Process cartridge and electrophotographic image forming apparatus

Abstract

To provide a configuration for a process cartridge to receive an input of a driving force from the outside thereof.SOLUTION: The body of an electrophotographic image forming apparatus comprises a drive output part that is provided with an output gear part and an output coupling part. A process cartridge removably attached to the body of the electrophotographic photoreceptor includes a photoreceptor, an input coupling part that is provided at an end of the photoreceptor and can be coupled to the output coupling part; and an input gear part that can be engaged with the output gear part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Here, the process cartridge is a cartridge in which a photosensitive member and a process means acting on the photosensitive member are integrated, and which is removably mounted in the main body of an electrophotographic image forming apparatus.

[0003] For example, a cartridge may be used in which a photosensitive member and at least one of a developing means, a charging means, and a cleaning means as the process means are integrated together. An electrophotographic image forming apparatus is an apparatus that forms an image on a recording medium using an electrophotographic image forming method.

[0004] Examples of electrophotographic image forming apparatuses include electrophotographic copying machines, electrophotographic printers (LED printers, laser beam printers, etc.), facsimile machines, and word processors. [Background technology]

[0005] In an electrophotographic image forming apparatus (hereinafter simply referred to as an "image forming apparatus"), an electrophotographic photosensitive member, generally drum-shaped, serving as an image carrier, i.e., a photosensitive drum (electrophotographic photosensitive drum), is uniformly charged. Next, an electrostatic latent image (electrostatic image) is formed on the photosensitive drum by selectively exposing the charged photosensitive drum to light. Next, the electrostatic latent image formed on the photosensitive drum is developed into a toner image using toner as a developer. The toner image formed on the photosensitive drum is then transferred to a recording material such as recording paper or a plastic sheet, and the toner image transferred to the recording material is fixed to the recording material by applying heat and pressure, thereby recording an image.

[0006] Such image forming apparatuses generally require toner replenishment and maintenance of various process means. To facilitate this toner replenishment and maintenance, a process cartridge has been put into practical use, in which the photosensitive drum, charging means, developing means, cleaning means, etc. are all housed within a frame and integrated into a cartridge that can be detachably attached to the image forming apparatus main body.

[0007] This process cartridge system allows users to perform some of the maintenance of the device themselves, without relying on service personnel in charge of after-sales service. This significantly improves the operability of the device, making it possible to provide an image forming device with excellent usability. For this reason, this process cartridge system is widely used in image forming devices.

[0008] Furthermore, as described in Patent Document 1, the image forming device generally known as described above has a coupling at its tip that transmits drive from the image forming device main body to the process cartridge, and a drive transmission member that is biased toward the process cartridge by a spring.

[0009] When the door of the image forming apparatus main body is closed, the drive transmission member of this image forming apparatus is pressed by a spring and moves toward the process cartridge. This causes the drive transmission member to engage (couple) with the coupling of the process cartridge, enabling drive transmission to the process cartridge. Furthermore, when the door of the image forming apparatus main body is opened, a cam causes the drive transmission member to move in a direction away from the process cartridge against the spring. This causes the drive transmission member to disengage (coupling) from the coupling of the process cartridge, enabling the process cartridge to be removed from the image forming apparatus main body. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP-A-8-328449 (see page 20, FIG. 16) Summary of the Invention [Problem to be solved by the invention]

[0011] The object of the present invention is to further develop the above-mentioned prior art. [Means for solving the problem]

[0012] A typical configuration according to the present application is: In a process cartridge detachably mountable to a main body of an electrophotographic image forming apparatus, A photoreceptor; a coupling portion provided at an end of the photosensitive member, the coupling portion having a driving force receiving portion for receiving a driving force for rotating the photosensitive member from the outside of the process cartridge; a gear portion having gear teeth for receiving a driving force from the outside of the process cartridge independently of the coupling portion; and the gear teeth have an exposed portion that is exposed to the outside of the process cartridge, At least a portion of the exposed portion (a) faces the axis of the photosensitive body, and (b) is located further outward than the driving force receiving portion in the axial direction of the photosensitive body, and (c) is located near the peripheral surface of the photosensitive body in a plane perpendicular to the axis of the photosensitive body.

[0013] Another configuration according to the present application is A process cartridge detachably mountable to a main body of an electrophotographic image forming apparatus, the process cartridge having a drive output member in which an output gear portion and an output coupling portion are coaxially provided, A photoreceptor; an input coupling unit provided at an end of the photosensitive member and capable of coupling with the output coupling unit; an input gear portion that can mesh with the output gear portion; and The input gear portion is configured to rotate in a state of meshing with the output gear portion, so that the input gear portion and the output gear portion pull against each other.

[0014] Another configuration is In a process cartridge detachably mountable to a main body of an electrophotographic image forming apparatus, A photoreceptor; a coupling portion provided at an end of the photosensitive member, the coupling portion having a driving force receiving portion for receiving a driving force for rotating the photosensitive member from the outside of the process cartridge; a gear portion having gear teeth for receiving a driving force from the outside of the process cartridge independently of the coupling portion; and the gear teeth are helical teeth and have an exposed portion exposed to the outside of the process cartridge, At least a part of the exposed portion is located further outward than the driving force receiving portion in the axial direction of the photosensitive member and faces the axis of the photosensitive member.

[0015] Another configuration is In a process cartridge detachably mountable to a main body of an electrophotographic image forming apparatus, A photoreceptor; a coupling portion provided at an end of the photosensitive member, the coupling portion having a driving force receiving portion configured to receive a driving force for rotating the photosensitive member from the outside of the process cartridge; a gear portion having gear teeth configured to receive a driving force from the outside of the process cartridge independently of the coupling portion; a developer carrier configured to carry a developer to develop a latent image formed on the photosensitive member, the developer carrier configured to rotate clockwise when viewed so that the rotation direction of the gear portion is clockwise; and the gear teeth have an exposed portion that is exposed to the outside of the process cartridge, At least a part of the exposed portion faces the axis of the photosensitive member and is located further outward than the driving force receiving portion in the axial direction of the photosensitive member.

[0016] Another configuration is In a process cartridge detachably mountable to a main body of an electrophotographic image forming apparatus, A photoreceptor; a centering unit arranged coaxially with the photosensitive member; a gear portion having gear teeth for receiving a driving force from the outside of the process cartridge, the gear teeth have an exposed portion that is exposed to the outside of the process cartridge, At least a portion of the exposed portion (a) faces the axis of the photosensitive body, and (b) is located further outward than the alignment portion in the axial direction of the photosensitive body, and (c) is located near the peripheral surface of the photosensitive body in a plane perpendicular to the axis of the photosensitive body.

[0017] Another configuration is A process cartridge detachably mountable to a main body of an electrophotographic image forming apparatus, the process cartridge having a drive output member in which an output gear portion and a main body side centering portion are coaxially provided, A photoreceptor; a cartridge-side centering section configured to engage with the main body-side centering section to perform centering between the photosensitive member and the drive output member; an input gear portion that can mesh with the output gear portion; and The input gear portion is configured to rotate in a state of meshing with the output gear portion, so that the input gear portion and the output gear portion pull against each other.

[0018] Another configuration is In a process cartridge detachably mountable to a main body of an electrophotographic image forming apparatus, A photoreceptor; a centering unit arranged coaxially with the photosensitive member; a gear portion having gear teeth for receiving a driving force from the outside of the process cartridge, the gear teeth are helical teeth and have an exposed portion exposed to the outside of the process cartridge, At least a part of the exposed portion is located further outward than the centering portion in the axial direction of the photosensitive member and faces the axis of the photosensitive member.

[0019] Another configuration is In a process cartridge detachably mountable to a main body of an electrophotographic image forming apparatus, A photoreceptor; a centering unit arranged coaxially with the photosensitive member; a gear portion having gear teeth configured to receive a driving force from the outside of the process cartridge; a developer carrier configured to carry a developer to develop a latent image formed on the photosensitive member, the developer carrier configured to rotate clockwise when viewed so that the rotation direction of the gear portion is clockwise; and the gear teeth have an exposed portion that is exposed to the outside of the process cartridge, At least a part of the exposed portion faces the axis of the photosensitive member and is located further outward than the centering portion in the axial direction of the photosensitive member. [Effects of the Invention]

[0020] The above-mentioned prior art can be further developed. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 3 is an explanatory diagram of a drive transmission portion of the process cartridge according to the first embodiment. [Figure 2] 1 is a cross-sectional view of an image forming apparatus main body and a process cartridge of an electrophotographic image forming apparatus according to a first embodiment. [Figure 3] FIG. 2 is a cross-sectional view of the process cartridge according to the first embodiment. [Figure 4] 1 is a perspective view of a main body of an electrophotographic image forming apparatus according to a first embodiment with an opening / closing door open. [Figure 5] 1 is a perspective view of a process cartridge and a drive-side positioning portion of the main assembly of the electrophotographic image forming apparatus according to a first embodiment, in a state in which the process cartridge is mounted in the main assembly of the image forming apparatus. FIG. [Figure 6] FIG. 2 is an explanatory diagram of a link portion of the electrophotographic image forming apparatus according to the first embodiment. [Figure 7] FIG. 2 is an explanatory diagram of a link portion of the electrophotographic image forming apparatus according to the first embodiment. [Figure 8] 2 is a cross-sectional view of a guide portion of the electrophotographic image forming apparatus according to the first embodiment. FIG. [Figure 9] FIG. 2 is an explanatory diagram of a drive train section of the electrophotographic image forming apparatus according to the first embodiment. [Figure 10] FIG. 2 is an explanatory view of a longitudinal positioning portion of the electrophotographic image forming apparatus according to the first embodiment. [Figure 11] 2 is a cross-sectional view of a positioning portion of the electrophotographic image forming apparatus according to the first embodiment. FIG. [Figure 12] 2 is a cross-sectional view of a drive transmission portion of the electrophotographic image forming apparatus according to the first embodiment. FIG. [Figure 13] 1 is a perspective view of a drive transmission section of an electrophotographic image forming apparatus according to a first embodiment. [Figure 14] FIG. 2 is a perspective view of a developing roller gear of the electrophotographic image forming apparatus according to the first embodiment. [Figure 15] 1 is a perspective view of a drive transmission section of an electrophotographic image forming apparatus according to a first embodiment. [Figure 16] 2 is a cross-sectional view of a drive transmission portion of the electrophotographic image forming apparatus according to the first embodiment. FIG. [Figure 17] 1 is a cross-sectional view of the drum and its surroundings in an electrophotographic image forming apparatus according to a first embodiment. [Figure 18] 2 is a cross-sectional view of a drive transmission portion of the electrophotographic image forming apparatus according to the first embodiment. FIG. [Figure 19] FIG. 2 is a perspective view of a drive transmission portion of the process cartridge according to the first embodiment. [Figure 20] 2 is a cross-sectional view of a drive transmission portion of the electrophotographic image forming apparatus according to the first embodiment. FIG. [Figure 21] FIG. 2 is a perspective view of a developing roller gear of the process cartridge according to the first embodiment. [Figure 22] FIG. 2 is an explanatory diagram of a drive train of the process cartridge according to the first embodiment. [Figure 23] FIG. 2 is an explanatory diagram of a drive transmission section of the electrophotographic image forming apparatus according to the first embodiment. [Figure 24] FIG. 2 is an explanatory diagram of a regulating portion of the electrophotographic image forming apparatus according to the first embodiment. [Figure 25] FIG. 2 is a cross-sectional view of a drive transmission portion of the process cartridge according to the first embodiment. [Figure 26] FIG. 2 is a perspective view of a regulating portion of the process cartridge according to the first embodiment. [Figure 27] FIG. 2 is an explanatory diagram of a regulating portion of the electrophotographic image forming apparatus according to the first embodiment. [Figure 28] FIG. 2 is an explanatory diagram of a drive transmission section of the electrophotographic image forming apparatus according to the first embodiment. [Figure 29] FIG. 10 is a perspective view of a regulating portion of an electrophotographic image forming apparatus according to a second embodiment. [Figure 30] FIG. 10 is an explanatory diagram of a regulating portion of an electrophotographic image forming apparatus according to a second embodiment. [Figure 31] FIG. 10 is an explanatory diagram of a regulating portion of an electrophotographic image forming apparatus according to a second embodiment. [Figure 32] FIG. 10 is an explanatory diagram of a regulating portion of an electrophotographic image forming apparatus according to a second embodiment. [Figure 33] FIG. 2 is an explanatory diagram of a process cartridge according to a first embodiment. [Figure 34] FIG. 2 is an explanatory diagram of a process cartridge according to a first embodiment. [Figure 35] FIG. 10 is an explanatory diagram showing a modified example of the first embodiment. [Figure 36] FIG. 10 is an explanatory diagram showing a modified example of the first embodiment. [Figure 37] FIG. 2 is a perspective view showing a gear portion and a coupling portion in the first embodiment. [Figure 38] FIG. 10 is a perspective view showing a modified example of the first embodiment. [Figure 39] FIG. 10 is an explanatory diagram according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] Example 1 Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The direction of the rotation axis of the electrophotographic photosensitive drum is defined as the longitudinal direction. In addition, in the longitudinal direction, the side where the electrophotographic photosensitive drum receives a driving force from the image forming apparatus main body is referred to as a driving side, and the opposite side is referred to as a non-driving side.

[0023] The overall configuration and image forming process will be described with reference to FIGS. FIG. 2 is a cross-sectional view of an apparatus main body (electrophotographic image forming apparatus main body, image forming apparatus main body) A of an electrophotographic image forming apparatus according to one embodiment of the present invention and a process cartridge (hereinafter referred to as cartridge B).

[0024] FIG. 3 is a cross-sectional view of the cartridge B. Here, the apparatus main body A is the portion of the electrophotographic image forming apparatus excluding the cartridge B.

[0025] <Overall configuration of electrophotographic image forming apparatus> The electrophotographic image forming apparatus (image forming apparatus) shown in Figure 2 is a laser beam printer that uses electrophotographic technology and in which a cartridge B is detachably mounted in an apparatus main body A. When the cartridge B is mounted in the apparatus main body A, an exposure device 3 (laser scanner unit) is disposed for forming a latent image on an electrophotographic photosensitive drum 62 serving as an image carrier of the cartridge B. Also disposed below the cartridge B is a sheet tray 4 that stores a recording medium (hereinafter referred to as sheet material PA) on which an image is to be formed. The electrophotographic photosensitive drum 62 is a photosensitive member (electrophotographic photosensitive member) used for forming an electrophotographic image.

[0026] Furthermore, in the apparatus main body A, a pickup roller 5a, a pair of feeding rollers 5b, a pair of conveying rollers 5c, a transfer guide 6, a transfer roller 7, a conveying guide 8, a fixing device 9, a pair of discharge rollers 10, and a discharge tray 11 are arranged in this order along the conveying direction D of the sheet material PA. The fixing device 9 is composed of a heating roller 9a and a pressure roller 9b.

[0027] <Image formation process> Next, an outline of the image forming process will be described. Based on a print start signal, the electrophotographic photosensitive drum (hereinafter referred to as the photosensitive drum 62 or simply as the drum 62) is rotated in the direction of arrow R at a predetermined peripheral speed (process speed).

[0028] A charging roller (charging member) 66 to which a bias voltage is applied comes into contact with the outer peripheral surface of the drum 62 and charges the outer peripheral surface of the drum 62 uniformly.

[0029] The exposure device 3 outputs laser light L corresponding to the image information. The laser light L passes through a laser opening 71h provided in the cleaning frame 71 of the cartridge B and scans and exposes the outer peripheral surface of the drum 62. As a result, an electrostatic latent image corresponding to the image information is formed on the outer peripheral surface of the drum 62.

[0030] On the other hand, as shown in FIG. 3, in the developing unit 20 as a developing device, the toner T in the toner chamber 29 is stirred and transported by the rotation of the transport member (stirring member) 43, and is sent out to the toner supply chamber .

[0031] The toner T is carried on the surface of the developing roller 32 by the magnetic force of the magnet roller 34 (fixed magnet). The developing roller 32 is a developer carrier that carries the developer (toner T) on its surface in order to develop the latent image formed on the drum 62.

[0032] The toner T is frictionally charged by the developing blade 42, and the thickness of the layer on the circumferential surface of the developing roller 32 as a developer carrier is regulated.

[0033] The toner T is supplied to the drum 62 in accordance with the electrostatic latent image, and develops the latent image. This makes the latent image visible as a toner image. The drum 62 is an image carrier that carries on its surface the latent image and an image formed with toner (toner image, developer image). As shown in FIG. 2, a sheet material PA stored in the lower part of the apparatus main body A is fed from the sheet tray 4 by a pickup roller 5a, a pair of feeding rollers 5b, and a pair of conveying rollers 5c in synchronization with the output timing of the laser light L. The sheet material PA is then conveyed via a transfer guide 6 to a transfer position between the drum 62 and a transfer roller 7. At this transfer position, the toner image is sequentially transferred from the drum 62 to the sheet material PA.

[0034] The sheet material PA onto which the toner image has been transferred is separated from the drum 62 and transported along a transport guide 8 to a fixing device 9. The sheet material PA then passes through a nip between a heating roller 9a and a pressure roller 9b that constitute the fixing device 9. A pressure and heat fixing process is carried out at this nip, and the toner image is fixed to the sheet material PA. The sheet material PA, which has undergone the toner image fixing process, is transported to a pair of discharge rollers 10 and discharged onto a discharge tray 11.

[0035] 3, after transfer, the drum 62 has residual toner removed from its outer peripheral surface by a cleaning blade 77, and is then reused in the image formation process. The toner removed from the drum 62 is stored in a waste toner chamber 71b of the cleaning unit 60. The cleaning unit 60 is a unit that includes the photosensitive drum 62.

[0036] In the above, the charging roller 66, the developing roller 32, the transfer roller 7, and the cleaning blade 77 are process means that act on the drum 62.

[0037] <Overall cartridge configuration> Next, the overall structure of cartridge B will be described with reference to Figures 3, 4, and 5. Figure 3 is a cross-sectional view of cartridge B, and Figures 4 and 5 are perspective views illustrating the structure of cartridge B. Note that in this embodiment, the screws used to join the various parts will not be described.

[0038] The cartridge B has a cleaning unit (photosensitive member holding unit, drum holding unit, image carrier holding unit, first unit) 60 and a developing unit (developer carrier holding unit, second unit) 20.

[0039] Generally, a process cartridge is a cartridge in which an electrophotographic photosensitive member and at least one process means acting on the electrophotographic photosensitive member are integrated into one cartridge, and which is detachably mountable to the main body (main body) of an electrophotographic image forming apparatus. Examples of the process means include a charging means, a developing means, and a cleaning means.

[0040] 3, the cleaning unit 60 includes a drum 62, a charging roller 66, a cleaning member 77, and a cleaning frame 71 that supports these components. On the drive side of the drum 62, a drive-side drum flange 63 provided on the drive side is rotatably supported by a hole 73a in a drum bearing 73. In a broad sense, the drum bearing 73 and the cleaning frame 71 can be collectively referred to as the cleaning frame.

[0041] On the non-drive side, as shown in FIG. 5, a drum shaft 78 is press-fitted into a hole 71c provided in the cleaning frame 71, and the hole (not shown) of the non-drive side drum flange is rotatably supported.

[0042] Each drum flange is a bearing portion that is rotatably supported by a bearing portion.

[0043] In the cleaning unit 60, the charging roller 66 and the cleaning member 77 are disposed in contact with the outer peripheral surface of the drum 62, respectively.

[0044] The cleaning member 77 has 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. The rubber blade 77a abuts against the drum 62 in a counter direction to the rotation direction of the drum 62. In other words, the rubber blade 77a abuts against the drum 62 with its tip facing upstream in the rotation direction of the drum 62.

[0045] As shown in FIG. 3, the waste toner removed from the surface of the drum 62 by the cleaning member 77 is stored in a waste toner chamber 71b formed by the cleaning frame 71 and the cleaning member 77.

[0046] As shown in FIG. 3, a collecting sheet 65 for preventing waste toner from leaking from the cleaning frame 71 is provided on the edge of the cleaning frame 71 so as to come into contact with the drum 62.

[0047] The charging roller 66 is rotatably attached to the cleaning unit 60 via charging roller bearings (not shown) at both ends of the cleaning frame 71 in the longitudinal direction.

[0048] The longitudinal direction of the cleaning frame 71 (the longitudinal direction of the cartridge B) is approximately parallel to the direction in which the rotation axis of the drum 62 extends (the axial direction). Therefore, hereinafter, when simply referring to the longitudinal direction or the axial direction without any particular specification, this refers to the axial direction of the drum 62.

[0049] The charging roller 66 is pressed against the drum 62 by a charging roller bearing 67 being pressed against the drum 62 by a biasing member 68. The charging roller 66 is rotated by the rotation of the drum 62.

[0050] 3, the developing unit 20 includes a developing roller 32, a developing container 23 that supports the developing roller 32, and a developing blade 42. The developing roller 32 is rotatably attached to the developing container 23 by bearing members 27 (FIG. 5) and 37 (FIG. 4) provided at both ends.

[0051] A magnet roller 34 is provided within the developing roller 32. A developing blade 42 is disposed in the developing unit 20 to regulate the toner layer on the developing roller 32. As shown in FIGS. 4 and 5, spacing members 38 are attached to both ends of the developing roller 32, and the developing roller 32 is held with a small gap between it and the drum 62 when the spacing members 38 abut against the drum 62. As shown in FIG. 3, a blowout prevention sheet 33 is provided on the edge of the bottom member 22 so as to abut against the developing roller 32 to prevent toner from leaking from the developing unit 20. Furthermore, a transport member 43 is provided in the toner chamber 29 formed by the developer container 23 and the bottom member 22. The transport member 43 agitates the toner contained in the toner chamber 29 and transports the toner to the toner supply chamber 28.

[0052] As shown in FIGS. 4 and 5, the cartridge B is configured by combining a cleaning unit 60 and a developing unit 20.

[0053] When connecting the developing unit and the cleaning unit, first, the center of the first developer support boss 26a of the developer container 23 is aligned with the first hanging hole 71i on the drive side of the cleaning frame 71, and the center of the second developer support boss 23b is aligned with the second hanging hole 71j on the non-drive side. Specifically, by moving the developing unit 20 in the direction of arrow G, the first developer support boss 26a and the second developer support boss 23b fit into the first hanging hole 71i and the second hanging hole 71j. This allows the developing unit 20 to be movably connected to the cleaning unit 60. More specifically, the developing unit 20 is rotatably connected to the cleaning unit 60. Thereafter, the drum bearing 73 is assembled to the cleaning unit 60 to complete the cartridge B.

[0054] Further, the first end 46La of the drive-side urging member 46L is fixed to the surface 23c of the developing container 23, and the second end 46Lb abuts against the surface 71k that is part of the cleaning unit.

[0055] A first end 46Ra of the non-driven side urging member 46R is fixed to the surface 23k of the developing container 23, and a second end 46Rb abuts against a surface 71l that is a part of the cleaning unit.

[0056] In this embodiment, the drive-side urging member 46L (FIG. 5) and the non-drive-side urging member 46R (FIG. 4) are formed of compression springs. The urging forces of these springs cause the drive-side urging member 46L and the non-drive-side urging member 46R to urge the developing unit 20 toward the cleaning unit 60, thereby reliably pressing the developing roller 32 toward the drum 62. The developing roller 32 is maintained at a predetermined distance from the drum 62 by spacing members 38 attached to both ends of the developing roller 32.

[0057] <Cartridge installation> Next, the installation of the cartridge will be specifically explained using Figures 1(a) and 1(b), 6(a), 6(b), 6(c), 7(a), 8(a), 8(b), 9, 10(a), 10(b), 11(a), 11(b), 12(a), 12(b), 13(a), 13(b), 14, 15, 16, and 17. Figures 1(a) and 1(b) are perspective views of the cartridge to explain the shape of the drive transmission unit and its surroundings. Figure 6(a) is a perspective view of the cylindrical cam, Figure 6(b) is a perspective view of the drive side plate as seen from outside the device main body A, and Figure 6(c) is a cross-sectional view (indicated by the arrow in Figure 6(b)) of the cylindrical cam attached to the drive side plate. FIG. 7(a) is a cross-sectional view of the image forming apparatus link section to explain the link structure, and FIG. 7(b) is a cross-sectional view of the image forming apparatus drive section to explain movement of the drive transmission member. FIG. 8(a) is a cross-sectional view of the image forming apparatus drive side guide section to explain cartridge installation, and FIG. 8(b) is a cross-sectional view of the image forming apparatus non-drive side guide section to explain cartridge installation. FIG. 9 is an explanatory diagram of the image forming apparatus drive train section to explain the positional relationship of the drive train before the opening and closing door is closed. FIG. 10(a) is an explanatory diagram of the image forming apparatus positioning section just before engagement to explain longitudinal positioning of process cartridge B. FIG. 10(b) is an explanatory diagram of the image forming apparatus positioning section after engagement to explain longitudinal positioning of process cartridge B. FIG. 11(a) is a cross-sectional view of the image forming apparatus drive side to explain cartridge positioning. FIG. 11(b) is a cross-sectional view of the image forming apparatus non-drive side to explain cartridge positioning. FIG. 12(a) is a cross-sectional view of the image forming apparatus link section to explain the link structure, and FIG. 12(b) is a cross-sectional view of the image forming apparatus drive section to explain movement of the drive transmission member. Figure 13(a) is a perspective view of the drive transmission member to explain its shape. Figure 13(b) is an explanatory diagram of the drive transmission part of the main assembly A of the image forming apparatus to explain the drive transmission part. Figure 15 is a perspective view of the drive part of the image forming apparatus to explain the engagement space of the drive transmission part. Figure 16 is a cross-sectional view of the drive transmission member to explain the engagement space of the drive transmission member. Figure 17 is a cross-sectional view of the drum 62 and its surroundings of the main assembly A of the image forming apparatus to explain the arrangement of the developing roller gear.FIG. 18 is a cross-sectional view of the drive transmission member for explaining engagement of the drive transmission member.

[0058] First, we will explain the state when the door of the apparatus main body A is open. As shown in Figure 7(a), the apparatus main body A is provided with the door 13, a cylindrical cam link 85, a cylindrical cam 86, cartridge pressing members 1 and 2, cartridge pressing springs 19 and 21, and a front plate 18. Also, as shown in Figure 7(b), the apparatus main body A is provided with a drive transmission member bearing 83, a drive transmission member 81, a drive transmission member biasing spring 84, a drive side plate 15, and a non-drive side plate 16 (see Figure 10a).

[0059] The door 13 is rotatably attached to the drive side plate 15 and the non-drive side plate 16. As shown in FIGS. 6(a), 6(b), and 6(c), the cylindrical cam 86 is rotatably attached to the drive side plate 15 and movably in the longitudinal direction AM. The cylindrical cam 86 has two inclined surfaces 86a and 86b, and an end 86c on the non-drive side in the longitudinal direction, continuing from the inclined surfaces. The drive side plate 15 has two inclined surfaces 15d and 15e facing the two inclined surfaces 86a and 86b, and an end surface 15f facing the end 86c of the cylindrical cam 86. As shown in FIG. 7(a), the cylindrical cam link 85 has bosses 85a and 85b on both ends. The bosses 85a and 85b are rotatably attached to mounting holes 13a in the door 13 and mounting holes 86e in the cylindrical cam 86, respectively. When the opening / closing door 13 is rotated to open, the rotating cam link 85 moves in conjunction with the opening / closing door 13. The movement of the rotating cam link 85 rotates the cylindrical cam 86, and first, the inclined surfaces 86a and 86b come into contact with the inclined surfaces 15d and 15e provided on the drive side plate 15, respectively. As the cylindrical cam 86 further rotates, the inclined surfaces 86a and 86b slide along the inclined surfaces 15d and 15e, causing the cylindrical cam 86 to move toward the drive side in the longitudinal direction. Finally, the cylindrical cam 86 moves until one end 86c of the cylindrical cam 86 abuts against the end face 15f of the drive side plate 15.

[0060] As shown in FIG. 7(b), one end (fixed end 81c) of the drive transmission member 81 on the driving side in the axial direction is fitted into the drive transmission member bearing 83, and is supported rotatably and movably in the axial direction. A central portion 81d of the drive transmission member 81 in the longitudinal direction has a gap M between it and the drive-side plate 15. The drive transmission member 81 has an abutment surface 81e, and the cylindrical cam 86 has another end 86d facing the abutment surface 81e. The drive transmission member spring 84 is a compression spring, and one end 84a abuts against a spring seat 83a provided on the drive transmission member bearing 83, and the other end 84b abuts against a spring seat 81f provided on the drive transmission member 81. This biases the drive transmission member 81 toward the non-driving side in the axial direction (the left side in FIG. 7(b)). This bias causes the abutment surface 81e of the drive transmission member 81 to abut against the other end 86d of the cylindrical cam 86.

[0061] As described above, when the cylindrical cam 86 moves longitudinally toward the driving side (the right side in FIG. 7(b)), the drive transmission member 81 is pushed by the cylindrical cam 86 and moves toward the driving side. This causes the drive transmission member 81 to take a retracted position. In other words, by retracting the drive transmission member 81 from the movement path of the cartridge B, a space for installing the cartridge B is secured within the image forming apparatus main body A.

[0062] Next, the installation of the cartridge B will be described. As shown in Figures 8(a) and 8(b), the drive-side plate 15 has upper guide rails 15g and 15h as guides, and the non-drive-side plate 16 has upper guide rails 16d and 16e. The drum bearing 73 provided on the drive side of the cartridge B has a guided portion 73g and a rotation-stopped portion 73c. ​​In the installation direction of the cartridge B (see arrow C), the guided portion 73g and the rotation-stopped portion 73c are located upstream (the side of arrow AO in Figure 16) of the axis of the coupling protrusion 63b (see Figure 1(a), details of which will be described later).

[0063] The mounting direction of the cartridge B is a direction substantially perpendicular to the axis of the drum 62. When referring to upstream or downstream in the mounting direction, upstream and downstream are defined in terms of the movement direction of the cartridge B immediately before the mounting of the cartridge B into the main assembly A of the apparatus is completed.

[0064] Furthermore, the cleaning frame 71 has a positioned portion 71d and a rotation-stopped portion 71g on the non-drive side in the longitudinal direction. When the cartridge B is mounted through the cartridge insertion opening 17 of the main body A of the apparatus, the guided portion 73g and the rotation-stopped portion 73c of the cartridge B on the drive side are guided by the guide rail top 15g and guide rail 15h of the main body A of the apparatus. The positioned portion 71d and the rotation-stopped portion 71g of the cartridge B on the non-drive side are guided by the guide rails 16d and guide rail 16e of the main body A of the apparatus. In this way, the cartridge B is mounted in the main body A of the apparatus.

[0065] Here, a developing roller gear 30 is provided at the end of the developing roller 32 (see FIGS. 9 and 13(b)). That is, the developing roller gear 30 is attached to the shaft of the developing roller 32.

[0066] The developing roller 32 and the developing roller gear 30 are coaxial and rotate about the axis Ax2 shown in FIG. 9. The developing roller 32 is disposed so that its axis Ax2 is substantially parallel to the axis Ax1 of the drum 62. Therefore, the axial direction of the developing roller 32 (the axial direction of the developing roller gear 30) is substantially the same as the axial direction of the drum 62.

[0067] The developing roller gear 30 is a drive input gear (cartridge side gear, drive input member) to which a drive force is input from the outside of the cartridge B (i.e., the apparatus main body A). The developing roller 32 is configured to rotate by the drive force received by the developing roller gear 30.

[0068] As shown in Figures 1(a) and (b), on the drive side of cartridge B, on the drum 62 side of the developing roller gear 30, there is provided an open space 87 that exposes the developing roller gear 30 and the coupling protrusion 63b.

[0069] The coupling protrusion 63b is formed on the drive-side drum flange 63 attached to the end of the drum (see FIG. 9). The coupling protrusion 63b is a coupling portion (drum-side coupling portion, cartridge-side coupling portion, photosensitive-element-side coupling portion, input coupling portion, drive input portion) to which a driving force is input from the outside of the cartridge B (i.e., the apparatus main body A) (see FIG. 9). The coupling protrusion 63b is disposed coaxially with the drum 62. In other words, the coupling protrusion 63b rotates around the axis Ax1.

[0070] The drive side drum flange 63 having the coupling protrusion 63b is sometimes called a coupling member (drum side coupling member, cartridge side coupling member, photosensitive member side coupling member, drive input coupling member, input coupling member).

[0071] In addition, in the longitudinal direction of the cartridge B, the side on which the coupling protrusion 63b is provided corresponds to the driving side, and the opposite side corresponds to the non-driving side.

[0072] 9, the developing roller gear 30 has a gear portion (input gear portion, cartridge side gear portion, developing side gear portion) 30a and an end face 30a1 provided on the drive side of the gear portion (see FIGS. 1(a), 1(b), and 9). The teeth (gear teeth) formed on the outer periphery of the gear portion 30a are helical teeth inclined with respect to the axis of the developing roller gear 30. In other words, the developing roller gear 30 is a helical gear (see FIG. 1(a)).

[0073] Here, "helical teeth" also includes a shape in which multiple protrusions 232a are arranged along a line tilted relative to the gear axis, essentially forming a helical tooth portion 232b (see FIG. 14). In the configuration shown in FIG. 14, the gear 232 has many protrusions 232b on its circumferential surface. A set of five protrusions 232b can be considered to form a row tilted relative to the gear axis. Each row of five protrusions 232b corresponds to a tooth of the gear portion 30a described above.

[0074] The drive transmission member (drive output member, main body side drive member) 81 has a gear portion (main body side gear portion, output gear portion) 81a for driving the developing roller gear 30. The gear portion 81a has an end face 81a1 at the end portion on the non-drive side (see FIGS. 13(a) and 13(b)).

[0075] The teeth (gear teeth) formed on the gear portion 81a are also helical teeth inclined with respect to the axis of the drive transmission member 81. In other words, the drive transmission member 81 also has a portion that becomes a helical gear.

[0076] The drive transmission member 81 also has a coupling recess 81b. The coupling recess 81b is a coupling portion (main body side coupling portion, output coupling portion) provided on the device main body side. The coupling recess 81b is formed by forming a recess in a protrusion (cylindrical portion) provided on the tip of the drive transmission member 81, which can be coupled with a coupling protrusion 63b provided on the drum side.

[0077] A space 87 (see FIG. 1) configured to expose the gear portion 30a and the coupling protrusion 63b is for arranging the gear portion 81a of the drive transmission member 81 when the cartridge B is mounted in the apparatus main body A. Therefore, the space 87 is larger than the gear portion 81a of the drive transmission member 81 (see FIG. 15).

[0078] More specifically, in a cross section of cartridge B passing through gear portion 30a and perpendicular to the axis of drum 62 (axis of coupling protrusion 63b), an imaginary circle is drawn with the axis of drum 62 (axis of coupling protrusion 63b) as its center and the same radius as gear portion 81a. The interior of this imaginary circle is a space in which no components of cartridge B are disposed. The space defined by this imaginary circle is included within space 87 described above. In other words, space 87 is larger than the space indicated by the imaginary circle.

[0079] To put this another way, in the above cross section, an imaginary circle is drawn concentrically with the drum 62, with the radius being the distance from the axis of the drum 62 to the tooth tip of the gear portion 30a of the developing roller 30. Then, the inside of this imaginary circle is also a space in which the components of the cartridge B are not placed.

[0080] Due to the presence of the space 87, when the cartridge B is mounted in the apparatus main body A, the drive transmission member 81 does not interfere with the cartridge B. As shown in Figure 15, the space 87 allows the drive transmission member 81 to be disposed therein, thereby allowing the cartridge B to be mounted in the apparatus main body A.

[0081] When the cartridge B is viewed along the axis of the drum 62 (the axis of the coupling protrusion 63b), the gear teeth formed on the gear portion 30a are disposed in close proximity to the peripheral surface of the drum 62.

[0082] As shown in Figure 16, the gear portion 30a is positioned so that the distance AV (the distance along a direction perpendicular to the axis) from the axis of the drum 62 to the tip (tooth tip) of the gear tooth of the gear portion 30a is in the range of 90 to 110 percent of the radius of the drum 62.

[0083] In particular, in this embodiment, the radius of the drum 62 is 12 mm, and the distance from the axis of the drum 62 to the tip of the gear tooth (tooth tip) of the gear portion 30a is set within the range of 11.165 mm to 12.74 mm. In other words, the distance from the axis of the drum 62 to the tip of the gear tooth (tooth tip) of the gear portion 30a is within the range of 93% to 107% of the drum radius.

[0084] In the longitudinal direction, the end face 30a1 of the gear portion 30a of the developing roller gear 30 is positioned closer to the driving side (outside the cartridge B) than the tip end 63b1 of the coupling protrusion 63b of the driving side drum flange 63 (see Figures 9 and 33).

[0085] As a result, in the axial direction of the developing roller gear 30, the gear teeth of the gear portion 30a have an exposed portion that is exposed from the cartridge B (see FIG. 1). In particular, in this embodiment, as shown in FIG. 16, the gear portion 30a is exposed over a range of 64° or more. In other words, when viewing the cartridge B from the drive side, if the line connecting the center of the drum 62 and the center of the developing roller gear 30 is taken as the reference line, then both sides of the developing roller gear 30 relative to this reference line are each exposed over a range of at least 32° or more. In FIG. 16, the angle AW is the angle from the center (axis) of the developing roller gear 30 as the origin to the reference line to the position where the gear portion 30a begins to be covered by the drive-side developer side member 26, and is "AW≧32°."

[0086] The overall exposure angle of the gear portion 30a can be expressed as 2AW, which satisfies the relationship "2AW≧64°" as described above.

[0087] If the gear portion 30a of the developing roller gear 30 is exposed from the driving side developing member 26 so as to satisfy the above relationship, the gear portion 81a meshes with the gear portion 30a without interfering with the driving side developing member 26, thereby enabling drive transmission.

[0088] At least a part of the exposed portion of the gear portion 30a is located further outside (on the driving side) of the cartridge B than the tip 63b1 of the coupling protrusion 63b, and faces the axis of the drum (see FIGS. 1, 9, and 33). FIGS. 9 and 33 show a state in which the gear teeth located on the exposed portion 30a3 of the gear portion 30a face the rotation axis Ax1 of the drum 62 (the rotation axis of the coupling portion 63b). In FIG. 33, the axis Ax1 of the drum 62 is located above the exposed portion 30a3 of the gear portion 30a.

[0089] 9, at least a part of the gear portion 30a protrudes further toward the driving side than the coupling protrusion 63b in the axial direction, and therefore the gear portion 30a overlaps in the axial direction with the gear portion 81a of the drive transmission member 81. Furthermore, a part of the gear portion 30a is exposed so as to face the axis Ax1 of the drum 62, and therefore the gear portion 30a and the gear portion 81a of the drive transmission member 81 may come into contact with each other in the process of inserting the cartridge B into the apparatus main body A.

[0090] 33 shows a state in which the outer end 30a1 of the gear portion 30a is positioned on the arrow D1 side of the tip end 63b1 of the coupling protrusion 63b. The arrow D1 points outward in the axial direction.

[0091] Due to the above-mentioned positional relationship, the gear portion 30a of the developing roller gear 30 and the gear portion 81a of the drive transmission member 81 can mesh with each other during the process of mounting the cartridge B into the main assembly A of the apparatus.

[0092] In addition, in the mounting direction C of the cartridge B, the center (axis) of the gear portion 30a is arranged on the upstream side (the side of the arrow AO in FIG. 16) of the center (axis) of the drum 62.

[0093] The arrangement of the developing roller gear 30 will be described in more detail. As shown in Figure 17, which is a cross-sectional view from the non-drive side, a line connecting the center of the drum 62 to the center of the charging roller 66 is set as a reference line (start line) indicating the angle reference (0°). At this time, the center (axis) of the developing roller gear 30 is located in an angle range of 64° to 190° downstream in the rotation direction of the drum 62 (clockwise in Figure 17) with respect to the reference line.

[0094] More precisely, the center of the drum 62 is set as the origin, the half line extending from the center of the drum 62 to the center of the charging roller 66 is set as the starting line, and the direction of rotation of the drum is set as the positive direction of the angle. Then, the deflection angle of the polar coordinate indicating the center of the developing roller satisfies the following relationship: 64°≦Declination angle of polar coordinates indicating the center of the developing roller≦190°

[0095] There is a certain degree of freedom in the arrangement of the charging roller 66 and the developing roller gear 30. The angle at which the charging roller 66 and the developing roller gear 30 are closest to each other is indicated by arrow BM, which is 64° in this embodiment as described above. On the other hand, the angle at which they are farthest apart is indicated by arrow BN, which is 190° in this embodiment.

[0096] As described above, the unit provided with the developing roller gear 30 (developing unit 20) is movable relative to the drum 62 and the unit provided with the coupling protrusion 63b (cleaning unit 60). In other words, the developing unit 20 is rotatable relative to the cleaning unit 60, with the first developing support boss 26a and the second developing support boss 23b (see FIGS. 4 and 5) as the rotation center (rotation axis). Therefore, the center-to-center distance (distance between the axes) of the developing roller gear 30 and the drum 62 is variable, and the developing roller gear 30 can move within a certain range relative to the axis of the drum 62 (axis of the coupling protrusion 63b).

[0097] 9, when the gear portion 30a and the gear portion 81a come into contact with each other during the insertion of the cartridge B, the gear portion 30a is pushed by the gear portion 81a and moves away from the axis of the drum 62 (the axis of the coupling protrusion 63b).This reduces the impact of the contact between the gear portion 30a and the gear portion 81a.

[0098] As shown in FIGS. 10(a) and 10(b), the drum bearing 73 has a fitted portion 73h as a portion to be positioned in the longitudinal direction (axial direction) (portion to be positioned in the axial direction).

[0099] The drive side plate 15 of the apparatus main assembly A has a fitting portion 15j that can fit into the fitting portion 73h. The fitting portion 73h of the cartridge B fits into the fitting portion 15j of the apparatus main assembly A during the above-mentioned installation process, thereby determining the longitudinal (axial) position of the cartridge B (see FIG. 10(b)). In this embodiment, the fitting portion 73h is a slit (groove) (see FIG. 1(b)). This slit communicates with the space 87. In other words, the slit (fitting portion 73h) forms an open space relative to the space 87.

[0100] The arrangement of the fitted portion 73h will be described in detail using Figure 33. Note that Figure 33 is an explanatory diagram (schematic diagram) for showing the arrangement of the fitted portion 73h relative to the gear portion 30a or the coupling protrusion 63b. As shown in Figure 33, this slit (fitted portion 73h) is a space formed between two portions (an outer portion 73h1 and an inner portion 73h2 of the fitted portion 73h) arranged along the axial direction. In the axial direction, the inner end portion (inner portion 73h2) of the fitted portion 73h is arranged more inward (on the side of arrow D2) than the outer end portion 30a1 of the gear portion 30a. In the axial direction, the outer end portion (outer portion 73h1) of the fitted portion 73h is arranged more outward (on the side of arrow D1) than the tip portion 63b of the coupling protrusion 63b.

[0101] Next, the state of closing the door 13 will be described. As shown in Figures 8(a), 8(b), 11(a), and 11(b), the drive side plate 15 has an upper positioning portion 15a, a lower positioning portion 15b, and a rotation stop portion 15c for positioning, and the non-drive side plate 16 has a positioning portion 16a and a rotation stop portion 16c. The drum bearing 73 has an upper positioned portion (first positioned portion, first protrusion, first protrusion) 73d and a lower positioned portion (second positioned portion, second protrusion, second protrusion) 73f.

[0102] Furthermore, the cartridge pressing members 1 and 2 are rotatably attached to both axial ends of the opening / closing door 13. The cartridge pressing springs 19 and 21 are respectively attached to both longitudinal ends of a front plate provided in the image forming apparatus A. The drum bearing 73 has a pressed portion 73e as a biasing force receiving portion, and the cleaning frame 71 has a pressed portion 71o on the non-drive side (see FIG. 3). By closing the opening / closing door 13, the pressed portions 73e and 71o of the cartridge B are pressed by the cartridge pressing members 1 and 2 biased by the cartridge pressing springs 19 and 21 of the apparatus main body A.

[0103] As a result, on the drive side, the upper positioned portion 73d, the lower positioned portion 73f, and the rotation stop portion 73c of the cartridge B abut against the upper positioning portion 15a, the lower positioning portion 15b, and the rotation stop portion 15c of the main assembly A of the apparatus, respectively. As a result, the cartridge B and the drum 62 are positioned on the drive side. Also, on the non-drive side, the positioned portion 71d and the rotation stop portion 71g of the cartridge B abut against the positioning portion 16a and the rotation stop portion 16c of the main assembly A of the apparatus, respectively. As a result, the cartridge B and the drum 62 are positioned on the non-drive side.

[0104] 1(a) and 1(b), the upper positioned portion 73d and the lower positioned portion 73f are arranged near the drum 62. The upper positioned portion 73d and the lower positioned portion 73f are also aligned along the rotation direction of the drum 62.

[0105] Furthermore, in the drum bearing 73, a space (arc-shaped recess) 73l for disposing the transfer roller 7 (see FIG. 11) needs to be secured between the upper positioned portion 73d and the lower positioned portion 73f. Therefore, the upper positioned portion 73d and the lower positioned portion 73f are disposed apart from each other.

[0106] Additionally, the upper positioned portion 73d and the lower positioned portion 73f are protrusions that protrude inward in the axial direction from the drum bearing 73. As described above, it is necessary to ensure a space 87 around the coupling protrusion 63b. Therefore, the upper positioned portion 73d and the lower positioned portion 73f do not protrude outward in the axial direction, but instead protrude inward, thereby ensuring the space 87.

[0107] The upper positioned portion 73d and the lower positioned portion 73f are protrusions arranged to partially cover the photosensitive drum 62. In other words, the positioned portions 73d and 73f are protruding portions that protrude (overhang) inward in the axial direction of the photosensitive drum 62. When the upper positioned portion 73d and the photosensitive drum 62 are projected onto the axis of the drum 62, the projected areas of the upper positioned portion 73d and the photosensitive drum 62 at least partially overlap. In this regard, the lower positioned portion 73f is similar to the upper positioned portion 73d.

[0108] Additionally, the upper positioned portion 73d and the lower positioned portion 73f are arranged so as to partially cover the drive-side drum flange 63 provided at the end of the photosensitive drum 62. When the upper positioned portion 73d and the drive-side drum flange 63 are projected onto the axis of the drum 62, the projected areas of the upper positioned portion 73d and the drive-side drum flange 63 at least partially overlap. In this regard, the lower positioned portion 73f is similar to the upper positioned portion 73d.

[0109] The pressed portions 73e and 71o are protruding portions of the frame bodies of the cleaning units arranged at one end (drive side) and the other end (non-drive side) of the cartridge B in the longitudinal direction. In particular, the pressed portion 73e is provided on the drum bearing 73. The pressed portions 73e and 71o protrude in a direction intersecting the axial direction of the drum 62 and away from the drum 62.

[0110] On the other hand, as shown in Figures 12(a) and 12(b), the driving side drum flange 63 has a coupling protrusion 63b on the driving side and a tip end portion 63b1 at the tip of the coupling protrusion 63b. The drive transmission member 81 has a coupling recess 81b and a tip end 81b1 of the coupling recess 81b on the non-drive side. When the opening / closing door 13 is closed, the cylindrical cam 86 moves longitudinally toward the non-drive side (the side approaching cartridge B) via the rotating cam link 85 while the inclined surfaces 86a and 86b rotate along the inclined surfaces 15d and 15e of the drive side plate 15. As a result, the drive transmission member 81, which was in the retracted position, moves longitudinally toward the non-drive side (the side approaching cartridge B) due to the drive transmission member spring 84. Because the gear teeth of the gear portion 81a and the gear portion 30a are inclined with respect to the moving direction of the drive transmission member 81, the movement of the drive transmission member 81 causes the gear teeth of the gear portion 81a to abut against the gear teeth of the gear portion 30a. At this point, the movement of the drive transmission member 81 toward the non-drive side stops.

[0111] Even after the drive transmission member 81 stops, the cylindrical cam 86 continues to move toward the non-drive side, and the drive transmission member 81 and the cylindrical cam 86 move away from each other.

[0112] Next, as shown in FIGS. 1, 13(a), and 18, the drum bearing 73 has a concave bottom surface 73i. The drive transmission member 81 has a bottom portion 81b2 at the bottom of the coupling recess 81b as a positioning element. The coupling recess 81b of the drive transmission member 81 is a hole with a substantially triangular cross section. When viewed from the non-drive side (the cartridge side, the opening side of the recess 81b), the coupling recess 81b has a shape that twists in the counterclockwise direction N toward the drive side (the innermost side of the recess 81b). The gear portion 81a of the drive transmission member 81 is a helical gear, and when viewed from the non-drive side (the cartridge side), it has gear teeth that twist in the counterclockwise direction N toward the drive side. In other words, the coupling recess 81b and the gear portion 81a are inclined (twisted) in the direction opposite to the rotational direction CW of the drive transmission member 81 as they approach the rear end (fixed end 81c) of the drive transmission member 81.

[0113] The gear portion 81a and the coupling recess 81b are arranged so that the axis of the gear portion 81a and the axis of the coupling recess 81b overlap with the axis of the drive transmission member 81. In other words, the gear portion 81a and the coupling recess 81b are arranged coaxially (concentrically).

[0114] The coupling protrusion 63b of the drive-side drum flange 63 has a convex shape (protrusion) with a substantially triangular cross section. The coupling protrusion 63b is twisted counterclockwise O from the drive side (the tip end of the coupling protrusion 63b) to the non-drive side (the bottom end of the coupling protrusion 63b) (see Figure 37). In other words, the coupling protrusion 63b is inclined (twisted) counterclockwise (in the direction of drum rotation) from the outside to the inside of the cartridge in the axial direction.

[0115] The coupling protrusion 63b has a triangular prism whose corners (ridges) form the vertices of the triangle, which act as driving force receiving portions that actually receive the driving force from the coupling recess 81b. This driving force receiving portion is inclined toward the drum rotation direction as it moves from the outside to the inside of the cartridge in the axial direction. The inner surface (inner peripheral surface) of the coupling recess 81b acts as a driving force applying portion that applies driving force to the coupling protrusion 63b.

[0116] Although the cross-sectional shapes of the coupling protrusion 63b and the coupling recess 81b are not strictly triangular (polygonal) because the corners are rounded, they are referred to as substantially triangular (polygonal) shapes. In other words, the coupling protrusion 63b has a shape that is a twisted protrusion that is substantially a triangular prism (prism). However, the shape of the coupling protrusion 63b is not limited to this. The shape of the coupling protrusion 63b may be changed as long as it can couple with the coupling recess 81b, that is, can engage and drive. For example, three bosses 163a may be arranged at the vertices of a triangle, and each boss 163a may be twisted with respect to the axial direction of the drum 62 (see Figure 19).

[0117] The gear portion 30a of the developing roller gear 30 is a helical gear, and has a shape that is twisted (inclined) in the clockwise direction P from the drive side to the non-drive side (see Figure 37). In other words, the gear teeth (helical teeth) of the gear portion 30a are inclined (twisted) in the clockwise direction P (the rotation direction of the developing roller and developing roller gear) from the outside to the inside of the cartridge in the axial direction of the gear portion 30a. In other words, the gear 30a is inclined (twisted) in the opposite direction to the rotation direction of the drum 62 from the outside to the inside in the axial direction.

[0118] As shown in FIG. 13, the drive transmission member 81 is rotated by a motor (not shown) in the clockwise direction CW (the opposite direction of arrow N in FIG. 13) when viewed from the non-drive side (cartridge side). As a result, a thrust force (a force generated in the axial direction) is generated by the helical meshing of the gear portion 81a of the drive transmission member 81 and the gear portion 30a of the developing roller gear 30. An axial (longitudinal) force FA is applied to the drive transmission member 81, and the drive transmission member 81 attempts to move longitudinally toward the non-drive side (the side approaching the cartridge). In other words, the drive transmission member 81 approaches and comes into contact with the coupling protrusion 63b.

[0119] In particular, in this embodiment, the gear portion 81a of the drive transmission member 81 has helical teeth that are twisted so that each tooth moves 5 to 8.7 mm in the axial direction (see FIG. 13). This corresponds to a twist angle of the gear portion 81a of 15° to 30°. The twist angle of the developing roller gear 30 (gear portion 30a) is also 15° to 30°. In this embodiment, a twist angle of 20° was adopted for the gear portion 81a and the gear portion 30a.

[0120] When the drive transmission member 81 rotates and the phases of the triangular shapes of the coupling recess 81b and the coupling protrusion 63b match, the coupling protrusion 63b and the coupling recess 81b engage (couple).

[0121] When the convex portion 63b and the coupling concave portion 81b engage with each other, a new thrust force FC is generated because both the coupling concave portion 81b and the coupling convex portion 63b are twisted (inclined) with respect to the axis.

[0122] That is, a force FC acting toward the non-drive side (the side approaching the cartridge) in the longitudinal direction acts on the drive transmission member 81. This force FC and the aforementioned force FA combine to move the drive transmission member 81 further toward the non-drive side (the side approaching the cartridge) in the longitudinal direction. That is, the coupling protrusion 63 acts to move the drive transmission member 81 closer to the coupling protrusion 63b of the cartridge B.

[0123] The drive transmission member 81 drawn by the coupling protrusion 63b has a tip end 81b1 thereof abutting against the concave bottom surface 73i of the drum bearing 73, and is positioned in the longitudinal direction (axial direction).

[0124] Furthermore, a reaction force FB of the force FC acts on the drum 62, and this reaction force (resistance) FB moves the drum 62 to the driving side (the side closer to the drive transmission member 81, the outside of the cartridge B) in the longitudinal direction. In other words, the drum 62 and the coupling protrusion 63b are attracted to the drive transmission member 81 side. As a result, the tip end 63b1 of the coupling protrusion 63b of the drum 62 abuts against the bottom 81b2 of the coupling recess 81b. This also positions the drum 62 in the axial direction (longitudinal direction).

[0125] That is, the coupling protrusion 63b and the coupling recess 81b are attracted to each other, so that the positions of the drum 62 and the drive transmission member 81 in the axial direction are determined.

[0126] In this state, the drive transmission member 81 is in the drive position, i.e., the drive transmission member 81 is in a position for transmitting drive force to the coupling protrusion 63b and the gear portion 30b.

[0127] Furthermore, the centering effect of the triangular shape of the coupling recess 81b determines the center of the tip of the drive transmission member 81 with respect to the drive-side drum flange 63. In other words, the drive transmission member 81 is aligned with the drum flange 63, and the drive transmission member 81 and the photosensitive member are coaxial. This allows the drive to be transmitted from the drive transmission member 81 to the developing roller gear 30 and the drive-side drum flange 63 with high precision.

[0128] The coupling recess 81b and the coupling protrusion 63b that engages with it can also be considered as a centering portion. That is, when the coupling recess 81b engages with the coupling protrusion 63b, the drive transmission member 81 and the drum become coaxial with each other. In particular, the coupling recess 81b will be called the main body side centering portion (image forming apparatus main body side centering portion), and the coupling protrusion 63b will be called the cartridge side centering portion.

[0129] As described above, the forces FA and FC acting on the drive transmission member 81 toward the non-drive side assist the engagement of the coupling.

[0130] Furthermore, by positioning the drive transmission member 81 by the drum bearing (bearing member) 73 provided on the cartridge B, the positioning accuracy of the drive transmission member 81 relative to the cartridge B can be improved.

[0131] Since the positional accuracy in the longitudinal direction between the gear portion 30a of the developing roller gear 30 and the gear portion 81a of the drive transmission member 81 is improved, it is possible to reduce the width of the gear portion 30a of the developing roller gear 30. This makes it possible to reduce the size of the cartridge B and the apparatus main body A into which the cartridge B is attached.

[0132] To summarize this embodiment, the gear portion 81a of the drive transmission member 81 and the gear portion 30a of the developing roller gear 30 have helical teeth. Helical teeth provide a higher contact ratio between the gears than spur teeth. As a result, the rotation accuracy of the developing roller 30 is improved, and the developing roller 30 rotates smoothly.

[0133] Furthermore, the inclination direction of the helical teeth of the gear portion 30a and the gear portion 81a is specified so that forces (forces FA and FB) that attract each other are generated between the gear portion 30a and the gear portion 81a. In other words, when the gear portion 30a and the gear portion 81a rotate in an engaged state, a force is generated that moves the coupling recess 81b provided in the drive transmission member 81 and the coupling protrusion 63b provided at the end of the photosensitive drum 62 closer to each other. As a result, the drive transmission member 81 moves toward the cartridge B, and the coupling recess 81b also moves closer to the coupling protrusion 63b. This assists the engagement (coupling) of the coupling recess 81b and the coupling protrusion 63b.

[0134] Furthermore, the direction in which the coupling protrusion 63b (driving force receiving portion) is inclined relative to the drum axis and the direction in which the helical teeth of the gear portion 30a of the developing roller gear 30 are inclined relative to the axis of the gear portion 30a are opposite to each other (see FIG. 38). As a result, the movement of the drive transmission member 81 is assisted not only by the force generated by the engagement (meshing) of the gear portion 30a and the gear portion 81a, but also by the force (force FC) generated by the engagement (coupling) of the coupling protrusion 63b and the coupling recess 81b. In other words, as the coupling protrusion 63b and the coupling recess 81b rotate in a coupled state, the coupling protrusion 63b and the coupling recess 81b attract each other. As a result, the coupling protrusion 63b and the coupling recess 81b are stably engaged (coupled).

[0135] The drive transmission member 81 is biased toward the coupling protrusion 63b by an elastic member (drive transmission member spring 84) (see FIG. 7(a)). In this embodiment, the force of the drive transmission member spring 84 can be weakened by the amount of forces FA and FC (see FIG. 13(b)). This reduces the frictional force between the drive transmission member spring 84 and the drive transmission member 81 that occurs when the drive transmission member 81 rotates, thereby reducing the torque required to rotate the drive transmission member 81. The load applied to the motor that rotates the drive transmission member 81 can also be reduced. In addition, the sliding noise between the drive transmission member 81 and the drive transmission member spring 84 can also be reduced.

[0136] In this embodiment, the drive transmission member 81 is biased by an elastic member (spring 84), but the elastic member is not necessarily required. That is, if the gear portion 81a and the gear portion 30a are arranged so as to overlap at least partially with each other in the axial direction and the gear portion 81a and the gear portion 30a mesh with each other when the cartridge is attached to the main assembly of the apparatus, the elastic member can be eliminated. In other words, in this case, when the gear portion 81a rotates, the meshing of the gear portion 81a and the gear portion 30a generates a force that attracts the coupling protrusion 63b and the coupling recess 81b together. In other words, even without the elastic member (spring 84), the force generated by the meshing of the gears moves the drive transmission member 81 toward the cartridge B. This allows the coupling protrusion 63b to engage with the coupling recess 81b.

[0137] In this way, when there is no elastic member, there is no friction between the elastic member and drive transmission member 81, which further reduces the rotational torque of drive transmission member 81. It is also possible to eliminate noise caused by sliding between drive transmission member 81 and the elastic member. It is also possible to reduce the number of parts in the image forming apparatus, which makes it possible to simplify the configuration of the image forming apparatus and reduce costs.

[0138] Furthermore, the coupling protrusion 63b of the drive-side drum flange 63 is coupled to the recess 81b of the drive transmission member 81 while the drive transmission member 81 is rotating. Here, the coupling protrusion 63b is inclined (twisted) in the rotation direction of the photosensitive drum as it moves from the outside to the inside of the cartridge in the axial direction of the drum 62. In other words, because the coupling protrusion 63b is inclined (twisted) along the rotation direction of the drive transmission member 81, the coupling protrusion 63b is easily coupled to the rotating recess 81b.

[0139] In this embodiment, a helical gear is used for the developing roller gear 30 that meshes with the drive transmission member 81, but other gears may be used as long as they are capable of transmitting drive. For example, a thin spur gear 230 that can fit into the gaps 81e between the teeth of the drive transmission member 81 is used. The thickness of the spur gear is set to 1 mm or less. In this case, too, because the gear portion 81a of the drive transmission member 81 has helical teeth, meshing between the gear portion 81a and the spur gear 230 generates a force that urges the drive transmission member 81 toward the non-drive side (see Figure 21).

[0140] In this embodiment, as shown in Figures 1(a) and (b), when cartridge B is viewed from the drive side, the coupling protrusion 63b (drum 62) rotates counterclockwise O, and the developing roller gear 30 (developing roller 32) rotates clockwise P.

[0141] However, when viewed from the non-drive side, cartridge B can also be configured so that the coupling protrusion 63b (drum 62) rotates counterclockwise and the developing roller gear 30 (developing roller 32) rotates clockwise. In other words, by changing the layout of the main assembly A of the apparatus or cartridge B, the rotation directions of the coupling protrusion 63b (drum 62) and the developing roller gear 30 can be opposite to those in this embodiment. In any case, when the coupling protrusion 63b and the developing roller gear 30 are viewed from the same direction, the rotation directions of the coupling protrusion 63b and the developing roller gear 30 are opposite to each other. One of them rotates clockwise and the other rotates counterclockwise.

[0142] That is, if the cartridge B is viewed so that the rotation direction of the coupling protrusion 63b is counterclockwise (in this embodiment, if the cartridge B is viewed from the drive side), the rotation direction of the developing roller gear 30 is clockwise.

[0143] In this embodiment, the developing roller gear 30 is used as the drive input gear that meshes with the drive transmission member 81, but another gear may also be used as the drive input gear.

[0144] FIG. 22 shows a drive input gear 88 that meshes with the drive transmission member 81, a developing roller gear 80 provided on the developing roller, idler gears 101 and 102, and a transport gear (agitating gear, developer transport gear) 103.

[0145] 22, the driving force is transmitted from the drive input gear 88 to the developing roller gear 80 via one idler gear 101. The idler gear 101 and the developing roller gear 80 constitute a drive transmission mechanism (cartridge-side drive transmission mechanism, developing-side drive transmission mechanism) for transmitting the driving force from the drive input gear 88 to the developing roller 32.

[0146] On the other hand, the idler gear 102 is a gear that transmits the driving force from the drive input gear 88 to the agitating gear 103. The conveying gear 103 is attached to the conveying member 43 (see FIG. 3), and the conveying member 43 rotates due to the driving force received by the conveying gear 103.

[0147] It is also possible to use a plurality of gears to transmit the driving force between the drive input gear 88 and the developing roller gear 80. In this case, in order to rotate the developing roller 32 in the direction of arrow P (see FIG. 1), it is advisable to use an odd number of idler gears to transmit the driving force between the drive input gear 88 and the developing roller gear 80. In FIG. 22, a configuration with one idler gear is shown to simplify the configuration of the gear train.

[0148] In other words, with regard to the number of gears, in order to rotate the developing roller 32 in the direction of arrow P (see FIG. 1), an odd number of gears may be provided in the cartridge B to transmit drive to the developing roller 32. In the configuration shown in FIG. 22, there are three gears that transmit drive to the developing roller 32: the developing roller gear 80, the idler gear 101, and the drive input gear 88. On the other hand, in the configuration shown in FIG. 1, there is only one gear that transmits drive to the developing roller 32: the developing roller gear 32.

[0149] In other words, the cartridge B only needs to have a drive transmission mechanism (cartridge-side drive transmission mechanism, development-side drive transmission mechanism) for rotating the developing roller 32 in the same rotation direction as the drive input gear 88.

[0150] In other words, when cartridge B is viewed so that the rotation direction of the drive input gear 88 is clockwise, the rotation direction of the developing roller 32 is also clockwise. In the configuration shown in Figure 22, when cartridge B is viewed from the drive side, the rotation direction of the drive input gear 88 and the developing roller 32 is clockwise.

[0151] 1 or 22, the drive input gear (30, 88) receives the drive force from the drive transmission member 81, independently of the coupling protrusion 63b. In other words, the cartridge B is provided with two input portions (drive input portions) for receiving the drive force from the outside of the cartridge B (i.e., the apparatus main body A), one each for the cleaning unit and the developing unit.

[0152] A configuration in which the photosensitive drum (cleaning unit) and the developing roller (developing unit) each receive driving force independently from the drive transmission member 81 has the advantage of increasing the stability of the rotation of the photosensitive drum. This is because there is no need to transmit driving force (rotational force) between the photosensitive drum and another member (e.g., the developing roller), and therefore, when rotational irregularities occur in this other member (e.g., the developing roller), the rotational irregularities are less likely to affect the rotation of the photosensitive drum.

[0153] 22, a force in the direction of arrow FA (see FIG. 13(b)) is applied to the drive transmission member 81 to assist the coupling between the coupling recess 81b and the coupling protrusion 63b. To achieve this, a load (torque) must be generated when the drive input gear 88 rotates. Conversely, as long as a load is generated to rotate the drive input gear 88, the drive input gear 88 does not necessarily have to be configured to receive a drive force for rotating the developing roller 32.

[0154] For example, it is possible to adopt a configuration in which the driving force received by the drive input gear 88 is transmitted only to the conveying member 43 (see FIG. 3) without being transmitted to the developing roller 32. However, if such a configuration is adopted in a cartridge having the developing roller 32, it will be necessary to transmit the driving force separately to the developing roller 32. For example, a gear or the like that transmits the driving force from the drum 62 to the developing roller 32 will be required in the cartridge B.

[0155] <Coupling engagement conditions> Next, the conditions for coupling engagement will be specifically described using Figures 1, 13(a), 18, 24(a), 24(b), 25(a), 25(b), and 27. Figure 24(a) is a cross-sectional view of the image forming apparatus drive unit as seen from the opposite direction to the cartridge B installation direction to explain the distance of the drive transmission unit. Figure 24(b) is a cross-sectional view of the image forming apparatus drive unit as seen from the drive side to explain the distance of the drive transmission unit. Figure 25(a) is a cross-sectional view of the image forming apparatus drive unit as seen from the drive side to explain the gap in the coupling unit. Figure 25(b) is a cross-sectional view of the image forming apparatus drive unit as seen from the drive side to explain the gap in the coupling unit. Figure 27 is a cross-sectional view of the image forming apparatus as seen from the drive side to explain the range of the regulating unit (stopper).

[0156] As shown in Figures 1, 24(a) and 24(b), the drum bearing 73 has a regulating portion 73j which serves as a tilt regulating portion (movement regulating portion, position regulating portion, stopper) for regulating the movement of the drive transmission member 81 and regulating (suppressing) tilting of the drive transmission member 81.

[0157] The drive transmission member 81 has a cylindrical portion 81i (see FIG. 24(a)) on the non-drive side (the side closer to the cartridge B). The cylindrical portion 81i is a cylindrical portion (protrusion) in which a coupling recess 81b is formed.

[0158] As described above, when the drive transmission member 81 starts to rotate, the gear portion 81a of the drive transmission member 81 and the gear portion 30a of the developing roller gear 30 mesh together, as shown in Figure 9. Meanwhile, the coupling recess 81b and the coupling protrusion 63b are not coupled, or are insufficiently coupled. In this state, when the gear portion 81a transmits driving force to the gear portion 30a, meshing of the gears generates a meshing force FD (Figure 24(b)) in the gear portion 81a.

[0159] When this meshing force FD is applied to the drive transmission member 81, the drive transmission member 81 tilts. In other words, since the drive transmission member 81 is supported only by the fixed end 81c (see FIG. 24(a) : the end farther from the cartridge B), which is the end on the driving side, as described above, the drive transmission member 81 tilts with the end 81c (fixed end) on the driving side as the fulcrum. This causes the end (free end, tip) of the drive transmission member 81 on the side where the coupling recess 81b is provided to move.

[0160] If the drive transmission member 81 tilts significantly, the coupling recess 81b will not be able to couple with the coupling protrusion 63b. To avoid this, the cartridge B is provided with a regulating portion 73j, which limits (regulates) the tilt of the drive transmission member 81 within a certain range. In other words, when the drive transmission member 81 tilts, the regulating portion 73j supports the drive transmission member 81, thereby preventing the tilt from becoming too large.

[0161] The regulating portion 73j of the drum bearing 73 is an arc-shaped curved surface portion disposed so as to face the axis of the drum 62 (the axis of the coupling protrusion 63b). The regulating portion 73j can also be considered as a protruding portion that protrudes so as to cover the drum axis. A space is formed between the regulating portion 73i and the drum axis in which no components of the process cartridge B are disposed, and the drive transmission member 81 is configured to be disposed in this space. The regulating portion 73i faces the space 87 shown in FIG. 1, and the regulating portion 73i forms the edge (outer edge) of the space 87.

[0162] The restricting portion 73j is disposed at a position where it can prevent the drive transmission member 81 from moving (tilting) due to the meshing force FD.

[0163] The direction in which the meshing force FD is generated is determined by the front pressure angle α of the gear portion 81a (i.e., the front pressure angle α of the developing roller gear 30). The direction in which the meshing force FD is generated is inclined by (90+α') degrees toward the upstream AK in the rotation direction of the photosensitive drum 62 with respect to the arrow (semi-straight line) LN extending from the center 62a of the photosensitive drum (i.e., the center of the drive transmission member 81) toward the center 30b of the developing roller gear 30.

[0164] In addition, the standard front pressure angle α for a helical gear with a 20° helix angle is 21.2°. In this embodiment, the front pressure angle α of the gear portion 81a and the gear portion 30a is also 21.2°. In this case, the inclination of the meshing force FD with respect to the arrow LN is 111.2°. However, a different value can be used as the front pressure angle of the gear portion 81a and the gear portion 30a, and in that case, the direction of the meshing force FD will also change. The front pressure angle α also changes depending on the helical angle of the helical gear, and the front pressure angle α is preferably 20.6° or more and 22.8° or less.

[0165] 24(b), if a half line FDa is extended starting from the center 62a of the photosensitive drum in the same direction as the meshing force FD, the restriction portion 73j is disposed so as to straddle this half line FDa. Note that the half line FDa is a line obtained by tilting (rotating) the half line LN by (90+α') degrees upstream in the rotation direction of the drum 62, with the center of the drum 62 as the origin (axis, fulcrum). In this embodiment, the half line FDa is tilted by 111.2 degrees with respect to the half line LN.

[0166] Note that the restricting portion 73j does not necessarily need to be located on this line FDa; it is preferable that the restricting portion 73j be located near the half line FDa. Specifically, it is preferable that at least a portion of the restricting portion 73j be located somewhere within a range of ±15° from the half line FDa. The half line FDa is a line obtained by rotating the half line LN by (90 + α) degrees upstream in the rotation direction of the drum 62. Therefore, the restricting portion 73j is preferably located in a range of (75 + α) degrees to (105 + α) degrees upstream in the drum rotation direction from the half line LN, with the center of the drum 62 as the origin. Considering that the preferred value of the front pressure angle α is 20.6 degrees or more and 22.8 degrees or less, the preferred range for the restricting portion 73j to be located is 95.6 degrees or more and 127.8 degrees or less with respect to the half line LN. In this embodiment, since the front pressure angle α is 21.2 degrees, the preferred range for the restricting portion 73j is 96.2 degrees or more and 126.2 degrees or less.

[0167] As another example of a suitable arrangement of the restriction portions 73j, a plurality of restriction portions 73j may be arranged on both sides of the half-line FDa at a distance from each other, with the half-line FDa sandwiched between them (see FIG. 26). In this case, too, the restriction portions 73j can be considered to be arranged across the line FDa.

[0168] Furthermore, it is desirable that the regulating portion 73j be disposed on the upstream side AO (see FIG. 16) in the cartridge mounting direction C (see FIG. 11(a)) with respect to the center (axis) of the coupling protrusion 63b, in order to prevent the regulating portion 73j from interfering with the mounting of the cartridge B.

[0169] The range (area) in which the restricting portion 73j is disposed on the drum bearing 73 can also be described as follows.

[0170] In a plane perpendicular to the axis of the drum 62 (see FIG. 24(b)), a straight line LA is drawn that passes through the center 62a of the drum 62 and the center 30b of the developing roller gear 30. In this case, the regulating portion 73j is disposed on the side of the straight line LA where the charging roller is disposed (i.e., the side indicated by the arrow AL).

[0171] Alternatively, the regulating portion 73j is disposed in an area AL on the opposite side of the line LA passing through the drum center 62a and the gear center 30b from the side where the drum 62 is exposed (the side where the drum 62 faces the transfer roller 7). Note that before the cartridge B is mounted in the apparatus main body A, a cover, shutter, etc. covering the drum 62 may be provided on the cartridge B, and the drum 62 may not be exposed. However, the side where the drum 62 is exposed here means the side where the drum 62 is exposed when the cover, shutter, etc. are removed.

[0172] Furthermore, in a plane perpendicular to the axis of the photosensitive drum 62, the range (area AL) in which the regulating portion 73j is disposed can also be described as follows using the circumferential direction (rotational direction) of the photosensitive drum 62.

[0173] A half line (primary line) LN is drawn starting from the center 62a of the drum 62 and extending toward the center 30b of the gear portion 30a of the developing roller gear 30. The area AL is a range (area) of an angle greater than 0° and less than 180° toward the upstream side (arrow AK side) in the drum rotation direction relative to this half line LN.

[0174] In yet another way, the area AL is a range that is on the upstream side (the side indicated by the arrow AK) of the midpoint MA between the drum center 62a and the developing roller gear center 30b in the drum rotation direction O, and does not exceed a straight line (extension line) LA that passes through the center 62a of the drum 62 and the center 30b of the gear portion 30a of the developing roller gear 30.

[0175] Furthermore, when the door 13 is open and the drive transmission member 81 is moved to the drive side, the regulating portion 73j is positioned so as to overlap the gear portion 81a of the drive transmission member 81 in the longitudinal direction. That is, the regulating portion 73j also overlaps the developing roller gear 30 in the longitudinal direction. As shown in FIG. 34, when the developing roller gear 30 and the regulating portion 73j are projected onto the axis Ax2 of the developing roller gear 30, at least a portion of their projected areas overlap. That is, the regulating portion 73j is located close to the gear portion 81a (gear portion 30a) where the meshing force is generated. Therefore, when the meshing force received by the drive transmission member 81 is supported by the regulating portion 73j, bending of the drive transmission member 81 is suppressed.

[0176] Furthermore, at least a portion of the restricting portion 73j is located outside (on the side of the arrow D1 shown in FIG. 34) the coupling protrusion 63b in the axial direction.

[0177] Next, the radial position of the restricting portion 73j with respect to the drum 62 will be described (see FIG. 24(a)).

[0178] Each distance shown below is a distance measured in a direction perpendicular to the axial direction of the drum 62 (radial distance of the drum 62). S is the distance from the axis (center 62a) of the drum 62 to the restricting portion 73j. U is the radius of the tooth tip of the gear portion 81a of the drive transmission member 81. AC is the distance from the center 81j of the drive transmission member 81 to the radial outermost portion of the coupling recess. AD is the distance from the center 63d of the drive-side drum flange 63 to the radial outermost portion of the coupling protrusion 63b. AA is the distance between the restricting portion 73j and the tooth tip of the gear portion 81a of the drive transmission member 81. AB is the amount of misalignment between the coupling protrusion 63b and the coupling recess 81b when the drive transmission member 81 is tilted by the amount of the gap with the restricting portion 73j (when the drive transmission member 81 is tilted and the gear portion 81a comes into contact with the restricting portion 73j) (see Figure 25(b)).

[0179] Then, the gap AA between the gear portion 81a of the drive transmission member 81 and the restricting portion 73j of the drum bearing 73 is defined as follows. AA=SU

[0180] In the following description, the distance is measured along the axial direction of the drive transmission member 81 from the fixed end 81c, which is the fulcrum for the inclination of the drive transmission member 81. The axial distance from one end 81c of the drive transmission member 81 to the gear portion 81a is defined as X. Furthermore, the axial distance from one end 81c of the drive transmission member 81 to the coupling recess 81b is defined as W.

[0181] The distance X and the distance W satisfy W>X. Therefore, when the drive transmission member 81 is tilted by the gap AA between the restricting portion 73j and the gear portion 81a, the amount of misalignment AB is longer than the gap AA and is defined as follows: AB=AA×(W / X)

[0182] Furthermore, the gap between the coupling protrusion 63b of the drive-side drum flange 63 and the coupling recess 81a of the drive transmission member 81 when there is no misalignment is defined as V. Here, the gap V is the smallest value (minimum distance) among the distances between the surfaces of both coupling parts (the distance measured along a direction perpendicular to the axis of the drum 62, i.e., the radial distance).

[0183] When the triangular phases of the couplings are in sync, the shortest gap V is defined as follows: V=AC-AD

[0184] In order for the couplings to engage even when the drive transmission member 81 is tilted by the gap AA and misalignment of the amount AB occurs between the couplings, the gap V between the couplings should satisfy the following. V=AC-AD>AB

[0185] In other words, if the misalignment AB is smaller than the shortest gap V between the coupling protrusion 63b and the coupling recess 81b, the coupling protrusion 63b and the coupling recess 81b can tolerate the misalignment AB and engage with each other.

[0186] If the phase of the coupling recess 81b relative to the coupling protrusion 63b changes, the shortest gap V between the two coupling portions also changes. In other words, if the phases of the two coupling portions are misaligned, the shortest gap V between the coupling protrusion 63b and the coupling recess 81b becomes smaller than (AC - AD). There may also be cases where V becomes smaller than the amount of misalignment AB.

[0187] However, if there is at least one phase relationship between the two coupling portions that satisfies "V>AB," the coupling protrusion 63b and the coupling recess 81b will engage with each other. This is because the coupling recess 81b comes into contact with the coupling protrusion 63b while rotating. When the coupling recess 81b rotates to an angle that satisfies "V>AB," it can engage (couple) with the coupling protrusion 63b.

[0188] Furthermore, when the distance S from the center 62a of the drum 62 to the restriction portion 73i is measured along the radial direction of the drum 62, S=AA+U Substituting "AB=AA×(W / X)" and "AA=S―U" into "V>AB", we get V>(SU)×(W / X) It is sufficient if there is at least one phase relationship between the coupling protrusion 63b and the coupling recess 81b that satisfies this formula.

[0189] Furthermore, by further modifying the above equation, the condition for distance S is as follows: S <U+V×(X / W)

[0190] Furthermore, when the drive transmission member 81 rotates, it is desirable that the restricting portion 73j not come into contact with the gear portion 81a, and therefore it is desirable that the restricting portion 73j be spaced apart from the tooth tips of the gear portion 81a. This can be expressed by the following equation: S>U is.

[0191] Summarizing this with the above equation, U <S<U+V×(X / W) holds true.

[0192] If the cross-sectional shapes of the coupling protrusion 63b and the coupling recess 81b are both substantially equilateral triangles as in this embodiment, the gap V will be at its maximum when the phases of both coupling portions are aligned. The value of V at that time can be substituted into the above equation to find the required range of S.

[0193] The operation when the coupling engages will be described. Before the coupling recess 81b of the drive transmission member 81 engages with the coupling protrusion 63b of the drive-side drum flange 63, a meshing force FD is applied to the drive transmission member 81. As described above, the meshing force FD is a force generated by the meshing between the gear portion 81a of the drive transmission member 81 and the gear portion 30a of the developing roller gear 30.

[0194] Due to the meshing force FD, the drive transmission member 81 tilts in the direction FD in which the meshing force is applied, with the drive transmission member bearing 83 as the fulcrum, by the amount of the gap AA between the restricting portion 73j of the drum bearing 73 and the gear portion 81a. The amount of misalignment AB between the coupling recess 81b and the coupling protrusion 63b caused by this tilt becomes smaller than the gap V between the coupling recess 81b and the coupling protrusion 63b at a predetermined phase. As a result, when the drive transmission member 81 rotates and the triangular phases of the coupling recess 81b and the coupling protrusion 63b are aligned, the coupling recess 81b fits into and engages with the coupling protrusion 63b without the end faces of the coupling interfering with each other.

[0195] Here, an example of dimensions that satisfy the above condition when the radius of the drum 62 is 12 mm is shown below.

[0196] In this embodiment, the dimensions of each part of the drive transmission member 81 adaptable to the drum 62 with a radius of 12 mm are as follows. The distance AC from the center of the coupling recess 81b to the apex of the substantially equilateral triangle that the coupling recess 81b has is 6.5 mm, and the radius AE of the inscribed circle of the substantially equilateral triangle of the coupling recess 81b is 4.65 mm. The substantially equilateral triangle that the coupling recess 81b has is not a pure equilateral triangle, and the apex (angle) is crushed in an arc shape. The radius AF of the relief portion 81b3 of the coupling recess is 4.8 mm, the radius U of the tip circle of the gear portion 81a of the coupling recess is 12.715 mm, the distance X from one end portion 81c to the non-driving side end face 81a1 is 30.25 mm, and the distance W from one end portion 81c to the tip portion 81b1 of the coupling recess is 33.25 mm.

[0197] Note that the shortest distance V between the coupling recess 81b and the coupling projection 63b satisfies the following relationship.

[0198] 0 < V < 1.7 V becomes the lower limit when the size of the triangular shape that the coupling recess 81b has is equal to the size of the triangular shape that the coupling projection 63b has, and the lower limit value of V is "0". On the other hand, V becomes the upper limit when the distance AC from the center to the apex of the coupling projection 63b is 4.8 mm, which is the radius AF of the relief portion of the coupling recess 81b. At this time, the gap V (mm) between the coupling projection 63b and the coupling recess 81b is obtained as "1.7 = 6.5 - 4.8".

[0199] Substituting each value and V = 1.7 into the formula "U < S < U + V × (X / W)" shown above, we get "12.715 < S < 14.262" (the unit is mm).

[0200] We actually confirm that the above formula holds using two examples. <000078​First, the first example shows the dimensions when the coupling protrusion 63b is made as large as possible while still being able to engage with the coupling recess 81b. In this case, the gap V between the coupling protrusion 63b and the coupling recess 81b is minimized, reducing the allowable tilt of the drive transmission member 81. Therefore, in order to reduce the tilt of the drive transmission member 81, it becomes necessary to move the restricting portion 73j as close as possible to the normal position of the gear portion 81a.

[0202] On the other hand, the second example shows the dimensions when the coupling protrusion 63b is made as small as possible to engage with the coupling recess 81b. In this case, the gap V between the coupling protrusion 63b and the coupling recess 81b is maximized, allowing the coupling protrusion 63b and the coupling recess 81b to engage even if the drive transmission member 81 is tilted. In other words, the restricting portion 73j can tolerate the drive transmission member 81 tilt to a certain extent, allowing the restricting portion 73j to be relatively far away from the normal position of the gear portion 81a. The first example shows the case where the size of the coupling protrusion 63b is maximized, thereby maximizing the radial engagement between the coupling protrusion 63b and the coupling recess 81b (the area where they engage). In this case, V (the gap between the couplings) approaches its minimum (minimum), so S (the distance from the center of the drum 62 to the restricting portion 73j) must approach its minimum (12.715 mm). The distance AD ​​from the center to the apex of the coupling protrusion 63b on the drive-side drum flange 63 is set to 6.498 mm. When the coupling protrusion 63b has a dimension slightly smaller than the 6.5 mm distance from the center of the coupling recess 81b to the apex of the triangle, the radial engagement between the coupling parts is approximately maximum. The radius AG of the inscribed circle inscribed in the triangle that makes up the coupling protrusion 63b of the drive-side drum flange 63 is 4.648 mm. Note that the approximate triangular shape of the coupling protrusion 63b is not a pure equilateral triangle, but rather the apex (corner) is flattened into an arc shape.

[0203] In this case, the distance S from the center 62a of the drum 62 to the restricting portion 73j of the drum bearing is set to 12.716 mm, which is slightly larger than the radius U of the tip circle of the gear portion 81a.

[0204] As a result, the gap AA between the regulating portion 73j of the drum bearing and the gear portion 81a of the drive transmission member is 0.001 mm (= 12.716 - 12.715). Here, the misalignment AB between the coupling portions when the drive transmission member 81 is tilted by the gap AA with the regulating portion 73j is amplified by the difference in the longitudinal positions of the regulating portion 73j and the coupling portion. The misalignment AB is 0.0011 mm (= 0.001 x 33.25 / 30.25). Furthermore, when the coupling portions are in phase, the shortest gap V between the coupling protrusion 63b and the coupling recess 81b is 0.002 mm (the smaller of "6.5 - 6.498" and "4.65 - 4.648").

[0205] Therefore, even if the drive transmission member 81 is tilted by the meshing force, engagement is possible because the gap V between the couplings is larger than the amount of misalignment AB between the coupling portions.

[0206] As can be seen from the above explanation, it is preferable that the radial distance from the center of the drum 62 to the outermost part of the coupling portion is greater than 4.8 mm, and the radial distance from the center of the drum 62 to the restricting portion 73j is greater than 12.715 mm.

[0207] In the second example, as mentioned above, the size of the coupling protrusion 63b is made as small as possible, and the radial engagement between the coupling protrusion 61b and the coupling recess 81b (the area where they engage) is made as small as possible. In this case, V (the gap between the couplings) approaches its maximum (upper limit), and S (the distance from the center of the drum 62 to the restriction portion 73j) can also take a value close to its upper limit.

[0208] The distance AD ​​between the center and apex of the coupling protrusion 63b of the drive-side drum flange 63 is set to 4.801 mm. This is slightly larger than the 4.8 mm radius of the lightening hole 81b3 of the coupling recess 81b, and is the diameter at which the radial engagement between the couplings is approximately minimized. If the distance AD ​​of the coupling protrusion 63b were shorter than the radius of the lightening hole 81b3, the tip of the protrusion 63b would not engage with the coupling recess 81b, and drive transmission would be impossible.

[0209] In this case, the radius AG of the triangular inscribed circle of the coupling protrusion 63b is 2.951 mm. The distance S from the center 62a of the drum 62 to the restriction portion 73j of the drum bearing is 14.259 mm.

[0210] As a result, the gap AA between the restricting portion 73j of the drum bearing 73 and the gear portion 81a of the drive transmission member 81 is 1.544 mm (= 14.259 - 12.715). When the drive transmission member 81 is tilted by the gap AA between the restricting portion 73j and the coupling, the misalignment AB between the coupling portions is amplified by the difference in longitudinal position between the restricting portion 73j and the coupling, and is 1.697 mm (= 1.544 x 33.25 / 30.25). When the coupling portions are in phase, the gap V between the coupling protrusion 63b and the coupling recess 81b is 1.699 mm (the smaller of "6.5 - 4.801" and "4.65 - 2.951"). Therefore, even if the drive transmission member 81 is tilted by the meshing force FD, the gap V between the couplings is larger than the misalignment AB between the coupling portions, and therefore the coupling protrusion 63b and the coupling recess 81b can engage with each other.

[0211] As can be seen from the second example, the radial distance from the center of the drum 62 to the outermost part of the coupling protrusion 63b should be greater than 4.8 mm, and the radial distance from the center of the drum 62 to the regulating portion 73j should be less than 14.262 mm.

[0212] Combining the first and second examples, in this embodiment, the radial distance S from the center 62a of the drum 62 to the restricting portion 73j of the drum bearing should be greater than 12.715 mm and smaller than 14.262 mm.

[0213] Next, we will generally define a suitable positional relationship for the restriction portion 73j by taking as an example a case where the shape of the coupling protrusion 363b is not limited to a substantially equilateral triangle, but a more general shape is used. For convenience, the shape of the coupling recess will be discussed as being a virtual pure equilateral triangle.

[0214] First, an example of a coupling protrusion of a general shape is shown in Figures 28(a) and (b). The coupling protrusion 363b shown in Figures 28(a) and (b) has a substantially cylindrical shape and further has a protrusion 363b1 provided on the outer periphery of the cylinder. The coupling protrusion 363b is configured to receive a driving force via the protrusion 363b1.

[0215] A case where the regulating portion is located farthest from the center of the drum will be described with reference to FIG.

[0216] First, consider the smallest equilateral triangle BD that circumscribes the coupling protrusion 363b, and regard this equilateral triangle BD as a virtual coupling protrusion. The center of gravity of the equilateral triangle BD is aligned with the center of the coupling protrusion 363b (the center of the drum 62), while minimizing the size of the equilateral triangle BD. From here on, consider the placement of the restriction portion 73j that corresponds to this virtual coupling protrusion (equilateral triangle DB).

[0217] The circle inscribed in this imaginary coupling convex portion (equilateral triangle BD) is called circle BE, and its radius is called BA.

[0218] When the coupling recess has an equilateral triangle shape, in order for the coupling recess to engage with the imaginary coupling protrusion (equilibrium triangle BD), the coupling recess must be larger than the equilateral triangle BD. In other words, the size of the equilateral triangle BD can be considered the lower limit of the dimensions that the coupling recess can have.

[0219] Next, consider the maximum possible shape of the coupling recess. First, consider a circle BU that circumscribes the imaginary coupling protrusion (equilateral triangle BD), and let its radius be AZ. Then, draw an equilateral triangle BQ with this circle BU as its inscribed circle. If the coupling recess has an equilateral triangular shape, the equilateral triangle BQ is the maximum (upper limit) equilateral triangular shape that can be set as the coupling recess. This is because if the coupling recess were larger than the equilateral triangle BQ, it would not be able to come into contact with the imaginary coupling protrusion BD, and drive transmission would be impossible. This equilateral triangle BQ is defined as the maximum coupling recess.

[0220] Let AY be the shortest distance between these two equilateral triangles when they are in the same phase. The distance AY is equivalent to the difference between the radius (AZ) of the inscribed circle BU inscribed in the equilateral triangle BQ and the radius (BA) of the inscribed circle BE inscribed in the equilateral triangle BD. In other words, AY=AZ―BA is.

[0221] When the coupling recess is an equilateral triangle, the distance between the imaginary coupling protrusion and the coupling recess is limited to the above-mentioned distance AY. If the misalignment distance of the coupling recess from the imaginary coupling protrusion is smaller than AY, the coupling recess can engage with the imaginary coupling protrusion.

[0222] The distance of misalignment between the couplings is equal to or greater than the gap BC between the tooth tip of the gear portion 81a of the drive transmission member and the restricting portion 73j. Therefore, in order for the coupling recess to engage with the imaginary coupling protrusion BD, the gap BC between the gear portion 81a of the drive transmission member and the restricting portion 73j must be at least smaller than the above distance AY. This can be expressed as BC <AY is.

[0223] The clearance BC is the difference between the distance BB from the drum center to the regulating portion 73j and the radius of the tip circle of the gear portion 81a. Considering the radius of the tip circle of the gear portion 81a, the tip of the gear portion 81a of the drive transmission member can extend to the root of the gear portion 30a of the developing roller gear 30. That is, the tip of the gear portion 81a can be extended to the extent that it does not touch the root. If the shortest distance from the drum center to the root of the gear portion 30a of the developing roller gear 30 is AX, the upper limit of the radius of the tip circle 81a of the gear portion 81a is also AX.

[0224] Therefore, the clearance BC between the tip of the gear portion 81a and the regulating portion 73j is always greater than "BB - AX".

[0225] BC > BB - AX That is. Using the relational expressions of "BC > BB - AX" and the above-mentioned "BC < AY", the distance BB from the drum center to the regulating portion 73j is BB - AX < AY BB < AY + AX It can be seen that this is satisfied. Here, AY = AZ - BA = BA(1 / sin30° - 1) = BA That is. Therefore, BB < BA + AX That is.

[0226] When the drive transmission member 81 is tilted by the meshing force between the gears, as a necessary condition for the couplings to engage with each other, "BB < BA + AX" can be obtained for the distance BB from the drum center to the regulating portion 73j.

[0227] Next, the case where the regulating portion is located on the side closest to the center of the drum will be described. For the gear portion 81a of the drive transmission member 81 to mesh with the gear portion 30a, the radius of the tip circle of the gear portion 81a needs to be greater than the distance BF (the distance measured in the direction perpendicular to the axis of the drum) from the center of the drum 62 to the tip of the gear portion 30a of the developing roller.

[0228] Also, during image formation, it is necessary that the tooth tips of the regulation unit 73j and the drive transmission member 81a do not contact each other. That is, the distance BB (the distance measured in the direction perpendicular to the axis of the drum) from the center of the drum 62 to the regulation unit 73j needs to be longer than the distance BF (the distance measured in the direction perpendicular to the axis of the drum) from the center of the drum 62 to the tooth tip of the gear portion 30a of the developing roller. From the above two conditions BB > BF needs to be satisfied.

[0229] Combined with the above-mentioned "BB < BA + AX", it is necessary to be arranged within a range that satisfies the following relationship with respect to the center of the drum (the axis of the drum, the axis of the input coupling) of the regulation unit 73j. BF < BB < AX + BA

[0230] The definitions of each value are summarized as follows.

[0231] BB: The distance measured from the center of the photoreceptor (the axis of the photoreceptor, the axis of the coupling convex portion) to the regulation unit 73j along the direction perpendicular to the axis of the photoreceptor BA: The radius of the inscribed circle of the smallest equilateral triangle circumscribing the coupling convex portion when the centroid of the equilateral triangle is made to coincide with the axis of the drum (the axis of the coupling convex portion).

[0232] AX: The distance measured from the center of the photoreceptor (the rotation axis of the coupling convex portion) to the bottom of the teeth of the developing roller gear (the bottom of the teeth of the input gear) along the direction perpendicular to the axis of the photoreceptor BF: The shortest distance measured from the center of rotation (axis) of the photoreceptor to the tooth tip of the input gear portion (gear portion 30a) along the direction perpendicular to the axis of the photoreceptor is as follows.

[0233] In this embodiment, the regulation unit 73j is formed of a continuous surface. Specifically, the regulation unit 73j is an arced curved surface (arc surface) that is open on the axis side of the drum 62 and is curved like an arch. In another way of saying, it is a bay shape (bay portion) that is open on the axis side of the drum 62.

[0234] 26, the restricting portion 89j may be formed by a plurality of portions (a plurality of surfaces 89j) that are discontinuous in the rotation direction of the drum 62. In this case, too, by connecting the plurality of discontinuous portions, the restricting portion can be considered to form a bay shape (bay portion) that is open toward the axial side of the drum 62.

[0235] That is, although the regulating portion may be one continuous part or multiple discontinuous parts, the regulating portion shown in Figure 1 and the regulating portion shown in Figure 26 both have a bow-like shape (bay shape, curved portion, bent portion) that opens toward the axis of the drum 62.

[0236] Furthermore, in this embodiment, the triangular aligning action of the coupling protrusion 63b and the coupling recess 81b is utilized as a means for aligning the core of the drive transmission member 81 with the core of the drum 62. In other words, the coupling protrusion 63b and the coupling recess 81b come into contact with each other at three points, aligning the axis of the coupling protrusion 63b with the axis of the coupling recess 81b. By making the drive transmission member 81 and the photosensitive drum coaxial, it becomes easier to maintain the accuracy of the center-to-center distance (axis-to-axis distance) between the gear portion 81a and the gear portion 30a, and drive is transmitted to the developing roller gear 30 in a stable manner.

[0237] However, a cylindrical boss (protrusion) may be provided on one of the drive transmission member 81 and the drive-side drum flange 63, and a hole that fits into the boss may be provided on the other. Even with this configuration, the axes of the drive transmission member 81 and the drum 62 can be aligned. Figure 38 shows such a modification. The drive transmission member 181 shown in Figure 38 has a protrusion (boss) 181c at the center of its coupling recess 181b. The protrusion 181c is positioned so as to overlap the axis of the drive transmission member 181 and is a protrusion that protrudes along that axis. On the other hand, the coupling protrusion shown in Figure 38 has a recess (recess) in its center for engaging with the protrusion 181c. The recess is positioned so as to overlap the rotation axis of the drum 62 and is a recess that is recessed along this axis. By making the drive transmission member 81 and the photosensitive drum coaxial, it becomes easier to maintain the accuracy of the center-to-center distance (axis-to-axis distance) between the gear portion 81a and the gear portion 30a, and drive is transmitted to the developing roller gear 30 stably.

[0238] Next, the arrangement of the coupling protrusion 63b in the longitudinal direction (drum axial direction) will be described. As shown in Figure 18, the drive-side drum flange 63 has a flange 63c. The cleaning frame 71 has a drum regulating rib 71m (drum regulating portion, drum longitudinal position regulating portion, drum axial position regulating portion).

[0239] The drum restriction rib 71m is disposed on the non-drive side in the longitudinal direction relative to the flange portion 63c of the drive-side drum flange 63, and faces the flange portion 63c with a gap therebetween.

[0240] If the drum 62 moves beyond this gap to the non-drive side, the flange 63c and the drum restricting rib 71m come into contact, restricting the movement of the drum 62. In other words, the drum 62 is configured to not move longitudinally (axially) beyond a certain range. This improves the longitudinal positional accuracy of the coupling protrusion 63b of the drive-side drum flange 63 before the coupling protrusion 63b of the drive-side drum flange 63 engages with the coupling recess 81b. Therefore, even if the longitudinal movement of the drive transmission member 81 is reduced, the coupling protrusion 63b and the coupling recess 81b can be engaged. By reducing the longitudinal movement of the drive transmission member 81, the device main body A can be made more compact.

[0241] Next, the arrangement of the gear portion 30a of the developing roller gear 30 in the longitudinal direction (drum axial direction) will be described. As shown in Figure 18, the developing roller gear 30 has an end face 30a2 on the non-drive side of the gear portion 30a. The developing container 23 has a developing roller gear regulating rib 23d (gear regulating portion, gear longitudinal position regulating portion, gear axial position regulating portion).

[0242] The developing roller gear regulation rib 23d is disposed on the non-drive side in the axial direction relative to the non-drive side end face 30a2 of the gear portion 30a, and faces the non-drive side end face 30a2 with a gap therebetween.

[0243] As a result, the developing roller gear restricting rib 23d arranged on the drive side of the cartridge B restricts the developing roller gear 30 from moving longitudinally toward the non-drive side. This improves the axial positional accuracy of the gear portion 30a of the developing roller gear 30 before the gear portion 30a of the developing roller gear 30 meshes with the gear portion 81a of the drive transmission member 81. This makes it possible to reduce the gear width of the gear portion 30a of the developing roller gear 30. As a result, it is possible to reduce the size of the cartridge B and the apparatus main body A into which the cartridge B is to be mounted.

[0244] <Removing the cartridge> Next, removal of the cartridge B from the apparatus main assembly A will be described with reference to FIGS.

[0245] 7, when the door 13 is rotated open, the cylindrical cam 86 rotates along the inclined surfaces 86a and 86b via the rotating cam link 85 and moves until an end surface 86c of the cylindrical cam 86 abuts against an end surface 15f of the driving side plate 15 on the driving side in the axial direction. Then, the movement of the cylindrical cam 86 enables the drive transmission member 81 to move to the driving side in the axial direction (the side away from the cartridge B).

[0246] As shown in FIGS. 24(a), 24(b) and 25(a), the radial tooth engagement between the gear portion 81a of the drive transmission member 81 and the gear portion 30a of the developing roller gear 30 is defined as engagement amount AH.

[0247] In order for the gear portion 81a to disengage from the gear portion 30a, the gear portion 81a must move away from the gear portion 30a by more than the engagement amount AH of both gear portions. Therefore, the regulating portion 73j of the drum bearing 73 is positioned so as not to impede the movement of the drive transmission member 81 when the gear portion 81a disengages from the gear portion 30a. To achieve this, the direction in which the gear portion 81a of the drive transmission member 81 moves away from the gear portion 30a of the developing roller gear 30 is indicated by the arrow AI, which is the direction connecting the center 81j of the drive transmission member 81 and the center 30b of the developing roller gear 30. It is preferable not to provide the regulating portion 73j in the direction of the arrow AI. In other words, it is preferable not to position the regulating portion 73j so that it straddles the line LA, and to prevent the drive transmission member 81 from coming into contact with the regulating portion 73j when the gear portion 81a disengages from the gear portion 30a.

[0248] When the gear portion 81a disengages from the gear portion 30a, it is desirable that the drive transmission member 81 does not come into contact with the recessed circumferential surface 73k of the drum bearing 73. Therefore, when the door 13 is open (FIGS. 7(a) and 7(b)), the drive transmission member 81 is retracted to a position where it does not come into contact with the recessed circumferential surface 73k of the drum bearing 73.

[0249] 24(a), the drive transmission member 81 retreats until it is no longer coupled to the coupling protrusion 63b. In this state, the tip of the drive transmission member 81 is located in approximately the same position as the tip of the recessed circumferential surface 73k in the longitudinal direction, or further to the left of the tip of the recessed circumferential surface 73k.

[0250] In this state, even if the drive transmission member 81 tilts to release the meshing between the gear portion 81a and the gear portion 30a, the drive transmission member 81 and the recessed circumferential surface 73k will not come into contact with each other.

[0251] It is also possible that the distance that drive transmission member 81 moves when retracting is short, and the tip of drive transmission member 81 in the retracted position is located to the right of the tip of recessed circumferential surface 73k. In such a case, contact between drive transmission member 81 and recessed circumferential surface 73k can be avoided if the following conditions are met.

[0252] The radial distance from the center 62a of the drum 62 to the concave circumferential surface 73k of the drum bearing 73 is defined as Z. The radial distance from the center 81j of the drive transmission member 81 to the outer circumferential surface of the cylindrical portion 81i of the drive transmission member 81 is defined as Y. The radial distance of the gap between the concave circumferential surface 73k and the cylindrical portion 81i is defined as AJ. In this case, the gap AJ satisfies the following formula. AJ=ZY AJ>AH

[0253] That is, a recess is provided around the periphery of the drum 62. The drive transmission member 81 can move within a range where the inner circumferential surface of the recess (recessed circumferential surface 73k) does not come into contact with the gear portion 81a.

[0254] The radial position of the concave circumferential surface 73k of the drum bearing 73 may be such that the distance Z from the center 62a of the drum 62 is as follows: Z>AH+Y

[0255] With the above-described configuration, when the cartridge B is removed from the main assembly A of the apparatus, the drive transmission member 81 can be tilted in the separating direction AD by an amount equal to or greater than the engagement amount AH between the gear portion 81a of the drive transmission member 81 and the gear portion 30a of the developing roller gear 30. Then, the meshing between the gear portion 81a of the drive transmission member 81 and the gear portion 30a of the developing roller gear 30 is released, allowing the cartridge B to be smoothly removed from the main assembly A of the apparatus.

[0256] As described above, the drive transmission member 81 moves in a direction approaching the coupling portion on the cartridge side due to the thrust force caused by the meshing of the helical gears.

[0257] Furthermore, the drive transmission member 81 moves (tilts) due to the force generated by the meshing of the gears, but the amount of movement (tilt) is regulated by a regulating section provided on the cartridge side. This ensures reliable engagement (coupling) between the drive transmission member 81 and the coupling section on the cartridge side, ensuring reliable drive transmission.

[0258] Furthermore, by providing a gap that allows the drive transmission member 81 to move radially beyond the gear meshing height, the gears are smoothly disengaged when removing the cartridge B from the main body of the apparatus. In other words, the cartridge can be easily removed.

[0259] Furthermore, while in this embodiment the coupling protrusion 63b is fixed relative to the drum 62, a movable coupling protrusion may also be provided. For example, the coupling 263b shown in FIG. 20 is movable in the axial direction relative to the drum 62 and is biased toward the drive side by a spring 94 when not receiving external force. When the cartridge B is installed in the main assembly A of the apparatus, the end 263a of the coupling 263b contacts the drive transmission member 81. The force received from the drive transmission member 81 causes the coupling protrusion 263b to compress the spring 94 and retract toward the non-drive side (the side away from the drive transmission member 81). With this configuration, it is not necessary to retract the drive transmission member 81 to an extent that it does not come into contact with the coupling protrusion 263b. In other words, the amount of retraction of the drive transmission member 81 linked to the opening of the opening / closing door 13 (see FIG. 2) can be reduced by the amount that the coupling protrusion 263b can retract. This means that the main assembly A of the apparatus can be made more compact.

[0260] The end 263a of the coupling protrusion 263b is formed as an inclined portion (inclined surface, chamfered surface). With this configuration, when the end 263a comes into contact with the drive transmission member 81 during installation or removal of the cartridge, the end 263a is likely to receive a force that retracts the coupling protrusion 263b. However, this configuration is not limited to this. For example, the contact portion on the drive transmission member 81 side that comes into contact with the coupling protrusion 263b may be formed as an inclined portion.

[0261] Another modified example is shown in Figure 23. In this embodiment, the drum 62 is driven by the engagement between the drive transmission member 81 and the coupling protrusion 63b, but as shown in Figure 23, the drum 62 can also be driven by gears 330b, 95b provided inside the cartridge.

[0262] 23, the developing roller gear 330 has not only a gear portion (input gear portion) 330a for receiving drive force from the gear portion 81a of the drive transmission member 81, but also a gear portion 330b (output gear portion) for outputting drive force toward the drum 62. Furthermore, the drum flange 95 fixed to the end of the drum 62 does not have a coupling protrusion, but instead has a gear portion 95b (input gear portion) for receiving drive force from the gear portion 330b. Furthermore, the drum flange 95 has a cylindrical portion 95a.

[0263] In this case, a cylindrical portion 95 a provided at the end of the drum 62 functions to position the drive transmission member 81 by fitting into a coupling recess 81 b provided at the tip of the drive transmission member 81 .

[0264] The recess 81b and the cylindrical portion 95a both act as alignment portions for aligning the axis of the drive transmission member recess 81 with the axis of the drum 62. When the coupling recess 81b and the cylindrical portion 95a are engaged, the axes of the drum 62 and the drive transmission member 81 substantially overlap, and they are arranged coaxially. Note that the coupling recess 81b may be referred to as the main body side alignment portion (alignment recess), and the cylindrical portion 95a may be referred to as the cartridge side alignment portion (alignment protrusion).

[0265] More precisely, the outer peripheral surface of the cylindrical portion 95a corresponds to the cartridge-side alignment portion. The hollowed-out portion 81b3 of the coupling protrusion 81b corresponds to the main-body-side alignment portion. The circular hollowed-out portion 81b3 fits into the outer peripheral surface of the cylindrical portion 95a, thereby aligning the drum 62 and the drive transmission member 81.

[0266] In the cartridge shown in Figure 23, the engagement of the gear portion 30a of the gear 30 and the gear portion 81a of the drive transmission member 81 generates a force that attracts the coupling recess 81b and the cylindrical portion 95a to each other, in the same manner as in the above-described embodiment. Drive is transmitted between the gear portion 30a and the gear portion 81a, causing the coupling recess 81b and the cylindrical portion 95a to engage with each other. To facilitate engagement between the coupling recess 81b and the cylindrical portion 95a, an inclined portion (taper, chamfer) 95a1 (see Figure 23(b)) is provided on the edge of the tip of the cylindrical portion 95a. In other words, the diameter of the cylindrical portion 95a becomes smaller as it approaches the tip.

[0267] As mentioned above, when the coupling protrusion 63b is provided at the end of the drum 62, the coupling recess 81b acts as an output coupling for transmitting driving force to the coupling protrusion 63b. Furthermore, when the coupling protrusion 63b is substantially triangular, the drive transmission member 81 is aligned by connecting the coupling recess 81b to the coupling protrusion 63b. Therefore, the coupling recess 81b also acts as an alignment portion.

[0268] On the other hand, when a cylindrical portion 95a is provided at the end of the drum 62 as in the configuration shown in Figure 23(a), the coupling recess 81b does not function as a coupling portion (output coupling), but acts only as an alignment recess (main body side alignment portion).

[0269] In other words, the coupling recess 81b serves as both an output coupling and a main body side alignment portion (alignment recess), and depending on the configuration of the drum 62, the function of the coupling recess 81b can be either that of an alignment recess or a coupling recess, or both.

[0270] Furthermore, while the cartridge-side alignment portion shown in FIG. 23 is a cylindrical portion 95a whose outer periphery forms a perfect circle, the invention is not limited to such a structure. FIG. 35 shows schematic diagrams of examples of alignment portion shapes. FIG. 35(a) shows the state in which the cylindrical portion 95a shown in FIG. 23 is provided on the drum flange 63. In contrast, FIG. 35(b) shows the shape of the alignment portion 95b forming only a part of a circle. If the arc portion of the alignment portion 95b is sufficiently large relative to the arc shape of the lightening portion 81b3, the alignment portion 95b will have an alignment effect. The distance (radius) from the center of the drum to the outermost portion of each alignment portion 95a, 95b is 4.8 mm or less, and the closer it is to 4.8 mm, the greater the alignment effect.

[0271] In this embodiment, the coupling recess 81b, which serves as the main body-side alignment portion, has a substantially triangular shape and includes an arc-shaped recess 81b3 on one side of the triangle to transmit drive when engaged with the coupling protrusion 63b. However, if the main body-side alignment portion does not need to transmit drive to the drum 62, the main body-side alignment portion can have another shape. For example, the main body-side alignment portion may be a substantially circular recess. In this case, an alignment portion 95c such as that shown in FIG. 35(c) can be used as the cartridge-side alignment portion. The alignment portion shown in FIG. 35(c) has a configuration in which multiple protrusions 95c are arranged in a circle. That is, the circumscribing circle of the protrusions 95c (shown by the dotted line) is a circle coaxial with the drum. Furthermore, the size of this circumscribing circle corresponds to the recess of the main body-side alignment portion. That is, the radius of the circumscribing circle is 4.8 mm or less.

[0272] 35(a), (b), and (c) can be considered as alignment parts that are substantially coaxial with the drum, i.e., each of alignment parts 95a, 95b, and 95c is positioned so that its center is on the axis of the drum.

[0273] Strictly speaking, the outer peripheral surfaces of the alignment portions 95a, 95b, and 95c, i.e., the portions facing the opposite side of the drum axis (in other words, the portions facing the radially outer side of the drum), act as alignment portions. The outer peripheral surfaces acting as alignment portions are arranged to surround the drum axis.

[0274] Each of the centering portions 95a, 95b, and 95c is exposed toward the outside of the cartridge in the axial direction.

[0275] 23 also desirably has the above-described regulating portion 73j. The positional relationship (dimensional relationship) of the developing roller gear 30 and the regulating portion 73j relative to the centering portion can be considered to be the same as the positional relationship (dimensional relationship) of the developing roller gear 30 and the regulating portion 73j relative to the cartridge protrusion 63b.

[0276] For example, for the reasons described above, the following relationship holds for the lower limit of the distance BB from the center of the drum to the center of the restricting portion 73j. BF <BB Roar.

[0277] BB: Distance measured from the center of the photosensitive member (axis of the photosensitive member, axis of the coupling protrusion) to the regulating portion 73j along a direction perpendicular to the axis of the photosensitive member BF: The shortest distance measured from the rotation center (axis) of the photosensitive member to the tip of the teeth of the input gear portion (gear portion 30a) along a direction perpendicular to the axis of the photosensitive member. The upper limit of the distance BB will also be considered. When the power transmission member 81 tilts until the gear portion 81a contacts the restricting portion 73j, the amount of misalignment that occurs between the coupling recess 81b and the alignment portion 95a desirably satisfies the following relationship: The alignment portion 95a has an inclined portion 95a1 (see FIG. 23(a)) at the tip thereof, and when the width of the inclined portion 95a is measured along the radial direction of the drum, it is desirably greater than the amount of misalignment. If this relationship is satisfied, the inclined portion 95a1 of the alignment portion 95a will come into contact with the edge of the coupling recess 81b, assisting the engagement between the coupling recess 81b and the alignment portion 95a, even if misalignment occurs.

[0278] If the difference between the distance BB and the radius U of the tip circle of the gear part 81a is defined as "BB - U", the amount of core deviation will be greater than "BB - U". Therefore, at least the width BX of the inclined part 95a needs to be greater than "BB - U". Also, the radius U of the tip circle of the gear part 81a is shorter than the distance AX from the center of the drum to the root of the teeth of the developing roller gear. Therefore, the width BX of the inclined part 95a is greater than "BB - AX".

[0279] BX > BB - AX When this is transformed, BB < BX + AX That is.

[0280] BB: The distance measured from the center of the photoreceptor (the axis of the photoreceptor, the axis of the coupling convex part) to the regulating part 73j along the direction perpendicular to the axis of the photoreceptor BX: The width of the inclined part 95a measured along the radial direction of the photoreceptor AX: The distance measured from the axis of the photoreceptor to the root of the teeth of the developing roller gear along the direction perpendicular to the axis of the photoreceptor To summarize, "BF < BB < BX + AX" holds.

[0281] In the configuration shown in FIG. 23, the cylindrical part 95a is provided on the drum 62. However, the centering part such as the cylindrical part 95a may be provided on the frame of the cleaning unit 60 (that is, the drum bearing 73). That is, a configuration in which the drum bearing 73 covers the end of the drum 62 and the centering part is provided on the drum bearing 73 is also conceivable. Also, as the centering part on the cartridge side, instead of the concave part 81b of the drive transmission member 81, a configuration that engages with the cylindrical part 81i (see FIG. 13(a)) of the drive transmission member 81 can also be used.

[0282] The modified example shown in Figure 36 has a configuration in which an arc-shaped protrusion 173a for contacting the periphery of the cylindrical portion 81i is provided on the drum bearing 173. Figure 36(a) shows a perspective view of the cartridge, and Figure 36(b) shows a cross-sectional view of the cartridge and the main body drive member in a state in which their respective alignment portions are engaged. In this modified example, the protrusion 173a corresponds to the alignment portion that aligns the drive transmission member 81 by engaging with the cylindrical portion 81i. More strictly speaking, the inner peripheral surface of the protrusion 173a that faces the axial side of the drum (in other words, that faces radially inward of the drum) is the alignment portion.

[0283] This centering portion is provided in the drum bearing 173, not in the drum flange 195. Therefore, the drum flange 195 has a gear portion 195a for receiving the driving force from the developing roller gear, but does not have a centering portion.

[0284] The center of the alignment portion is positioned so as to overlap with the axis of the drum. In other words, the protrusion 173a is positioned so as to be substantially coaxial with the drum. In other words, the inner peripheral surface of the protrusion 173a facing the axis of the drum is positioned so as to surround the axis of the drum. In addition, the edge of the tip of the protrusion 173a is tapered (inclined), so that when the tip of the protrusion 173a hits the cylindrical portion 81i, the cylindrical portion 81i is easily guided into the internal space of the protrusion 173a.

[0285] Furthermore, the distance (radius) from the drum axis to the centering portion (protrusion 173a) corresponds to the radius of the cylindrical portion 81i. If the radius of the cylindrical portion 81i is 7.05 mm, the radius of the protrusion 173a should be 7.05 mm or more.

[0286] The protrusion 173a also functions as a restricting portion (stopper) that restricts tilting and movement of the drive transmission member 81 by coming into contact with the cylindrical portion 81i. That is, the protrusion 173a can also serve as the restricting portion 73j (see FIG. 24, etc.). A configuration in which the restricting portion is configured to come into contact with the cylindrical portion 81i will be described later in Example 2. The tip of the protrusion 173a is provided with an inclined portion (tapered, chamfered), and when the drive transmission member 81 is tilted, the tip of the cylindrical portion 81i comes into contact with the inclined portion, thereby assisting the engagement between the cylindrical portion 81i and the protrusion 173a. That is, the diameter of the inner circumferential surface of the protrusion 173a increases toward the tip of the protrusion 173a.

[0287] The functions, materials, shapes, relative arrangements, etc. of the components described in the above-mentioned embodiments and variations are not intended to limit the scope of the present invention to those alone, unless otherwise specified.

[0288] <Example 2> Next, a second embodiment of the present invention will be described with reference to Figures 29, 30(a), 30(b), 30(c), 31(a), and 31(b). Figure 29 is a perspective view of the cartridge for illustrating a regulating portion of the drive transmission member. Figure 30(a) is a cross-sectional view of the drive unit of the image forming apparatus as seen from the opposite direction to the cartridge mounting direction to illustrate the regulation of the drive transmission unit. Figure 30(b) is a cross-sectional view of the drive unit of the image forming apparatus as seen from the drive side to illustrate the regulation of the drive transmission unit. Figure 30(c) is a cross-sectional view of the drive unit of the image forming apparatus as seen from the drive side to illustrate the regulation of the drive transmission unit. Figure 31(a) is a cross-sectional view of the drive unit of the image forming apparatus as seen from the drive side to illustrate the regulation of the drive transmission unit. Figure 31(b) is a cross-sectional view of the drive unit of the image forming apparatus as seen from the drive side to illustrate the regulation of the drive transmission unit.

[0289] In this embodiment, only the parts that differ from the previous embodiment will be described in detail. Unless otherwise specified, the materials, shapes, etc. are the same as those in the previous embodiment. Such parts are given the same numbers, and detailed descriptions will be omitted.

[0290] As shown in Figures 29, 30(a), 30(b), and 30(c), the drum bearing 90 has a recess around the protrusion of the coupling portion. A restricting portion 90k1 for restricting movement of the drive transmission member 91 is provided as a small-diameter portion (a portion where the inner diameter of the recess is smaller than other portions) within the recessed circumferential surface 90k (the inner circumferential surface of the recess). The restricting portion 90k1 is an arc-shaped curved surface portion facing the drum axis.

[0291] The restricting portion 90k1 is a restricting portion (stopper) for suppressing movement and tilt of the drive transmission member 91, and corresponds to the restricting portion 73j (see FIGS. 1, 24, etc.) in the first embodiment. Below, the differences between 90k1 in the present embodiment and restricting portion 73j in the first embodiment will be described in detail.

[0292] The location where the restricting portion 90k1 restricts the inclination of the drive transmission member 91 is a cylindrical portion (columnar portion) 91i provided at the tip of the non-driving side in the axial direction of the drive transmission member 91. The cylindrical portion 91i corresponds to a columnar protrusion in which a coupling recess is formed.

[0293] When the door 13 is open and the drive transmission member 91 moves to the driving side (away from the cartridge side), the restricting portion 90k1 overlaps with the cylindrical portion 91i of the drive transmission member 91 in the axial direction.

[0294] 39, in this embodiment, at least a portion of the restricting portion 90k1 is located outside (on the side of arrow D1) the outer peripheral surface 63b2 of the input coupling portion (coupling protrusion 63b) in the axial direction. Here, the outer peripheral surface 63b2 is a portion (drive receiving portion) that receives the driving force from the coupling recess. In this embodiment, at least a portion of the restricting portion 90k1 is particularly located outside the tip 63b1 of the coupling protrusion 63b.

[0295] Furthermore, a portion of the restricting portion 90k1 is disposed so as to at least partially overlap with the input coupling portion (the coupling protrusion 63b) in the axial direction. That is, when the coupling protrusion 63b and the restricting portion 90k1 are projected onto the drum axis Ax1, at least a portion of their projected areas overlap. In other words, at least a portion of the restricting portion 90k1 is disposed so as to face the input coupling portion (the coupling protrusion 63b) provided at the end of the drum.

[0296] The restricting portion 90k1 can also be regarded as a protruding portion that protrudes so as to cover the axis of the drum.

[0297] Here, in Example 1 (see FIGS. 24(a), (b), and 25(a)), AB=AA×(W / X) S=AA+U V>AB V>(SU)×(W / X) U <S<U+V×(X / W) It was explained that the following holds true.

[0298] In this embodiment, of the dimensions shown in Figures 30(a), (b), and (c), AU corresponds to V, and AS corresponds to S. AT corresponds to AA, and AP corresponds to U. Furthermore, W = X, and (W / X) = 1.

[0299] In this embodiment, based on the same discussion as in the first embodiment, when the drive transmission member 91 is tilted to the point of contacting the restricting portion 90k1, the conditions under which the coupling protrusion 63b and the coupling recess can be coupled are as follows: AB=AT AS=AT+AP AU>AT AU>(AS-AP) AP <AS<AP+AU

[0300] In other words, if there is at least one phase relationship between the coupling protrusion and the coupling recess that satisfies "AU>AT=AS-AP," the two coupling portions will engage (couple). AB: Misalignment between the couplings measured perpendicular to the drum axis AT: The distance from the drive transmission member 91 (cylindrical portion 91i) to the regulating portion 90k1 measured in a direction perpendicular to the drum axis. AS: The distance from the drum axis (the axis of the coupling protrusion) to the regulating portion 90k1, measured along a direction perpendicular to the drum axis. AP: Radius of the cylindrical portion 91i of the drive transmission member 91. is.

[0301] In the first embodiment described above, the gear portion 81a of the drive transmission member 81 is restricted by the restricting portion 73j. In contrast, in this embodiment, the cylindrical portion 91i that forms the outer peripheral surface of the coupling recess 91b is restricted by the restricting portion 90k1. Therefore, the restricting portion 90k1 and the coupling recess 91b are positioned approximately in the same position in the axial direction.

[0302] Compared to when the gear portion 81a of the drive transmission member 81 is restricted by a restricting portion (see FIG. 24(a)), this embodiment allows the inclination of the drive transmission member 91 to be restricted with higher precision. As a result, even if the gap between the coupling recess 91 and the coupling protrusion 63b is small, the two can be engaged. Since the dimensions (sizes) of the coupling recess 91 and the coupling protrusion 63b are close, the precision of drive transmission is improved.

[0303] Here, examples of dimensions that hold when the radius of the drum 62 is 12 mm are shown below. First, in this embodiment, the dimensions of each part of the drive transmission member 91 that can be used with the drum 62 having a radius of 12 mm are the same as those of the drive transmission member 81 in the first embodiment, and are as follows: The distance AJ from the center of the coupling recess 91b to the apex of the approximately equilateral triangle of the recess 91b is 6.5 mm, and the radius AK of the inscribed circle of the approximately triangular shape of the coupling recess 91b is 4.65 mm. Note that the approximately equilateral triangle of the recess 91b is not a pure equilateral triangle, but rather the corners of the apex are arc-shaped. In addition, the radius AN of the lightening portion 91b3 of the coupling recess 91b is 4.8 mm, and the radius AP of the cylindrical portion 91i of the drive transmission member 91 is 7.05 mm.

[0304] Note that the shortest distance AU between the coupling concave portion 91b and the coupling convex portion 63b satisfies the following relationship. 0 < AU < 1.7

[0305] AU becomes the lower limit when the sizes of the triangular shapes of the coupling concave portion 91b and the coupling convex portion 63b are equal. On the other hand, AU becomes the upper limit when the distance from the center to the vertex of the coupling convex portion 63b is 4.8 mm, which is the radius AC of the cutout portion of the coupling concave portion 91b. At this time, the gap AU between the coupling convex portion 63b and the coupling concave portion 81b is "1.7 = 6.5 - 4.8".

[0306] Therefore, substituting each value and AU = 1.7 into the formula "AP < AS < AP + AU" shown above, "7.05 < S < 8.75".

[0307] It is actually confirmed using two examples that the above formula holds. In the first example, the dimensions when the coupling convex portion 63b is made as large as possible within the range that can be engaged with the coupling concave portion 91b are shown. In this case, since the gap AU between the coupling convex portion 63b and the coupling concave portion 91b approaches the lower limit, the allowable inclination of the drive transmission member 81 becomes small. Therefore, in order to reduce the inclination of the drive transmission member 91, it is necessary to bring the regulating portion 90k1 closer to the normal position of the cylindrical portion 91i.

[0308] In the second example, the dimensions when the coupling convex portion 63b is made as small as possible within the range that can be engaged with the coupling concave portion 91b are shown. Since the gap AU between the coupling convex portion 63b and the coupling concave portion 91b approaches the upper limit, the coupling convex portion 63b and the coupling concave portion 91b can be engaged even if the drive transmission member 81 is inclined relatively. That is, since the regulating portion 73j can relatively tolerate the inclination of the drive transmission member 91, the regulating portion 93j can be relatively separated from the normal position of the cylindrical portion 91i.

[0309] The first example is an example in which the coupling protrusion 63b is made as large as possible, and the radial engagement between the coupling portions is maximized.

[0310] The distance AQ from the center to the apex of the coupling protrusion 63b of the drive-side drum flange 63 is set to 6.498 mm, slightly smaller than the distance AJ (6.5 mm) from the center of the coupling recess to the apex of the triangle. In this case, the radius AR of the inscribed circle of the triangle of the coupling protrusion 63b of the drive-side drum flange 63 is 4.648 mm.

[0311] Furthermore, since the radius AP of the cylindrical portion 91i of the drive transmission member 91 is 7.05 mm, the distance AS from the center of the drum 62 to the restricting portion 90k1 of the drum bearing is set to 7.051 mm, which is slightly larger than the radius AP.

[0312] As a result, the gap AT between the restricting portion 90k1 of the drum bearing and the cylindrical portion 91i of the drive transmission member is 0.001 mm (=7.051-7.05). Furthermore, the gap AU between the coupling protrusion 63b and the coupling recess 91b when the coupling portions are in phase is 0.002 mm (the smaller of "6.5-6.498" and "4.65-4.648"). Therefore, even if the drive transmission member 91 is tilted by the meshing force, the coupling protrusion 63b and the coupling recess 91b can engage with each other because the gap AU between the couplings is larger than the amount of misalignment AT between the coupling portions.

[0313] From the first example, it can be seen that it is preferable to set the radial distance from the center of the drum 62 to the restriction portion 90k1 to be greater than 7.05 mm.

[0314] The second example is an example in which the coupling protrusion 63b is made the smallest, thereby minimizing the amount of engagement between the coupling portions.

[0315] The distance AQ from the center to the apex of the coupling protrusion 63b provided on the drive-side drum flange 63 is 4.801 mm, which is slightly larger than the radius AN of the cutout portion 91b3 of the coupling recess, which is 4.8 mm. In this case, the radius AR of the inscribed circle inscribed in the triangular shape of the coupling protrusion is 2.951 mm.

[0316] The distance AS from the center of the drum 62 to the regulating portion 90k1 of the drum bearing is set to 8.749 mm. As a result, the gap AT between the regulating portion 90k1 of the drum bearing 90 and the gear portion 91a of the drive transmission member 91 is 1.698 mm (= 8.748 - 7.05). Furthermore, the gap AU between the coupling protrusion 63b and the coupling recess 91b when the coupling portions are in phase is 1.699 mm (the smaller of "6.5 - 4.801" and "4.65 - 2.951"). Therefore, even if the drive transmission member 91 tilts due to the meshing force, the gap AU between the couplings is larger than the amount of misalignment AT between the coupling portions, and therefore engagement is possible.

[0317] From the second example, it can be seen that it is preferable that the radial distance from the center of the drum 62 to the restriction portion 90k1 of the drum bearing is smaller than 8.75 mm.

[0318] That is, it is preferable that the radial distance from the center of the drum 62 to the restricting portion 90k1 of the drum bearing is greater than 7.05 mm and smaller than 8.75 mm.

[0319] The shape of the coupling protrusion provided on the drum 62 is not limited to a substantially equilateral triangle, and a suitable arrangement of the restricting portion will be considered for more general shapes. For convenience, the shape of the coupling recess is assumed to be a virtual equilateral triangle. The coupling protrusion 363b (see Figures 27 and 28) described above will be used as a coupling protrusion of a general shape.

[0320] First, using the restricting portion 90k1 and the drive transmission member 191 shown in FIG. 31, the upper limit of the distance from the axis of the drum to the restricting portion 90k1 will be considered.

[0321] The position of the regulating portion 90k1 depends on the radius of the cylindrical portion 191i of the drive transmission member 191. In other words, the larger the radius of the cylindrical portion 191i, the farther the regulating portion 90k1 needs to be from the drum axis. Therefore, first, as shown in FIG. 31 , assume that the diameter of the cylindrical portion 191i of the drive transmission member 191 is larger than the diameter of the gear portion (output gear portion) 191a of the drive transmission member 191. In this case, the cylindrical portion 191i is disposed so as to be sandwiched between the roller portion 132a of the developing roller 132 and the developing roller gear 30, and the cylindrical portion 191i faces the shaft portion 132b of the developing roller 132.

[0322] The distance from the center (axis) of the drum 62 to the regulating portion 90k1 is defined as distance BG (measured in a direction perpendicular to the axis of the drum). The distance from the center of the drum 62 to the axis of the developing roller is defined as distance BK (measured in a direction perpendicular to the axis of the drum).

[0323] Here, when the drive transmission member 191 tilts and the cylindrical portion 191i comes into contact with the regulating portion 90k1, it is desirable that the cylindrical portion 191i does not interfere with the shaft portion 32b of the developing roller. In other words, it is desirable that the regulating portion 90k1 regulates the movement of the cylindrical portion 191i so that the cylindrical portion 191i does not tilt beyond the axis of the developing roller. To achieve this, it is desirable that the distance BG from the drum center to the regulating portion 90k1 is shorter than the distance BK from the drum center to the axis of the developing roller 132. BG <BK is.

[0324] Next, the lower limit of the distance from the drum center to the restriction portion 90k1 will be considered using Figure 31. The smallest equilateral triangle B0 circumscribing the coupling protrusion 363b (see Figure 28) is defined as a virtual coupling protrusion. However, the center of gravity of the equilateral triangle B0 is set to coincide with the center of the coupling protrusion 363b.

[0325] The circle inscribed in this imaginary coupling protrusion (equilateral triangle BO) is called circle BP, and its radius is called radius BH. Here, in order for the imaginary coupling protrusion BO to engage with the coupling recess provided in the cylindrical portion 191i, the cylindrical portion 191i of the drive transmission member needs to be larger than this inscribed circle BP. This is because if the cylindrical portion 191i were smaller than the inscribed circle BP of the imaginary coupling protrusion BO, it would be impossible to form an output coupling portion on the cylindrical portion 191i for transmitting drive to the imaginary coupling protrusion BO.

[0326] The distance BG from the drum center to the restriction portion 90k1 is greater than the radius of the cylindrical portion 191i, and therefore the distance BG is greater than the radius BH of the inscribed surface BP.

[0327] Therefore, the distance BG from the center of the drum to the regulating portion 90k1 is: BH <BG is.

[0328] That is, the preferable range of the restricting portion 90k1 is as follows. BH <BG<BK

[0329] Next, a more preferable range of the restricting portion 90k1 will be described below using the drive transmission member 291 shown in FIG.

[0330] In FIG. 32, the cylindrical portion 291i of the drive transmission member 291 has a smaller diameter than the gear portion 291a and is disposed so as to face the developing roller gear 30. If the diameter of the cylindrical portion 191i were increased as in FIG. 31, the cylindrical portion 191i could not be disposed in front of the developing roller gear 30, and it was necessary to dispose the cylindrical portion 191i so as to face the shaft portion of the developing roller. In this case, it would be necessary to increase the length of the shaft portion of the developing roller or the length of the drive transmission member. In contrast, if the cylindrical portion 291i of the drive transmission member is disposed in front of the developing roller gear 30 as in FIG. 32, it is not necessary to elongate the shaft portion 232b of the developing roller 232 or the drive transmission member 291, and this allows the cartridge and image forming apparatus to be made more compact.

[0331] First, the upper limit of the distance from the center of the drum to the restriction portion 90k1 will be considered with reference to FIG.

[0332] The distance from the center of the drum 162 to the regulating portion 90k1 is defined as distance BG (measured in a direction perpendicular to the drum axis). The shortest distance from the center of the drum 162 to the tip of the teeth of the gear portion of the developing roller gear 30 is defined as distance BJ (measured in a direction perpendicular to the drum axis). In order to prevent the cylindrical portion 291i from interfering with the gear 30 of the developing roller when the regulating portion 90k1 comes into contact with the cylindrical portion 291i, it is desirable to make the distance BG from the drum center to the regulating portion 90k1 shorter than the distance BJ from the drum center to the tip of the teeth of the developing roller gear. Therefore, BG>BJ is.

[0333] Next, the lower limit of the distance from the drum center to the restriction portion 90k1 will be considered. The smallest circle circumscribing the coupling protrusion 163a is defined as BS, and its radius is defined as BL. The circle BS is arranged concentrically (coaxially) with the drum 162.

[0334] Here, if the cylindrical portion 291i of the drive transmission member 291 is larger than the circle BS, a coupling recess can be formed in the cylindrical portion 291i so as to surround the entire periphery of the coupling protrusion 163a.

[0335] This increases the strength of the output coupling portion (coupling recess), and stabilizes the engagement between the couplings.

[0336] When the radius of the cylindrical portion 291i is larger than the radius BL of the circle BS, the distance BG from the drum center to the regulating portion 90k1 is also larger than the radius BL. BG <BL is.

[0337] That is, the range of the restricting portion 90j is as follows. BJ <BG<BL Combining this "BJ < BG < BL" with the aforementioned "BH < BG < BK", the suitable range for the regulating portion can be defined as follows. BH < BJ < BG < BL < BK

[0338] Summarizing the definitions of each value, it is as follows. BH: The radius of the inscribed circle inscribed in the smallest equilateral triangle circumscribing the coupling convex portion (input coupling portion) when the centroid of the equilateral triangle is aligned with the axis of the drum (axis of the coupling convex portion). BJ: The shortest distance from the axis of the drum to the tooth tip of the gear portion (input gear portion) 30a measured along the direction perpendicular to the axis of the drum. BG: The distance from the center of the drum to the regulating portion measured along the direction perpendicular to the axis of the drum. BL: The radius of the circumscribed circle when the smallest circumscribed circle circumscribing the coupling convex portion (input coupling portion) is drawn coaxially with the drum. BK: The distance from the axis of the drum to the axis of the developing roller gear (axis of the developing roller) measured along the direction perpendicular to the axis of the drum.

[0339] The functions, materials, shapes, and relative arrangements of the components described in this embodiment or its variations are not intended to limit the scope of this invention only to those, unless specifically described otherwise.

Explanation of Reference Numerals

[0340] 30 Developing roller gear 30a Gear portion 32 Developing roller (developer carrier) 62 Drum (electrophotographic photosensitive drum) 62a Drum center 63 Driving-side drum flange (driven transmission member) 63b Coupling convex portion

Claims

1. In a process cartridge detachably mountable to a main body of an electrophotographic image forming apparatus, A photoreceptor; a coupling portion provided at an end of the photosensitive member, the coupling portion having a driving force receiving portion for receiving a driving force for rotating the photosensitive member from the outside of the process cartridge; a gear portion having gear teeth for receiving a driving force from the outside of the process cartridge independently of the coupling portion; and the gear teeth have an exposed portion that is exposed to the outside of the process cartridge, At least a portion of the exposed portion (a) faces the axis of the photosensitive member, and (b) is located further outward than the driving force receiving portion in the axial direction of the photosensitive member, and (c) is located near the peripheral surface of the photosensitive member in a plane perpendicular to the axis of the photosensitive member.

2. 2. A process cartridge according to claim 1, wherein the distance from the center of said photosensitive member to the tip of said gear tooth on a plane perpendicular to the axis of said photosensitive member is greater than 90 percent and less than 110 percent of the radius of said photosensitive member.

3. 3. A process cartridge according to claim 1, wherein said gear teeth are helical teeth.

4. 4. A process cartridge according to claim 3, wherein said gear teeth are inclined toward the rotation direction of said gear portion as they move from the outside to the inside in the axial direction of said photosensitive member.

5. 5. A process cartridge according to claim 3, wherein, when viewed so that the rotation direction of said photosensitive member is counterclockwise, said gear teeth are inclined counterclockwise from the outside to the inside in the axial direction of said photosensitive member.

6. 3. A process cartridge according to claim 1, wherein said gear teeth are spur teeth having a thickness of less than 1 mm.

7. 7. A process cartridge according to claim 1, wherein said driving force receiving portion is inclined in the rotation direction of said photosensitive member from the outer side to the inner side in the axial direction of said photosensitive member.

8. 8. The process cartridge according to claim 1, further comprising a developer carrier configured to carry developer for developing the latent image formed on said photosensitive member.

9. 9. A process cartridge according to claim 8, wherein said developer carrying member is rotated by said driving force received by said gear portion.

10. 10. The process cartridge according to claim 8, wherein when the rotation direction of said gear portion is viewed as being clockwise, the rotation direction of said developer carrying body is also clockwise.

11. 11. A process cartridge according to claim 8, wherein said gear portion and said developer carrying member are arranged coaxially.

12. the process cartridge has a development gear provided on the developer carrier, 11. The process cartridge according to claim 8, wherein the developing gear has the gear portion.

13. a drive input gear having the gear portion; a developing gear provided on the developer carrier; at least one idler gear that transmits a driving force from the drive input gear to the development gear; 10. The process cartridge according to claim 8, further comprising:

14. 14. A process cartridge according to claim 13, wherein the number of said idler gears is an odd number.

15. 15. A process cartridge according to claim 14, wherein the number of said idler gear is one.

16. 16. A process cartridge according to claim 1, wherein the distance between the axes of said gear portion and said coupling portion is variable.

17. The process cartridge is a first unit having the coupling portion; a second unit having the gear portion; and 17. The process cartridge according to claim 16, wherein the distance between the axes of the gear portion and the coupling portion changes when the second unit moves relative to the first unit.

18. 18. A process cartridge according to claim 17, wherein said second unit is rotatably connected to said first unit.

19. 19. A process cartridge according to claim 1, further comprising a stopper facing the axis of the photosensitive member, at least a portion of which is positioned outside the driving force receiving portion of the coupling portion in the axial direction of the photosensitive member.

20. 19. A process cartridge according to claim 1, further comprising a stopper provided on the same side of the process cartridge in the axial direction as the coupling portion, the stopper facing the axis of the photosensitive member, and protruding outward in the axial direction.

21. 21. A process cartridge according to claim 19, wherein at least a part of said stopper is disposed outside the tip of said coupling portion in the axial direction of said photosensitive member.

22. 22. A process cartridge according to claim 19, wherein the stopper is disposed within an angle range of more than 0° and less than 180°, with the center of the photosensitive member as the origin, toward the upstream side of the rotation direction of the photosensitive member, relative to a half line extending from the center of the photosensitive member toward the center of the gear portion, in a plane perpendicular to the axis of the photosensitive member.

23. 23. A process cartridge according to claim 19, wherein, in a plane perpendicular to the axis of the photosensitive member, the stopper is arranged on the opposite side of a line passing through the center of the photosensitive member and the center of the gear portion from the direction in which the photosensitive member is exposed from the process cartridge.

24. The process cartridge is a charging member for charging the photoreceptor; 24. A process cartridge according to claim 19, wherein, in a plane perpendicular to the axis of the photosensitive member, the stopper is arranged on the same side as the charging member with respect to a line passing through the center of the photosensitive member and the center of the gear portion.

25. If the front pressure angle of the gear portion is α, then 25. A process cartridge according to any one of claims 19 to 24, wherein the stopper is arranged in a plane perpendicular to the axis of the photosensitive member so as to straddle a half line extending from the center of the photosensitive member toward the center of the gear portion, the half line being inclined at (90+α) degrees from the center of the photosensitive member as the origin toward the upstream side in the rotation direction of the photosensitive member.

26. A process cartridge according to any one of claims 19 to 25, wherein in a plane perpendicular to the axis of the photosensitive member, at least a portion of the stopper is positioned within a range of (75 + α) degrees or more and (105 + α) degrees or less, with the center of the photosensitive member as the origin, toward the upstream side of the rotation direction of the photosensitive member, relative to a half line extending from the center of the photosensitive member toward the center of the gear portion.

27. 27. A process cartridge according to claim 19, wherein in a plane perpendicular to the axis of the photosensitive member, the distance from the center of the photosensitive member to the stopper is longer than the distance from the center of the photosensitive member to the tip of the gear tooth and shorter than the distance from the center of the photosensitive member to the center of the gear portion.

28. 28. The process cartridge according to claim 19, wherein the stopper is disposed so as to satisfy the following formula: BF<BB where BB is the distance measured from the axis of the photosensitive member to the stopper along a direction perpendicular to the axis of the photosensitive member, and BF is the shortest distance measured from the axis of the photosensitive member to the tip of the gear teeth along a direction perpendicular to the axis of the photosensitive member.

29. 29. The process cartridge according to claim 19, wherein the stopper is disposed so as to satisfy the following formula: BB < AX + BA where BB is the distance measured from the axis of the photosensitive member to the stopper along a direction perpendicular to the axis of the photosensitive member, BA is the radius of the inscribed circle in the smallest equilateral triangle circumscribing the coupling portion when the center of gravity of the equilateral triangle is aligned with the axis of the photosensitive member, and AX is the distance measured from the axis of the photosensitive member to the tooth bottom of the gear portion along a direction perpendicular to the axis of the photosensitive member.

30. 28. The process cartridge according to claim 19, wherein the stopper is disposed so as to satisfy the following formula: BH<BG where BG is the distance from the axis of the photosensitive member to the stopper measured along a direction perpendicular to the axis of the photosensitive member, and BH is the radius of the inscribed circle in the smallest equilateral triangle circumscribing the coupling portion when the center of gravity of the equilateral triangle is aligned with the axis of the photosensitive member.

31. 31. The process cartridge according to claim 19, wherein the stopper is disposed so as to satisfy the following formula: BJ<BG where BG is the distance from the axis of the photosensitive member to the stopper, measured along a direction perpendicular to the axis of the photosensitive member, and BJ is the shortest distance from the axis of the photosensitive member to the tip of the gear teeth, measured along a direction perpendicular to the axis of the photosensitive member.

32. 32. The process cartridge according to claim 19, wherein the stopper is disposed so as to satisfy the following formula: BG<BK where BG is the distance from the axis of the photosensitive member to the stopper measured in a direction perpendicular to the axis of the photosensitive member, and BK is the distance from the axis of the photosensitive member to the axis of the gear portion measured in a direction perpendicular to the axis of the photosensitive member.

33. 33. The process cartridge according to claim 19, wherein the stopper is disposed so as to satisfy the following formula: BG<BL where BG is the distance from the axis of the photosensitive member to the stopper measured along a direction perpendicular to the axis of the photosensitive member, and BL is the radius of the smallest circumscribing circle that circumscribes the coupling portion when the smallest circumscribing circle is drawn coaxially with the photosensitive member.

34. 34. A process cartridge according to claim 19, wherein said stopper forms a bay portion that is open toward the axis of said photosensitive member.

35. 35. A process cartridge according to claim 19, wherein said stopper has a curved surface that opens toward the axis of said photosensitive member.

36. 36. A process cartridge according to claim 19, wherein said stopper is formed of a plurality of portions spaced apart from one another.

37. 37. The process cartridge according to claim 19, wherein when the gear portion and the stopper are projected onto the axis of the photosensitive member, at least a part of their projected areas overlap each other.

38. 38. A process cartridge according to claim 19, wherein a distance from the center of said photosensitive member to said stopper in a plane perpendicular to the axis of said photosensitive member is greater than 12.715 mm and smaller than 14.262 mm.

39. 39. A process cartridge according to claim 19, wherein a distance from the center of said photosensitive member to said stopper in a plane perpendicular to the axis of said photosensitive member is greater than 7.05 mm and smaller than 8.75 mm.

40. The process cartridge is a charging member for charging the photoreceptor; 40. A process cartridge according to any one of claims 1 to 39, wherein in a plane perpendicular to the axis of the photosensitive member, the center of the gear portion is located within an angle range of more than 64° and less than 190°, with the center of the photosensitive member as the origin, toward the downstream side in the rotation direction of the photosensitive member, relative to a half line extending from the center of the photosensitive member toward the center of the charging member.

41. 41. A process cartridge according to claim 1, further comprising an agitating member configured to agitate the developer by the driving force received by said gear portion.

42. 42. A process cartridge according to claim 1, wherein said coupling portion is a convex portion.

43. 43. A process cartridge according to claim 1, wherein said coupling portion is formed by twisting a substantially triangular prism.

44. In a cross section of the process cartridge that passes through the exposed portion and is perpendicular to the axis of the photosensitive member, 44. A process cartridge according to claim 1, wherein when an imaginary circle having a radius equal to the shortest distance from the center of said photosensitive member to the tip of said gear tooth is drawn coaxially with said photosensitive member, the inside of said imaginary circle is a space.

45. a positioned portion provided on the same side of the process cartridge as the coupling portion in the axial direction of the photosensitive member, the positioned portion protruding inward in the axial direction of the photosensitive member; 45. A process cartridge according to claim 1, wherein when said positioned portion and said photosensitive member are projected onto the axis of said photosensitive member, their projected areas at least partially overlap each other.

46. a positioned portion provided on the same side of the process cartridge as the coupling portion in the axial direction of the photosensitive member, the positioned portion protruding inward in the axial direction of the photosensitive member; a coupling member provided with the coupling portion and attached to an end of the photosensitive member; and 46. ​​A process cartridge according to claim 1, wherein when said positioned portion and said coupling member are projected onto the axis of said photosensitive member, their projected areas at least partially overlap each other.

47. 47. A process cartridge according to claim 1, further comprising a slit provided on the same side of said process cartridge as said coupling portion in the axial direction of said photosensitive member.

48. 48. A process cartridge according to claim 47, wherein an inner end of said slit in said axial direction is positioned more inward than an outer end of said gear portion, and an outer end of said slit is positioned more outward than a tip end of said coupling portion.

49. A process cartridge detachably mountable to a main body of an electrophotographic image forming apparatus, the process cartridge having a drive output member in which an output gear portion and an output coupling portion are coaxially provided, A photoreceptor; an input coupling unit provided at an end of the photosensitive member and capable of coupling with the output coupling unit; an input gear portion that can mesh with the output gear portion; and The process cartridge is configured such that the input gear portion rotates while meshing with the output gear portion, thereby causing the input gear portion and the output gear portion to attract each other.

50. 50. A process cartridge according to claim 49, wherein said input gear portion is configured so as to generate a force that moves said output coupling portion and said input coupling portion closer together by rotating while meshing with said output gear portion.

51. 51. A process cartridge according to claim 49 or 50, wherein said input gear portion is configured to rotate in a state of meshing with said output gear portion, thereby moving said drive output member closer to said cartridge side.

52. the input gear portion has gear teeth for meshing with the output gear portion, at least a portion of which is exposed to the outside of the process cartridge; the input coupling portion has a driving force receiving portion for receiving a force from the output coupling portion, 52. A process cartridge according to any one of claims 49 to 51, wherein at least a portion of the exposed portion of the gear teeth is located further outward than the driving force receiving portion in the axial direction of the photosensitive member and faces the axis of the photosensitive member.

53. 53. A process cartridge according to any one of claims 49 to 52, wherein said input gear portion has helical teeth for meshing with said output gear portion.

54. 54. A process cartridge according to claim 53, wherein said helical teeth of said input gear portion are inclined toward the rotation direction of said input gear portion as they go from the outside to the inside in the axial direction of said photosensitive member.

55. 53. A process cartridge according to any one of claims 49 to 52, wherein said input gear portion is provided with spur teeth that can mesh with helical teeth that said output gear portion has.

56. 56. A process cartridge according to claim 55, wherein the thickness of said input gear portion is less than 1 mm.

57. 57. A process cartridge according to any one of claims 49 to 56, wherein the input coupling portion is configured to rotate in a state coupled with the output coupling portion, thereby causing the output coupling portion and the input coupling portion to attract each other.

58. the input coupling section has a driving force receiving section configured to receive a driving force from the output coupling section, 58. A process cartridge according to any one of claims 49 to 57, wherein said driving force receiving portion is inclined toward the rotation direction of said input coupling portion as it moves from the outer side to the inner side in the axial direction of said photosensitive member.

59. 59. A process cartridge according to any one of claims 49 to 58, wherein one of said input coupling portion and said input gear portion is configured to rotate clockwise, and the other is configured to rotate counterclockwise.

60. 60. A process cartridge according to any one of claims 49 to 59, further comprising a developer carrying member configured to carry developer for developing the latent image formed on said photosensitive member.

61. 61. A process cartridge according to claim 60, wherein said developer carrying member is rotated by a driving force received by said input gear portion from said output gear portion.

62. 62. A process cartridge according to claim 60 or 61, wherein when viewed so that the rotation direction of said input gear portion is clockwise, the rotation direction of said developer carrying body is also clockwise.

63. 63. A process cartridge according to any one of claims 60 to 62, wherein said input gear portion and said developer carrying member are arranged coaxially.

64. the process cartridge has a development gear provided on the developer carrier, 64. The process cartridge according to any one of claims 60 to 63, wherein said development gear has said input gear portion.

65. a drive input gear having the input gear portion; a developing gear provided on the developer carrier; at least one idler gear that transmits a driving force from the drive input gear to the development gear; 64. The process cartridge according to any one of claims 60 to 63, further comprising:

66. 66. A process cartridge according to claim 65, wherein the number of said idler gears is odd.

67. 67. A process cartridge according to claim 66, wherein the number of said idler gear is one.

68. 68. A process cartridge according to any one of claims 49 to 67, wherein the distance between the axes of said input gear portion and said input coupling portion is variable.

69. The process cartridge is a first unit having the input coupling section; a second unit having the input gear portion; and 69. A process cartridge according to claim 68, wherein the distance between the axes of said input gear portion and said input coupling portion changes when said second unit moves relative to said first unit.

70. 70. A process cartridge according to claim 69, wherein said second unit is rotatably coupled to said first unit.

71. 71. A process cartridge according to claim 49, further comprising a regulating portion that regulates tilting of said drive output member.

72. 72. A process cartridge according to claim 71, wherein said regulating portion regulates movement of said output gear portion, thereby regulating tilting of said drive output member.

73. 72. A process cartridge according to claim 71, wherein said regulating portion regulates movement of said output coupling portion, thereby regulating tilting of said drive output portion.

74. 74. A process cartridge according to any one of claims 71 to 73, wherein said regulating portion regulates the inclination of said drive output member so as to allow coupling of said input coupling portion with said output coupling portion.

75. 75. The process cartridge according to claim 71, wherein the regulating portion is disposed so as to satisfy the following formula: BF<BB Here, BB is the distance measured from the axis of the photosensitive member to the regulating portion along a direction perpendicular to the axis of the photosensitive member, and BF is the shortest distance measured from the axis of the photosensitive member to the tip of the tooth of the input gear along a direction perpendicular to the axis of the photosensitive member.

76. 76. The process cartridge according to claim 71, wherein the regulating portion is disposed so as to satisfy the following formula: BB < AX + BA where BB is the distance measured from the axis of the photosensitive drum to the regulating portion along a direction perpendicular to the axis of the photosensitive drum. BA is the radius of the inscribed circle in the smallest equilateral triangle circumscribing the input coupling portion when the center of gravity of the equilateral triangle is aligned with the axis of the photosensitive drum. AX is the distance measured from the axis of the photosensitive drum to the tooth bottom of the input gear portion along a direction perpendicular to the axis of the photosensitive drum.

77. 75. The process cartridge according to claim 71, wherein the regulating portion is disposed so as to satisfy the following formula: BH<BG where BG is the distance from the axis of the photoconductor to the regulating portion measured along a direction perpendicular to the axis of the photoconductor, and BH is the radius of the inscribed circle in the smallest equilateral triangle circumscribing the input coupling portion when the center of gravity of the equilateral triangle is aligned with the axis.

78. 78. A process cartridge according to claim 71, wherein said regulating portion is disposed so as to satisfy the following formula: BJ<BG where BG is the distance from the axis of the photosensitive member to the regulating portion measured in a direction perpendicular to the axis of the photosensitive member, and BJ is the shortest distance from the axis of the photosensitive member to the tip of the tooth of the input gear portion measured in a direction perpendicular to the axis of the photosensitive member.

79. 79. A process cartridge according to any one of claims 71 to 74, 77 and 78, wherein said regulating portion is disposed so as to satisfy the following formula: BG<BK where BG is the distance from the axis of the photosensitive member to the regulating portion measured in a direction perpendicular to the axis of the photosensitive member, and BK is the distance from the axis of the photosensitive member to the axis of the input gear portion measured in a direction perpendicular to the axis of the photosensitive member.

80. 80. The process cartridge according to claim 71, wherein the regulating portion is disposed so as to satisfy the following formula: ##EQU1## BG<BL where BG is the distance from the axis of the photosensitive member to the regulating portion measured along a direction perpendicular to the axis of the photosensitive member, and BL is the radius of the smallest circumscribing circle that circumscribes the input coupling portion when the smallest circumscribing circle is drawn coaxially with the photosensitive member.

81. 81. A process cartridge according to any one of claims 49 to 80, further comprising a positioned portion arranged on the same side of the process cartridge as the input coupling portion in the axial direction of the photosensitive member, the positioned portion being positioned by the main body of the electrophotographic image forming apparatus when the process cartridge is mounted in the main body of the electrophotographic image forming apparatus.

82. 82. A process cartridge according to claim 81, wherein when said positioned portion and said photosensitive member are projected onto the axis of said photosensitive member, their projected areas at least partially overlap each other.

83. The input coupling portion has a coupling member attached to an end of the photoreceptor, 83. A process cartridge according to claim 81, wherein when said positioned portion and said coupling member are projected onto the axis of said photosensitive member, their projected areas at least partially overlap each other.

84. 84. A process cartridge according to any one of claims 81 to 83, wherein said portion to be positioned comprises a first portion to be positioned and a second portion to be positioned apart from said first portion to be positioned.

85. 85. A process cartridge according to claim 84, wherein said first positioned portion and said second positioned portion are arranged along the rotation direction of said photosensitive member.

86. 86. A process cartridge according to any one of claims 81 to 85, wherein said positioning portion protrudes inward in the axial direction of said photosensitive member.

87. 87. A process cartridge according to any one of claims 49 to 86, wherein an axis of said input gear portion is located upstream of an axis of said input coupling portion in the mounting direction of said process cartridge.

88. a guided portion configured to be guided when the process cartridge is mounted in the main body of the electrophotographic image forming apparatus, the guided portion being disposed on the same side of the process cartridge as the input coupling portion in the axial direction of the photosensitive member; 88. A process cartridge according to any one of claims 49 to 87, wherein said guided portion is arranged upstream of said input coupling portion in the mounting direction of said process cartridge.

89. 89. A process cartridge according to any one of claims 49 to 88, wherein said process cartridge is configured to be detachably mounted to said main assembly of the apparatus along a direction substantially perpendicular to the axis of said photosensitive member.

90. In a process cartridge detachably mountable to a main body of an electrophotographic image forming apparatus, A photoreceptor; a coupling portion provided at an end of the photosensitive member, the coupling portion having a driving force receiving portion for receiving a driving force for rotating the photosensitive member from the outside of the process cartridge; a gear portion having gear teeth for receiving a driving force from the outside of the process cartridge independently of the coupling portion; and the gear teeth are helical teeth and have an exposed portion exposed to the outside of the process cartridge, In a process cartridge, at least a part of the exposed portion is located further outward than the driving force receiving portion in the axial direction of the photosensitive member and faces the axial line of the photosensitive member.

91. 91. A process cartridge according to claim 90, wherein said gear teeth are inclined toward the rotation direction of said gear portion as they go from the outside to the inside in the axial direction of said photosensitive member.

92. 92. A process cartridge according to claim 90 or 91, wherein, when viewed so that the rotation direction of said photosensitive member is counterclockwise, said gear teeth are inclined counterclockwise from the outside to the inside in the axial direction of said photosensitive member.

93. 93. A process cartridge according to any one of claims 90 to 92, wherein said driving force receiving portion is inclined toward the rotation direction of said photosensitive member as it moves from the outer side to the inner side in the axial direction of said photosensitive member.

94. 94. A process cartridge according to any one of claims 90 to 93, further comprising a developer carrying member configured to carry developer for developing a latent image formed on said photosensitive member.

95. 95. A process cartridge according to claim 94, wherein said developer carrying member is configured to rotate by said driving force received by said gear portion.

96. 96. A process cartridge according to claim 94 or 95, wherein when viewed so that the rotation direction of said gear portion is clockwise, the rotation direction of said developer carrying body is also clockwise.

97. 97. A process cartridge according to any one of claims 94 to 96, wherein said gear portion and said developer carrying member are arranged coaxially.

98. the process cartridge has a development gear provided on the developer carrier, 98. The process cartridge according to any one of claims 94 to 97, wherein said development gear has said gear portion.

99. a drive input gear having the gear portion; a developing gear provided on the developer carrier; at least one idler gear that transmits a driving force from the drive input gear to the development gear; 96. The process cartridge according to claim 94 or 95, comprising:

100. 100. A process cartridge according to claim 99, wherein the number of said idler gears is an odd number.

101. 101. A process cartridge according to claim 100, wherein the number of said idler gear is one.

102. 102. The process cartridge according to claim 90, wherein the distance between the axes of said gear portion and said coupling portion is variable.

103. The process cartridge is a first unit having the coupling portion; a second unit having the gear portion; and 103. A process cartridge according to claim 102, wherein the distance between the axes of said gear portion and said coupling portion changes when said second unit moves relative to said first unit.

104. 104. A process cartridge according to claim 103, wherein said second unit is rotatably connected to said first unit.

105. 105. A process cartridge according to any one of claims 90 to 104, further comprising a stopper facing the axis of the photosensitive member, at least a portion of which is positioned outside the driving force receiving portion of the coupling portion in the axial direction of the photosensitive member.

106. A process cartridge according to any one of claims 90 to 104, comprising a stopper provided on the same side of the process cartridge in the axial direction as the coupling portion, the stopper facing the axis of the photosensitive member, and protruding outward in the axial direction.

107. 107. A process cartridge according to claim 105, wherein at least a part of said stopper is disposed outside a tip of said coupling portion.

108. A process cartridge according to any one of claims 105 to 107, wherein the stopper is arranged in a plane perpendicular to the axis of the photosensitive member, within an angle range of more than 0° and less than 180°, with the center of the photosensitive member as the origin, toward the upstream side of the rotation direction of the photosensitive member, relative to a half line extending from the center of the photosensitive member toward the center of the gear portion.

109. A process cartridge according to any one of claims 105 to 108, wherein in a plane perpendicular to the axis of the photosensitive member, the stopper is positioned on the opposite side of a line passing through the center of the photosensitive member and the center of the gear portion from the direction in which the photosensitive member is exposed from the process cartridge.

110. The process cartridge is a charging member for charging the photoreceptor; A process cartridge according to any one of claims 105 to 109, wherein, in a plane perpendicular to the axis of the photosensitive member, the stopper is arranged on the same side as the charging member with respect to a line passing through the center of the photosensitive member and the center of the gear portion.

111. If the front pressure angle of the gear portion is α, then A process cartridge as described in any one of claims 105 to 110, wherein the stopper is arranged in a plane perpendicular to the axis of the photosensitive body so as to straddle a half line extending from the center of the photosensitive body toward the center of the gear portion, and a line inclined at (90 + α) degrees from the center of the photosensitive body as the origin toward the upstream side of the rotation direction of the photosensitive body.

112. A process cartridge according to any one of claims 105 to 111, wherein in a plane perpendicular to the axis of the photosensitive member, at least a portion of the stopper is positioned within a range of (75 + α) degrees or more and (105 + α) degrees or less, with the center of the photosensitive member as the origin, toward the upstream side of the rotation direction of the photosensitive member, relative to a half line extending from the center of the photosensitive member toward the center of the gear portion.

113. A process cartridge according to any one of claims 105 to 112, wherein in a plane perpendicular to the axis of the photosensitive member, the distance from the center of the photosensitive member to the stopper is longer than the distance from the center of the photosensitive member to the tip of the gear tooth, and shorter than the distance from the center of the photosensitive member to the center of the gear portion.

114. 114. The process cartridge according to any one of claims 105 to 113, wherein the stopper is disposed so as to satisfy the following formula: BF<BB where BB is the distance measured from the axis of the photosensitive member to the stopper along a direction perpendicular to the axis of the photosensitive member, and BF is the shortest distance measured from the axis of the photosensitive member to the tip of the gear teeth along a direction perpendicular to the axis of the photosensitive member.

115. 115. The process cartridge according to claim 105, wherein the stopper is disposed so as to satisfy the following formula: BB < AX + BA where BB is the distance measured from the axis of the photosensitive member to the stopper along a direction perpendicular to the axis of the photosensitive member, BA is the radius of the inscribed circle in the smallest equilateral triangle circumscribing the coupling portion when the center of gravity of the equilateral triangle is aligned with the axis of the photosensitive member, and AX is the distance measured from the axis of the photosensitive member to the tooth bottom of the gear portion along a direction perpendicular to the axis of the photosensitive member.

116. 114. The process cartridge according to any one of claims 105 to 113, wherein the stopper is disposed so as to satisfy the following formula: BH<BG where BG is the distance from the axis of the photosensitive member to the stopper measured along a direction perpendicular to the axis of the photosensitive member, and BH is the radius of the inscribed circle in the smallest equilateral triangle circumscribing the coupling part when the center of gravity of the equilateral triangle is aligned with the axis.

117. 117. The process cartridge according to claim 105, wherein the stopper is disposed so as to satisfy the following formula: BJ<BG where BG is the distance from the axis of the photosensitive member to the stopper, measured along a direction perpendicular to the axis of the photosensitive member, and BJ is the shortest distance from the axis of the photosensitive member to the tip of the gear teeth, measured along a direction perpendicular to the axis of the photosensitive member.

118. 118. A process cartridge according to any one of claims 105 to 113, 116 and 117, wherein the stopper is disposed so as to satisfy the following formula: BG<BK where BG is the distance from the axis of the photosensitive member to the stopper measured in a direction perpendicular to the axis of the photosensitive member, and BK is the distance from the axis of the photosensitive member to the axis of the gear portion measured in a direction perpendicular to the axis of the photosensitive member.

119. 119. The process cartridge according to claim 105, wherein the stopper is disposed so as to satisfy the following formula: BG<BL where BG is the distance from the axis of the photosensitive member to the stopper measured along a direction perpendicular to the axis of the photosensitive member, and BL is the radius of the smallest circumscribing circle that circumscribes the coupling portion when the smallest circumscribing circle is drawn coaxially with the photosensitive member.

120. 120. A process cartridge according to any one of claims 105 to 119, wherein said stopper forms a bay portion that is open to the axial side of said photosensitive member.

121. 121. A process cartridge according to any one of claims 105 to 120, wherein said stopper has a curved surface that opens toward the axis of said photosensitive member.

122. 122. A process cartridge according to any one of claims 105 to 121, wherein said stopper is formed of a plurality of portions spaced apart from each other.

123. 123. A process cartridge according to any one of claims 105 to 122, wherein when the gear portion and the stopper are projected onto the axis of the photosensitive member, at least a part of their projected areas overlap each other.

124. 124. A process cartridge according to any one of claims 105 to 123, wherein a distance from the center of said photosensitive member to said stopper in a plane perpendicular to the axis of said photosensitive member is greater than 12.715 mm and smaller than 14.262 mm.

125. 124. A process cartridge according to any one of claims 105 to 123, wherein a distance from the center of said photosensitive member to said stopper is greater than 7.05 mm and smaller than 8.75 mm in a plane perpendicular to the axis of said photosensitive member.

126. The process cartridge is a charging member for charging the photoreceptor; A process cartridge according to any one of claims 90 to 125, wherein in a plane perpendicular to the axis of the photosensitive member, the center of the gear portion is located within an angle range of more than 64° and less than 190°, with the center of the photosensitive member as the origin, toward the downstream side in the rotation direction of the photosensitive member, relative to a half line extending from the center of the photosensitive member toward the center of the charging member.

127. 127. A process cartridge according to any one of claims 90 to 126, further comprising an agitating member configured to agitate the developer by the driving force received by said gear portion.

128. 128. A process cartridge according to any one of claims 90 to 127, wherein said coupling portion is a convex portion.

129. 129. A process cartridge according to any one of claims 90 to 128, wherein said coupling portion is formed by twisting a substantially triangular prism.

130. In a cross section of the process cartridge that passes through the exposed portion and is perpendicular to the axis of the photosensitive member, 130. A process cartridge according to any one of claims 90 to 129, wherein when an imaginary circle having a radius equal to the shortest distance from the center of the photosensitive member to the tip of the gear tooth is drawn coaxially with the photosensitive member, the inside of the imaginary circle is a space.

131. a positioned portion provided on the same side of the process cartridge as the coupling portion in the axial direction of the photosensitive member, the positioned portion protruding inward in the axial direction of the photosensitive member; 131. The process cartridge according to claim 90, wherein when the positioned portion and the photosensitive member are projected onto the axis of the photosensitive member, their projected areas at least partially overlap each other.

132. a positioned portion provided on the same side of the process cartridge as the coupling portion in the axial direction of the photosensitive member, the positioned portion protruding inward in the axial direction of the photosensitive member; a coupling member provided with the coupling portion and attached to an end of the photosensitive member; and 132. A process cartridge according to claim 90, wherein when said positioned portion and said coupling member are projected onto the axis of said photosensitive member, their projected areas at least partially overlap each other.

133. 133. The process cartridge according to any one of claims 90 to 132, further comprising a slit provided on the same side of said process cartridge as said coupling portion in the axial direction of said photosensitive member.

134. In a process cartridge detachably mountable to a main body of an electrophotographic image forming apparatus, A photoreceptor; a coupling portion provided at an end of the photosensitive member, the coupling portion having a driving force receiving portion configured to receive a driving force for rotating the photosensitive member from the outside of the process cartridge; a gear portion having gear teeth configured to receive a driving force from the outside of the process cartridge independently of the coupling portion; a developer carrier configured to carry a developer to develop a latent image formed on the photosensitive member, the developer carrier configured to rotate clockwise when viewed so that the rotation direction of the gear portion is clockwise; and the gear teeth have an exposed portion that is exposed to the outside of the process cartridge, At least a part of the exposed portion faces the axis of the photosensitive member and is positioned further outward than the driving force receiving portion in the axial direction of the photosensitive member.

135. a developing gear provided on the developer carrier, 135. The process cartridge according to claim 134, wherein said development gear has said gear portion.

136. A process cartridge as described in claim 134, having a transmission mechanism that transmits the driving force received by the gear portion to the developer carrier, and is configured to make the rotation direction of the gear portion the same as the rotation direction of the developer carrier.

137. The transmission mechanism includes: a drive input gear having the gear portion; a developing gear provided on the developer carrier; at least one idler gear that transmits a driving force from the drive input gear to the development gear; 137. The process cartridge according to claim 136, comprising:

138. In a process cartridge detachably mountable to a main body of an electrophotographic image forming apparatus, A photoreceptor; a centering unit arranged coaxially with the photosensitive member; a gear portion having gear teeth for receiving a driving force from the outside of the process cartridge, the gear teeth have an exposed portion that is exposed to the outside of the process cartridge, A process cartridge in which at least a portion of the exposed portion (a) faces the axis of the photosensitive member, and (b) is located further outward than the alignment portion in the axial direction of the photosensitive member, and (c) is located near the peripheral surface of the photosensitive member in a plane perpendicular to the axis of the photosensitive member.

139. 139. A process cartridge according to claim 138, wherein the photosensitive member is rotated by the driving force received by the gear portion.

140. 140. A process cartridge according to claim 138 or 139, wherein said gear teeth are helical teeth.

141. 141. A process cartridge according to claim 140, wherein, when viewed so that the rotation direction of said photosensitive member is counterclockwise, said gear teeth are inclined counterclockwise from the outside to the inside in the axial direction of said photosensitive member.

142. 140. A process cartridge according to claim 138 or 139, wherein said gear teeth are spur teeth having a thickness of less than 1 mm.

143. 143. A process cartridge according to any one of claims 138 to 142, further comprising a developer carrier configured to carry developer for developing a latent image formed on said photosensitive member.

144. the process cartridge has a development gear provided on the developer carrier, 144. The process cartridge according to claim 143, wherein the development gear has the gear portion.

145. The process cartridge is 145. A process cartridge according to any one of claims 138 to 144, further comprising a stopper, at least a part of which is positioned outside said centering portion in the axial direction of said photosensitive member and faces the axis of said photosensitive member.

146. If the front pressure angle of the gear portion is α, then A process cartridge as described in claim 145, wherein the stopper is arranged in a plane perpendicular to the axis of the photosensitive body so that it straddles a half-line extending from the center of the photosensitive body toward the center of the gear portion and a line inclined (90 + α) degrees from the center of the photosensitive body as the origin toward the upstream side of the rotation direction of the photosensitive body.

147. A process cartridge as described in claim 145 or 146, wherein at least a portion of the stopper is positioned in a plane perpendicular to the axis of the photosensitive body, within a range of (75 + α) degrees or more and (105 + α) degrees or less, with the center of the photosensitive body as the origin, toward the upstream side of the rotation direction of the photosensitive body, relative to a half line extending from the center of the photosensitive body toward the center of the gear portion.

148. 148. A process cartridge according to any one of claims 145 to 147, wherein the stopper is arranged so as to satisfy the following formula: BF<BB where BB is the distance measured from the axis of the photosensitive member to the stopper along a direction perpendicular to the axis of the photosensitive member, and BF is the shortest distance measured from the center of rotation of the photosensitive member to the tip of the gear teeth along a direction perpendicular to the axis of the photosensitive member.

149. 149. A process cartridge according to any one of claims 145 to 148, wherein the stopper is arranged so as to satisfy the following formula: BB < BX + AX where BB is the distance measured from the axis of the photosensitive member to the stopper along a direction perpendicular to the axis of the photosensitive member, BX is the width of the inclined portion provided at the tip of the centering portion measured along the radial direction of the photosensitive member, and AX is the distance measured from the axis of the photosensitive member to the bottom of the gear teeth along a direction perpendicular to the axis of the photosensitive member.

150. A process cartridge detachably mountable to a main body of an electrophotographic image forming apparatus, the process cartridge having a drive output member in which an output gear portion and a main body side centering portion are coaxially provided, A photoreceptor; a cartridge-side centering section configured to engage with the main body-side centering section to perform centering between the photosensitive member and the drive output member; an input gear portion that can mesh with the output gear portion; and The process cartridge is configured such that the input gear portion rotates while meshing with the output gear portion, thereby causing the input gear portion and the output gear portion to attract each other.

151. 151. A process cartridge according to claim 150, wherein the photosensitive member is rotated by the driving force received by the input gear portion.

152. A process cartridge as described in claim 150 or 151, wherein the input gear portion is configured to generate a force that brings the main body side centering portion and the cartridge side centering portion closer together by rotating while meshing with the output gear portion.

153. 153. A process cartridge according to any one of claims 150 to 152, further comprising a developer carrier configured to carry developer for developing a latent image formed on said photosensitive member.

154. 154. A process cartridge according to claim 153, wherein said developer carrier is rotated by a driving force received by said input gear portion from said output gear portion.

155. 155. A process cartridge according to claim 153 or 154, wherein when viewed so that the rotation direction of said input gear portion is clockwise, the rotation direction of said developer carrying body is also clockwise.

156. the process cartridge has a development gear provided on the developer carrier, 156. A process cartridge according to any one of claims 153 to 155, wherein said development gear has said input gear portion.

157. a drive input gear having the input gear portion; a developing gear provided on the developer carrier; at least one idler gear that transmits a driving force from the drive input gear to the development gear; 156. The process cartridge according to any one of claims 153 to 155, comprising:

158. 158. A process cartridge according to any one of claims 150 to 157, further comprising a regulating portion that regulates tilting of said drive output member.

159. 159. A process cartridge according to claim 158, wherein said regulating portion regulates movement of said output gear portion, thereby regulating tilting of said drive output member.

160. 160. A process cartridge according to claim 158, wherein the regulating portion regulates movement of the main body side centering portion, thereby regulating tilting of the drive output member.

161. 161. A process cartridge according to any one of claims 158 to 160, wherein said regulating portion regulates the inclination of said drive output member so as to allow said cartridge side centering portion to engage with said main body side centering portion.

162. 162. The process cartridge according to any one of claims 158 to 161, wherein the regulating portion is disposed so as to satisfy the following formula: BF<BB Here, BB is the distance measured from the axis of the photosensitive member to the regulating portion along a direction perpendicular to the axis of the photosensitive member, and BF is the shortest distance measured from the center of rotation of the photosensitive member to the tip of the teeth of the input gear along a direction perpendicular to the axis of the photosensitive member.

163. 163. A process cartridge according to any one of claims 158 to 162, wherein the regulating portion is arranged so as to satisfy the following formula: BB < BX + AX where BB is the distance measured from the axis of the photosensitive member to the regulating portion along a direction perpendicular to the axis of the photosensitive member, BX is the width of the inclined portion provided at the tip of the cartridge-side centering portion measured along the radial direction of the photosensitive member, and AX is the distance measured from the axis of the photosensitive member to the bottom of the teeth of the input gear portion along a direction perpendicular to the axis of the photosensitive member.

164. In a process cartridge detachably mountable to a main body of an electrophotographic image forming apparatus, A photoreceptor; a centering unit arranged coaxially with the photosensitive member; a gear portion having gear teeth for receiving a driving force from the outside of the process cartridge, the gear teeth are helical teeth and have an exposed portion exposed to the outside of the process cartridge, In a process cartridge, at least a part of the exposed portion is located further outward than the centering portion in the axial direction of the photosensitive member and faces the axis of the photosensitive member.

165. 165. The process cartridge according to claim 164, wherein the photosensitive member is rotated by the driving force received by the gear portion.

166. 166. A process cartridge according to claim 164 or 165, wherein said gear teeth are helical teeth.

167. A process cartridge as described in any one of claims 164 to 166, wherein when viewed so that the rotation direction of the photosensitive member is counterclockwise, the gear teeth are inclined counterclockwise as they move from the outside to the inside in the axial direction of the photosensitive member.

168. 166. A process cartridge according to claim 164 or 165, wherein said gear teeth are spur teeth having a thickness of less than 1 mm.

169. 169. A process cartridge according to any one of claims 164 to 168, further comprising a developer carrier configured to carry developer for developing a latent image formed on said photosensitive member.

170. the process cartridge has a development gear provided on the developer carrier, 170. The process cartridge according to claim 169, wherein the development gear has the gear portion.

171. 171. A process cartridge according to any one of claims 164 to 170, further comprising a stopper, at least a part of which is arranged outside said centering portion in the axial direction of said photosensitive member and faces the axis of said photosensitive member.

172. If the front pressure angle of the gear portion is α, then A process cartridge as described in claim 171, wherein the stopper is positioned in a plane perpendicular to the axis of the photosensitive body so that it straddles a half-line extending from the center of the photosensitive body toward the center of the gear portion, and a line inclined (90 + α) degrees from the center of the photosensitive body as the origin toward the upstream side of the rotation direction of the photosensitive body.

173. A process cartridge as described in claim 171 or 172, wherein, in a plane perpendicular to the axis of the photosensitive body, at least a portion of the stopper is positioned within a range of (75 + α) degrees or more and (105 + α) degrees or less, with the center of the photosensitive body as the origin, toward the upstream side of the rotation direction of the photosensitive body, relative to a half line extending from the center of the photosensitive body toward the center of the gear portion.

174. 174. A process cartridge according to any one of claims 171 to 173, wherein the stopper is arranged so as to satisfy the following formula: BF<BB where BB is the distance measured from the axis of the photosensitive member to the stopper along a direction perpendicular to the axis of the photosensitive member, and BF is the shortest distance measured from the center of rotation of the photosensitive member to the tip of the gear teeth along a direction perpendicular to the axis of the photosensitive member.

175. 175. A process cartridge according to any one of claims 171 to 174, wherein the stopper is arranged so as to satisfy the following formula: BB < BX + AX where BB is the distance measured from the axis of the photosensitive member to the stopper along a direction perpendicular to the axis of the photosensitive member, BX is the width of the inclined portion provided at the tip of the centering portion measured along the radial direction of the photosensitive member, and AX is the distance measured from the axis of the photosensitive member to the bottom of the gear teeth along a direction perpendicular to the axis of the photosensitive member.

176. In a process cartridge detachably mountable to a main body of an electrophotographic image forming apparatus, A photoreceptor; a centering unit arranged coaxially with the photosensitive member; a gear portion having gear teeth configured to receive a driving force from the outside of the process cartridge; a developer carrier configured to carry a developer to develop a latent image formed on the photosensitive member, the developer carrier configured to rotate clockwise when viewed so that the rotation direction of the gear portion is clockwise; and the gear teeth have an exposed portion that is exposed to the outside of the process cartridge, At least a part of the exposed portion faces the axis of the photosensitive member and is positioned further outward than the centering portion in the axial direction of the photosensitive member.

177. a developing gear provided on the developer carrier, 177. The process cartridge according to claim 176, wherein the development gear has the gear portion.

178. A process cartridge as described in claim 176, having a transmission mechanism that transmits the driving force received by the gear portion to the developer carrier, and is configured to make the rotational direction of the gear portion the same as the rotational direction of the developer carrier.

179. The transmission mechanism includes: a drive input gear having the gear portion; a developing gear provided on the developer carrier; at least one idler gear that transmits a driving force from the drive input gear to the development gear; 179. The process cartridge according to claim 178, comprising:

180. the electrophotographic image forming apparatus main body; A process cartridge according to any one of claims 1 to 179; An electrophotographic image forming apparatus having:

Images