Drum unit, drive transmission unit, cartridge, and electrophotographic image forming apparatus

Abstract

To achieve engagement of a coupling member and a drive transmission member of an apparatus body.SOLUTION: A drum unit has a photoreceptor drum, and a coupling member that is arranged near an end of the photoreceptor drum and connected to the photoreceptor drum in a drive transmittable manner. The coupling member can be inclined with respect to the axis of rotation of the photoreceptor drum, and is configured to be driven to rotate to reduce the inclination angle with respect to the photoreceptor drum.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a drum unit, a drive transmission unit, a cartridge, and an electrophotographic image forming apparatus.

[0002] An electrophotographic image forming apparatus (image forming apparatus) is an apparatus that forms an image on a recording medium using an electrophotographic image forming process. Examples of such an apparatus include electrophotographic copying machines, electrophotographic printers (LED printers, laser beam printers, etc.), facsimile machines, and word processors.

[0003] The cartridge is removably mounted in the main body of an electrophotographic image forming apparatus, the drum unit is a unit having a photosensitive drum, and the drive transmission unit is a unit having a coupling member. [Background technology]

[0004] In an electrophotographic image forming apparatus (hereinafter, also simply referred to as an "image forming apparatus"), an electrophotographic photosensitive member, which is generally a drum type, 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. Next, the electrostatic latent image formed on the photosensitive drum is developed into a toner image with toner as a developer. Then, the toner image formed on the photosensitive drum is transferred to a recording material such as recording paper or a plastic sheet. Furthermore, the toner image transferred to the recording material is fixed to the recording material by applying heat or pressure thereto, thereby performing image recording.

[0005] Such image forming apparatuses generally require toner replenishment and maintenance of various process means. To facilitate this toner replenishment and maintenance, a photosensitive drum, charging means, developing means, cleaning means, etc. are integrated into a frame to form a unit, which is a cartridge that can be detachably attached to the main body of the image forming apparatus.

[0006] By making some units of an image forming apparatus detachable from the main body of the apparatus, as in the case of this cartridge, the user can carry out some maintenance of the apparatus by himself, without relying on a service person in charge of after-sales service. This makes it possible to significantly improve the operability of the apparatus and provide an image forming apparatus with excellent usability. For this reason, this type of cartridge system is widely used in image forming apparatuses.

[0007] As an example of a cartridge that is a removable unit, a process cartridge is known in which a photosensitive drum and a process means acting on the photosensitive drum are integrated (combined into a cartridge). In a process cartridge, a coupling member is provided at the tip of the photosensitive drum to transmit a driving force from the main body of the device to the photosensitive drum (see Patent Document 1). [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2017-223802 A Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention is a further development of the above-mentioned conventional technology. [Means for solving the problem]

[0010] Representative configurations disclosed in the present application include: In a drum unit used in a cartridge, A photoconductor drum; a coupling member disposed near an end of the photosensitive drum and connected to the photosensitive drum so as to be capable of transmitting driving force; having The coupling member is a drum unit that is inclined with respect to the rotation axis of the photosensitive drum and is configured to reduce an angle of inclination with respect to the rotation axis of the photosensitive drum as the coupling member is rotated.

[0011] Another representative configuration disclosed herein is: A drive transmission unit that can be attached to a main body of an electrophotographic image forming apparatus, A coupling member; A support member for supporting the coupling member; having The coupling member is a drive transmission unit that is inclined with respect to the rotation axis of the support member and is configured to reduce an angle of inclination with respect to the rotation axis of the support member as the coupling member is driven.

[0012] Another representative configuration disclosed in the present application is a cartridge and an electrophotographic image forming apparatus that include the above-mentioned drum unit and drive transmission unit. Effect of the Invention

[0013] It is possible to develop the prior art. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is a diagram illustrating the configuration of an image forming apparatus main body and a process cartridge. [Diagram 2] 1 is a cross-sectional view of an image forming apparatus main body and a process cartridge; [Diagram 3] 1 is a cross-sectional view of a process cartridge; [Figure 4] FIG. 1 is an exploded perspective view of a process cartridge; [Diagram 5] FIG. 1 is an exploded perspective view of a process cartridge; [Figure 6] 1 is a cross-sectional view of an image forming apparatus main body and a process cartridge; [Figure 7] FIG. 2 is an explanatory diagram of the main body of the image forming apparatus; [Figure 8]Exploded view of the drum unit [Figure 9] FIG. [Figure 10] 1 is a cross-sectional view of an image forming apparatus main body and a process cartridge; [Figure 11] FIG. 2 is an explanatory diagram of a coupling unit. [Figure 12] FIG. 1 is a perspective view of an image forming apparatus main body; [Figure 13] Exploded perspective view of the drum flange unit [Figure 14] 1 is a cross-sectional view of an image forming apparatus main body and a process cartridge; [Figure 15] FIG. 2 is an explanatory diagram of a coupling unit. [Figure 16] 1 is a cross-sectional view of a drive transmission portion and a non-drive transmission portion; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] <Example 1> The first embodiment will be described in detail below with reference to the drawings.

[0016] The direction of the axis of rotation of the electrophotographic photosensitive drum is defined as the longitudinal direction.

[0017] In addition, in the longitudinal direction, the side where the electrophotographic photosensitive drum receives a driving force from the main body of the image forming apparatus is referred to as a driving side, and the opposite side is referred to as a non-driving side.

[0018] The overall configuration and the image forming process will be described with reference to FIG. 2 and FIG.

[0019] FIG. 2 is a sectional view of an apparatus main body (electrophotographic image forming apparatus main body, image forming apparatus main body) A of the electrophotographic image forming apparatus according to the first embodiment and a process cartridge (hereinafter, referred to as cartridge B).

[0020] FIG. 3 is a cross-sectional view of the cartridge B.

[0021] Here, the apparatus main body A refers to the portion of the electrophotographic image forming apparatus excluding the cartridge B.

[0022] <Overall Configuration of Electrophotographic Image Forming Apparatus> The electrophotographic image forming apparatus (image forming apparatus) shown in Fig. 2 is a laser beam printer utilizing electrophotographic technology in which a cartridge B is detachably attached to an apparatus main body A. When the cartridge B is attached to 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. In addition, a sheet tray 4 is disposed below the cartridge B, which stores a recording medium (hereinafter referred to as a 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.

[0023] Furthermore, in the apparatus main body A, a pickup roller 5a, a pair of feeding rollers 5b, a transfer guide 6, a transfer roller 7, a conveyance guide 8, a fixing device 9, a pair of discharge rollers 10, a discharge tray 11, etc. are arranged in this order along the conveyance direction C of the sheet material PA. The fixing device 9 is composed of a heating roller 9a and a pressure roller 9b.

[0024] <Image formation process> Next, an outline of the image forming process will be described. Based on a print start signal, an electrophotographic photosensitive drum (hereinafter referred to as photosensitive drum 62 or simply drum 62) is rotated in the direction of arrow R at a predetermined peripheral speed (process speed).

[0025] 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.

[0026] The exposure device 3 outputs a laser beam L corresponding to the image information. The laser beam L passes through a laser aperture 61h provided in the cleaning frame 61 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.

[0027] On the other hand, in a developing unit 20 serving as a developing device, toner T in a toner chamber 28 is stirred and transported by rotation of a transport member (stirring member) 30, and is sent out to a toner supply chamber 29, as shown in FIG.

[0028] The toner T is carried on the surface of the developing roller 23 by the magnetic force of the magnet roller 24 (fixed magnet). The developing roller 23 is a developer carrier that carries a developer (toner T) on its surface in order to develop the latent image formed on the drum 62.

[0029] The toner T is frictionally charged by the developing blade 25, while the layer thickness on the circumferential surface of the developing roller 23 serving as a developer carrier is regulated.

[0030] The toner T is supplied to the drum 62 in accordance with the electrostatic latent image, and develops the latent image. As a result, the latent image is visualized as a toner image. The drum 62 is an image carrier that carries the latent image and the image (toner image, developer image) formed with the toner on its surface. As shown in FIG. 2, the sheet material PA stored in the lower part of the device main body A is sent out from the sheet tray 4 by the pickup roller 5a and the pair of feeding rollers 5b in synchronization with the output timing of the laser light L. Then, the sheet material PA is transported to the transfer position between the drum 62 and the transfer roller 7 via the transfer guide 6. At this transfer position, the toner image is sequentially transferred from the drum 62 to the sheet material PA.

[0031] 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 which constitute the fixing device 9. A pressure / heat fixing process is performed in this nip, and the toner image is fixed onto the sheet material PA. The sheet material PA which has had the toner image fixed is transported to a pair of discharge rollers 10 and discharged onto a discharge tray 11.

[0032] 3, the drum 62 after transfer has residual toner on its outer peripheral surface removed by a cleaning member 65, and is used again in the image forming process. The toner removed from the drum 62 is stored in a waste toner chamber 61b of the cleaning unit 60. The cleaning unit 60 is a unit having the photosensitive drum 62.

[0033] In the above, the charging roller 66, the developing roller 23, the transfer roller 7, and the cleaning member 65 are process means that act on the drum 62.

[0034] <Overall cartridge configuration> Next, the overall structure of the cartridge B will be described with reference to Figures 3, 4, and 5. Figure 3 is a cross-sectional view of the cartridge B, and Figures 4 and 5 are perspective views for explaining the structure of the cartridge B. Note that in this embodiment, the screws used to join the various parts will be omitted from the description.

[0035] Moreover, the acting member unit including the lever member will be described later, and therefore will not be described here.

[0036] Cartridge B has a cleaning unit.

[0037] 3, the cleaning unit 60 has a drum 62, a charging roller 66, a cleaning member 65, and a cleaning frame 61 that supports these. On the driving side of the drum 62, a driving-side drum flange 71 provided on the driving side is rotatably supported by a hole 69a of a drum bearing 69. In a broad sense, the drum bearing 69 and the cleaning frame 61 can be collectively referred to as the cleaning frame.

[0038] On the non-drive side, as shown in FIG. 4, a drum shaft 64 is press-fitted into a hole 61c provided in the cleaning frame 61, and a hole 63a (see FIG. 8(e)) of the non-drive side drum flange 63 is rotatably supported by the drum shaft 64.

[0039] In the cleaning unit 60 , the charging roller 66 and the cleaning member 65 are disposed in contact with the outer circumferential surface of the drum 62 .

[0040] The cleaning member 65 has a rubber blade 65a, which is a blade-shaped elastic member made of rubber as an elastic material, and a support member 65b that supports the rubber blade. The rubber blade 65a abuts against the drum 62 in a counter direction to the rotation direction of the drum 62. In other words, the rubber blade 65a abuts against the drum 62 such that its tip portion faces upstream in the rotation direction of the drum 62.

[0041] As shown in FIG. 3, the waste toner removed from the surface of the drum 62 by the cleaning member 65 is stored in a waste toner chamber 61b formed by the cleaning frame 61 and the cleaning member 65.

[0042] As shown in FIG. 3, a catch sheet 34 for preventing waste toner from leaking from the cleaning frame 61 is provided on the edge of the cleaning frame 61 so as to come into contact with the drum 62.

[0043] 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 61 in the longitudinal direction.

[0044] The longitudinal direction of the cleaning frame 61 (the longitudinal direction of the cartridge B) is a direction (axial direction) parallel to the rotation axis of the drum 62. Therefore, hereinafter, when the longitudinal direction or the axial direction is simply mentioned without any particular specification, the axial direction of the drum 62 is intended.

[0045] The charging roller 66 is in pressure contact with the drum 62 by a charging roller bearing 67 being pressed toward the drum 62 by a charging roller biasing member 68. The charging roller 66 is rotated by the rotation of the drum 62.

[0046] 3, the developing unit 20 includes a developing roller 23, a developing container 21 that supports the developing roller 23, and a developing blade 25. The developing roller 23 is rotatably attached to the developing container 21 by a driving side bearing member 26 and a non-driving side bearing member 27 provided on both ends.

[0047] In addition, a magnet roller 24 is provided in the developing roller 23. In the developing unit 20, a developing blade 25 for regulating the toner layer on the developing roller 23 is disposed. As shown in FIG. 4, the developing roller 23 is provided with a spacing member 31 attached to both ends of the developing roller 23, and the developing roller 23 is held with a small gap between the drum 62 and the spacing member 31 when the spacing member 31 abuts against the drum 62. In addition, as shown in FIG. 3, a blowout prevention sheet 33 for preventing toner from leaking from the developing unit 20 is provided on the edge of the bottom member 22 so as to abut against the developing roller 23. Furthermore, a transport member 30 is provided in the toner chamber 28 formed by the developing container 21 and the bottom member 22. The transport member 30 agitates the toner contained in the toner chamber 28 and transports the toner to the toner supply chamber 29.

[0048] As shown in FIGS. 4 and 5, the cartridge B is configured by combining a cleaning unit 60 and a developing unit 20 together.

[0049] First, the support boss 26a provided on the driving side bearing member 26 is fitted into the first hanging hole 61i on the driving side of the cleaning frame 61, and the support boss 27a provided on the non-driving side bearing member 27 is fitted into the second hanging hole 61j on the non-driving side. This allows the developing unit 20 to be rotatably (pivotally) connected to the cleaning unit 60. Thereafter, the cartridge B is constructed by assembling the drum bearing 69 to the cleaning unit 60.

[0050] In this embodiment, the driving side biasing member 32L and the non-driving side biasing member 32R are formed of compression springs. The biasing force of these springs biases the developing unit 20 toward the cleaning unit 60, and the developing roller 23 is reliably pressed toward the drum 62. The developing roller 23 is held at a predetermined distance from the drum 62 by the spacing retaining members 31 attached to both ends of the developing roller 23.

[0051] <Cartridge installation operation> In this embodiment, the operation of mounting cartridge B to the main assembly A of the apparatus will be described with reference to Figs. 1(a), 6 and 7. Fig. 1(a) is a cross-sectional view showing the state of the drive transmission member (drive shaft, drive output member) 1 and the drive side drum flange unit (drive transmission unit) 70 when cartridge B is mounted to the main assembly A of the apparatus and is not driven. Fig. 6(a) is a cross-sectional view showing the state of mounting cartridge B to the main assembly A of the apparatus. Fig. 6(b) is a cross-sectional view showing the state of cartridge B after mounting to the main assembly A of the apparatus. Fig. 7 is an explanatory view showing the state of drive transmission member 1 before cartridge B is mounted to the main assembly A of the apparatus.

[0052] As shown in Fig. 6(a), when mounting the cartridge B to the main assembly A of the apparatus, first, the opening / closing door 13 of the main assembly A of the apparatus is rotated around a rotation center (not shown) to open it. Next, the guided portions 69d, 69e of the cartridge B are inserted along the guide rails 15d, 15e (only the driving side is shown). Then, as shown in Fig. 6(b), the mounting of the cartridge B is completed when the positioned portions 69b, 69c provided on the drum bearing member 69 abut against the positioning portions 15b, 15c of the main assembly of the apparatus or are inserted to the vicinity thereof.

[0053] Two cartridge pressing members 17 are rotatably attached near both ends of the opening / closing door 13 in the axial direction. Two cartridge pressing springs 19 are attached to both longitudinal ends of the apparatus main body A. Cartridge pressed portions 61e are provided at both longitudinal ends of the cleaning frame 61 as portions receiving the urging force of the cartridge pressing springs 19. By completely closing the opening / closing door 13, a predetermined force is applied from the cartridge pressing spring 19 to the cartridge pressed portion 61e. As a result, the positioned portions 69b, 69c are maintained in contact with the apparatus main body positioning portions 15b, 15c, and the cartridge B is positioned at a position where an image can be formed (FIG. 6(b)).

[0054] Here, the mounting / positioning configuration and pressing configuration of the cartridge B on the driving side have been described, but the same configuration applies to the non-driving side as well.

[0055] In this embodiment, as shown in FIG. 7, one end of the drive transmission member 1 is provisionally supported in the hole 15a of the drive side plate 15. Before the cartridge B is mounted, the drive transmission member is inclined by its own weight within the range of the backlash (gap) generated between the hole 15a and the drive transmission member 1. In addition, the first coupling portion 72 is inclined in approximately the same direction as the drive transmission member 1 by the biasing force of the third biasing member 76 (coupling biasing member, third elastic member, third spring) (FIG. 9) in order to engage with the drive transmission member 1. At this time, since the rotation axes of the drive transmission member 1 and the first coupling portion 72 have an angle, the axis of the drive transmission member 1 is shifted from the axis of the drum 62 (see FIG. 1(a)). In such a case, in order for the drum 62 to rotate stably during driving, the drum 62 needs to rotate in a state in which the rotation axis of the drive transmission member 1 and the rotation axis of the drum 62 are aligned.

[0056] <Configuration of the drive side drum flange unit and coupling engagement operation> Next, we will explain the operation from a state in which the axis of the drive transmission member 1 is inclined relative to the axis of the drum 62 after the installation of the cartridge B is complete, to a state in which a driving force is applied, the drive transmission member 1 engages with the first coupling portion 72, and becomes coaxial with the axis of the drum 62.

[0057] First, the configuration of the drive side drum flange unit (drive transmission unit) 70 will be described with reference to Figures 8, 9, and 10. Figures 8(a), 8(b), and 8(c) are diagrams for explaining a method of assembling the coupling unit 79. Figure 8(d) is a diagram for explaining a method of assembling the drive side drum flange unit 70. Figure 8(e) is a diagram for explaining a method of assembling the drum unit.

[0058] Fig. 9 is a perspective view showing the configurations of the first coupling portion 72 and the third biasing member (third elastic member, third spring) 76. Fig. 10 is a sectional view showing the state of the drive transmission member 1 and the driving side drum flange unit 70 when the cartridge B is attached to the apparatus main body A and is not driven.

[0059] The individual members that rotate together with the photosensitive drum 62 are unitized and referred to as a drum unit. The drum unit has the photosensitive drum 62, a driving side drum flange unit 70, and a non-driving side drum flange 63. The driving side drum flange unit 70 is fixed to one end of the photosensitive drum, and the non-driving side drum flange 63 is fixed to the other end (second end) of the photosensitive drum opposite to the one end.

[0060] The driving side drum flange unit 70 is composed of a driving side drum flange 71, a first coupling portion 72, a second coupling portion 73, a first biasing member 74 (first elastic member, first spring, axial biasing member), a second biasing member 75 (second elastic member, second spring, radial biasing member), a pin 78, and a lid member 77.

[0061] The first coupling part 72 is provided with a driven transmission part (driving force receiving part) 72a to which a driving force is transmitted from the drive transmission member 1 of the apparatus main body A. The first coupling part 72 transmits the driving force to the second coupling part 73 via a pin 78 (second abutment part). The first coupling part 72 and the pin 78 may be integral. The second coupling part 73 is provided with a driven transmission part 73a (second abutment part) to which the driving force is transmitted from the first coupling part 72, and a drive transmission part 73b (first abutment part) that transmits the drive to the lid member 77. The lid member 77 is provided with a driven transmission part 77a (first abutment part) to which the driving force is transmitted from the second coupling part 73.

[0062] As shown in FIG. 8(a), the shaft 72k of the first coupling part 72 and the second coupling part 73 are inserted into the hole 73k, and the second coupling part 73 is supported rotatably relative to the first coupling part 72. As shown in FIG. 8(b), a second biasing member 75 that biases in the rotational direction is disposed between the first coupling part 72 and the second coupling part 73. In this embodiment, the second biasing member 75 is made of a torsion coil spring, and both ends of the spring abut against the spring hook part 72h of the first coupling part 72 and the spring hook part 73h of the second coupling part 73, respectively, to restrict movement in the rotational direction. Then, as shown in FIG. 8(c), a pin 78 is inserted into each of the pin insertion holes 72d, 73d to form a coupling unit (coupling member) 79.

[0063] Next, as shown in Fig. 8(d), after the coupling unit 79 is inserted into the driving side drum flange 71, a first biasing member 74 for biasing the coupling unit 79 to the driving side is inserted. Then, the lid member 77 is fixed to the driving side drum flange 71 by means such as welding to form the driving side drum flange unit 70. As shown in Fig. 8(e), the driving side drum flange unit 70 and the non-driving side drum flange 63 are inserted into the drum 62 and fixed by means such as press fitting or crimping.

[0064] The drum unit (62, 70, 63) configured in this manner is rotatably supported by a frame (drum bearing 69) of the cartridge B. The drum unit (62, 70, 73) can be installed in the apparatus main body A as a part of the cartridge B.

[0065] The pin 78, the first coupling portion 72, and the second coupling portion 73 of the drum unit are collectively referred to as coupling members. The coupling members (72, 73, 78) are members for connecting with a drive transmission member (described later) of the main body A of the apparatus to transmit a driving force (rotational force) from the main body A of the apparatus to the drum 62. In this embodiment, the coupling member is a unit that can be disassembled into a plurality of members (78, 72, 73), but is not limited to such a configuration and may be configured as a single body. For example, instead of connecting the first coupling portion 72 and the second coupling portion 73 with the pin 78, the first coupling portion 72 and the second coupling portion 73 may be originally configured as a single part. Such a configuration will be described later. Also, the lid member 77 and the driving side drum flange 71 may be collectively referred to as flange members, or the lid member 77 may be considered as a part of the driving side drum flange 71.

[0066] The flange members (71, 77) are fixed to one end of the drum 62 and connect the drum 62 and the coupling members (72, 73, 78) in a drive-transmitting manner. The flange members are end members attached to the ends of the drum 62. The coupling members (72, 73, 78) are supported by the flange members and are disposed in the vicinity of the ends of the photosensitive drum 62.

[0067] The flange members (71, 77) transmit the driving force from the coupling members (72, 73, 78) to the drum 62. The flange members (71, 77) are cartridge-side transmission members (driving force transmission members) that transmit the driving force.

[0068] The flange members (71, 77) are also connecting members that connect the coupling members (72, 73, 78) to the drum 62. The coupling members (72, 73, 78) are indirectly connected to the drum 62 via the flange members (71, 77). As described above, the coupling members are connected to the drum 62 in a drive-transmittable manner. In other words, the coupling members (72, 73, 78) are operatively connected to the drum 62. In other words, the coupling members (72, 73, 78) are connected to the drum 62 such that the drum 62 is also driven to rotate (operates) as the coupling members (72, 73, 78) are driven to rotate.

[0069] As will be described in detail later, the coupling members (72, 73, 78) are tiltably supported by the flange members (71, 77). The flange members (71, 77) also serve as support members that support the coupling members.

[0070] In this embodiment, the driven portion (driving force receiving portion, driving force input portion) 72a of the first coupling portion 72 has a substantially triangular convex cross section (see FIG. 16). Specifically, the substantially triangular cross section is twisted counterclockwise on the axis of the drum 62 from the driving side to the non-driving side.

[0071] As shown in Fig. 9, a chamfered portion 72e inclined in the longitudinal direction is provided on the triangular ridge of the driving side end of the first coupling part 72. Also, as shown in Fig. 10, the size of the chamfered portion 72e is such that, in the radial direction, a part of the chamfered portion 72e is located within the drive transmission part 1a of the drive transmission member 1 when the drive transmission member 1 is inclined in the V direction due to its own weight. More specifically, as shown in Fig. 10, the minimum distance D1 of the chamfered portion 72e from the drum central axis to the drive transmission part 1a is smaller than the distance D2 from the drum central axis to the inlet of the drive transmission part of the drive transmission member 1.

[0072] Further, the drive transmitting portion 73b of the second coupling portion 73 and the drive transmitted portion (driving force receiving portion) 77a of the lid member 77 engage with each other, and the cross section of the drive transmitting portion 73b is substantially triangular.

[0073] Furthermore, as shown in FIG. 10, the first coupling part 72 is moved toward the driving side in the longitudinal direction (the direction of the arrow G) by the first biasing member 74. As a result, the spherical regulated part 72c of the first coupling part 72 abuts against the conical regulated part 71c of the driving side drum flange 71. As a result, when the cartridge B is completely mounted, a part of the first coupling part 72 is arranged so as to be surely engaged inside the drive transmitting part 1a in the longitudinal direction (see FIG. 1(a)). Here, the drive transmitting part 73b and the driven transmitting part 77a correspond to a centering part (centering part) having a centering action for matching the rotation axis of the second coupling part 73 with the rotation axis of the cover member 77 (drum 62). In other words, the drive transmitting part 73b and the driven transmitting part 77a bias the second coupling part 73 in a direction to reduce the inclination angle of the second coupling part 73 with respect to the cover member 77 when the second coupling part 73 rotates relative to the cover member 77.

[0074] Next, the engagement operation of the first coupling portion 72 and the second coupling portion 73 will be described with reference to Fig. 1 and Fig. 11. Fig. 1 is a diagram illustrating the engagement operation of the drive transmission member 1, the first coupling portion 72, and the second coupling portion 73. Fig. 11 is a diagram illustrating the relative positional relationship of the first coupling portion 72 with respect to the second coupling portion 73.

[0075] FIG. 1(a) shows a state in which the phases of the drive transmission portion 1a of the drive transmission member 1 and the driven transmission portion 72a of the first coupling portion 72 are not aligned after the cartridge B is mounted in the main assembly A of the apparatus. When the drive transmission member 1 is rotated from this state, the chamfered portion 72e of the first coupling portion 72 swings the drive transmission member 1 in a direction (the direction of the arrow W in FIG. 1(a)) that reduces the inclination angle of the drive transmission member 1, which is inclined in the direction of the arrow V (FIG. 10) due to its own weight. At the same time, the drive transmission member 1 is drawn to the non-driven side (the direction of the arrow N) due to its twisted shape, and as shown in FIG. 1(b), the surface 1f of the drive transmission member 1 abuts against the end surface 72f of the first coupling portion 72. Here, the surface 1f of the drive transmission member 1 and the end surface 72f of the first coupling portion 72 are surfaces perpendicular to the rotation axes of the drive transmission member 1 and the first coupling portion 72, respectively. At this time, the driven transmission part 72a of the first coupling part 72 and the drive transmission part 1a of the drive transmission member 1 are configured to ensure the amount of engagement in the longitudinal direction required for stable drive transmission. In addition, the phases of the triangles match, so that the centers of the triangles match, and the faces perpendicular to the rotation axis butt against each other, so that the rotation axes of the drive transmission member 1 and the first coupling part 72 match. Then, the engagement between the drive transmission member 1 and the first coupling part 72 is completed.

[0076] In this embodiment, the inclination direction of the drive transmission member 1 is the direction of gravity, but the inclination direction is not limited to the direction of gravity, and engagement is possible even if the inclination direction is in any direction as long as the condition that a part of the chamfered portion 72e is located inside the drive transmission member 1a is satisfied as described above. Moreover, even if the rotation axes of the first coupling part 72 and the drive transmission member 1 are not parallel and coaxial, the first coupling part 72 can engage with the drive transmission member 1 as long as the same condition is satisfied.

[0077] As explained above, the drive transmission member 1 and the first coupling portion 72 are engaged with each other, enabling drive transmission from the main assembly A of the apparatus to the cartridge B. At this time, the drive transmission member 1 and the first coupling portion 72 are both coaxial, but are still inclined with respect to the drum 62. Next, a configuration will be described in which the drive transmission member 1 and the first coupling portion 72, whose rotation axes are inclined with respect to the rotation axis of the drum 62, are aligned with each other.

[0078] Inside the driving side drum flange 71, the second coupling part 73 is disposed, which is supported coaxially and rotatably with respect to the first coupling part 72. Between the first coupling part 72 and the second coupling part 73, there is a degree of freedom in the rotation direction of 120° or more due to the pin insertion hole 73d. Before starting rotation, the first coupling part 72 is located at a first position (see FIG. 11(a)) where the second coupling part 72 is urged by the second urging member 75 in the opposite direction (the direction of the arrow F) to the rotation direction during driving with respect to the second coupling part 73. Then, when the first coupling part 72 rotates by 120° or more, it moves to a second position (see FIG. 11(b)) where the pin 78 abuts against the non-drive transmission part 73a. Here, the pin 78 of the second coupling part 73 abuts against the non-drive transmission part 73a. As a result, the second coupling part 73 receives a driving force from the first coupling part 72, and therefore does not rotate until the first coupling part 72 moves from the first position to the second position.

[0079] Next, when the second coupling part 73 reaches the second position (see FIG. 11(b)), the pin 78 abuts against the driven transmission part 73a, so that the driving force of the first coupling part 72 is transmitted, and the second coupling part 73 becomes rotatable. Furthermore, when the second coupling part 73 rotates, the drive transmission part 73b of the second coupling part 73 engages with the driven transmission part 77a of the lid member 77, as shown in FIG. 1(c), and the lid member 77 becomes rotatable. At this time, the triangular phases of the drive transmission part 73b and the driven transmission part 77a match, and the second coupling part 73 is drawn to the non-driving side (direction of the arrow N) due to the twisted shape, and the end face 73f abuts against the face 77f of the lid member 77. Here, the end face 73f of the second coupling part 73 and the face 77f of the lid member 77 are faces perpendicular to the rotation axis of the second coupling part 73 and the lid member 77, respectively. The phases of the triangles match, so that the centers of the triangles match, and the faces perpendicular to the rotation axis abut against each other, so that the rotation axes are parallel to each other. Therefore, the rotation axes of the second coupling part 73 and the lid member 77 match. Since the lid member 77 is fixed to the drive side drum flange 71, and the drive side drum flange 71 is fixed to the drum 62, the rotation axis of the second coupling part 73 matches with that of the drum 62.

[0080] Here, the rotation axes of the drive transmission member 1 and the first coupling portion 72 coincide with each other, and the rotation axes of the second coupling portion 73 and the drum 62 coincide with each other. Since the first coupling portion 72 and the second coupling portion 73 are coaxial, the drive transmission member 1 and the drum 62 can rotate with their rotation axes also coinciding with each other.

[0081] As described above, in this embodiment, the first coupling portion 72 can be engaged with the drive transmission member 1 having an axis inclined with respect to the axis of the drum 62, making it possible to make it coaxial with the drum 62. With this configuration, the accuracy of drive transmission from the apparatus main body A to the cartridge B can be improved.

[0082] In this embodiment, the coupling member has the first coupling portion 72 and the second coupling portion 73, which are movable relative to each other. This provides the following advantages.

[0083] At the stage when the drive transmission member 1 starts to rotate, the first coupling portion 72 of the coupling member may not be engaged with the drive transmission member 1. Even in this state, frictional force is generated between the first coupling portion 72 and the drive transmission member 1, and this frictional force may cause the first coupling portion 72 to rotate slightly before engaging with the drive transmission member 1. If rotation is transmitted from the first coupling portion 72 to the second coupling portion 73 in a state in which the first coupling portion 72 is not engaged with the drive transmission member 1, the above-mentioned centering action unintentionally occurs between the second coupling portion 73 and the flange member (the cover member 77). That is, as the second coupling portion 73 engages with the cover member 77 of the flange member, the inclination angle of the second coupling portion 73 with respect to the drum 62 becomes smaller. Accordingly, the inclination angle of the first coupling portion 72 with respect to the drum 62 also becomes smaller. If the inclination angle of the first coupling part 72 is reduced before the first coupling part 72 engages with the drive transmission member 1, there is a risk that the first coupling part 72 will move away from the drive transmission member 1 and will not be able to engage with the drive transmission member 1.

[0084] Therefore, in this embodiment, the first coupling part 72 is made rotatable relative to the second coupling part 73 within a certain range. Therefore, even if the first coupling part 72 rotates slightly unintentionally before engaging with the drive transmission member 1, the rotation is not transmitted to the second coupling part 73. Only after the drive transmission member 1 and the first coupling part 72 are securely engaged with each other can the rotation be transmitted from the first coupling part 72 to the second coupling part 73. Therefore, no unintentional centering action occurs before the first coupling part 72 and the drive transmission member 1 engage with each other.

[0085] In particular, in this embodiment, as described above, the angle (phase difference) by which the first coupling part 72 can rotate relatively to the second coupling part 73 from the first position to the second position is set to 120 degrees or more.

[0086] The 120 degrees is the angle θ between the straight lines connecting the center of the equilateral triangle to each vertex (see FIG. 16). Even if the phases of the triangular shapes of the drive transmission member 1 and the first coupling part 72 are different when the cartridge is mounted in the apparatus main body, the phase difference is 120 degrees or less. That is, normally, if the drive transmission member 1 rotates a maximum of 120 degrees, the triangular shapes of the drive transmission member 1 and the first coupling part 72 can engage with each other. Even if the first coupling part 72 rotates slightly due to the above-mentioned frictional force before this engagement, the rotation angle is less than 120 degrees, and such rotation of the first coupling part 72 does not cause the second coupling part 73 to start rotating.

[0087] As a result, the first coupling portion 72 reliably engages with the drive transmission member 1 and rotates first, and then the second coupling portion 73 starts to rotate, and further thereafter the drum 62 becomes rotatable.

[0088] The alignment force generated between the second coupling portion 72 and the flange member (77) can prevent the inclination of the first coupling portion 72 from being corrected before the first coupling portion 72 engages with the drive transmission member 1. As a result, the occurrence of poor engagement between the drive transmission member 1 and the first coupling portion 72 can be prevented.

[0089] However, the coupling member of the coupling unit 79 does not necessarily have to be divided into the first coupling portion 72 and the second coupling portion 73 as described above. For example, if the first coupling portion 72 does not rotate before engaging with the drive transmission member 1 (for example, if the frictional force generated between the first coupling portion 72 and the drive transmission member 1 is sufficiently small), the above-mentioned configuration is not necessary. In this case, the coupling portion does not have to be divided into the first coupling portion 72 and the second coupling portion 73, and these may be integrated. Furthermore, even if the coupling member is divided into the first coupling portion 72 and the second coupling portion 73, the rotatable angle of the first coupling portion 72 relative to the second coupling portion 73 may be smaller than 120 degrees.

[0090] As described above, in order to enable engagement between the drive transmission part 1a of the drive transmission member 1 and the driven transmission part 72a of the first coupling part 72, and between the drive transmission part 73b of the second coupling part 73 and the driven transmission part 77a of the cover member 77, each of them has a characteristic shape. In this embodiment, a shape is adopted in which the triangular shape of the cross section perpendicular to the rotation axis is an equilateral triangle, and each apex is chamfered in an arc shape (see FIG. 16). However, in order to obtain the same effect as this embodiment, the shape is not necessarily limited to this.

[0091] <Cartridge removal operation> Next, the operation of releasing the engagement between the drive transmission member 1 and the first coupling portion 72 and removing the cartridge B from the main assembly A of the apparatus will be described.

[0092] When the cartridge B is pulled out to the outside, the connecting member 2 (FIG. 12) linked to the opening / closing door 13 rotates in the process of opening the opening / closing door 13, and the connecting member 2 moves toward the driving side (in the direction of the arrow G) along the inclined portion (not shown) provided on the driving side side plate 15. Accordingly, the drive transmission member 1 moves toward the driving side. As a result, the drive transmission member 1 moves while rotating in the reverse direction due to its triangular twisted shape, and the engagement with the first coupling part 72 is released. When the engagement is released, the drive transmission member 1 and the first coupling part 72 are inclined again.

[0093] The configuration of this embodiment described so far can be briefly summarized as follows. The drum unit of this embodiment has a coupling member (79) that can receive a driving force (rotational force) by engaging and connecting with the drive transmission member 1 (see FIG. 8). The coupling member 79 is supported so as to be tiltable by flange members (71, 77) fixed to the photosensitive drum 1. In other words, the angle between the rotation axis of the coupling member 79 and the rotation axis of the photosensitive drum 62 varies.

[0094] The drive transmission member 1 is inclined inside the main body A of the apparatus (see FIG. 4). The coupling member 79 can also be inclined with respect to the photosensitive drum 62 so as to be able to engage with the drive transmission member 1 (see FIG. 4). In particular, in this embodiment, the cartridge B is provided with a biasing member (elastic member, spring) 76 for inclining the coupling member 79 to a predetermined direction in which the coupling member 79 can be engaged with the drive transmission member 1 (see FIG. 9). In the inclined state, the coupling member 79 receives a driving force from the drive transmission member 1 and rotates (see FIG. 1). When the coupling member 79 rotates with respect to the flange members (71, 79), a force for reducing the inclination angle is applied to the coupling member 79 by the action of the centering portion (drive transmission portion 73b, driven transmission portion 77a: see FIG. 8) provided between the coupling member 79 and the flange members (71, 79). This reduces the inclination angle of the coupling member 79 and the drive transmission member 1 connected thereto. As a result, the driving force can be stably transmitted from the drive transmission member 1 to the photosensitive drum 62 via the coupling members (72, 73) and the flange members (71, 77). In this embodiment, the drive transmission member 1, the coupling members (72, 73), and the photosensitive drum 62 are arranged substantially coaxially when transmitting the driving force, but they do not necessarily have to be coaxial. In other words, if the inclination angle of the drive transmission member 1 and the coupling members (72, 73) is reduced, the accuracy of the drive transmission is improved.

[0095] As described above, the drive transmission member 1 may tilt or incline inside the main body of the electrophotographic image forming apparatus depending on the support structure for supporting it. In order to transmit drive by engaging and connecting the coupling members (72, 73) to such a drive transmission member 1, the drive transmission structure including the coupling members described in this embodiment is suitable.

[0096] In addition, a support structure may be considered in which the drive transmission member 1 is intentionally tilted so that the drive transmission member 1 does not get in the way of attaching or detaching the drum unit or cartridge. The drive transmission structure of this embodiment is also useful for such a support structure.

[0097] In addition, the driving side drum flange unit (drive transmission unit) 70 in this embodiment is integrated with the photosensitive drum to form the drum unit. In other words, the drive transmission unit 70 is detachable from the image forming apparatus body as a part of the drum unit or a cartridge including the same. However, the drive transmission unit 70 does not necessarily have to be integrated with the photosensitive drum, and the drive transmission unit 70 does not necessarily have to be a part of the drum unit or a part of the cartridge.

[0098] In other words, the drive transmission unit 70 may be a unit (detachable unit, attachment) that can be attached to the main body of the electrophotographic image forming apparatus by a user, or a part thereof. In other words, the drive transmission unit 70 may be one that can receive a drive force by being coupled to the drive transmission member 1 when attached to the main body of the electrophotographic image forming apparatus.

[0099] The object to which the drive transmission unit 70 transmits the drive force may not be the photosensitive drum 62 but may be another member, such as the developing roller 23. The drive transmission unit 70 does not have to be directly connected to the object to which the drive force is transmitted (the photosensitive drum in this embodiment). For example, a cartridge may have the drive transmission unit 70 and the photosensitive drum 62, but the two may be arranged separately and indirectly connected via gears or the like. In this case as well, the coupling member of the drive transmission unit 70 can be connected to the photosensitive drum 62 so as to be drive-transmittable, i.e., operatively connected.

[0100] Alternatively, a configuration in which the drive transmission unit 70 is separable from the drum unit and the cartridge may be considered. In this case, the user first installs the drive transmission unit 70 to the image forming apparatus main body. After that, the user may install the cartridge and the drum unit to the image forming apparatus main body and connect them to the drive transmission unit 70.

[0101] In this embodiment, one of the drive transmitting part 73b and the driven transmitting part 77a, which are the centering parts, has a convex shape (projection, convex portion), and the other has a concave shape (depression, concave portion) that can engage with the projection. When the drive transmitting part 73b rotates relative to the driven transmitting part 77a, one of the convex shape and the concave shape rotates relative to the other while engaging. At least one of the convex shape and the concave shape is twisted, so when one of the convex shape and the concave shape rotates relative to the other while engaging, the axis of the convex shape and the concave shape coincide due to the action of this twist. As a result, the inclination angle of the flange member (71, 77) relative to the coupling member 79 becomes smaller, and the inclination angle of the coupling member 79 relative to the drum 62 also becomes smaller. As a result, the rotation axis of the coupling member 79 and the drum 62 almost coincide. In this embodiment, the drive transmitting part 73b is made convex, and the driven transmitting part 77a is made concave. In addition, a twist is added to both the convex shape and the concave shape.

[0102] The cross-sectional shape of the drive transmitting portion 73b and the driven transmitting portion 77a is substantially triangular, i.e., the cross-sectional shape is an equilateral triangle with the apex portion being an arc, but the cross-sectional shape may be another shape.

[0103] <Example 2> Next, a second embodiment will be described. In this embodiment, the drive transmission member 1 is also tiltable (inclinable). In the second embodiment, the mounting and dismounting operation of the cartridge B and the engagement between the drive transmission member 1 and the first coupling portion 82 are the same as those in the first embodiment, so the description will be omitted. The second embodiment is a modified example of the configuration of the drive side drum flange unit 80 for changing the rotation axis of the first coupling portion 82 and the rotation axis of the drum 62 from a misaligned state to a coaxial state. Therefore, the following description will be given with reference to Figures 13, 14, and 15 regarding the configuration in which the drive transmission member 1 and the first coupling portion 82 become coaxial with the rotation axis of the drum 62 after they are engaged. Figure 13 is a diagram for explaining a method of assembling the coupling unit 89 and the drive side drum flange unit 80.

[0104] Fig. 14 is a diagram illustrating the engagement operation of the drive transmission member 1, the first coupling portion 82, and the second coupling portion 83. Fig. 15 is a diagram illustrating the relative positional relationship of the first coupling portion 82 with respect to the second coupling portion 83.

[0105] 13(a), the coupling unit 89 is composed of a first coupling portion 82, a second coupling portion 83, a second biasing member 85, and a pin 88. As shown in Fig. 13(b), the driving side drum flange unit 80 is composed of a driving side drum flange 81, a coupling unit 89, a first biasing member 84, and a lid member 87.

[0106] The drum unit in this embodiment corresponds to the drum unit in embodiment 1, in which the driving side drum flange unit 70 (see FIG. 8(e)) is replaced with a driving side drum flange unit. That is, the drum unit in this embodiment has a driving side drum flange unit 80, a photosensitive drum 62, and a driven side drum flange 63 (see FIG. 8(e)).

[0107] The driving side drum flange 81 and the lid member 87 may be collectively referred to as the flange member, or the lid member 87 may be regarded as a part of the driving side drum flange 81. The first coupling portion 82 has a driven transmission portion 82a that engages with the drive transmission member 1 to receive the driving force, and a shaft portion 82k, and is inclined by a third biasing member 86 (not shown). The second coupling portion 83 has a hole portion 83k into which the shaft portion 82k is inserted and which supports the first coupling portion 82 rotatably and coaxially, and a drive transmission portion 83b that engages with the driven transmission portion 81a of the driving side drum flange 81 to transmit the driving force. The first biasing member (first elastic member, first spring) 84 biases the first coupling portion 82 and the second coupling portion 83 toward the driving side in the longitudinal direction (the direction of the arrow G in FIG. 14). The second biasing member 85 biases the first coupling portion 82 in the rotational direction relative to the second coupling portion 83, as in the first embodiment.

[0108] In addition, the first coupling part 82 and the second coupling part 83 are provided with inclined parts 82g, 83g that come into contact with each other, and the first coupling part 82 can move in the longitudinal direction by rotating. When the first coupling part 82 is not transmitting drive, the first coupling part 82 is urged in the rotational direction by the second urging member 85, and is located at a first position (see FIG. 15(a)) where the pin 88 abuts against an end face of the pin insertion hole 83d of the second coupling part 83. As in the first embodiment, the pin insertion hole 83d of the second coupling part 83 has a degree of freedom in the rotational direction of 120° or more. Therefore, when the first coupling part 82 rotates by 120° or more, the pin 88 reaches a second position (see FIG. 15(b)) where it abuts against the driven part 83a. Then, the driving force of the first coupling part 82 is transmitted, and the second coupling part 83 becomes rotatable. At the same time, in the second position, the second coupling portion 83 moves along the inclined portions 82g, 83g toward the non-driving side (the direction of arrow N), and the spherical regulated portion 83c (second regulated portion) abuts against the conical regulating portion 87c (second regulating portion) of the lid member 87.

[0109] The second coupling part 83 is provided with a drive transmission part 83b, and the driving side drum flange 81 is provided with a drive transmitted part 81a corresponding to the drive transmission part 83b, and the second coupling part 83 is movable in the longitudinal direction relative to the driving side drum flange 81. When the second coupling part 83 rotates, the driving side drum flange 81 and the drum 62 become rotatable.

[0110] The first coupling portion 82, the second coupling portion 83, and the pin 88 may be collectively referred to as coupling members. The coupling members (82, 83, 88) are configured to transmit a driving force (rotational force) to the photoconductor drum 62 via flange members (81, 87).

[0111] Next, the engagement operation of the first coupling portion 82 and the second coupling portion 83 will be described.

[0112] As shown in FIG. 14(a), after the cartridge B is completely mounted, the drive transmission member is inclined and is not engaged with the first coupling portion 82. At this time, the spherical regulated portion 82c (first regulating portion) of the first coupling portion 82 is in contact with the conical regulating portion 81c (first regulating portion) of the driving side drum flange 81 by the first biasing member 84. Next, as shown in FIG. 14(b), when the drive transmission member 1 rotates, the triangular phases of the drive transmission portion 1a and the driven transmission portion 82a match, and the face 1f of the drive transmission member 1 abuts against the end face 82f of the first coupling portion 82 and rotates, as in the first embodiment. Therefore, the first coupling portion 82 rotates with the rotation axis of the drive transmission member 1 matched with the rotation axis of the first coupling portion 82. Then, the inclined portion 83g of the second coupling portion 83 moves along the inclined portion 82g toward the non-driving side in the longitudinal direction (the direction of the arrow N). At this time, while moving along the inclined portion 82g, the second coupling portion 83 does not rotate because the hole portion 83d provides a degree of freedom in the rotational direction of 120° or more between the first coupling portion 82 and the second coupling portion 83. When rotated to a predetermined angle of 120° or more, the second coupling portion 83 moves along the inclined portion 82g to a second position (see FIG. 15(b)) on the non-driving side, as shown in FIG. 14(c), and the spherical regulated portion 83c abuts against the conical regulating portion 87c of the lid member 87. At the same time, the second coupling portion 83 rotates, and the drive transmitting portion 83b of the second coupling portion 83 abuts against the driven transmitting portion 81a of the driving side drum flange 81 to rotate the drum 62.

[0113] Here, the first coupling part 82 abuts against the regulating part 81c of the driving side drum flange 81, and the second coupling part 83 abuts against the regulating part 87c of the lid member 87. Therefore, the positions of the centers Q1 and Q2 of the regulated part 82c of the first coupling part 82 and the regulated part 83c of the second coupling part 83 are determined as shown in FIG. 14(c). Here, the central axis of the cone shape of the regulating part 81c of the driving side drum flange 81 and the central axis of the cone shape of the regulating part 87c of the lid member 87 are set so as to be coaxial with the rotation axis of the drum 62. In addition, the centers Q1 and Q2 are set so as to be located on the rotation axis lines of the first coupling part 82 and the second coupling part 83, respectively. Therefore, since the first coupling part 82 and the second coupling part 83 are coaxial, the straight line connecting the centers Q1 and Q2, i.e., the rotation axes of the first coupling part 82 and the second coupling part 83, all coincide with the rotation axis of the drum 62.

[0114] As a result of the above, the drive transmission member 1, the first coupling portion 82, the second coupling portion 83, the cover member 88, the drive side drum flange 81, and the drum 62 can all rotate with their rotation axes aligned.

[0115] As in the first embodiment, the first coupling part 82 in this embodiment can engage with the drive transmission member 1 even if the drive transmission member 1 has a configuration in which the rotation axis before engagement is inclined with respect to the first coupling part 82. Furthermore, the first coupling part 82 in this embodiment can engage with the drive transmission member 1 even if the rotation axes of the first coupling part 82 and the drive transmission member 1 before engagement are parallel but not coaxial.

[0116] In this embodiment, the regulating portion 81c of the driving side drum flange 81 and the regulated portion 82c of the first coupling portion 82 are respectively formed with a concave shape having a conical surface and a convex shape having a spherical surface. Similarly, the regulating portion 87c of the lid member 87 and the regulated portion 83c of the second coupling portion 83 are respectively formed with a concave shape having a conical surface and a convex shape having a spherical surface. To obtain the same effect as in this embodiment, the relationship between the concave shape having a conical surface and the convex shape having a spherical surface may be reversed.

[0117] The restricting portions 81c and 87c and the restricted portions 82c and 83c are the alignment portions in the second embodiment.

[0118] As described above, in the second embodiment, similarly to the first embodiment, the first coupling portion 82 can be engaged with the drive transmission member 1 having an axis inclined with respect to the axis of the drum 62, and made coaxial with the drum 62. With this configuration, the accuracy of drive transmission from the main assembly A of the apparatus to the cartridge B can be improved.

[0119] The present embodiment described so far can be summarized as follows.

[0120] Regarding the coupling member of this embodiment, the first coupling part 82 and the second coupling part 83 are configured to be relatively movable. As shown in Fig. 14(b), the first coupling part 82 rotates by engaging with the drive transmission member 1. Then, one of the first coupling part 82 and the second coupling member 83 moves in the axial direction relative to the other. In other words, the second coupling part 83 moves in the axial direction of the drum (the direction of the arrow N in Fig. 14(c)) relative to the first coupling part 82.

[0121] As a result, the regulated portion 82c provided on the first coupling portion 82 comes into contact with (is pressed against) the regulating portion 81c provided on the flange member (driving side drum flange 81). Also, the regulated portion 83c provided on the second coupling portion 83 comes into contact with (is pressed against) the regulating portion 87c provided on the flange member (lid member 77). Due to these contacts, the coupling members (first coupling portion 82, second coupling portion 83) are aligned. That is, the inclination angle of the coupling members (82, 83) relative to the photosensitive drum 62 becomes smaller. As a result, as shown in FIG. 14(c), the drive transmission member 1, the coupling members (82, 83), and the photosensitive drum 62 are arranged substantially coaxially, and the precision of the drive transmission therebetween is improved.

[0122] The first coupling part 82 and the second coupling part 83 have inclined parts 82g, 83g (see FIG. 13(a)) serving as a cam mechanism. Therefore, when the first coupling part 82 rotates with respect to the second coupling part 83, the relative positions of the first coupling part 82 and the second coupling part 83 change in the axial direction along the inclined parts 82g, 83g.

[0123] Moreover, one of the regulated portion 82c provided on the first coupling portion 82 and the regulating portion 81c provided on the flange member (drive-side drum flange 81) has a spherical convex shape, and the other has a spherical or conical concave shape. Moreover, one of the regulated portion 83c provided on the second coupling portion 83 and the regulating portion 87c provided on the flange member (lid member 77) has a spherical convex shape, and the other has a spherical or conical concave shape.

[0124] The above-mentioned concave and convex shapes engage with each other to produce an aligning effect. [Explanation of symbols]

[0125] 1 Drive transmission member 2 Connecting members 3 Exposure device (laser scanner unit) 9 Fixing device 13 Opening and closing doors 15 Drive side plate 17 Cartridge biasing member 19 Cartridge pressure spring 20 Development unit 23 Developing roller (developer carrier) 60 Cleaning unit 61 Cleaning frame 62 Drum (electrophotographic photosensitive drum) 69 Drum Bearing 70, 80 Drive side drum flange unit 71, 81 Drive side drum flange 72, 82 First coupling part 73, 83 Second coupling part 74, 84 First biasing member 75, 85 Second biasing member 76, 86 Third biasing member 77, 87 Lid parts 78, 88 pin 79, 89 Coupling unit A Image forming device body (device body) B Process cartridge (cartridge)

Claims

1. In a drum unit used in a cartridge, A photoconductor drum; a coupling member disposed near an end of the photosensitive drum and connected to the photosensitive drum so as to be capable of transmitting driving force; having The coupling member is inclined relative to the rotation axis of the photosensitive drum, and is configured to reduce an angle of inclination relative to the rotation axis of the photosensitive drum as the coupling member is rotated.

2. a flange member attached to an end of the photosensitive drum, 2. The drum unit according to claim 1, wherein the coupling member is tiltably supported by the flange member.

3. a convex shape provided on one of the coupling member and the flange member; a concave shape provided on the other of the coupling member and the flange member; having 3. The drum unit according to claim 2, wherein the inclination angle of the coupling member is reduced by the engagement of the convex shape and the concave shape with each other when the coupling member rotates relative to the flange member.

4. 4. The drum unit according to claim 3, wherein at least one of the convex shape and the concave shape has a twisted shape.

5. 5. The drum unit according to claim 3, wherein the convex shape has a cross section perpendicular to the rotation axis that is substantially triangular.

6. The coupling member is A first coupling portion; a second coupling portion capable of transmitting a driving force from the first coupling portion to the photosensitive drum; having 6. The drum unit according to claim 3, wherein the first coupling portion is rotatable within a certain angle range relative to the second coupling portion, and the second coupling portion has one of the convex shape and the concave shape.

7. the coupling member has a first coupling portion and a second coupling portion capable of transmitting a driving force from the first coupling portion to the flange member, The flange member has a first restricting portion and a second restricting portion, The first coupling portion has a first restricted portion, The second coupling portion has a second restricted portion, 3. The drum unit according to claim 2, wherein, when the first coupling portion is driven to rotate, (a) one of the first coupling portion and the second coupling portion moves relative to the other in the axial direction of the photosensitive drum, (b) the first regulated portion contacts the first regulating portion, (c) the second regulated portion contacts the second regulating portion, and (d) the coupling member moves so as to reduce the inclination angle.

8. one of the first restricting portion and the first restricted portion is a convex portion having a spherical surface, and the other is a concave portion having a conical surface or a spherical surface, 8. The drum unit according to claim 7, wherein one of the second regulating portion and the second regulated portion is a convex portion having a spherical surface, and the other is a concave portion having a conical surface or a spherical surface.

9. 9. The drum unit according to claim 7, wherein one of the first coupling portion and the second coupling portion moves in the axial direction of the photosensitive drum relative to the other by rotating the first coupling portion relative to the second coupling portion.

10. The drum unit according to any one of claims 7 to 9, characterized in that at least one of the first coupling portion and the second coupling portion has an inclined portion, and when the first coupling portion rotates relative to the second coupling portion, one of the first coupling portion and the second coupling portion moves relative to the other of the first coupling portion in the direction of the rotation axis along the inclined portion.

11. 11. The drum unit according to claim 6, further comprising a biasing member for biasing the first coupling portion so as to rotate with respect to the second coupling portion.

12. 12. The drum unit according to claim 6, wherein the first coupling portion is rotatable relative to the second coupling portion by 120 degrees or more.

13. 13. The drum unit according to claim 1, further comprising a biasing member for biasing the coupling member so as to incline the coupling member with respect to a rotation axis of the photosensitive drum.

14. 14. The drum unit according to claim 1, further comprising a biasing member for biasing the coupling member in the direction of the rotation axis of the photosensitive drum.

15. A drum unit according to any one of claims 1 to 14, a frame for rotatably supporting the drum unit; A cartridge having

16. A drive transmission unit that can be attached to a main body of an electrophotographic image forming apparatus, A coupling member; A support member for supporting the coupling member; having The coupling member is inclined relative to the rotation axis of the support member, and is configured to reduce an angle of inclination relative to the rotation axis of the support member as the coupling member is driven.

17. a convex shape provided on one of the coupling member and the support member; a concave shape provided on the other of the coupling member and the support member; having 17. The drive transmission unit according to claim 16, wherein when the coupling member rotates relative to the support member, the convex shape and the concave shape engage with each other, thereby reducing an inclination angle of the coupling member.

18. The drive transmission unit according to claim 3 , wherein at least one of the convex shape and the concave shape has a twisted shape.

19. 19. The drive transmission unit according to claim 17 or 18, wherein the convex shape has a cross section perpendicular to the rotation axis that is substantially triangular.

20. The coupling member is A first coupling portion; a second coupling portion capable of transmitting a driving force from the first coupling portion toward the support member; having 20. The drive transmission unit according to claim 16, wherein the first coupling portion is rotatable within a certain angle range relative to the second coupling portion, and the second coupling portion has one of the convex shape and the concave shape.

21. the coupling member has a first coupling portion and a second coupling portion capable of transmitting a driving force from the first coupling portion to the support member, The support member has a first restricting portion and a second restricting portion, The first coupling portion has a first restricted portion, The second coupling portion has a second restricted portion, 17. The drive transmission unit according to claim 16, wherein, when the first coupling portion is rotationally driven, (a) one of the first coupling portion and the second coupling portion moves relative to the other in the axial direction of the support member, (b) the first regulated portion contacts the first regulating portion, (c) the second regulated portion contacts the second regulating portion, and (d) the coupling member moves so as to reduce the inclination angle.

22. one of the first restricting portion and the first restricted portion is a convex portion having a spherical surface, and the other is a concave portion having a conical surface or a spherical surface, 22. The drive transmission unit according to claim 21, wherein one of the second restricting portion and the second restricted portion is a convex portion having a spherical surface, and the other is a concave portion having a conical surface or a spherical surface.

23. 23. The drive transmission unit according to claim 21 or 22, configured such that, by rotating the first coupling portion relative to the second coupling portion, one of the first coupling portion and the second coupling portion moves relative to the other in the axial direction of the support member.

24. 24. The drive transmission unit according to claim 23, characterized in that at least one of the first coupling portion and the second coupling portion has an inclined portion, and when the first coupling portion rotates relative to the second coupling portion, one of the first coupling portion and the second coupling portion moves relative to the other of the first coupling portion in the direction of the rotation axis along the inclined portion.

25. 25. The drive transmission unit according to claim 20, further comprising a biasing member for biasing the first coupling portion so as to rotate with respect to the second coupling portion.

26. 26. The drive transmission unit according to claim 20, wherein the first coupling part is rotatable relative to the second coupling part by 120 degrees or more.

27. 27. The drive transmission unit according to claim 16, further comprising a biasing member for biasing the coupling member so as to incline the coupling member relative to the rotation axis of the support member.

28. 28. The drive transmission unit according to claim 16, further comprising a biasing member for biasing the coupling member in the rotational axis direction of the support member.

29. A drive transmission unit according to any one of claims 16 to 28, a photoconductor drum capable of receiving a driving force from the drive transmission unit; A cartridge comprising:

30. A cartridge according to claim 15 or 29; an apparatus main body to which the cartridge can be removably attached, the apparatus main body including a drive output member that is tiltable and connectable with a coupling member of the cartridge; An electrophotographic image forming apparatus comprising:

31. A drive transmission unit according to any one of claims 16 to 28, an apparatus main body to which the drive transmission unit can be removably attached, the apparatus main body including a drive output member that is tiltable and connectable to a coupling member of the drive transmission unit; An electrophotographic image forming apparatus comprising:

Images