceptor unit according to claim 11, characterized in that it satisfies the requirements.

42. The tooth width Wc1 of the largest tooth in the first helical gear section with respect to the rotation axis direction of the photoreceptor and the tooth width Wd1 of the largest tooth in the second helical gear section with respect to the rotation axis direction of the photoreceptor are given by the following equation Wd1≦(3 / 4)・Wc1 The photoreceptor unit according to claim 11, characterized in that it satisfies the requirements.

43. The tooth width Wc1 of the largest tooth in the first helical gear section with respect to the rotation axis direction of the photoreceptor and the tooth width Wd1 of the largest tooth in the second helical gear section with respect to the rotation axis direction of the photoreceptor are given by the following equation Wd1≧(1 / 10)・Wc1 A photoreceptor unit according to any one of claims 11, 41, or 42, characterized in that it satisfies the requirements.

44. The photoreceptor unit according to any one of claims 1 to 43, characterized in that the twisting direction of the teeth of the second main body side helical gear portion is the same as the twisting direction of the teeth of the first main body side helical gear portion, the twist angle of the teeth of the second main body side helical gear portion is greater than the twist angle of the teeth of the first main body side helical gear portion, and the first main body side helical gear portion and the second main body side helical gear portion rotate integrally.

45. The photoreceptor unit according to any one of claims 1 to 44 is detachable from the main body of the image forming apparatus by moving it in a direction perpendicular to the rotation axis of the first main body side helical gear portion.

46. A cartridge comprising a photosensitive unit according to any one of claims 1 to 45, and a frame that rotatably supports the photosensitive unit.

47. A photoreceptor unit that can be attached to the main body of an image forming apparatus, having a first main body-side helical gear section and a second main body-side helical gear section that rotate coaxially, wherein the twist direction of the teeth of the second main body-side helical gear section is the same as the twist direction of the teeth of the first main body-side helical gear section, and the twist angle of the teeth of the second main body-side helical gear section is greater than the twist angle of the teeth of the first main body-side helical gear section, A photoreceptor that can rotate around its axis of rotation, The gear portion on the first unit side, which serves as a helical gear portion for meshing with the helical gear portion on the first main body side, A second unit-side gear portion having multiple teeth for meshing with the second main body-side inclined gear portion, It has, A photoreceptor unit characterized in that the gear portion on the first unit side meshes with the helical gear portion on the first body side, and the gear portion on the second unit side meshes with the helical gear portion on the second body side, and the gear portion on the first unit side and the gear portion on the second unit side are rotatable.

48. The photoreceptor unit according to claim 47, characterized in that, with respect to the direction of the rotation axis of the photoreceptor, the second unit side gear portion is arranged between the photoreceptor and the first unit side gear portion.

49. The photoreceptor unit according to 47 or 48, characterized in that a gap is formed between the gear portion on the first unit side and the gear portion on the second unit side with respect to the direction of the rotation axis of the photoreceptor.

50. The photoreceptor unit according to claim 49, characterized in that the apparatus body of the image forming apparatus has a protrusion between the first body-side helical gear portion and the second body-side helical gear portion, and the protrusion is inserted into the gap when the first unit-side gear portion meshes with the first body-side helical gear portion and the second unit-side gear portion meshes with the second body-side helical gear portion.

51. The photoreceptor unit according to 49 or 50, characterized in that, with respect to the direction of the rotation axis of the photoreceptor, there is an intermediate member between the gear portion on the first unit side and the gear portion on the second unit side that can fill the gap.

52. The photoreceptor unit according to claim 51, characterized in that the intermediate member is movable between a position that forms the gap and a position that fills the gap by rotation.

53. The photoreceptor unit according to claim 51, characterized in that the intermediate member is movable between a position that forms the gap and a position that fills the gap by moving in a direction perpendicular to the rotation axis of the photoreceptor.

54. The photoreceptor unit according to claim 51, characterized in that the intermediate member is an elastic member and can take on a state of forming the gap and a state of filling the gap by elastic deformation.

55. With respect to the direction of the rotation axis of the photoreceptor, the tooth width Wc of the gear portion on the first unit side and the gap width We are given by the following formula Wc>We≧Wc / 5 A photoreceptor unit according to any one of claims 49 to 54, characterized in that it satisfies the requirements.

56. With respect to the direction of the rotation axis of the photoreceptor, the gap width We and the tooth width Wd of the gear portion on the second unit side are given by the following equation Wd > We The photoreceptor unit according to claim 55, characterized in that it satisfies the requirements.

57. The tooth width Wc of the first helical gear portion and the tooth width Wd of the second helical gear portion, respectively, with respect to the direction of the rotation axis of the photoreceptor, are given by the following equation Wc > Wd A photoreceptor unit according to any one of claims 47 to 56, characterized in that it is provided with at least one tooth that satisfies the condition.

58. The photoreceptor unit according to any one of claims 47 to 57, characterized in that the twist angle of the teeth of the gear portion on the first unit side is 15° or more and 40° or less.

59. The photoreceptor unit according to any one of claims 47 to 57, characterized in that the twist angle of the teeth of the gear portion on the first unit side is 20° or more and 35° or less.

60. At least one of the multiple teeth of the gear portion on the first unit side is a tooth composed of a plurality of first protrusions arranged separately with respect to the direction of the rotation axis of the photoreceptor or the rotation direction of the gear portion on the first unit side, The photoreceptor unit according to any one of claims 47 to 59, characterized in that the plurality of first protrusions are arranged to be able to contact one tooth of the first main body side inclined gear portion at a plurality of locations separated in the direction of the rotation axis.

61. At least one of the multiple teeth of the gear portion on the second unit side has a corner. The photoreceptor unit according to any one of claims 47 to 60, characterized in that the corner portion is arranged such that it contacts one tooth of the second main body side inclined gear portion at only one point with respect to the direction of the rotation axis.

62. The photoreceptor unit according to any one of claims 47 to 60, characterized in that the gear portion on the second unit side is an inclined gear portion, and the twisting direction of the teeth of the gear portion on the second unit side is the same as the twisting direction of the teeth of the gear portion on the first unit side.

63. At least one of the multiple teeth of the gear portion on the second unit side is a tooth composed of a plurality of second protrusions that are arranged separately with respect to the direction of the rotation axis of the photoreceptor or the rotation direction of the gear portion on the second unit side, The photoreceptor unit according to 62, characterized in that the plurality of second protrusions are arranged to be able to contact one tooth of the second main body side oblique gear portion at multiple locations separated in the direction of the rotation axis.

64. The photoreceptor unit according to any one of claims 47 to 63, characterized in that the number of teeth of the gear portion on the first unit side and the number of teeth of the gear portion on the second unit side are the same.

65. The photoreceptor unit according to any one of claims 47 to 63, characterized in that the gear portion on the first unit side is provided with a missing tooth portion.

66. The photoreceptor unit according to any one of claims 47 to 63, characterized in that the second unit side gear portion is provided with a missing tooth portion.

67. The photoreceptor unit according to 47 to 66, characterized in that the direction in which the teeth of the gear portion on the first unit side protrude, and / or the direction in which the teeth of the gear portion on the second unit side protrude, has a component parallel to the rotation axis of the photoreceptor drum.

68. The photoreceptor unit according to any one of claims 47 to 67, characterized in that it has an elastic member covering the gear portion on the first unit side and / or the gear portion on the second unit side.

69. The photoreceptor unit according to any one of claims 47 to 68, characterized in that, while the first unit-side gear portion and the second unit-side gear portion rotate in a predetermined direction due to the rotation of the first main body-side helical gear portion and the second main body-side helical gear portion, the teeth of the first unit-side gear portion are in contact with the teeth of the first main body-side helical gear portion located upstream in the predetermined direction, the teeth of the second unit-side gear portion are in contact with the teeth of the second main body-side helical gear portion located downstream in the predetermined direction, and the teeth of the second unit-side gear portion are fixed in such a state that they cannot rotate relative to the teeth of the first unit-side gear portion in the direction opposite to the predetermined direction.

70. The photoreceptor unit according to any one of claims 47 to 69, characterized in that the gear portion on the first unit side is capable of transmitting driving force to the gear portion on the second unit side.

71. The photoreceptor unit according to any one of claims 47 to 70, characterized in that the gear portion on the first unit side and the gear portion on the second unit side are rotatable coaxially.

72. The photoreceptor unit according to claim 71, characterized in that the rotation axis of the gear portion on the first unit side and the rotation axis of the gear portion on the second unit side are coaxial with the rotation axis of the photoreceptor.

73. The photoreceptor unit according to claim 71 or 72, characterized in that the gear portion on the first unit side and the gear portion on the second unit side are integrally molded.

74. The photoreceptor unit according to claim 73, characterized in that the gear portion on the first unit side and the gear portion on the second unit side are integrally molded from resin.

75. The photoreceptor unit according to any one of claims 71 to 74, characterized in that the tip circle diameter of the gear portion on the second unit side is greater than 0.8 times the root circle diameter or tip circle diameter of the gear portion on the first unit side, and less than 1.1 times the tip circle diameter of the gear portion on the first unit side.

76. The photoreceptor unit according to any one of claims 47 to 70, characterized in that the rotation axis of the gear portion on the first unit side and the rotation axis of the gear portion on the second unit side are not coaxial.

77. The photoreceptor unit according to claim 76, characterized in that the rotation axis of the gear portion on the first unit side or the rotation axis of the gear portion on the second unit side is coaxial with the rotation axis of the photoreceptor.

78. The photoreceptor unit according to claim 76 or 77, characterized in that the rotation axis of the gear portion on the first unit side and the rotation axis of the gear portion on the second unit side are parallel.

79. The photoreceptor unit according to any one of claims 47 to 70, characterized in that the gear portion on the first unit side and / or the gear portion on the second unit side are provided on a belt-shaped member.

80. The photoreceptor unit according to any one of claims 47 to 69, characterized in that the gear portion on the first unit side is connected to the gear portion on the second unit side so as to be able to transmit driving force.

81. The photoreceptor unit according to claim 80, characterized in that the gear portion on the first unit side is connected to the gear portion on the second unit side in such a manner that there is play in the rotational direction.

82. The photoreceptor unit according to claim 80 or 81, characterized in that the gear portion on the first unit side can be connected to the gear portion on the second unit side in a connected state in which driving force can be transmitted, and disconnected state in which driving force cannot be transmitted to the gear portion on the second unit side.

83. The photoreceptor unit according to any one of claims 47 to 70, characterized in that the rotational driving force received by the gear portion on the first unit side is transmitted to the photoreceptor.

84. The photoreceptor unit according to any one of claims 47 to 70, characterized in that it has a flange attached to the end of the photoreceptor with respect to the rotation axis direction of the photoreceptor, and the first unit side gear portion and the second unit side gear portion are provided on the flange.

85. The photoreceptor unit according to any one of claims 47 to 82, characterized in that it has a drive force receiving portion that meshes with the first main body side bevel gear portion or the second main body side bevel gear portion and transmits a driving force to rotate the photoreceptor.

86. The photoreceptor unit according to any one of claims 47 to 82, characterized in that it has a drive force receiving portion that engages with a drive force applying portion provided in the main body of the image forming apparatus and transmits a drive force to rotate the photoreceptor.

87. The tooth width Wc1 of the largest tooth in the first helical gear section with respect to the rotation axis direction of the photoreceptor and the tooth width Wd1 of the largest tooth in the second helical gear section with respect to the rotation axis direction of the photoreceptor are given by the following equation Wd1≦(4 / 5)・Wc1 The photoreceptor unit according to claim 57, characterized in that it satisfies the requirements.

88. The tooth width Wc1 of the largest tooth in the first helical gear section with respect to the rotation axis direction of the photoreceptor and the tooth width Wd1 of the largest tooth in the second helical gear section with respect to the rotation axis direction of the photoreceptor are given by the following equation Wd1≦(3 / 4)・Wc1 The photoreceptor unit according to claim 57, characterized in that it satisfies the requirements.

89. The tooth width Wc1 of the largest tooth in the first helical gear section with respect to the rotation axis direction of the photoreceptor and the tooth width Wd1 of the largest tooth in the second helical gear section with respect to the rotation axis direction of the photoreceptor are given by the following equation Wd1≧(1 / 10)・Wc1 A photoreceptor unit according to any one of claims 57, 87, or 88, characterized in that it satisfies the requirements.

90. The photoreceptor unit according to any one of claims 47 to 89, characterized in that the first main body-side beveled gear portion and the second main body-side beveled gear portion rotate integrally.

91. The photoreceptor unit according to any one of claims 47 to 90 is detachable from the main body of the image forming apparatus by moving it in a direction perpendicular to the rotation axis of the first main body side inclined gear portion.

92. A cartridge comprising a photosensitive unit according to any one of claims 47 to 91, and a frame that rotatably supports the photosensitive unit.

93. A photoreceptor unit that can be attached to and detached from the main body of an image forming apparatus, having a first main body-side bevel gear section and a second main body-side bevel gear section that rotate coaxially, A photoreceptor that can rotate around its axis of rotation, The gear portion on the first unit side, which serves as a helical gear portion for meshing with the helical gear portion on the first main body side, A second unit-side gear portion having multiple teeth for meshing with the second main body-side inclined gear portion, It has, A photoreceptor unit characterized in that, while the first unit-side gear portion and the second unit-side gear portion rotate in a predetermined direction due to the rotation of the first main body-side inclined gear portion and the second main body-side inclined gear portion, the teeth of the first unit-side gear portion are in contact with the teeth of the first main body-side inclined gear portion located upstream in the predetermined direction, and the teeth of the second unit-side gear portion are in contact with the teeth of the second main body-side inclined gear portion located downstream in the predetermined direction.

94. The photoreceptor unit according to 93, characterized in that, with respect to the direction of the rotation axis of the photoreceptor, the gear portion on the second unit side is arranged between the photoreceptor and the gear portion on the first unit side.

95. The photoreceptor unit according to 93 or 94, characterized in that a gap is formed between the gear portion on the first unit side and the gear portion on the second unit side with respect to the direction of the rotation axis of the photoreceptor.

96. The photoreceptor unit according to 95, characterized in that the apparatus body of the image forming apparatus has a protrusion between the first body-side helical gear portion and the second body-side helical gear portion, and the protrusion is inserted into the gap when the first unit-side gear portion meshes with the first body-side helical gear portion and the second unit-side gear portion meshes with the second body-side helical gear portion.

97. The photoreceptor unit according to 95 or 96, characterized in that, with respect to the direction of the rotation axis of the photoreceptor, there is an intermediate member between the gear portion on the first unit side and the gear portion on the second unit side that can fill the gap.

98. The photoreceptor unit according to 97, characterized in that the intermediate member is movable between a position that forms the gap and a position that fills the gap by rotation.

99. The photoreceptor unit according to 97, characterized in that the intermediate member is movable between a position that forms the gap and a position that fills the gap by moving in a direction perpendicular to the rotation axis of the photoreceptor.

100. The photoreceptor unit according to 97, characterized in that the intermediate member is an elastic member and can take on a state of forming the gap and a state of filling the gap by elastic deformation.

101. With respect to the direction of the rotation axis of the photoreceptor, the tooth width Wc of the gear portion on the first unit side and the gap width We are given by the following formula Wc>We≧Wc / 5 A photoreceptor unit according to any one of claims 95 to 100, characterized in that it satisfies the requirements.

102. With respect to the direction of the rotation axis of the photoreceptor, the gap width We and the tooth width Wd of the gear portion on the second unit side are given by the following equation Wd > We A photoreceptor unit according to 101, characterized in that it satisfies the requirements.

103. The tooth width Wc of the first helical gear portion and the tooth width Wd of the second helical gear portion, respectively, with respect to the direction of the rotation axis of the photoreceptor, are given by the following equation Wc > Wd The photoreceptor unit according to any one of claims 93 to 102, characterized in that it is provided with at least one tooth that satisfies the condition.

104. The photoreceptor unit according to any one of claims 93 to 103, characterized in that the twist angle of the teeth of the gear portion on the first unit side is 15° or more and 40° or less.

105. The photoreceptor unit according to any one of claims 93 to 103, characterized in that the twist angle of the teeth of the gear portion on the first unit side is 20° or more and 35° or less.

106. At least one of the multiple teeth of the gear portion on the first unit side is a tooth composed of a plurality of first protrusions arranged separately with respect to the direction of the rotation axis of the photoreceptor or the rotation direction of the gear portion on the first unit side, The photoreceptor unit according to any one of claims 93 to 105, characterized in that the plurality of first protrusions are arranged to be able to contact one tooth of the first main body side inclined gear portion at a plurality of locations separated in the direction of the rotation axis.

107. At least one of the multiple teeth of the gear portion on the second unit side has a corner. The photoreceptor unit according to any one of claims 93 to 106, characterized in that the corner portion is arranged such that it contacts one tooth of the second main body side inclined gear portion at only one point with respect to the direction of the rotation axis.

108. The photoreceptor unit according to any one of claims 93 to 106, characterized in that the gear portion on the second unit side is an inclined gear portion, and the twisting direction of the teeth of the gear portion on the second unit side is the same as the twisting direction of the teeth of the gear portion on the first unit side.

109. At least one of the multiple teeth of the gear portion on the second unit side is a tooth composed of a plurality of second protrusions that are arranged separately with respect to the direction of the rotation axis of the photoreceptor or the rotation direction of the gear portion on the second unit side, The photoreceptor unit according to claim 108, characterized in that the plurality of second protrusions are arranged to be able to contact one tooth of the second main body side oblique gear portion at multiple locations separated in the direction of the rotation axis.

110. The photoreceptor unit according to any one of claims 93 to 109, characterized in that the number of teeth of the gear portion on the first unit side and the number of teeth of the gear portion on the second unit side are the same.

111. The photoreceptor unit according to any one of claims 93 to 109, characterized in that the gear portion on the first unit side is provided with a missing tooth portion.

112. The photoreceptor unit according to any one of claims 93 to 109, characterized in that the second unit side gear portion is provided with a missing tooth portion.

113. The photoreceptor unit according to claims 93 to 112, characterized in that the direction in which the teeth of the gear portion on the first unit side protrude, and / or the direction in which the teeth of the gear portion on the second unit side protrude, has a component parallel to the rotation axis of the photoreceptor drum.

114. The photoreceptor unit according to any one of claims 93 to 113, characterized in that it has an elastic member covering the gear portion on the first unit side and / or the gear portion on the second unit side.

115. The photoreceptor unit according to any one of claims 93 to 114, characterized in that, while the first unit-side gear portion and the second unit-side gear portion are rotating in a predetermined direction due to the rotation of the first main body-side helical gear portion and the second main body-side helical gear portion, the teeth of the second unit-side gear portion are fixed in such a state that they cannot rotate relative to the teeth of the first unit-side gear portion in the direction opposite to the predetermined direction.

116. The photoreceptor unit according to any one of claims 93 to 115, characterized in that the gear portion on the first unit side is capable of transmitting driving force to the gear portion on the second unit side.

117. The photoreceptor unit according to any one of claims 93 to 116, characterized in that the gear portion on the first unit side and the gear portion on the second unit side are rotatable coaxially.

118. The photoreceptor unit according to claim 117, characterized in that the rotation axis of the gear portion on the first unit side and the rotation axis of the gear portion on the second unit side are coaxial with the rotation axis of the photoreceptor.

119. The photoreceptor unit according to claim 117 or 118, characterized in that the gear portion on the first unit side and the gear portion on the second unit side are integrally molded.

120. The photoreceptor unit according to claim 119, characterized in that the gear portion on the first unit side and the gear portion on the second unit side are integrally molded from resin.

121. The photoreceptor unit according to any one of claims 117 to 120, characterized in that the tip circle diameter of the gear portion on the second unit side is greater than 0.8 times the root circle diameter or tip circle diameter of the gear portion on the first unit side, and less than 1.1 times the tip circle diameter of the gear portion on the first unit side.

122. The photoreceptor unit according to any one of claims 93 to 116, characterized in that the rotation axis of the gear portion on the first unit side and the rotation axis of the gear portion on the second unit side are not coaxial.

123. The photoreceptor unit according to claim 122, characterized in that the rotation axis of the gear portion on the first unit side or the rotation axis of the gear portion on the second unit side is coaxial with the rotation axis of the photoreceptor.

124. The photoreceptor unit according to claim 122 or 123, characterized in that the rotation axis of the gear portion on the first unit side and the rotation axis of the gear portion on the second unit side are parallel.

125. The photoreceptor unit according to any one of claims 93 to 116, characterized in that the gear portion on the first unit side and / or the gear portion on the second unit side are provided on a belt-shaped member.

126. The photoreceptor unit according to any one of claims 93 to 115, characterized in that the gear portion on the first unit side is connected to the gear portion on the second unit side so as to be able to transmit driving force.

127. The photoreceptor unit according to claim 126, characterized in that the gear portion on the first unit side is connected to the gear portion on the second unit side in such a manner that there is play in the rotational direction.

128. The photoreceptor unit according to claim 126 or 127, characterized in that the gear portion on the first unit side can be connected to the gear portion on the second unit side in a connected state in which driving force can be transmitted, and a disconnected state in which driving force cannot be transmitted to the gear portion on the second unit side.

129. The photoreceptor unit according to any one of claims 93 to 116, characterized in that the rotational driving force received by the gear portion on the first unit side is transmitted to the photoreceptor.

130. A photoreceptor unit according to any one of claims 93 to 116, characterized in that it has a flange attached to the end of the photoreceptor with respect to the rotation axis direction of the photoreceptor, and the first unit side gear portion and the second unit side gear portion are provided on the flange.

131. The photoreceptor unit according to any one of claims 93 to 128, characterized in that it has a drive force receiving portion that meshes with the first main body side bevel gear portion or the second main body side bevel gear portion and transmits a driving force to rotate the photoreceptor.

132. The photoreceptor unit according to any one of claims 93 to 128, characterized in that it has a drive force receiving portion that engages with a drive force applying portion provided in the main body of the image forming apparatus and transmits a drive force to rotate the photoreceptor.

133. The tooth width Wc1 of the largest tooth in the first helical gear section with respect to the rotation axis direction of the photoreceptor and the tooth width Wd1 of the largest tooth in the second helical gear section with respect to the rotation axis direction of the photoreceptor are given by the following equation Wd1≦(4 / 5)・Wc1 The photoreceptor unit according to 103, characterized in that it satisfies the requirements.

134. The tooth width Wc1 of the largest tooth in the first helical gear section with respect to the rotation axis direction of the photoreceptor and the tooth width Wd1 of the largest tooth in the second helical gear section with respect to the rotation axis direction of the photoreceptor are given by the following equation Wd1≦(3 / 4)・Wc1 The photoreceptor unit according to 103, characterized in that it satisfies the requirements.

135. The tooth width Wc1 of the largest tooth in the first helical gear section with respect to the rotation axis direction of the photoreceptor and the tooth width Wd1 of the largest tooth in the second helical gear section with respect to the rotation axis direction of the photoreceptor are given by the following equation Wd1≧(1 / 10)・Wc1 A photoreceptor unit according to any one of claims 103, 133, or 134, characterized in that it satisfies the requirements.

136. The photoreceptor unit according to any one of claims 93 to 135, characterized in that the first main body-side beveled gear portion and the second main body-side beveled gear portion rotate integrally.

137. The photoreceptor unit according to any one of claims 93 to 136 is detachable from the main body of the image forming apparatus by moving it in a direction perpendicular to the rotation axis of the first main body side helical gear portion.

138. A cartridge comprising a photosensitive unit according to any one of claims 93 to 137, and a frame that rotatably supports the photosensitive unit.

139. A photoreceptor unit that can be attached to and detached from the main body of an image forming apparatus, A photoreceptor that can rotate around its axis of rotation, A rotatable first inclined gear section, A second helical gear portion that can rotate integrally with the first helical gear portion, It has, A photoreceptor unit characterized in that the twisting direction of the teeth of the second helical gear portion is the same as the twisting direction of the teeth of the first helical gear portion, and the twist angle of the teeth of the second helical gear portion is greater than the twist angle of the teeth of the first helical gear portion.

140. The photoreceptor unit according to claim 139, characterized in that the second helical gear portion is arranged between the photoreceptor and the first helical gear portion with respect to the direction of the rotation axis of the photoreceptor.

141. The photoreceptor unit according to claim 139 or 140, characterized in that a gap is formed between the first helical gear portion and the second helical gear portion with respect to the direction of the rotation axis of the photoreceptor.

142. The photoreceptor unit according to claim 141, characterized in that, with respect to the direction of the rotation axis of the photoreceptor, an intermediate member capable of filling the gap is provided between the first helical gear portion and the second helical gear portion.

143. The photoreceptor unit according to claim 142, characterized in that the intermediate member is movable between a position that forms the gap and a position that fills the gap by rotation.

144. The photoreceptor unit according to claim 142, characterized in that the intermediate member is movable between a position that forms the gap and a position that fills the gap by moving in a direction perpendicular to the rotation axis of the photoreceptor.

145. The photoreceptor unit according to 142, characterized in that the intermediate member is an elastic member and can take on a state of forming the gap and a state of filling the gap by elastic deformation.

146. With respect to the direction of the rotation axis of the photoreceptor, the tooth width Wc of the first helical gear portion and the gap width We are given by the following formula Wc>We≧Wc / 5 A photoreceptor unit according to any one of claims 141 to 145, characterized in that it satisfies the requirements.

147. With respect to the direction of the rotation axis of the photoreceptor, the gap width We and the tooth width Wd of the second helical gear portion are given by the following equation Wd > We A photoreceptor unit according to claim 146, characterized in that it satisfies the requirements.

148. The tooth width Wc of the first helical gear portion and the tooth width Wd of the second helical gear portion, respectively, with respect to the direction of the rotation axis of the photoreceptor, are given by the following equation Wc > Wd A photoreceptor unit according to any one of claims 139 to 147, characterized in that it is provided with at least one tooth that satisfies the condition.

149. The tooth width Wc1 of the largest tooth in the first helical gear section with respect to the rotation axis direction of the photoreceptor and the tooth width Wd1 of the largest tooth in the second helical gear section with respect to the rotation axis direction of the photoreceptor are given by the following equation Wd1≦(4 / 5)・Wc1 A photoreceptor unit according to claim 148, characterized in that it satisfies the requirements.

150. The tooth width Wc1 of the largest tooth in the first helical gear section with respect to the rotation axis direction of the photoreceptor and the tooth width Wd1 of the largest tooth in the second helical gear section with respect to the rotation axis direction of the photoreceptor are given by the following equation Wd1≦(3 / 4)・Wc1 A photoreceptor unit according to claim 148, characterized in that it satisfies the requirements.

151. The tooth width Wc1 of the largest tooth in the first helical gear section with respect to the rotation axis direction of the photoreceptor and the tooth width Wd1 of the largest tooth in the second helical gear section with respect to the rotation axis direction of the photoreceptor are given by the following equation Wd1≧(1 / 10)・Wc1 A photoreceptor unit according to any one of claims 148 to 150, characterized in that it satisfies the requirements.

152. The photoreceptor unit according to any one of claims 139 to 148, characterized in that the helix angle of the teeth of the first helical gear portion is 15° or more and 40° or less.

153. The photoreceptor unit according to claim 152, characterized in that the helix angle of the teeth of the first helical gear portion is 20° or more and 35° or less.

154. The photoreceptor unit according to any one of claims 139 to 150, characterized in that the helix angle of the teeth of the second helical gear portion is 20° or more and 40° or less.

155. The photoreceptor unit according to any one of claims 139 to 150, characterized in that the helix angle of the teeth of the second helical gear portion is 25° or more and 35° or less.

156. The photoreceptor unit according to any one of claims 139 to 153, characterized in that at least one of the plurality of teeth of the first helical gear portion is a tooth composed of a plurality of first protrusions arranged separately with respect to the direction of the rotation axis of the photoreceptor or the rotation direction of the first helical gear portion.

157. The photoreceptor unit according to any one of claims 139 to 156, characterized in that at least one of the multiple teeth of the second helical gear portion is a tooth composed of a plurality of second protrusions arranged separately with respect to the direction of the rotation axis of the photoreceptor or the rotation direction of the second helical gear portion.

158. The photoreceptor unit according to any one of claims 139 to 157, characterized in that the number of teeth of the first helical gear portion and the number of teeth of the second helical gear portion are the same.

159. The photoreceptor unit according to any one of claims 139 to 157, characterized in that the first inclined gear portion is provided with a missing tooth portion.

160. The photoreceptor unit according to any one of claims 139 to 157, characterized in that the second inclined gear portion is provided with a missing tooth portion.

161. The photoreceptor unit according to claims 139 to 160, characterized in that the direction in which the teeth of the first helical gear portion and / or the direction in which the teeth of the second helical gear portion protrude has a component parallel to the rotation axis of the photoreceptor drum.

162. The photoreceptor unit according to any one of claims 139 to 161, characterized in that it has an elastic member covering the first helical gear portion and / or the second helical gear portion.

163. The photoreceptor unit according to any one of claims 139 to 162, characterized in that, while the first helical gear portion and the second helical gear portion are rotating in a predetermined direction, the teeth of the second helical gear portion can be fixed in such a state that they cannot rotate relative to the teeth of the first helical gear portion in the direction opposite to the predetermined direction.

164. The photoreceptor unit according to any one of claims 139 to 161, characterized in that the first helical gear portion is capable of transmitting driving force to the second helical gear portion.

165. The photoreceptor unit according to any one of claims 139 to 164, characterized in that the first helical gear portion and the second helical gear portion are rotatable coaxially.

166. The photoreceptor unit according to claim 165, characterized in that the rotation axis of the first helical gear portion and the rotation axis of the second helical gear portion are coaxial with the rotation axis of the photoreceptor.

167. The photoreceptor unit according to claim 165 or 166, characterized in that the first helical gear portion and the second helical gear portion are integrally molded.

168. The photoreceptor unit according to claim 167, characterized in that the first helical gear portion and the second helical gear portion are integrally molded from resin.

169. The photoreceptor unit according to any one of claims 165 to 168, characterized in that the tip circle diameter of the second helical gear portion is greater than 0.8 times the root circle diameter or tip circle diameter of the first helical gear portion, and less than 1.1 times the tip circle diameter of the first helical gear portion.

170. The photoreceptor unit according to claim 169, characterized in that the tip circle diameter of the second helical gear portion is greater than 0.9 times the tip circle diameter.

171. The photoreceptor unit according to any one of claims 139 to 164, characterized in that the rotation axis of the first helical gear portion and the rotation axis of the second helical gear portion are not coaxial.

172. The photoreceptor unit according to claim 171, characterized in that the rotation axis of the first helical gear portion or the rotation axis of the second helical gear portion is coaxial with the rotation axis of the photoreceptor.

173. The photoreceptor unit according to claim 171 or 172, characterized in that the rotation axis of the first helical gear portion and the rotation axis of the second helical gear portion are parallel.

174. The photoreceptor unit according to any one of claims 139 to 164, characterized in that the first helical gear portion and / or the second helical gear portion are provided on a belt-shaped member.

175. The photoreceptor unit according to any one of claims 139 to 163, characterized in that the first helical gear portion is connected to the second helical gear portion in a manner that can transmit driving force.

176. The photoreceptor unit according to claim 175, characterized in that the first helical gear portion is connected to the second helical gear portion in a manner that has play in the rotational direction.

177. The photoreceptor unit according to claim 175 or 176, characterized in that the first helical gear portion can be connected to the second helical gear portion in a connected state in which driving force can be transmitted, and a disconnected state in which driving force cannot be transmitted to the second helical gear portion.

178. The photoreceptor unit according to any one of claims 139 to 164, characterized in that the first helical gear portion is connected to the photoreceptor in a manner that rotational driving force can be transmitted.

179. The photoreceptor unit according to any one of claims 139 to 164, characterized in that it has a flange attached to the end of the photoreceptor with respect to the rotation axis direction of the photoreceptor, and the first helical gear portion and the second helical gear portion are provided on the flange.

180. The photoreceptor unit according to any one of claims 139 to 177, characterized in that it has a third gear portion connected to the photoreceptor in a manner that can transmit driving force.

181. A cartridge that can be attached to and detached from the main body of an image forming apparatus, A rotating body that can rotate around its axis of rotation, A frame that rotatably supports the aforementioned rotating body, The first gear section, which is the helical gear section, A second gear section having multiple teeth, It has, With respect to the direction of the rotation axis of the rotating body, the second gear portion is positioned between the first gear portion and the rotating body. With respect to the direction of the rotation axis of the rotating body, a gap is provided between the first gear portion and the second gear portion. The tooth width Wc of the first gear portion and the tooth width Wd of the second gear portion, respectively, with respect to the direction of the rotation axis of the rotating body, are given by the following equation Wc > Wd A cartridge characterized by having at least one tooth on each side that satisfies the following conditions.

182. A cartridge that can be attached to and detached from the main body of an image forming apparatus, A rotating body that can rotate around its axis of rotation, A frame that rotatably supports the aforementioned rotating body, The first gear section, which is the helical gear section, A second gear section having multiple teeth, It has, With respect to the direction of the rotation axis of the rotating body, the second gear portion is positioned between the first gear portion and the rotating body. With respect to the direction of the rotation axis of the rotating body, a gap is provided between the first gear portion and the second gear portion. With respect to the direction of the rotation axis of the rotating body, the tooth width Wc of the first gear portion and the gap width We are given by the following equation Wc>We≧Wc / 5 A photoreceptor unit characterized by satisfying the following conditions.

183. A cartridge that can be attached to and detached from the main body of an image forming apparatus, A photoreceptor that can rotate around its axis of rotation, A frame that rotatably supports the aforementioned photoreceptor, The first gear section, which is the helical gear section, A second gear section having multiple teeth, The memory board supported by the frame and The electrode portion electrically connected to the memory board, It has, With respect to the direction of the rotation axis of the photoreceptor, the second gear portion is positioned between the first gear portion and the photoreceptor, and a gap is provided between the first gear portion and the second gear portion. A cartridge characterized in that, with respect to the direction of the rotation axis of the photoreceptor, the first gear portion and the second gear portion are arranged at the first end of the frame, and the electrode portion is arranged at the second end of the frame opposite to the first end.

184. A cartridge that can be attached to and detached from the main body of an image forming apparatus, A photoreceptor unit comprising a photoreceptor rotatable around a rotation axis, a first gear section having multiple teeth, and a second gear section having multiple teeth, A frame comprising a first end of the frame and a second end of the frame opposite to the first end of the frame, with respect to the direction of the rotation axis of the photoreceptor, A developing roller that carries a developer to be attached to the photosensitive material, A memory substrate having an electrode portion It has, With respect to the direction of the rotation axis of the photoreceptor, the first gear portion is positioned closer to the first end of the frame than to the second end of the frame, the second gear portion is positioned between the first gear portion and the photoreceptor, and a gap is provided between the first gear portion and the second gear portion. The frame comprises a first bearing member located at the first end of the frame and a second bearing member located at the second end of the frame. The first bearing member has a projection that protrudes in the direction of the rotation axis of the photoreceptor and has a hole formed on its inner side, and the first bearing member rotatably supports the photoreceptor unit with the inner circumferential surface of the hole. The cartridge is characterized in that the second bearing member rotatably supports the photoreceptor unit and supports the memory substrate.

185. A cartridge that can be attached to and detached from the main body of an image forming apparatus, A photoreceptor unit comprising a photoreceptor rotatable around a rotation axis, a first gear section having multiple teeth, and a second gear section having multiple teeth, A frame comprising a first end of the frame and a second end of the frame opposite to the first end of the frame, with respect to the direction of the rotation axis of the photoreceptor, A developing roller that carries a developer to be attached to the photosensitive material, It has, With respect to the direction of the rotation axis of the photoreceptor, the first gear portion is positioned closer to the first end of the frame than to the second end of the frame, the second gear portion is positioned between the first gear portion and the photoreceptor, and a gap is provided between the first gear portion and the second gear portion. The frame comprises a first bearing member positioned at the first end of the frame, The first bearing member comprises a projection that protrudes in the direction of the rotation axis of the photoreceptor, and a support portion provided on the inner circumferential surface of a hole formed inside the projection, which rotatably supports the photoreceptor unit. The cartridge is characterized in that the projection is elongated in a direction perpendicular to the axis of rotation and parallel to the straight line connecting the center of rotation of the developing roller and the axis of rotation of the photoreceptor.

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