Drum unit, cartridge, electrophotographic image forming apparatus, and coupling member

Abstract

The present disclosure relates to a drum unit including a photosensitive drum in a coupling member. The coupling member includes an engageable member having a driving force receiving portion that can enter the recess of the drive shaft to receive a driving force for rotating the photosensitive drum. The coupling member includes a retaining member configured to retain the engageable member so as to be slidable at least in a radial direction of the drum unit.

Description

[0001] This divisional application is a divisional application based on the Chinese patent application with application number 202111149202.9, application date August 26, 2016, and invention name “Drum unit, box, electronic photographic imaging device and connecting member”. Technical Field

[0002] The present invention relates to an image forming apparatus using an electrophotographic process, a drum unit, a cartridge, and a coupling member usable with the image forming apparatus and the like. Background Art

[0003] In an electrophotographic image forming apparatus, there is known a structure in which elements such as a photosensitive drum and a developing roller, which are rotatable members related to image formation, are integrated into a cartridge that can be detachably mounted relative to an image forming apparatus main assembly (hereinafter referred to as an apparatus main assembly). In such a structure, a structure for receiving a driving force from the apparatus main assembly to rotate the photosensitive drum in the cartridge is adopted in many apparatuses. At this time, there is known a structure in which the driving force is transmitted by engagement between a coupling member on the cartridge side and a driving force transmitting portion such as a driving pin on the apparatus main assembly side.

[0004] For example, Patent Document 1 discloses a cartridge having a coupling member provided at an end portion of a photosensitive drum so as to be tiltable with respect to the rotation axis of the photosensitive drum. Summary of the invention

[0005] [Problems to be Solved by the Invention]

[0006] Another object of the present invention is to improve the above-mentioned conventional technology.

[0007] [Methods used to solve problems]

[0008] A typical structure provides a drum unit that can be detachably mounted to a main component of an electronic photographic imaging device, the main component including a drive shaft provided with a recess, the drum unit including (1) a photosensitive drum; and (2) a connecting member, the connecting member being provided on the photosensitive drum and including (2-1) an engageable member having a driving force receiving portion configured to enter the recess to receive a driving force for rotating the photosensitive drum, (2-2) a retaining member configured to retain the engageable member so as to be slidable at least in a radial direction of the drum unit, and (2-3) a pushing member configured to push the engageable member.

[0009] Effects of the Invention

[0010] The above conventional technology is further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a schematic cross-sectional view of the imaging apparatus 100 .

[0012] Figure 2 is a perspective view of the appearance of the process cartridge 7.

[0013] Figure 3 is a schematic cross-sectional view of the process cartridge 7 .

[0014] Figure 4 is a sectional view of the process cartridge 7.

[0015] Figure 5 is a sectional view of the process cartridge 7.

[0016] Figure 6 The outer appearance of the main assembly drive shaft 101 is shown.

[0017] Figure 7 is a sectional view of the main assembly drive shaft 101.

[0018] Figure 8 It is a perspective view of the main assembly drive shaft 101.

[0019] Fig. 9 is a sectional view of the coupling unit 28 and the main assembly drive shaft 101.

[0020] Fig.10 2 is a sectional view of the coupling unit 28 and the main assembly drive shaft 101 taken along a plane perpendicular to the rotation axis.

[0021] Fig.11 is a perspective view of the driving side of the drum unit 30 .

[0022] Fig.12 It is a cross-sectional view of the driving side of the drum unit 30 .

[0023] Fig.13 Parts (a) and (b) are perspective views of the engaging member 65.

[0024] Fig.14 Parts (a) and (b) are perspective views of components of the coupling unit 28.

[0025] Fig.15 is a cross-sectional view of the coupling unit 28 taken along a plane perpendicular to the rotation axis.

[0026] Fig.16 10A is a perspective view showing the mounting of the process cartridge 7 to the image forming apparatus main assembly 100A.

[0027] Fig.17 1 is a sectional view showing the mounting operation of the process cartridge 7 to the image forming apparatus main assembly 100A.

[0028] Fig.18 1 is a sectional view showing the mounting operation of the process cartridge 7 to the image forming apparatus main assembly 100A.

[0029] Fig.19 1 is a sectional view showing the mounting operation of the process cartridge 7 to the image forming apparatus main assembly 100A.

[0030] Fig. 20 is a sectional view showing the mounting of the coupling unit 28 to the main assembly drive shaft 101.

[0031] Fig.21 is a sectional view showing the mounting of the coupling unit 28 to the main assembly drive shaft 101.

[0032] Fig. 22 is a sectional view showing the mounting of the coupling unit 28 to the main assembly drive shaft 101.

[0033] Fig.23 2 is a sectional view of the coupling unit 28 and the main assembly drive shaft 101 taken along a plane perpendicular to the rotation axis.

[0034] Fig.24 2 is a sectional view of the coupling unit 28 and the main assembly drive shaft 101 taken along a plane perpendicular to the rotation axis.

[0035] Fig.25 Parts (a) and (b) are sectional views of the coupling unit 28 and the main assembly drive shaft 101 taken along a plane perpendicular to the rotation axis.

[0036] Fig.26 2 is a sectional view of the drive transmitting engagement surface of the engagement member 65 and the main assembly drive shaft 101.

[0037] Fig. 27 is a schematic sectional view of the image forming apparatus main assembly 4100A.

[0038] Fig.28 The appearance of the drum cartridge 4013 is shown.

[0039] Fig.29 It is a cross-sectional view of the drum cartridge 4013.

[0040] Fig.30 The appearance of the developer box 4004 is shown.

[0041] Fig.31 It is a cross-sectional view of the developer box 4004.

[0042] Fig.32 It is a perspective view of the main component drive shaft 4101.

[0043] Fig.33 It is a sectional view of the main assembly drive shaft 4101.

[0044] Fig.34 is a perspective view of the connection unit 4028.

[0045] Fig.35 Parts (a) and (b) are perspective views of the joining member 4065.

[0046] Fig.36 Parts (a) and (b) are perspective views of components of the connecting unit 4028.

[0047] Fig.37 Parts (a) and (b) are perspective views of the coupling unit 4028 and the toner supply roller 4020.

[0048] Fig.38 It is a sectional view of the coupling unit 4028 and the main assembly drive shaft 4101 taken along a plane perpendicular to the rotation axis.

[0049] Fig.39 It is a cross-sectional view of the developer box 4004.

[0050] Fig.40 41 is a perspective view showing the mounting of the developing box 4004 to the main assembly 4100 of the image forming apparatus.

[0051] Fig.41 41 is a sectional view showing the mounting of the developing cartridge 4004 to the main assembly 4100 of the image forming apparatus.

[0052] Fig.42 41 is a sectional view showing the mounting of the developing cartridge 4004 to the main assembly 4100 of the image forming apparatus.

[0053] Fig.43 41 is a sectional view showing the mounting of the developing cartridge 4004 to the main assembly 4100 of the image forming apparatus.

[0054] Fig.44 is a sectional view showing the mounting of the coupling unit 4028 to the main assembly drive shaft 4101.

[0055] Fig.45 is a sectional view showing the mounting of the coupling unit 4028 to the main assembly drive shaft 4101.

[0056] Fig.46 is a sectional view showing the mounting of the coupling unit 4028 to the main assembly drive shaft 4101.

[0057] Fig.47 is a sectional view showing the mounting of the coupling unit 4028 to the main assembly drive shaft 4101.

[0058] Fig.48Parts (a), (b), (c) and (d) are illustrations of joined members.

[0059] Fig.49 Parts (a) and (b) are cross-sectional views of the connection unit.

[0060] Fig.50 Parts (a), (b), (c) and (d) are illustrations of joined members.

[0061] Fig.51 Parts (a) and (b) are cross-sectional views of the connection unit.

[0062] Fig.52 Parts (a) and (b) are cross-sectional views of the connection unit.

[0063] Fig.53 is a cross-sectional view of the connection unit.

[0064] Fig.54 is a cross-sectional view of the connection unit.

[0065] Fig.55 is a cross-sectional view of the connection unit.

[0066] Fig.56 is a cross-sectional view of the connection unit.

[0067] Fig.57 is a cross-sectional view of the connection unit. DETAILED DESCRIPTION

[0068] Hereinafter, the imaging device and the processing box of the present embodiment will be described in conjunction with the accompanying drawings. For example, the imaging device uses an electrophotographic imaging process to form an image on a recording material. For example, the imaging device includes an electrophotographic copying device, an electrophotographic printer (for example, an LED printer, a laser beam printer, etc.), an electrophotographic fax machine, etc. In addition, the box can be installed to the main component (main component) of the imaging device and can be removed from the main component of the imaging device. In the box, the box integrated with the processing device acting on the photoreceptor and the photoreceptor is specifically called a processing box.

[0069] Furthermore, a unit including a photosensitive drum and a coupling member as one unit is referred to as a drum unit.

[0070] In the following embodiments, a full-color imaging device to which four process cartridges can be mounted and disassembled is taken as an example in Embodiment 4. However, the number of process cartridges that can be mounted to the imaging device is not limited thereto. Likewise, unless otherwise specified, the constituent elements disclosed in the embodiments are not intended to limit materials, arrangements, dimensions, other values, etc. Unless otherwise specified, "above" means upward in the direction of gravity when the imaging device is mounted.

[0071] <Example 1>

[0072] [General Description of Electrophotographic Image Forming Apparatus]

[0073] First, combine Figure 1 The overall structure of an embodiment of an electrophotographic image forming apparatus (image forming apparatus) according to this embodiment is described.

[0074] Figure 1 is a schematic cross-sectional view of the imaging apparatus 100 according to this embodiment.

[0075] like Figure 1 As shown, the imaging device 100 includes a first imaging unit SY, a second imaging unit SM, a third imaging unit SC and a fourth imaging unit SK as a plurality of imaging parts for forming images of corresponding colors, namely yellow (Y), magenta (M), cyan (C) and black (K). In this embodiment, the first to fourth imaging parts SY, SM, SC and SK are arranged in a row in a substantially horizontal direction.

[0076] In this embodiment, the structure and operation of the process box 7 (7Y, 7M, 7C, 7K) are basically the same, except that the color of the image to be formed is different. Therefore, hereinafter, Y, M, C and K will be omitted and will be described together unless otherwise specified.

[0077] In this embodiment, the image forming apparatus 100 has cylinders (hereinafter referred to as photosensitive drums) 1, each having a photosensitive layer, which are arranged side by side as a plurality of image bearing members in a direction slightly inclined relative to the vertical direction. A scanning unit (exposure device) 3 is provided below the process box 7. In addition, around the photosensitive drum 1, a charging roller 2 and the like are arranged, which serve as a processing device (processing device, processing member) acting on the photosensitive layer.

[0078] The charging roller 2 is a charging device (charging means, charging member) for uniformly charging the surface of the photosensitive drum 1. The scanning unit (exposure device) 3 is an exposure device (exposure device, exposure member) for forming an electrostatic image (electrostatic latent image) on the photosensitive drum 1 by irradiating laser light based on image information. Around the photosensitive drum 1, a cleaning blade 6 as a cleaning device (cleaning means, cleaning member) and a developing device (hereinafter referred to as a developing unit) 4 are provided.

[0079] Furthermore, an intermediate transfer belt 5 as an intermediate transfer member for transferring the toner image from the photosensitive drum 1 onto a recording material (sheet, recording medium) 12 is disposed so as to face the four photosensitive drums 1 .

[0080] The developing unit 4 of the present embodiment uses a non-magnetic one-component developer (hereinafter referred to as toner) as a developer, and adopts a contact developing system in which a developing roller 17 as a developer carrying member is in contact with the photosensitive drum 1 .

[0081] With the above structure, the toner image formed on the photosensitive drum 1 is transferred to the sheet (paper) 12, and the toner image transferred to the sheet is fixed. As a processing device acting on the photosensitive drum 1, the processing box includes a charging roller 2 for charging the photosensitive drum 1 and a cleaning blade 6 for cleaning the toner remaining but not transferred to the photosensitive drum 1. The untransferred residual toner remaining on the photosensitive drum 1 and not yet transferred to the sheet 12 is collected by the cleaning blade 6. In addition, the residual toner collected by the cleaning blade 6 is accommodated in the accommodating portion (hereinafter referred to as the waste toner accommodating portion) 14a of the removed developer from the opening 14b. The waste toner accommodating portion 14a and the cleaning blade 6 are integrated to form a cleaning unit (photosensitive body unit, image support member unit) 13.

[0082] In addition, the developing unit 4 and the cleaning unit 13 are integrated (formed into the box) to form the process cartridge 7. The image forming apparatus 100 is provided with guides (positioning means) such as a mounting guide and a positioning member (not shown) on the main assembly frame. The process cartridge 7 is guided by the above-mentioned guides and is configured to be mountable to and detachable from the image forming apparatus main assembly (main assembly of an electrophotographic image forming apparatus) 100A.

[0083] Toners of respective colors of yellow (Y), magenta (M), cyan (C), and black (K) are accommodated in process cartridges 7 for the respective colors.

[0084] The intermediate transfer belt 5 contacts the photosensitive drum 1 of each process cartridge and is Figure 1 The intermediate transfer belt 5 rotates (moves) in the direction indicated by the arrow B in the middle. The intermediate transfer belt 5 is wound around a plurality of supporting members (a driving roller 51, a secondary transfer opposing roller 52, and a driven roller 53). On the inner peripheral surface side of the intermediate transfer belt 5, four primary transfer rollers 8 as primary transfer devices are juxtaposed so as to face each photosensitive drum 1. A secondary transfer roller 9 as a secondary transfer device is provided at a position facing the secondary transfer opposing roller 52 on the outer peripheral surface side of the intermediate transfer belt 5.

[0085] At the time of image formation, the surface of the photosensitive drum 1 is first uniformly charged by the charging roller 2. Subsequently, the surface of the photosensitive drum 1 thus charged is scanned by and exposed to a laser beam corresponding to image information emitted from the scanning unit 3. Thus, an electrostatic latent image corresponding to the image information is formed on the photosensitive drum 1. The electrostatic latent image formed on the photosensitive drum 1 is developed into a toner image by the developing unit 4.

[0086] The photosensitive drum is a rotatable member (image bearing member) that rotates while carrying an image (developer image, toner image) formed with a developer (toner) on its surface.

[0087] The toner image formed on the photosensitive drum 1 is transferred (primary transfer) onto the intermediate transfer belt 5 by the operation of the primary transfer roller 8 .

[0088] For example, when forming a full-color image, the above-mentioned processing is performed in sequence in four process cartridges 7 (7Y, 7M, 7C, 7K). The toner images of the corresponding colors formed on the photosensitive drums 1 of the corresponding process cartridges 7 are primarily transferred in sequence so as to be superimposed on the intermediate transfer belt 5. Thereafter, in synchronization with the movement of the intermediate transfer belt 5, the recording material 12 is fed to the secondary transfer portion. The four-color toner images on the intermediate transfer belt 5 are transferred together to the recording material 12 conveyed to the secondary transfer portion composed of the intermediate transfer belt 5 and the secondary transfer roller 9.

[0089] The recording material 12 to which the toner image has been transferred is conveyed to the fixing device 10 as a fixing means. By applying heat and pressure to the recording material 12 in the fixing device 10, the toner image is fixed on the recording material 12. In addition, the primary transfer residual toner remaining on the photosensitive drum 1 after the primary transfer process is removed by the cleaning blade 6 and collected as waste toner. In addition, the secondary transfer residual toner remaining on the intermediate transfer belt 5 after the secondary transfer step is removed by the intermediate transfer belt cleaning device 11.

[0090] The imaging device 100 is also capable of forming a monochrome or multi-color image using a desired single or some (but not all) imaging units.

[0091] [General description of process cartridge]

[0092] refer to Figure 2 , Figure 3 and Figure 4 , the process cartridge 7 (cartridge 7) mounted in the image forming apparatus main assembly 100A of this embodiment will be described.

[0093] The box 7a containing yellow toner, the box 7b containing magenta toner, the box 7c containing cyan toner and the box 7d containing black toner have the same structure. Therefore, in the following description, each of the boxes 7a, 7b, 7c, 7d will be simply referred to as box 7. The corresponding box parts will also be described in the same way.

[0094] Figure 2 7 is an external perspective view of the process box 7. Here, Figure 2 As shown, the direction of the rotation axis of the photosensitive drum 1 is defined as the Z direction (arrow Z1, arrow Z2). Figure 1The horizontal direction in FIG. 1 is defined as the X direction (arrow X1 , arrow X2 ), and the vertical direction is the Y direction (arrow Y1 , arrow Y2 ).

[0095] Figure 3 1 is a schematic cross-sectional view of the process cartridge 7 , which is mounted to the image forming apparatus 100 , as viewed in the Z direction in a state (posture) in which the photosensitive drum 1 and the developing roller 17 are in contact with each other.

[0096] The process cartridge 7 includes two units, namely, a cleaning unit 13 including the photosensitive drum 1 , the charging roller 2 , and the cleaning blade 6 as one unit, and a developing unit 4 including a developing member such as a developing roller 17 .

[0097] The developing unit 4 has a developing frame 18 for supporting various components in the developing unit 4. The developing unit 4 includes a developing roller 17 as a developer carrying member, which is rotatable in the direction of arrow D (counterclockwise) and is in contact with the photosensitive drum 1. The developing roller 17 is rotatably supported by the developing frame 18 through developing bearings 19 (19R, 19L) at both end portions relative to the longitudinal direction (rotation axis direction) thereof. Here, the developing bearings 19 (19R, 19L) are respectively mounted to the respective side portions of the developing frame 18.

[0098] In addition, the developing unit 4 is provided with a developer accommodating chamber (hereinafter, toner accommodating chamber) 18 a and a developing chamber 18 b in which the developing roller 17 is provided.

[0099] In the developing chamber 18b, there are provided a toner supplying roller 20 as a developer supplying member which contacts the developing roller 17 and rotates in the direction of arrow E, and a developing blade 21 as a developer regulating member for regulating the toner layer of the developing roller 17. The developing blade 21 is fixed and integrated to the fixing member 22 by welding or the like.

[0100] A stirring member 23 for stirring the contained toner and for conveying the toner to the toner supply roller 20 is provided in the toner accommodating chamber 18 a of the developing frame 18 .

[0101] The developing unit 4 is rotatably coupled to the cleaning unit 13 around an adapting shaft 24 (24R, 24L) adapted in holes 19Ra, 19La provided in the bearing members 19R, 19L. Further, in the developing unit 4, the developing roller 17 is urged by a pressure spring 25 (25R, 25L) in a direction of contact with the photosensitive drum 1. Therefore, when image formation is performed using the process cartridge 7, the developing unit 4 is turned (rotated) around the adapting shaft 24 in the direction of the arrow F so that the photosensitive drum 1 and the developing roller 17 are in contact with each other.

[0102] The cleaning unit 13 has a cleaning frame 14 as a frame for supporting various elements in the cleaning unit 13 .

[0103] Figure 4 and Figure 5 It is a sectional view taken along an imaginary plane along the rotation axis of the photosensitive drum 1 of the process cartridge 7 .

[0104] exist Figure 4 In FIG. 7 , the side (relative to the Z1 direction) on which the coupling unit (coupling member) 28 receives the driving force from the main assembly of the image forming apparatus is referred to as the driving side of the process cartridge 7. Figure 5 , the side opposite to the driving side (with respect to the Z2 direction) is referred to as the non-driving side (front side) of the process box 7.

[0105] When the process cartridge 7 is mounted in the mounting portion of the image forming apparatus main assembly, the driving side of the process cartridge 7 is disposed in the rear side of the mounting portion of the process cartridge 7, and the non-driving side is disposed in the front side of the mounting portion.

[0106] On the end portion opposite to the connecting unit 28 (the end portion on the non-driving side of the processing box), an electrode (electrode portion) is provided which contacts the inner surface of the photosensitive drum 1, and the electrode serves as an electrical ground by contacting the main component.

[0107] The coupling unit 28 is mounted to one end of the photosensitive drum 1, and the non-driving side flange member 29 is mounted to the other end of the photosensitive drum 1 to constitute the photosensitive drum unit 30. The photosensitive drum unit 30 receives a driving force from a main assembly drive shaft 101 provided in the main assembly 100A of the image forming apparatus via the coupling unit 28 (the driving force is transmitted from the main assembly drive shaft 101). As will be described in detail below, in the case where the cartridge 7 is mounted to the main assembly 100A, the coupling unit 28 can be engaged with the main assembly drive shaft 101. In the case where the cartridge 7 is disassembled from the main assembly 100A, the coupling unit 28 can be disengaged from the main assembly drive shaft 101.

[0108] The coupling unit 28 is configured to be coupled to and detached from the main assembly drive shaft 101 .

[0109] The coupling unit 28 includes a flange member (driving side flange member) mounted to a driving side end portion of the photosensitive drum 1 .

[0110] like Figure 4As shown, the Z1 side of the coupling unit 28 has a cylindrical shape (cylindrical portion 71a). The cylindrical portion 71a protrudes beyond the end portion of the photosensitive drum 1 toward the Z1 side (outward in the axial direction). In the cylindrical portion 71a, the portion on the Z1 side close to the free end is a supported portion 71c. The supported portion 71c is rotatably supported by a supporting portion provided in the drum unit supporting member 39R. In other words, the supported portion 71c is supported by the supporting portion of the drum unit supporting member 39R so that the photosensitive drum unit 30 can rotate.

[0111] Similarly, in Figure 5 In the embodiment, the non-driving side flange member 29 provided on the non-driving side of the photosensitive drum unit 30 is rotatably supported by the drum unit supporting member 39L. The non-driving side flange member 29 has a cylindrical portion (cylindrical portion) protruding from the end portion of the photosensitive drum 1, and the outer peripheral surface of the cylindrical portion 29a is rotatably supported by the drum unit supporting member 39L.

[0112] The drum unit bearing member 39R is provided on the driving side of the process cartridge 7 , and the drum unit bearing member 39L is provided on the non-driving side of the process cartridge 7 .

[0113] like Figure 4 As shown, when the process cartridge 7 is installed in the apparatus main assembly 100A, the drum unit bearing member 39R abuts against the rear side cartridge positioning portion 108 provided in the imaging apparatus main assembly 100A. In addition, the drum unit bearing member 39L abuts against the front side cartridge positioning portion 110 of the imaging apparatus main assembly 100A. Thus, the process cartridge 7 is positioned in the imaging apparatus 100A.

[0114] In the Z direction of this embodiment, Figure 4 As shown, the position where the drum unit bearing member 39R supports the supported portion 71c is formed close to the position where the drum unit bearing member 39R is positioned at the rear cartridge positioning portion 108. By doing so, the inclination of the coupling unit 28 can be suppressed when the process cartridge 7 is mounted in the apparatus main assembly 100A.

[0115] The supported portion 71c is arranged so that the position where the supporting member 39R supports the supported portion 71c and the position where the supporting member 39R is positioned at the rear box positioning portion 108 can be close to each other. That is, the supported portion 71c is arranged on the free end side (Z1 direction side) of the outer peripheral surface 71a of the cylindrical portion 71 arranged in the connecting unit 28.

[0116] Similarly, in the Z direction, if Figure 5As shown, the position where the drum unit supporting member 39L rotatably supports the non-driving side flange member 29 is arranged at a position close to the position where the drum unit supporting member 39L is positioned on the front side cartridge positioning portion 110. Thus, inclination of the non-driving side flange member 29 is suppressed.

[0117] The drum unit supporting members 39R and 39L are respectively attached to the side portions of the cleaning frame 14, and support the photosensitive drum unit 30. Thus, the photosensitive drum unit 30 is supported so as to be rotatable relative to the cleaning frame 14.

[0118] In addition, the charging roller 2 and the cleaning blade 6 are mounted to the cleaning frame 14, and they are arranged so as to contact the surface of the photosensitive drum 1. In addition, the charging roller bearings 15 (15R, 15L) are mounted to the cleaning frame 14. The charging roller bearings 15 are bearings for supporting the shaft of the charging roller 2.

[0119] Here, the charging roller support 15 (15R, 15L) is installed so as to be able to Figure 3 The charging roller 2 moves in the direction of the arrow C shown. The rotation shaft 2a of the charging roller 2 is rotatably mounted to the charging roller support 15 (15R, 15L). The charging roller support 15 is urged toward the photosensitive drum 1 by a pressing spring 16 as an urging device. Therefore, the charging roller 2 abuts on the photosensitive drum 1 and rotates through the photosensitive drum 1.

[0120] The cleaning frame 14 is provided with a cleaning blade 6 as a cleaning device for removing the toner remaining on the surface of the photosensitive drum 1. The cleaning blade 6 is formed by integrating a blade-shaped rubber (elastic member) 6a that abuts against the photosensitive drum 1 to remove the toner on the photosensitive drum 1 and a supporting metal plate 6b that supports the blade-shaped rubber (elastic member) 6a. In this embodiment, the supporting metal plate 6b is fixed to the cleaning frame 14 with screws.

[0121] As described above, the cleaning frame 14 has the opening 14b for collecting the transfer residual toner collected by the cleaning blade 6. The opening 14b is provided with the blow-off prevention sheet 26 which contacts the photosensitive drum 1 and seals between the photosensitive drum 1 and the opening 14b so as to suppress the toner from leaking in the upward direction of the opening 14b.

[0122] In this way, by adopting a structure in which components related to imaging are integrated in a cartridge that can be detachably mounted to the main assembly of the apparatus, the convenience of maintenance is improved. In other words, the user can easily perform maintenance of the apparatus by replacing the process cartridge. Therefore, it is possible to provide an apparatus whose maintenance operation can be performed not only by a maintenance person but also by a user.

[0123] [Structure of the main assembly drive shaft]

[0124] refer to Figure 5 , Figure 6 , Figure 7 , Figure 8 , Fig. 9 and Fig.10 , the structure of the main assembly drive shaft 101 will be described.

[0125] Figure 6 It is an external view of the main assembly drive shaft.

[0126] Figure 7 1 is a sectional view taken along the rotational axis (rotational axis) of the main assembly drive shaft 101 mounted to the main assembly of the image forming apparatus.

[0127] Figure 8 is a perspective view of the main assembly drive shaft.

[0128] Fig. 9 1 is a sectional view of the coupling unit 28 and the main assembly drive shaft 101 taken along the rotation axis (rotation axis).

[0129] Fig.10 2 is a sectional view of the coupling member 28 and the main assembly drive shaft 101 taken along a plane perpendicular to the rotation axis.

[0130] like Figure 6 As shown, the main assembly driving shaft 101 is provided with a gear portion 101e, a shaft portion 101f, a rough guide portion 101g and a supported portion 101d.

[0131] A motor (not shown) as a driving source is provided in the main assembly 100A of the imaging device. The gear portion 101e receives a rotational driving force from the motor so that the main assembly driving shaft 101 rotates. In addition, the main assembly driving shaft 101 includes a rotatable protruding shaft portion 101f, which protrudes from the gear portion 101e toward the cartridge side along its rotation axis. The rotational driving force received from the motor is transmitted to the cartridge 7 side through a groove-shaped drive transmission groove 101a (recessed portion, drive transmission portion) provided in the shaft portion 101f. In addition, the shaft portion 101f has a hemispherical shape 101c at its free end portion.

[0132] The main component drive transfer groove 101a is formed so that a part of the engaging portion 65a of the coupling unit 28 to be described below can enter. Specifically, it is provided with a main component drive transfer surface 101b, which serves as a surface that contacts with the driving force receiving surface (driving force receiving portion) 65b of the coupling unit 28 to transfer the driving force.

[0133] In addition, if Figure 6As shown, the main component drive transmission surface 101b is not a flat surface, but a shape twisted around the rotation axis of the main component drive shaft 101. The twisting direction is such that the downstream side in the Z1 direction of the main component drive shaft 101 is upstream of the downstream side in the Z2 direction thereof with respect to the rotation direction of the main component drive shaft 101. In this embodiment, the twisting amount along the rotation axis direction of the cylinder of the engagement portion 65a is set to about 1 degree per 1 mm. The reason why the main component drive transmission surface 101b is twisted will be described below.

[0134] Moreover, the main component drive transmission groove 101a is provided with a main component side removal tapered portion 101i on the side surface in the Z2 direction. The main component side removal tapered portion 101i is a tapered portion (inclined surface, inclined portion) for disengaging the auxiliary engaging portion 65a from the drive transmission groove 101a when the processing box 7 is disassembled from the main component 100A of the device. The details will be described below.

[0135] Here, when the driving force is transmitted from the drive transmission groove 101a to the engaging portion 65a, it is desired that the main component drive transmission surface 101b and the driving force receiving surface (driving force receiving portion 65b) are surely in contact with each other. Therefore, in order to prevent the surface other than the main component drive transmission surface 101b from contacting the engaging portion 65a, the main component drive transmission groove 101a has a gap (G) ( Fig. 9 and Fig.10 ).

[0136] Furthermore, in the axial direction of the main assembly drive shaft 101, the center 101h of the hemispherical shape 101c is disposed within the range of the main assembly drive transmission groove 101a ( Figure 7 ). In other words, when the center 101h and the main component drive transmission groove 101a are projected on the axis of the main component drive shaft 101, the projection area of ​​the center 101h on the axis is located within the projection area of ​​the main component drive transmission groove 101a.

[0137] Here, the axis (rotation axis, rotation center line) of the drum unit and the main assembly drive shaft refer to an imaginary straight line extending so as to pass through the rotation center of the shaft. Moreover, the axial direction (rotation axis direction) refers to the direction in which the axis extends. The axial direction of the drum unit 30 has the same meaning as the longitudinal direction (Z direction) of the drum unit 30.

[0138] Furthermore, “X and Y overlap each other in the A direction” means that when X and Y are projected on a straight line extending parallel to the A direction, at least a portion of the projection area of ​​X overlaps at least a portion of the projection area of ​​Y on the straight line.

[0139] When projecting something onto a line, the direction of projection is perpendicular to the line unless otherwise specified. For example, "project A onto the axis" means "project A onto the axis in a direction perpendicular to the axis".

[0140] The rough guide portion 101g of the main assembly drive shaft 101 is provided between the shaft portion 101f and the gear portion 101e in the axial direction ( Figure 6 ).like Fig. 9 As shown, the rough guide portion 101g has a tapered shape at the free end portion on the shaft portion 101f side, and as shown in FIG. Fig. 9 As shown, the outer diameter D6 of the rough guide portion 101g is smaller than the inner diameter D2 of the inner surface 71b of the cylindrical portion 71 of the coupling unit 28. Figure 6 As shown, the outer diameter D6 of the rough guide portion 101g is larger than the outer diameter D5 of the shaft portion 101f. Therefore, when the cartridge 7 is inserted into the main assembly 100A of the imaging device, the main assembly drive shaft 101 is guided along the coupling unit 28 so as to reduce the axial misalignment between the rotation center of the cylindrical portion 71 and the rotation center of the shaft portion 101f. Therefore, the rough guide portion 101g can be said to be an insertion guide.

[0141] The rough guiding portion 101g is set to have such a dimensional relationship that it does not abut on the inner peripheral surface 71b after the completion of mounting of the cartridge 7 to the image forming apparatus main assembly 100A.

[0142] like Figure 7 As shown, the supported portion 101d of the main assembly driving shaft 101 is provided on the opposite side of the rough guide portion 101g across the gear portion 101e. The supported portion 101d is rotatably supported by a bearing member 102 provided in the image forming apparatus main assembly 100A.

[0143] In addition, if Figure 7 As shown, the main assembly drive shaft 101 is urged toward the cartridge 7 side by the spring member 103 of the image forming apparatus main assembly 100A. However, the movable amount (play) of the main assembly drive shaft 101 in the Z direction is about 1 mm, which is sufficiently smaller than the width of the driving force receiving surface 65b measured in the Z direction, which will be described below.

[0144] As described above, the main assembly drive shaft 101 is provided with the main assembly drive transmission groove 101a, and the coupling unit 28 is provided with the engaging portion 65a, to transmit the drive from the main assembly 100A to the cartridge 7 (drum unit 30).

[0145] As will be described in detail below, the engaging portion 65a is pushed by a pushing member, which is a compression spring that can be elastically extended and contracted. Therefore, when the cartridge 7 is mounted to the main assembly 100A of the device, the engaging portion 65a is configured to be movable at least outwardly in the radial direction of the drum unit 30. Therefore, when the cartridge 7 is inserted into the main assembly 100A of the device, the engaging portion 65a enters the drive transmission groove 101a, and the engaging portion 65a and the main assembly drive transmission groove 101a can engage with each other.

[0146] In the following description, the radial direction of the drum unit 30 may be simply referred to as the radial direction. The radial direction of the drum unit 30 is the radial direction of the photosensitive drum 1 and is also the radial direction of the coupling unit 28.

[0147] [Structure of connecting member]

[0148] refer to Fig.11 , Fig.12 , Fig.13 , Fig.14 and Fig.15 , the coupling unit 28 of this embodiment will be described in detail.

[0149] Fig.11 2 is a driving side perspective view of the drum unit 30 in which the coupling unit 28 is mounted to the photosensitive drum 1 .

[0150] Fig.12 is a sectional view of the drum unit 30 from the driving side.

[0151] Fig.13 is a perspective view of the engagement member 65, wherein Fig.13 Part (a) is a perspective view from the upper left, and Fig.13 Part (b) is a perspective view viewed from the upper right.

[0152] Fig.14 2 is a perspective view of components constituting the coupling unit 28 .

[0153] Fig.15 is a cross-sectional view of the coupling unit 28 .

[0154] like Fig.11 As shown, the coupling unit 28 is provided with three engaging portions 65a which can engage with the main assembly drive shaft 101. Fig.10 As shown, the coupling portion 65a enters the groove portion 101a of the main component drive shaft 101 so that the driving force receiving surface 65b of the coupling portion 65a and the driving transmission surface 101b of the main component drive shaft 101 contact each other, and the driving force is transmitted from the main component drive shaft 101 to the connecting unit 28.

[0155] Fig.12is a sectional view of a state where the coupling unit 28 is mounted to the photosensitive drum 1. The engaging member 65 including the engaging portion 65a is supported in the coupling unit 28 in a state where it is urged toward the inside in the radial direction of the coupling unit 28 by the urging member 66.

[0156] Hereinafter, the structure of the coupling unit 28 will be described in detail. Fig.12 The cross-sectional view and Fig.14 As shown in the perspective view of , the coupling unit 28 includes a flange member 71 , a flange cover member 72 , an engaging member 65 , and a pressing member 66 .

[0157] The flange member 71 is mounted to the inner periphery of the photosensitive drum 1 and fixed to the photosensitive drum 1. The flange member 71 has a substantially cylindrical shape and is provided with a hollow portion. The flange member 71 opens outward in the axial direction of the drum unit.

[0158] The flange cover member 72 is mounted to the inner surface of the hollow portion of the flange member 71. The flange cover member 72 closes the inner side (bottom side) of the flange member 71 in the axial direction of the drum unit.

[0159] The flange cover member 72 is fixed to the photosensitive drum 1 through the flange member 71 .

[0160] The structure is such that the engaging member 65 is movably (slidably) held on the flange cover member 72 and is movable (slidable) relative to the flange cover member 72. The urging member 66 is an elastic member (spring member) and is structured such that it urges the engaging member 65 inward at least in the radial direction of the drum unit.

[0161] In this embodiment, the flange member 71, the flange cover member 72, the engaging member 65 and the pushing member 66 are formed as separate bodies (separate members). In this example, the engaging member 65 is configured to be movable in the radial direction (substantially parallel to the radial direction) of the coupling unit. In addition, the engaging member 65 and the pushing member 66 are arranged in the radial direction. That is, the structure is such that both the engaging member 65 and the pushing member 66 are arranged on an imaginary line parallel to the radial direction of the coupling unit.

[0162] like Fig.11 As shown, three engagement members 65 are arranged at uniform intervals (at intervals of 120 degrees, substantially at equal intervals) in the circumferential direction of the coupling unit 28. Fig.13As shown, the engaging member 65 has an engaging portion 65a protruding inwardly in the radial direction and a driving force receiving surface 65b formed in the engaging portion 65a. The engaging member 65 also has a drive shaft abutting surface (drive shaft abutting portion) 65c, which is formed adjacent to the driving force receiving surface 65b and is formed in an arc shape so as to contact the outer peripheral surface 101f of the main component drive shaft. The driving force receiving surface 65b is a driving force receiving portion that receives the driving force from the main component drive shaft 101 by contacting the driving groove 101a. The engaging portion 65a is a protruding portion (protruding portion) protruding (protruding) from the surface of the engaging member 65.

[0163] The engaging member 65 is a driving force receiving member provided with a driving force receiving portion (driving force receiving surface 65 b ), and is also a supporting member for supporting the driving force receiving surface 65 b .

[0164] The engaging member 65 is provided with a first guided surface (surface to be guided) 65d and a second guided surface (surface to be guided) 65e for being guided (guided) in the radial direction in the coupling unit. The first guided surface 65d is a position control portion for controlling the position of the engaging member 65 in the circumferential direction, and is provided on the side closer to the engaging portion 65a. The second guided surface 65e is a position control portion for controlling the position of the engaging member 65 in the circumferential direction, and is provided on the side away from the engaging portion 65a.

[0165] The first guided surface 65d and the second guided surface 65e are guided portions guided by the flange cover member 72, which will be described below. The first guided surface 65d and the second guided surface 65e are restricted portions, the positions of which are regulated by the flange cover member 72 in the rotation direction (circumferential direction) of the drum unit. The first guided surface 65d is an upstream side guided portion (upstream side restricted portion) located on the downstream side of the coupling member 65 in the rotation direction of the coupling unit. The second guided surface 65e is a downstream side guided portion (downstream side regulated portion) positioned on the upstream side of the coupling member 65 in the rotation direction.

[0166] The first guided surface 65d and the second guided surface 65e are substantially parallel to each other.

[0167] In addition, a third guided surface 65f and a fourth guide surface 65g are provided for regulating the position of the engaging member 65 in the axial direction. The third guided surface 65f and the fourth guide surface 65g are guided portions to be guided by the flange cover member 72, which will be described below. The third guided surface 65f and the second guided surface 65g are regulated portions, the positions of which are regulated by the flange cover member 72 in the axial direction (longitudinal direction) of the drum unit. The third guided surface 65f is an external guided portion (and an external restricted portion) located outside the engaging member 65 in the axial direction of the drum unit. The fourth guide surface 65g is a downstream guided portion (and a downstream regulated portion) located on the downstream side of the engaging member 65 in the axial direction.

[0168] The third guided surface 65f and the fourth guide surface 65e are substantially parallel to each other.

[0169] Furthermore, the engaging member 65 is provided with a contact surface (pressed portion, pressed surface) 65h ( Fig.10 ) for receiving the urging force of the urging member 66. The engaging member 65 is also provided with a position regulating protrusion 65i for limiting the position of the engaging member 65 by abutting against the flange cover member 72 by the urging force of the urging member 66. Specifically, the structure is such that the urging force position regulating surface (engaged portion) 65j formed on the position limiting protrusion contacts the flange cover member 72. The position regulating protrusion 65i is provided on both sides of the engaging member 65, wherein a contact surface 65h associated with the urging member 66 is provided between the position regulating protrusions.

[0170] The engaging member 65 has an insertion tapered surface 65k on the outer side (Z1 direction side) of the photosensitive drum unit 30 in the Z direction. The insertion tapered surface 65k is an inclined portion facing outward in the axial direction. The insertion tapered surface 65k is an installation force receiving portion, which receives a force for retracting the engaging member 65 in the radial direction when the box is installed. In addition, the engaging member 65 has a tapered portion 65l as a disassembly force receiving portion on the inner side (Z2 direction side) of the photosensitive drum unit 30 in the Z direction. The removal tapered surface 65l is a disassembly force receiving portion, which receives a force for retracting the engaging member 65 in the radial direction when the box is disassembled.

[0171] The flange cap member 72 is provided with a coupling hole portion 72a for allowing the main component drive shaft 101 to pass therethrough and a mounting hole portion 72b for supporting the engaging member 65 so as to be movable in the radial direction. The engaging portion 65a of the engaging member 65 is exposed through the coupling hole portion 72a so as to engage the engaging member with the main component drive shaft. The mounting hole 72b is provided with a first guide surface 72d abutting against the first guided surface 65d (the first guided surface is a surface for regulating the position of the engaging member 65 in the circumferential direction), and a second guide surface 72e contacting the second guided surface 65e is provided. In addition, the mounting hole 72b is provided with a third guide surface 72f contacting the third guided surface 65f (the third guided surface is a surface that limits the position of the engaging member 65 in the axial direction), and a fourth guide surface 72g contacting the fourth guide surface 65g is provided, and the fourth guide surface is a surface opposite to the third guided surface.

[0172] The first guide surface 72d, the second guide surface 72e, the third guide surface 72f, and the fourth guide surface 72g are guide portions for guiding the engaging member 65, and are also restricting portions (position restricting portions) for restricting the position of the engaging member.

[0173] The first guide surface 72d is an upstream guide portion (upstream restriction portion) that guides the upstream side of the engagement member 65 in the rotation direction of the drum unit and regulates the position. Similarly, the second guide surface 72e is a downstream guide portion (downstream regulation portion) that guides the downstream side of the engagement member 65.

[0174] The engaging member 65 and the urging member 66 are provided in the space between the first guide surface 72 d and the second guide surface 72 e .

[0175] In addition, the third guide surface 72f is an outer guide portion (outer regulating portion) that guides the outer side of the engaging member 65 in the axial direction of the drum unit and regulates the position. Similarly, the fourth guide surface 72g is an inner guide portion (inner restricting portion) that guides the inner side of the engaging member 65 in the axial direction and regulates the position.

[0176] The flange cover member 72 is a guide member that guides the engaging member 65 by using these guide portions (the first guide surface 72d, the second guide surface 72e, the third guide surface 72f, and the fourth guide surface 72g). The flange cover member 72 is a holding member that holds the engaging member 65 movably (guideably).

[0177] The first guide surface 72d and the second guide surface 72e are substantially parallel to each other. The third guide surface 72f and the fourth guide surface 72g are substantially parallel to each other.

[0178] The engaging member 65 is a moving member that is movably held by the flange cover member 72 and is also a sliding member that is slidable relative to the flange cover member 72 .

[0179] In addition, in order to regulate the position of the engaging member 65 against the urging force of the urging member 66 , the flange cover member 72 is provided with a restricting surface (engaging portion) 72 j .

[0180] The limiting surface (engaging portion) 72j limits the radial inward movement of the engaging member 65 by contacting the urging force position regulating surface (radial protruding portion) 65j. That is, the limiting surface (locking portion) 72j locks the locking member 65 against the urging force of the urging member 66. In a state where the cartridge 7 is not mounted to the main assembly of the apparatus (a natural state where no external force is applied to the cartridge 7), the locking member 65 is urged toward the limiting surface 72j by the urging force of the urging member 66.

[0181] In addition, the flange cover member 72 is provided with an adapting surface 72k to be adapted to the inner peripheral surface of the flange member 71, and a position regulating groove 72l for regulating the position in the rotational direction relative to the flange member 71. In addition, the flange cover member 72 is in contact with the hemispherical shape 101c of the main assembly drive shaft 101 including the tapered surface 72m so as to position the main assembly drive shaft 101 relative to the flange cover member 72.

[0182] Here, the positioning portion does not need to be a tapered recess like the tapered surface 72m. If the position of the photosensitive drum unit 30 relative to the main component drive shaft 101 can be determined when the radial positioning portion and the longitudinal positioning portion are in contact with the free end portion (semi-closed shape 101c) of the main component drive shaft 101, the shape can be any shape. For example, a recessed portion (recessed portion) including a narrowing portion as it extends toward the bottom portion is preferred. As an example of such a shape, a conical shape that is not a polygonal pyramid, such as a pyramid (square pyramid, etc.) can also be used. However, as long as the conical shape is symmetrical with respect to the axis of the connecting unit 28 like the conical portion 72m of this embodiment, the position of the connecting unit 28 can be maintained with particularly high accuracy.

[0183] Here, the tapered portion 72m may have an area for contacting the main assembly drive shaft 101, and therefore, the non-contacted area may have any shape. For example, the bottom portion of the tapered portion 72m does not have to be contacted by the main assembly drive shaft 101, and therefore, the tapered portion 72m may not have a bottom surface.

[0184] The flange member 71 is provided with an adapting portion 71d relative to the photosensitive drum, and a flange portion 71e formed at an axial end portion of the adapting portion. In addition, the flange member 71 includes a cylindrical portion 71a further extending in the axial direction from the flange portion 71e. The cylindrical portion 71a is formed with an inner peripheral surface 71b through which the main component drive shaft 101 passes, and a supported portion 71c supported by a supporting member. Fig.14 As shown, the flange portion 71e has a shape protruding outward from the fitting portion 71d in the radial direction. When the photosensitive drum 1 of the coupling unit 28 is assembled, the end surface of the photosensitive drum 1 abuts against the end surface of the flange portion 71e, thereby determining the position of the photosensitive drum 1 and the coupling unit 28 in the Z direction.

[0185] like Fig.12 As shown, the fitting portion 71d of the flange member 71 is press-fitted into the inner diameter portion of the cylinder of the photosensitive drum 1. By advancing the flange member 71 in the axial direction until the flange portion 71e of the flange member 71 abuts against the end face of the photosensitive drum and pressing the fitting portion 71d into the photosensitive drum 1, the coupling unit 28 is accurately positioned relative to the photosensitive drum 1. More specifically, the dimensions of the inner diameter of the cylinder of the photosensitive drum 1 and the outer shape of the fitting portion 71d are designed to be in a close fitting relationship.

[0186] As described above, after the flange member 71 is mounted to the photosensitive drum 1, the flange member 71 and the photosensitive drum 1 are fixed by a clamping fixing method. More specifically, the portion of the cylindrical end portion of the photosensitive drum 1 that is plastically deformed is inserted into a groove (not shown) formed in the fitting portion 71d of the flange member 71 to firmly couple the photosensitive drum 1 and the flange member 71. Here, clamping refers to coupling a plurality of parts to each other by partial plastic deformation.

[0187] Here, the fixing method by clamping is an example of a method for firmly fixing the flange member 71 to the photosensitive drum 1 , and another fixing method of fixing the inner diameter of the cylinder and the fitting portion 71 d by bonding, for example, may be used.

[0188] As described above, the cylindrical portion 71a of the flange member 71 is provided with the supported portion 71c ( Figure 4 and Fig. 9 ). In other words, the coupling unit has a supported portion 71c having a cylindrical outer shape on the Z1 direction side (outer side in the axial direction) relative to the coupling member. By adopting this shape, the coupling portion 65a is not exposed at the outer surface of the box 7. Therefore, the coupling portion 65a of the coupling member 65 can be protected by the drum unit supporting member 39R and the supported portion 71c. Thereby, it is possible to prevent the user from accidentally contacting the coupling portion 65a or to prevent an object from directly hitting the coupling portion 65a when the box 7 falls. In addition, as Fig.14 As shown, the inner peripheral surface 71b of the cylindrical portion 71 is provided with a tapered shape 71g at the front end (Z1 direction) free end. The tapered shape 71g is an inclined portion (inclined surface) for guiding the main assembly drive shaft 101 to be inserted into the cylindrical portion 71.

[0189] The pushing member 66 is a compression coil spring that can be elastically expanded, and applies a reaction force in the direction in which the compression spring extends against an external force in the compression direction of the compression spring. Here, the pushing member 66 can apply a pushing force radially inward to the engaging member 65, and therefore, in addition to the compression coil spring as in this embodiment, a pushing member (elastic member, spring member) such as a leaf spring or a torsion coil spring can also be used.

[0190] It is also possible to make the pushing member 66 integrated with the engaging member 65 or the flange cover member 72. However, in this example, the pushing member 66 is formed separately from the engaging member 65 and the flange cover member 72. By doing so, the selection range of the pushing member 66 is increased, and an appropriate pushing member 66 can be easily selected. For example, it is easier to select a pushing member 66 that provides an appropriate pushing force (elastic force) for pushing the engaging member 65.

[0191] With respect to the coupling unit 28 configured as described above, the supporting structure of the engaging member 65 will be described in detail. Fig.15 It is a cross-sectional view taken along a direction perpendicular to the axial direction of the coupling unit.

[0192] The first guided surface 65d and the second guided surface 65e of the engaging member 65 contact and guide the first guide surface 72d and the second guide surface 72e of the flange cover member 72, respectively. Fig.12 As shown in FIG. 1 , the third guided surface 65f and the fourth guide surface 65g of the engaging member 65 are in contact with the third guide surface 72f and the fourth guide surface 72g of the flange cover member 72, respectively. By the abutment of these guide surfaces, the engaging member 65 is guided and supported so as to be movable at least in the radial direction relative to the flange cover member 72. That is, the vector in the direction in which the engaging member 65 moves has at least a component in the radial direction of the drum unit. In this embodiment, the engaging member 65 can move in parallel with the substantially radial direction.

[0193] The engaging member 65 is urged inward in the radial direction of the coupling unit 28 by the urging member 66. The urging member 66 is compressed while being sandwiched between the contact surface 65h of the engaging member 65 and the inner peripheral surface of the flange member 71, and therefore, an urging force is applied in the direction in which the urging member 66 expands, thereby urging the engaging member 65.

[0194] The position resistance urging force of the engaging member 65 is restricted by the contact between the position restricting surface 65 j and the restricting surface 72 j of the flange cover member 72 .

[0195] The engaging member 65 is supported by the flange cover member 72 in a state where its engaging portion 65a is exposed through the hole 72a of the flange cover member 72. In addition, similarly, the drive shaft abutting surface 65c formed in an arc shape on the engaging member 65 is exposed through the hole 72a of the flange cover member 72. The engaging portion 65a of the engaging member 65 protrudes inwardly in the radial direction from the inner peripheral surface of the hole portion 72a of the flange cover member 72.

[0196] The amount by which the engaging portion 65a protrudes relative to the drive shaft abutment surface 65c of the engaging member 65 is sufficient to allow the engaging portion 65a to surely enter the groove 101a of the drive shaft. The protruding amount is sufficient to allow the driving force receiving surface 65b formed in the engaging portion 65a to have a strength corresponding to the load torque of the photosensitive drum unit 30 as a member to be rotated. That is, it is sufficient as long as the driving force receiving surface 65b of the engaging portion 65a can stably transmit the driving force from the main component drive shaft 101. In the case of this embodiment, the protruding amount of the engaging portion 65a is selected so that the distance measured from the inner surface of the flange cover member 72 to the free end of the engaging portion 65a along the radial direction of the coupling unit is 1 mm to 3 mm.

[0197] In addition, similarly, the drive shaft abutment surface 65c of the coupling member 65 also protrudes inwardly in the radial direction from the inner peripheral surface of the hole portion (hollow portion) 72a of the flange cover member 72. The protrusion amount (exposure amount) of the drive shaft abutment surface 65c from the inner peripheral surface of the hole portion 72a is such that the drive shaft abutment surface 65c does protrude from the inner peripheral surface of the hole portion 72a even when the size of the corresponding parts changes. In the case of this embodiment, the protrusion amount of the drive shaft abutment surface 65c from the inner peripheral surface of the hole 72a is preferably 0.3mm to 1mm. That is, the distance from the inner surface of the flange cover member 72 to the drive shaft abutment surface 65c measured along the radial direction of the coupling unit is 0.3mm to 1mm.

[0198] As described above, the engaging portion 65a and the drive shaft abutment surface 65c of the engaging member 65 are exposed through the hole 72a and can engage and abut with the main assembly drive shaft 101. The structure of the engaging member 65 engaging with the main assembly drive shaft 101 and performing drive transmission will be described below.

[0199] [Installing the cartridge into the imaging device main assembly]

[0200] refer to Fig.16 , Fig.17 , Fig.18 and Fig.19, the installation and removal of the process cartridge 7 relative to the main assembly of the image forming apparatus will be described.

[0201] Fig.16 10A is a perspective view showing the mounting of the cartridge 7 to the image forming apparatus main assembly 100A.

[0202] Fig.17 , Fig.18 and Fig.19 1 is a sectional view showing an operation of mounting the cartridge 7 to the image forming apparatus main assembly 100A.

[0203] The imaging device main assembly 100A of this embodiment adopts a structure in which a cartridge can be installed in a substantially horizontal direction. Specifically, the imaging device main assembly 100A has an internal space in which a cartridge can be installed. The imaging device main assembly has a cartridge door 104 (front door) at the front side of the main assembly 100A (the side close to the user standing in use) for inserting the cartridge into the space.

[0204] like Fig.16 As shown, the cartridge door 104 of the imaging device main assembly 100A is arranged to be able to open and close. When the cartridge door 104 is opened, the lower cartridge guide rail 105 for guiding the process cartridge 7 is arranged on the bottom surface of the defined space, and the upper cartridge guide rail 106 is arranged on the upper surface. The cartridge 7 is guided to the installation position by the upper cartridge guide rail and the lower cartridge guide rail (105, 106) arranged above and below the space. The cartridge 7 is inserted into the installation position substantially along the axis of the photosensitive drum unit 30.

[0205] refer to Fig.17 , Fig.18 and Fig.19 , the operations of mounting and dismounting the cartridge to and from the main assembly of the image forming apparatus 100A will be described below.

[0206] like Fig.17 As shown, the drum unit supporting member 39R or the photosensitive drum 1 does not contact the intermediate transfer belt 5 at the start of insertion of the cartridge 7. In other words, the dimensional relationship is such that the photosensitive drum 1 and the intermediate transfer belt 5 do not contact each other in a state where the end portion on the rear side relative to the insertion direction of the cartridge 7 is supported by the lower cartridge guide 105.

[0207] like Fig.18 As shown, the imaging device main assembly 100A includes a rear side lower cartridge guide 107 which projects upward from the rear side of the lower cartridge guide 105 in the insertion direction toward the lower cartridge guide 105 with respect to the direction of gravity. The rear side lower cartridge guide 107 is provided with a tapered surface 107a on the front side with respect to the insertion direction of the cartridge 7. Along with the insertion, the cartridge 7 is supported on the tapered surface 107a and guided to the mounting position.

[0208] When the cartridge is inserted into the main assembly 100A of the apparatus, the position and shape of the rear lower cartridge guide 107 may be any position and shape as long as a part of the cartridge does not rub against the imaging area 5A of the intermediate transfer belt 5. Here, the imaging area 5A is an area where the toner image to be transferred onto the recording material 12 is carried on the intermediate transfer belt 5. Furthermore, in this embodiment, among the parts of the cartridge in the mounting posture, the drum unit support member 39R disposed at the rear side relative to the insertion direction of the cartridge 7 protrudes most upward relative to the direction of gravity. Therefore, it is sufficient if the arrangement and shape of each element are appropriately selected so that the trajectory of the farthest end of the drum unit support member 39R in the insertion direction (hereinafter referred to as the insertion trajectory) does not interfere with the imaging area 5A when the cartridge is inserted.

[0209] Thereafter, the cartridge 7 is further inserted to the rear side of the image forming apparatus main assembly 100A from the state in which it is positioned on the rear side lower cartridge guide 107. Subsequently, the drum unit bearing member 39R abuts against the rear side cartridge positioning portion 108 provided in the image forming apparatus main assembly 100A. At this time, the cartridge 7 (photosensitive drum unit 30) is tilted by about 0.5 to 2 degrees (0.6 to 1.8 degrees) relative to the state in which the cartridge 7 (photosensitive drum unit 30) is fully installed in the image forming apparatus main assembly 100A. Fig.17 That is, in the insertion direction of the process cartridge 7, the downstream side of the cartridge 7 (photosensitive drum unit 30) is located at a higher level than the upstream side.

[0210] Fig.19 100A is a diagram of the state of the apparatus main assembly and the cartridge when the cartridge door 104 is closed. The imaging apparatus 100A has a front lower cartridge guide 109 on the front side relative to the insertion direction of the lower cartridge guide 105. The front lower cartridge guide 109 is configured to move up and down in association with the opening and closing of the cartridge door (front door) 104.

[0211] When the cartridge door 104 is closed by the user, the front cartridge lower guide 109 rises. Then, the drum unit bearing member 39L and the front cartridge positioning portion 110 of the image forming apparatus main assembly 100A contact each other to position the cartridge 7 relative to the image forming apparatus main assembly 100A.

[0212] Through the above-described operations, the mounting of the cartridge 7 to the image forming apparatus main assembly 100A is completed.

[0213] In addition, the removal of the cartridge 7 from the main assembly 100A of the imaging device is performed in the reverse order of the above-mentioned insertion operation. Since the inclined mounting structure is adopted as described above, when the process cartridge 7 is mounted on the main assembly 100A of the device, the friction between the photosensitive drum and the intermediate transfer belt can be suppressed. Therefore, the occurrence of minute scratches (scratches) on the surface of the photosensitive drum or the surface of the intermediate transfer belt can be suppressed.

[0214] Furthermore, the structure of this embodiment can simplify the structure of the image forming apparatus main assembly 100A, compared with a structure in which the entire cartridge is lifted after the cartridge is horizontally moved and mounted to the apparatus main assembly.

[0215] [Joining process of the coupling member and the main drive shaft]

[0216] refer to Fig. 20 , Fig.21 , Fig. 22 , Fig.23 , Fig.24 , Fig.25 and Fig.26 , the engagement process of the coupling unit 28 and the main assembly drive shaft 101 will be described in detail.

[0217] Fig. 20 , Fig.21 and Fig. 22 2 is a sectional view showing an operation of mounting the coupling unit 28 to the main assembly drive shaft 101 .

[0218] Fig.23 and Fig.24 It is a sectional view showing the operation of installing the coupling unit 28 to the main component drive shaft 101 when the main component drive shaft 101 rotates from a phase-misaligned state of the main component drive transfer groove 101a and the engaging portion 65 (driving force receiving surface 65b) to a phase-aligned state.

[0219] Fig.25 It is a cross-sectional view showing the relationship of forces acting on the joining member.

[0220] Fig.26 is an axial sectional view showing the drive transmitting engagement surface of the engagement member and the main assembly drive shaft.

[0221] in addition, Fig.21 and Fig.23 A state in which the phases of the main assembly drive transmission groove 101a and the engaging portion 65 (driving force receiving surface 65b) are misaligned is shown.

[0222] As described above, the cartridge 7 is inserted into the apparatus main assembly 100A. Subsequently, together with the mounting operation of the cartridge, the coupling unit abuts against the hemispherical shape 101c formed at the free end of the main assembly drive shaft 101 and the inclined surface formed at the end of the rough guide portion 101g of the main assembly drive shaft. In this way, the main assembly drive shaft 101 is guided to the inner surface 71b of the flange member 71 of the coupling unit.

[0223] Fig. 20 The main assembly drive shaft 101 thus guided is shown in a state of contact with the engaging member 65 of the coupling unit. The hemispherical shape 101c of the main drive shaft abuts against the insertion tapered surface 65k formed on the engaging member 65.

[0224] From this state, force is further applied in the direction of further mounting the cartridge 7. Subsequently, the force in the cartridge mounting direction acts in the direction in which the engaging member 65 is retracted to the outside in the radial direction by the insertion tapered surface 65k. Therefore, with the free end of the main assembly drive shaft 101 in contact with the insertion tapered surface 65k, the cartridge 7 can be further moved to the rear side of the main assembly of the device.

[0225] Fig.21 and Fig.23 The state in which the cartridge 7 is moved to the rear side in this manner and the installation of the cartridge 7 to the main assembly 100A of the apparatus is completed is shown. In this state, the hemispherical shape 101c of the main assembly drive shaft abuts against the tapered surface 72m of the coupling unit, and the main assembly drive shaft 101 is positioned relative to the coupling unit 28 in the axial direction and the radial direction.

[0226] As described above, the engaging member 65 is guided by the first, second, third and fourth guiding surfaces of the flange cover member 72 on the first, second, third and fourth guided surfaces of the engaging member 65 so that it is retracted in the radial direction until the free end of the engaging portion contacts the outer peripheral surface of the shaft portion 101f of the main assembly drive shaft. Fig.23 As shown, the limiting surface 65j that resists the urging force of the engaging member 65 is separated from the limiting surface 72j of the flange cover member. Fig.15 As compared with the illustrated state in which the main assembly drive shaft 101 is not inserted into the coupling unit 28, the urging member 66 is further compressed and retracted.

[0227] Thereafter, when the main assembly of the image forming apparatus is started or when the image forming operation is started, the main assembly drive shaft 101 is rotated. Fig. 22 and Fig.24 As shown, the engaging portion 65a of the engaging member enters the groove 101a of the main assembly drive shaft. As a result, the engaging member 65 moves radially inward until the drive shaft abutment surface 65c of the engaging member contacts the outer peripheral surface of the shaft portion 101f of the main assembly drive shaft. Fig.24 In the embodiment, the position limiting surface 65j of the engaging member also contacts the limiting surface 72j of the flange cover member.

[0228] However, in order to make the drive shaft abutment surface 65c of the engaging member contact the outer peripheral surface of the shaft portion 101f of the main assembly drive shaft more reliably, it is desirable to select the dimensional relationship so that a predetermined gap is always formed between the position limiting surface 65j and the limiting surface 72j. That is, in order that even if a dimensional change occurs, in a state where the drive shaft abutment surface 65c of the engaging member contacts the outer peripheral surface of the shaft portion 101f of the main assembly drive shaft, a gap is definitely generated between the position limiting surface 65j and the limiting surface 72j.

[0229] In addition, when the main assembly drive shaft 101 is Fig.24 When the main assembly drives the drum 1 in a state of rotation, the drive transmission surface 101b of the drive shaft of the main assembly and the driving force receiving surface 65b of the engaging portion contact each other, so that the drive transmission to the photosensitive drum 1 is achieved, as shown in FIG. Fig.25 As described above, the engaging portion 65a of the engaging member is engaged with the main assembly drive shaft 101.

[0230] exist Fig. 22 In the embodiment, the engaging portion 65a is arranged so that in the Z direction, a distance L1 from the front end surface of the cylindrical portion 71 to the front end surface of the engaging portion 65a and a length L2 of the driving force receiving surface 65b satisfy L1>L2.

[0231] like Fig. 22 As shown, the tapered portion 72m is arranged so that the center 101h of the hemispherical shape 101c falls within the range L2 of the driving force receiving surface 65b of the engaging member 65 in the Z direction. If the engaging portion 65a and the center 101h are projected on the axis of the drum unit 30, the center 101h is set within the projected area L2 of the driving force receiving surface 65b of the engaging portion 65a. By establishing this arrangement relationship, the following effects can be provided.

[0232] like Figure 4 , Figure 5 and Fig.19 As shown, the drum unit bearing member 39R and the drum unit bearing member 39L abut against the rear side cartridge positioning portion 108 and the front side cartridge positioning portion 110, respectively. Thus, the position of the cartridge 7 relative to the main assembly 100A of the imaging device is determined. Here, the relative position between the main assembly drive shaft 101 and the coupling unit 28 is affected by the tolerance of the parts. More specifically, due to the influence of the tolerance of the components from the drum unit bearing member 39R to the coupling unit 28 and the tolerance of the components from the rear side cartridge positioning unit 108 to the main assembly drive shaft 101, the position is offset.

[0233] like Figure 6 and Fig. 22As shown, the hemispherical 101c of the main component drive shaft 101 abuts against the inverted conical shape 533a, and the supported portion 101d and the hemispherical 101c form a two-end support structure. That is, as observed from the coupling unit 28, the main component drive shaft 101 is tilted around the center 101h of the hemispherical 101c. The position that is the same as the center 101h in the Z-axis direction is the position that is least affected by the tilt. The driving force receiving surface 65b is arranged at the same position as the center 101h in the Z-axis direction so that the influence of positional deviation can be minimized. That is, the position at which the photosensitive drum 1 is stably driven can be determined.

[0234] Here, in this embodiment, a protrusion for receiving a driving force is provided on the engaging member 65 side, but a groove for receiving a drive through the engaging member may be provided, and a movable protrusion may be provided which can engage with the groove by moving in the radial direction on the main component drive shaft 101 side. However, the imaging device main component 100A is required to have higher durability than the cartridge 7. From the viewpoint of improving the durability of the imaging device main component 100A, it is preferable to provide a movable portion (engaging portion 65) that moves in the radial direction on the coupling unit 28 side of the cartridge 7 as in this embodiment.

[0235] [Drive the coupling unit via the main assembly drive shaft]

[0236] refer to Fig.25 and Fig.26 , a structure for transmitting the rotational driving force to the coupling unit 28 will be described.

[0237] First, the support structure for the engagement member 65 during the coupling drive will be described in detail. Fig.25 As shown, when the main assembly drive shaft 101 is rotationally driven in the arrow R direction, the drive transmission surface 101b formed in the groove 101a of the main assembly drive shaft abuts against the driving force receiving surface 65b formed on the engaging portion 65a of the engaging member to apply a force F in the normal direction of the driving force receiving surface 65b. When the driving force F acts on the driving force receiving surface, the first guided surface 65d of the engaging member and the first guide surface 72d of the flange cover member are brought into contact with each other by the force. In addition, more preferably, the drive shaft abutting surface 65c of the engaging member abuts against the outer peripheral surface of the shaft portion 101f of the main assembly drive shaft. Thus, the engaging member 65 is firmly supported between the flange cover member 72 and the main assembly drive shaft 101.

[0238] Next, a force generated to the engaging member 65 and a supporting structure of the engaging member 65 using the force will be described.

[0239] The driving force receiving surface 65b is inclined relative to the moving direction S of the coupling member 65 so as to face outward at least in the radial direction. That is, the normal vector of the driving force receiving surface 65b (a vector extending perpendicular to the driving force receiving surface 65b toward the side that the driving force receiving surface 65b faces) is a component facing outward in the radial direction of the coupling unit.

[0240] In other words, the radial inner side of the driving force receiving surface 65b (the free end side of the engaging portion 65a) is located upstream in the rotation direction of the drum unit than the radial outer side of the driving force receiving surface 65b (the rear end side of the engaging portion 65a).

[0241] When the driving force F is applied vertically to the driving force receiving surface 65b of the engaging portion, the direction in which the driving force F is generated is inclined radially inward relative to the circumferential direction (circumferential direction) of the coupling unit. That is, when an imaginary circle passing through the driving force receiving surface 65b concentric with the coupling unit is drawn, the driving force F is inclined so as to point radially inward relative to the tangent line of the imaginary circle.

[0242] Therefore, the driving force F is divided into a force F1 which is a tangential component (circumferential direction component, rotational direction component) along a tangent line of the imaginary circle and a force F2 which is a radial direction component directed inward in the radial direction.

[0243] The driving force receiving surface 65b of the engaging member is pushed radially inward by the force F2 applied to the driving force receiving surface 65b. The driving force receiving surface 65b can be prevented from moving radially outward and, therefore, can also be prevented from releasing the contact state with the drive transmitting surface 101b of the main assembly drive shaft.

[0244] In addition, the engaging member is movably guided radially inwardly to the flange cover member in a moving direction S that is inclined at an angle θ relative to the direction of the force F acting in the normal direction of the driving force receiving surface. Fig.25 As shown in part (b) of FIG. 6 , the force F acting on the driving force receiving surface has a component FS acting in the moving direction S of the engaging member. This force FS prevents the engaging member 65 from moving to the opposite side in the moving direction S, and therefore, can prevent the driving force receiving surface 65b of the engaging member from being disengaged from the drive transmitting surface 101b of the main component drive shaft to the outside. To put it simply in a different way, with respect to the moving direction of the engaging member 65, the direction of the driving force receiving surface 65b is inclined toward the direction in which the driving force receiving surface 65b bites into the drive transmitting surface 101b of the main component drive shaft.

[0245] Further, more preferably, the drive shaft abutment surface 65c of the engaging member may be brought into contact with the outer peripheral surface of the shaft portion 101f of the main assembly drive shaft.

[0246] like Fig.25 As shown, the drive shaft abutment surface 65c is arranged on a side opposite to the direction of the driving force F relative to the driving force receiving surface 65b. Thus, by the force F acting on the driving force receiving surface, the rotational moment M generated in the coupling member 65 is supported by the drive shaft abutment surface 65c, so that the coupling member 65 can be supported more firmly. The drive shaft abutment surface 65c of the coupling member protrudes radially inward from the inner peripheral surface 72a of the hole of the flange cover member. Thus, even when there are changes in the size and assembly accuracy of each part, the drive shaft abutment surface 65c can reliably contact the outer peripheral surface of the drive shaft 101f. That is, preferably, at least a portion of the drive shaft abutment surface 65c is arranged on the upstream side of the driving force receiving surface 65b in the rotation direction of the drum unit.

[0247] In this manner, the coupling member 65 is firmly supported between the flange cover member 72 and the main assembly drive shaft 101. Thus, the coupling member 65 can be prevented from being disengaged from the main assembly drive shaft 101 and the driving force can be stably transmitted from the main assembly drive shaft 101 to the coupling member 65. Moreover, the driving stability of the photosensitive drum 1 can be improved and the image quality can be improved.

[0248] Next, the inclination of the engaging portion in the axial direction of the driving force receiving surface 65 b will be described. Fig.26 65a is a cross-sectional view of the engaging portion 65a of the engaging member taken along a plane extending in the normal direction of the driving force receiving surface 65b. That is, Fig.26 It is along Fig.25 Here, the main component drive transmission surface 101b formed in the drive transmission groove 101a of the main component drive shaft 101 and the driving force receiving surface 65b formed on the engaging portion 65a of the engaging member are in contact with each other, and the driving force of the main component drive shaft 101 is transmitted to the engaging member 65.

[0249] As described above, the main assembly drive transmitting surface 101b has a shape twisted around the axis of the coupling unit 28, and Fig.26 , the main component drive transmission surface 101b is inclined relative to the rotation axis of the main component drive shaft 101. The driving force receiving surface 65b of the engaging portion also has the same twisted shape so as to contact with the main component drive transmission surface 101b, and therefore, the driving force receiving surface 65b is inclined relative to the rotation axis of the main component drive shaft 101. More specifically, the driving force receiving surface 65b is disposed on the upstream side in the rotation direction of the drum unit, as compared with the inner side, on the outer side in the axial direction of the drum unit.

[0250] Therefore, the force F in the normal direction applied from the main component drive transmission surface 101b to the drive force receiving surface 65b has a force F3 as a component in the direction of the rotation axis. That is, a force F3 is generated for pushing the coupling member 65 and the coupling unit 28 outward in the longitudinal direction of the photosensitive drum. Thus, it is possible to prevent a force from being applied to the main component drive shaft 101 in the direction in which the coupling unit 28 is disassembled in the axial direction. Moreover, as Fig.21 As shown, a force is generated to push the hemispherical shape 101c formed at the free end of the main component drive shaft in a direction to abut against the tapered portion 72m formed on the flange cover member. As a result, the hemispherical shape 101c of the main component drive shaft reliably abuts against the tapered portion 72m of the flange cover member, and the main component drive shaft 101 can be positioned more accurately relative to the coupling unit 28.

[0251] The driving force received by the driving force receiving surface 65b is transmitted from the engaging member 65 to the flange cover member 72. That is, the driving force is transmitted from the first guided surface 65d of the engaging member 65 to the first guide surface 72d of the flange cover member 72. The first guide surface 72d is a transmitted portion to which the driving force is transmitted, and the flange cover member 72 is a transmitted member. In addition, the first guide surface 72d is also a supporting portion for suppressing the engaging portion 65a from moving to the downstream side in the rotation direction of the drum unit when the driving force is applied to the engaging member 65. In addition, the first guided surface 65d is a transmitting portion for transmitting the driving force to the flange cover member 72.

[0252] The first guide surface 72d is inclined relative to the driving force receiving surface 65b. Therefore, the driving force F applied perpendicularly to the driving force receiving surface 65b has a component directed inward in the radial direction along the first guide surface 72d.

[0253] Due to the component of the driving force F, the engaging portion 65a is guided along the first guiding surface 72d toward the radial inner side of the coupling unit 28. That is, when the driving force F is transmitted, the first guiding surface 72d pushes the engaging portion 65a and the driving force receiving surface 65b toward the inner side (i.e., the rear side of the drive transmission groove 101a) in the radial direction.

[0254] exist Fig.25 The structure is such that when a tangent line to the first guide surface 72d and a tangent line to the drive force receiving surface 65b extend, the two tangent lines intersect each other at outer sides relative to the first guide surface 72d and the drive force receiving surface 65b in the radial direction.

[0255] In addition, in the rotation direction R of the drum unit, the radially inner side of the first guide surface 72d is arranged on the downstream side of the radially outer side ( Fig.25 ).

[0256] The driving force transmitted from the engaging member 65 to the flange cover member 72 is transmitted to the photosensitive drum 1 through the flange member 71. Therefore, the photosensitive drum 1 rotates together with the coupling unit 28.

[0257] That is, Fig.14 As shown, the flange cover member 72 is provided with a position control groove 721 (engagement portion, recessed portion) for engaging with a protrusion provided on the flange member 71. In addition, an adapting surface 72k is provided to engage with the inner periphery of the flange member 71. The driving force is transmitted to the flange member 71 through the adapting surface 72k and the position control groove 72l. The flange member 71 is mounted to the photosensitive drum 1, and therefore, the driving force is ultimately transmitted from the flange member 71 to the photosensitive drum 1.

[0258] Here, the protrusion is provided on the flange member 71, and a recessed portion (position limiting groove 721) for engaging with the flange cover member 72 is provided, but it is not limited to this structure. For example, the recessed portion may be provided in the flange member 71, and the flange cover member 72 is provided with a protrusion engaged with the flange cover member 72, so that the driving force can be transmitted from the flange cover member 72 to the flange member 71.

[0259] Here, as described above, since the driving force receiving surface 65b is a twisted surface, when the driving force F is applied to the driving force receiving surface 65b, the drum unit 30 is pushed outward in the axial direction. That is, the structure is such that when the driving force is applied from the main component drive shaft 101 to the driving force receiving surface 65b, the drum unit 30 and the main component drive shaft 101 attract each other. Here, the driving force receiving surface 65b may not necessarily have a twisted shape as long as it has the same function as the twisted surface. The driving force receiving surface 65b may be a surface that is inclined in the direction of generating the pushing force Fc2 when receiving the above-mentioned driving force F, and the surface shape may be, for example, a flat surface or a curved surface.

[0260] In addition, if Fig.10 and Fig.12 As shown, the flange member 71 is provided with a contact surface (pushing member abutting portion) 71f that contacts the pushing member, and when the engaging member 65 receives the radially inward pushing force from the pushing member 66, the contact surface receives the reaction force, that is, the radially external force. The contact surface 71f is a pressing force receiving portion (pushing force receiving portion) pressed and pushed by the pushing member. It is a pushing member supporting portion for supporting the pushing member.

[0261] like Fig.12As shown, the contact surface 71f of the flange member 71 is arranged at a position such that, in the longitudinal direction of the photosensitive drum 1, at least a portion of the contact surface 71f overlaps with a portion of the photosensitive drum 1 in the longitudinal direction. That is, when the contact surface 71f and the photosensitive drum 1 are projected perpendicularly to the axis of the photosensitive drum, at least a portion of their mutual projection areas overlap each other. In other words, at least a portion of the contact surface 71f is arranged inside the photosensitive drum 1. Specifically, in this embodiment, the entire contact surface 71f is located inside the photosensitive drum 1. This is due to the following reasons.

[0262] Due to the requirement of space in the radial direction, the contact surface 71f of the flange member 71 is arranged in the thin-walled portion of the flange member. The radially outward urging force applied from the urging member 66 to the contact surface 71f is received by the photosensitive drum 1 (which is made of aluminum alloy and has a strength generally higher than that of the flange member), so that the deformation of the flange member 71 in the vicinity of the contact surface 71f can be suppressed. By suppressing the deformation of the flange member 71, the deformation of the supported portion 71c formed on the flange member 71 for rotatably supporting the photosensitive drum 1 is suppressed, so that the photosensitive drum 1 can be rotatably supported with high precision.

[0263] At least a portion of the urging member 66 is disposed inside the photosensitive drum 1 so as to dispose at least a portion of the contact surface 71 f inside the photosensitive drum 1 .

[0264] More strictly speaking, at least a part of the contact portion (urging portion) of the urging member 66 that contacts the contact surface 71f is located inside the photosensitive drum 1. Specifically, the entire urging member 66 is located inside the photosensitive drum 1 in this embodiment.

[0265] In addition, at least a portion of the engaging member 65, the engaging portion 65a, and the driving force receiving surface 65b are also located inside the photosensitive drum 1. That is, the entire engaging member 65 is located inside the photosensitive drum 1 particularly in this embodiment.

[0266] The movable engaging member 65 and the elastically deformable urging member 66 are located inside the photosensitive drum 1 so that it is difficult for the user's hand to touch them. It is also suitable to protect the engaging member 65 and the urging member 66.

[0267] In addition, by disposing at least a portion of the engaging member 65 inside the photosensitive drum, the following effect is also provided.

[0268] That is, when the cartridge 7 is mounted in the apparatus main assembly ( Figure 8 and Fig. 9), if the coupling member 65 is located inside the photosensitive drum 1, the shaft portion 101f on which the drive transmission groove 101a is formed also enters the inside of the photosensitive drum 1. Moreover, the drive transmission shaft 101 is supported at two positions, and therefore, the length between the supported portion 101d and the shaft portion 101f preferably suppresses the inclination of the drive transmission shaft 101 relative to the drum unit. By moving the shaft portion 101f to the inside of the photosensitive drum 1, it is easy to ensure the distance between the supported portion 101d and the shaft portion 101f while keeping the main component of the device small.

[0269] [Remove the coupling unit from the main assembly drive shaft]

[0270] refer to Fig.10 , Fig. 20 , Fig.21 and Fig. 22 , the operation of removing the coupling unit 28 from the main assembly drive shaft 101 will be described.

[0271] like Fig.10 As shown, the driving force receiving surface 65b and the main assembly driving force transmitting surface 101b contact each other when the rotational drive of the main assembly drive shaft 101 is stopped. In this state, the engaging portion 65a enters the main assembly drive transmitting groove 101a.

[0272] When the cartridge 7 starts to be removed from the main assembly 100A of the image forming apparatus, the removal tapered surface 651 of the engaging portion 65a abuts against the main assembly side removal tapered portion 101i, as shown in FIG. Fig. 22 The removal tapered surface 651 abuts against the main assembly side removal tapered portion 101i, so that the urging member 66 starts to contract, and the engaging member 65 moves outward in the radial direction together with the main assembly side removal tapered portion 101i.

[0273] Furthermore, when the coupling unit 28 is pulled out from the main assembly drive shaft 101, the state is the same as Fig.21 , and the urging member 66 contracts so that the engaging portion 65a moves to the outer diameter of the shaft portion 101f of the main assembly drive shaft 101. When the engaging portion 65a moves to the outer diameter of the shaft portion 101f, the coupling unit 28 can be removed from the main assembly drive shaft 101.

[0274] Furthermore, when the coupling unit 28 is withdrawn from the main assembly drive shaft 101, the engaging member 65 returns to the position where the limiting portion 65j of the engaging member and the limiting portion 72j of the flange cover member contact each other, where the position in the pushing direction is limited, as shown in FIG. Fig. 20 , Fig.15 shown.

[0275] Through the above-described operation, the coupling unit 28 is removed from the main assembly drive shaft 101 .

[0276] Here, as described above, the driving force receiving surface 65b has a shape twisted around the rotation axis of the flange member 71. The twisting direction is such that the outer side (z1 direction side) of the driving force receiving surface 65b is located on the upstream side of the inner side (z2 direction side) with respect to the rotation direction of the photosensitive drum 1.

[0277] In this state, when an attempt is made to remove the coupling unit 28 from the main assembly drive shaft 101, the driving force receiving surface 65b is formed in a direction that hinders the removal operation. Fig.26 As shown, the outer side (z1 direction side) of the driving force receiving surface 65b is located on the upstream side of the inner side (Z2 direction side) relative to the rotation direction, and therefore, if the connecting unit 28 is pulled out from the main component drive shaft 101 during the removal operation, the removal load is greater than the insertion load.

[0278] On the contrary, the main assembly drive shaft 101 can be rotated in the reverse direction when the rotational drive of the main assembly drive shaft 101 is stopped and the cartridge 7 is removed from the main assembly 100A of the image forming apparatus. Thus, after the state in which the driving force receiving surface 65b is in contact with the drive transmitting surface 101b is released, the cartridge 7 is removed from the main assembly 100A of the image forming apparatus, and therefore, the removal load can be reduced.

[0279] As a reverse rotation method, in association with the opening operation of the cartridge door 104, the main assembly driving shaft 101 may be reversely rotated by a link mechanism or the like, or a motor of a driving source of the main assembly driving shaft 101 may be reversely rotated.

[0280] In the above-described embodiments, the operation and effects of the present invention will be summarized.

[0281] In this embodiment, a coupling member 65 is provided which is movable in the radial direction within the coupling unit 28, and therefore, the box 7 can be satisfactorily installed and removed through the coupling unit 28 and the drive can be transmitted without using a mechanism for retracting the main component drive shaft 101 in the axial direction.

[0282] The engaging portion 65a formed in the engaging member 65 projects radially inwardly from the hole portion 72a of the coupling unit 28. Thus, the engaging portion 65a in the cartridge 7 configured to be detachable from the apparatus main assembly 100A can be protected.

[0283] In addition, the driving force receiving surface 65b formed in the engaging portion extends radially inward. Therefore, after the engaging portion has entered the groove portion 101a of the main component drive shaft, the driving force receiving surface 65b and the drive transmitting surface 101b formed in the groove portion 101a contact each other, thereby achieving satisfactory drive transmission.

[0284] In addition, the direction of the driving force F received by the driving force receiving surface 65b in the normal direction during driving the coupling unit 28 is inclined inwardly in the radial direction of the photosensitive drum 1 relative to the tangent direction of a virtual circle centered on the rotation axis of the photosensitive drum 1. In addition, the direction of the driving force F is inclined relative to the direction in which the engaging member 65 is movably guided, and the angle formed by the directions is an acute angle. Therefore, after the engaging portion has entered the groove portion 101a of the main assembly drive shaft, the driving force receiving surface 65b and the drive transmitting surface 101b formed in the groove portion 101a contact each other, thereby achieving satisfactory drive transmission.

[0285] In addition, the direction of the driving force F received by the driving force receiving surface 65b in the normal direction during driving the coupling unit 28 is inclined inwardly in the radial direction of the photosensitive drum 1 relative to the tangent direction of the virtual circle centered on the rotation axis of the photosensitive drum 1. In addition, the direction of the driving force F is inclined relative to the direction in which the coupling member 65 is movably guided, and the angle formed between the directions is an acute angle. This prevents force from being applied radially outward to the coupling member 65, thereby preventing the driving force receiving surface 65b from being disengaged from the drive transmission surface 101b, and in addition, the driving force from the main component drive shaft 101 can be stably transmitted to the coupling member 65. Therefore, the driving stability of the photosensitive drum 1 is improved, and thus the image quality is improved.

[0286] In addition, the coupling member 65 is provided with a drive shaft abutting surface 65c abutting against the outer peripheral surface of the shaft portion 101f of the main assembly drive shaft. Thus, the rotational moment M generated in the coupling member 65 is supported by the drive shaft abutting surface 65c, so that the coupling member 65 is more firmly supported and the driving stability can be improved.

[0287] In addition, the direction of the driving force F received by the driving force receiving surface 65b in the normal direction is inclined toward the outside in the longitudinal direction of the photosensitive drum 1 relative to the direction of the rotation axis of the photosensitive drum 1. Thus, it is possible to prevent a force from being applied to the main assembly drive shaft 101 in the direction in which the coupling unit 28 is disassembled in the axial direction.

[0288] In addition, in the engaging portion 65a, an insertion tapered surface 65k is provided at one end portion on the outer side in the longitudinal direction of the photosensitive drum 1, and at the other end portion on the opposite side, a removal tapered surface 65l is provided. Thus, when the cartridge is mounted or removed, by bringing the insertion tapered surface 65k or the removal tapered surface 65l into contact with the groove portion 101a of the main assembly drive shaft, the process cartridge 7 can be mounted and removed smoothly without getting stuck.

[0289] In addition, at least a portion of the contact surface 71f is provided at a position overlapping the photosensitive drum 1 in the longitudinal direction together with the urging member provided on the flange member 71. The engaging member 65 receives the radially inward urging force from the urging member 66, and on the other hand, the contact portion 71f receives a force as a reaction force to the urging force in the radial direction. By providing such a contact surface 71f inside the photosensitive drum 1, deformation of the supported portion 71c formed on the flange member 71 is suppressed, and the photosensitive drum 1 can be rotatably supported with high accuracy.

[0290] <Example 2>

[0291] refer to Figures 27 to 47 , Embodiment 2 will be described. Elements corresponding to those in the previous embodiment are denoted by the same names, and the description of the same points as above may be omitted in some cases. Points different from the above elements will be mainly described.

[0292] The coupling unit disclosed in each of the foregoing embodiments is a member to which a driving force for rotating the photosensitive drum 1 is transmitted. However, the coupling unit described above can be used to rotate a member other than the photosensitive drum 1 .

[0293] As an example of this case, in this embodiment, the coupling unit 4028 receives a driving force for rotating the developing roller and the toner supply roller.

[0294] The photosensitive drum 1 , the developing roller 4017 , and the toner supplying roller 4020 are all rotatable members configured to rotate in a state where the developer (toner) is carried on the surface thereof.

[0295] [General arrangement of electrophotographic image forming apparatus]

[0296] First reference Fig. 27 , the overall structure of an embodiment of an electrophotographic image forming apparatus (image forming apparatus) according to this embodiment will be described.

[0297] Fig. 27 is a schematic cross-sectional view of the imaging apparatus 4100A of this embodiment.

[0298] like Fig. 27 As shown, the imaging device 4100A includes first, second, third and fourth imaging units SY, SM, SC and SK as a plurality of imaging parts for forming images of corresponding colors, namely yellow (Y), magenta (M), cyan (C) and black (K). In this embodiment, the first to fourth imaging parts SY, SM, SC and SK are arranged in a row in a substantially horizontal direction.

[0299] In this embodiment, the structure and operation of the drum box 4013 (4013Y, 4013M, 4013C and 4013K) are substantially the same as those of the drum box 4013, except that the colors of the images to be formed are different from each other. The structure and operation of the developing box 4004 (4004Y, 4004M, 4004C and 4004K) are substantially the same as those of the drum box 4004, except that the colors of the images to be formed are different from each other. Therefore, hereinafter, Y, M, C and K will be omitted and will be described together unless otherwise specified.

[0300] In this embodiment, the image forming apparatus 4100A has cylinders (hereinafter referred to as photosensitive drums) 1, each having a photosensitive layer, arranged side by side as a plurality of image bearing members in a direction slightly inclined relative to the vertical direction. A scanning unit (exposure device) 4013 is arranged below the drum box 4013 and the developing box 4004 relative to the direction of gravity. In addition, around the photosensitive drum 1, a charging roller 2 or the like serving as a processing device (processing device, processing member) acting on the photosensitive layer is arranged.

[0301] The charging roller 2 is a charging device (charging means, charging member) for uniformly charging the surface of the photosensitive drum 1. The scanning unit (exposure device) 3 is an exposure device (exposure device, exposure member) for forming an electrostatic image (electrostatic latent image) on the photosensitive drum 1 by irradiating laser light based on image information. Around the photosensitive drum 1, a cleaning blade 6 (cleaning means, cleaning member) as a cleaning device and a developing cartridge 4004 are provided.

[0302] Furthermore, an intermediate transfer belt 5 as an intermediate transfer member for transferring the toner image from the photosensitive drum 1 onto a recording material (sheet, recording medium) 12 is provided to face the four photosensitive drums 1 .

[0303] In the developing cartridge 4004 of this embodiment, a contact developing method is adopted in which a non-magnetic one-component developer (hereinafter referred to as toner) is used as a developer and a developing roller 4017 as a developer carrying member contacts the photosensitive drum 1 .

[0304] With the above structure, the toner image formed on the photosensitive drum 1 is transferred to the sheet (paper) 12, and the toner image transferred to the sheet is fixed. As a processing device that can act on the photosensitive drum 1, the drum box 4013 is provided with a charging roller 2 for charging the photosensitive drum 1 and a cleaning blade 6 for removing the toner that remains but is not transferred to the photosensitive drum 1. The untransferred residual toner that remains on the photosensitive drum 1 and has not been transferred to the sheet 12 is collected by the cleaning blade 6. In addition, the residual toner collected by the cleaning blade 6 is accommodated in the accommodating portion (hereinafter referred to as the waste toner accommodating portion) 4014a of the removed developer from the opening 4014b. The waste toner accommodating portion 4014a and the cleaning blade 6 are integrated into the drum box (photosensitive member unit, drum unit, image support member unit) 4013.

[0305] The image forming apparatus 4100A is provided with guides (positioning means) such as mounting guides and positioning members (not shown) on the main assembly frame. The developing cartridge 4004 and the drum cartridge 4013 are guided by the above-mentioned guides and can be mounted to and removed from the image forming apparatus main assembly 4100A.

[0306] Toners of respective colors of yellow (Y), magenta (M), cyan (C), and black (K) are accommodated in the developing cartridges 4004 for the respective colors.

[0307] The intermediate transfer belt 5 contacts the photosensitive drum 1 of each drum cartridge 4013 and Figure 1 The intermediate transfer belt 5 rotates (moves) in the direction of the arrow B in FIG. The intermediate transfer belt 5 is wound around a plurality of supporting members (a driving roller 51, a secondary transfer opposing roller 52, a driven roller 53). On the inner peripheral surface side of the intermediate transfer belt 5, four primary transfer rollers 8 as primary transfer devices are juxtaposed so as to face each photosensitive drum 1. A secondary transfer roller 9 as a secondary transfer device is provided on the outer peripheral surface side of the intermediate transfer belt 5 at a position facing the secondary transfer opposing roller 52.

[0308] At the time of image formation, the surface of the photosensitive drum 1 is first uniformly charged by the charging roller 2. Subsequently, the surface of the photosensitive drum 1 thus charged is scanned and exposed to the laser beam corresponding to the image information emitted from the scanning unit 3. Thus, an electrostatic latent image corresponding to the image information is formed on the photosensitive drum 1. The electrostatic latent image formed on the photosensitive drum 1 is developed into a toner image by the developing cartridge 4004. The toner image formed on the photosensitive drum 1 is transferred (primary transfer) onto the intermediate transfer belt 5 by the operation of the primary transfer roller 8.

[0309] For example, when a full-color image is formed, the above-mentioned processing is performed in sequence in four drum cartridges 4013 (4013Y, 4013M, 4013C, 4013K) and four developing cartridges 4004 (4004Y, 4004M, 4004C, 4004K). The toner images of the corresponding colors formed on the photosensitive drums 1 of the corresponding drum cartridges 4013 are primarily transferred in sequence so as to be superimposed on the intermediate transfer belt 5. Thereafter, in synchronization with the movement of the intermediate transfer belt 5, the recording material 12 is conveyed to the secondary transfer portion. The four-color toner images on the intermediate transfer belt 5 are transferred together to the recording material 12 conveyed to the secondary transfer portion composed of the intermediate transfer belt 5 and the secondary transfer roller 9.

[0310] The recording material 12 to which the toner image has been transferred is conveyed to the fixing device 10 as a fixing means. By applying heat and pressure to the recording material 12 in the fixing device 10, the toner image is fixed on the recording material 12. In addition, the primary transfer residual toner remaining on the photosensitive drum 1 after the primary transfer process is removed by the cleaning blade 6 and collected as waste toner. In addition, the secondary transfer residual toner remaining on the intermediate transfer belt 5 after the secondary transfer step is removed by the intermediate transfer belt cleaning device 11.

[0311] The imaging device 4100A is also capable of forming a monochrome or multi-color image using a desired single or some (but not all) imaging units.

[0312] [General arrangement of process cartridge]

[0313] refer to Fig.28 , Fig.29 , Fig.30 and Fig.31 , the general arrangement of the drum cartridge 4013 (4013Y, 4013M, 4013C, 4013K) and the developing cartridge 4004 (4004Y, 4004M, 4004C, 4004K) which can be mounted to the main assembly 4100A of the imaging device of this embodiment will be described.

[0314] Drum box 4013Y, drum box 4013M, drum box 4013C and drum box 4013K have the same structure. In addition, developer box 4004Y containing yellow toner, developer box 4004M containing magenta toner, developer box 4004C containing cyan toner and developer box 4004K containing black toner have the same structure. Therefore, in the following description, each of drum box 4013Y, 4013M, 4013C and 4013K will be generally referred to as drum box 4013, and each developer box 4004Y, 4004M, 4004C and 4004K will be generally referred to as developer box 4004. The corresponding box parts will also be described together in the same manner.

[0315] Fig.28 4013 is an external perspective view of the drum cartridge 4013. Fig.28 As shown, the direction of the rotation axis of the photosensitive drum 1 is defined as the Z direction (arrow Z1, arrow Z2). Fig. 27 The horizontal direction in is defined as the X direction (arrow X1, arrow X2), Fig. 27 The vertical direction in is the Y direction (arrow Y1, arrow Y2).

[0316] Drum unit supporting members 4039R and 4039L are respectively attached to the side portions of the cleaning frame 4014, and support the photosensitive drum unit 4030. Thus, the photosensitive drum unit 4030 is supported so as to be rotatable relative to the cleaning frame 4014.

[0317] In addition, the charging roller 2 and the cleaning blade 6 are mounted to the cleaning frame 4014, and they are arranged so as to contact the surface of the photosensitive drum 1. The charging roller bearing 15 is mounted to the cleaning frame 4014. The charging roller bearing 15 is a bearing for supporting the shaft of the charging roller 2.

[0318] Here, the charging roller support 15 (15R, 15L) is installed so as to be able to Fig.29 The charging roller 2 moves in the direction of the arrow C shown. The rotation shaft 2a of the charging roller 2 is rotatably mounted to the charging roller support 15 (15R, 15L). The charging roller support 15 is urged toward the photosensitive drum 1 by a pressing spring 16 as an urging device. Therefore, the charging roller 2 abuts on the photosensitive drum 1 and rotates through the photosensitive drum 1.

[0319] The cleaning frame 4014 is provided with a cleaning blade 6 as a cleaning device for removing the toner remaining on the surface of the photosensitive drum 1. The cleaning blade 6 is formed by combining a blade-shaped rubber (elastic member) 6a that abuts against the photosensitive drum 1 to remove the toner on the photosensitive drum 1 and a supporting metal plate 6b that supports the blade-shaped rubber (elastic member) 6a. In this embodiment, the supporting metal plate 6b is fixed to the cleaning frame 4014 with screws.

[0320] As described above, the cleaning frame 4014 has an opening 4014b for collecting transfer residual toner collected by the cleaning blade 6. The opening 4014b is provided with a blow-off prevention sheet 26 which contacts the photosensitive drum 1 and seals between the photosensitive drum 1 and the opening 4014b to prevent toner from leaking in the upper portion of the opening 4014b.

[0321] Fig.30 It is an external perspective view of the developer box 4004.

[0322] The developing box 4004 includes a developing frame 4018 for supporting various components. In the developing box 4004, a developing roller 4017 as a developer carrying member is provided. Fig.31 The developing roller 4017 rotates in the direction of the arrow D (counterclockwise) shown in FIG. 1 and contacts the photosensitive drum 1. The developing roller 4017 is rotatably supported by the developing frame 4018 at both end portions relative to the longitudinal direction (rotation axis direction) thereof through developing bearings 4019 (4019R, 4019L). Here, the developing bearings 4019 (4019R, 4019L) are respectively attached to the respective side portions of the developing frame 4018.

[0323] In addition, if Fig.31 As shown, the developing box 4004 includes a developer containing chamber (hereinafter referred to as a toner containing chamber) 4018a and a developing chamber 4018b in which the developing roller 4017 is disposed.

[0324] In the developing chamber 4018b, there are provided a toner supply roller 4020 as a developer supply member which contacts the developing roller 4017 and rotates in the direction of arrow E, and a developing blade 21 as a developer regulating member for regulating the toner layer of the developing roller 4017. The developing blade 21 is fixed and integrated to the fixing member 22 by welding or the like.

[0325] A stirring member 23 for stirring the contained toner and for conveying the toner to the toner supply roller 4020 is provided in the toner containing chamber 4018 a of the developing frame 4018 .

[0326] [Structure of the main assembly drive shaft]

[0327] refer to Fig.32 and Fig.33 , the structure of the main component drive shaft 4101 will be described.

[0328] Fig.32 It is an external view of the main component drive shaft 4101.

[0329] Fig.33 1 and 2 are sectional views taken along the rotational axis (rotational axis) of a main assembly driving shaft 4101 mounted to the main assembly of the image forming apparatus.

[0330] like Fig.32 As shown, the main assembly drive shaft 4101 includes a gear member 4101e, an intermediate member 4101p, an output member 4101q and a drive transmitting member 4101r.

[0331] A motor (not shown) as a driving source is provided in the main component 4100A of the imaging device. A gear member 4101e is supplied with a rotational driving force from the motor, and the driving force is transmitted in the order of an intermediate member 4101p, an output member 4101q and a drive transmission member 4101r, so that the main component drive shaft 4101 rotates. The gear member 4101e, the intermediate member 4101p and the output member 4101q constitute a mechanism of an Oldham coupling, in which it is possible to move in the X direction and the Y direction within a certain distance range. Therefore, the drive transmission member 4101r provided on the box side of the main component drive shaft 4101 by the Oldham coupling can also move in the X direction and the Y direction within a certain distance range. The drive transmission member 4101r is provided with a rotatable shaft portion 4101f, and the rotational driving force received from the motor is transmitted to the developer box 4004 side through a groove-shaped drive transmission groove 4101a (recessed portion, drive transmission portion) provided in the shaft portion 4101f. Furthermore, the shaft portion 4101f has a tapered portion 4101c at its free end portion.

[0332] The main component drive transfer groove 4101a has a shape into which a part of the engaging portion 4065a described below can enter. Specifically, the main component drive transfer groove is provided with a main component drive transfer surface 4101b as a surface that contacts with the driving force receiving surface (driving force receiving portion) 4065b of the coupling unit 4028 to transfer the driving force.

[0333] In addition, if Fig.32 As shown, the main component drive transmission surface 4101b is not a flat surface, but a shape twisted around the rotation axis of the main component drive shaft 4101. The twisting direction is such that the downstream side in the Z1 direction of the main component drive shaft 4101 is upstream of the downstream side in the Z2 direction thereof with respect to the rotation direction of the main component drive shaft 4101. In this embodiment, the twisting amount along the rotation axis direction of the cylinder of the engagement portion 4065a is set to about 1 degree per 1 mm. The reason why the main component drive transmission surface 4101b is twisted will be described below.

[0334] In addition, the main component side disassembly tapered portion 4101i is provided on the downstream side surface in the Z2 direction relative to the main component drive transmission groove 4101a. The main component side disassembly tapered portion 4101i has a tapered portion (inclined surface, inclined portion) for disengaging the auxiliary engaging portion 4065a from the drive transmission groove 4101a when the developing cartridge 4004 is disassembled from the apparatus main component 4100A.

[0335] like Fig.33As shown, the supported portion 4101d provided on the gear member 4101e is rotatably supported (axially supported) by a bearing member 4102 provided in the main component 4100A of the imaging device. The output member 4101q is rotatably supported by the coupling retainer 4101s. In addition, the drive transmission member 4101r is supported by the output member 4101q so as to be movable in the Z direction, and is pushed toward the developing box 4004 (Z2 direction) by the spring member 4103. However, the movable amount (play) of the drive transmission member 4101q in the Z direction is about 1 mm, which is sufficiently smaller than the width of the drive force receiving surface 4073a in the Z direction to be described below.

[0336] In addition, the coupling holder 4101s is urged by the urging spring 4101t in the substantially Y2 direction. Therefore, as will be described below, when the developing cartridge 4004 is mounted, the drive transmission member 4101r is in a position offset in the substantially Y2 direction relative to the axis of the gear member 4101e.

[0337] As described above, the drive transmission member 4101r is provided with the main assembly drive transmission groove 4101a, and the coupling unit 4028 is provided with the engaging portion (protrusion, projection) 4065a, so that the drive is transmitted from the apparatus main assembly 4100A to the developing cartridge 4004.

[0338] As will be described in detail below, the engaging portion 4065a is formed on the engaging member (sliding member, moving member, driving force receiving member) 4065, and the engaging member can move under the state of being pushed by the pushing member. Therefore, when the developing box 4004 is installed in the device main body 4100A, the engaging portion 4065a is configured to be movable outward at least in the radial direction. Thus, when the developing box 4004 is inserted into the device main body 4100A, the engaging portion 4065a enters the drive transmission groove 4101a, and the engaging portion 4065a and the main component drive transmission groove 4101a can engage with each other.

[0339] [Structure of the connection unit]

[0340] Next, refer to Fig.34 , Fig.35 , Fig.36 , Fig.37 , Fig.38 and Fig.39 , the connection unit 4028 of this embodiment will be described in detail. Fig.34 is a perspective view of the coupling unit 4028 attached to the toner supply roller 4020.

[0341] Fig.35 is a perspective view of the joint member 4065, Fig.35 Part (a) is a perspective view from the upper left, and Fig.35 Part (b) is a perspective view viewed from the upper right.

[0342] Fig.36 4028 is a perspective view of components constituting the coupling unit 4028.

[0343] Fig.37 is a perspective view of the coupling unit 4028 and the toner supply roller 4020.

[0344] Fig.38 4101r is a cross-sectional view showing a state in which the coupling unit 4028 is engaged with the drive transmission member 4101r.

[0345] Fig.39 It is a cross-sectional view of the developer box 4004.

[0346] The coupling unit 4028 of this embodiment is different from the coupling unit 28 of Embodiment 1 in that the member to be driven is the toner supply roller 4020, but other than that, the embodiments have a similar structure.

[0347] like Fig.34 As shown, the coupling unit 4028 is provided with three engaging portions 4065a that engage with the drive transmission member 4101r. Fig.38 As shown, the engaging portion 4065a is fitted into the groove portion 4101a of the drive transmitting member 4101r, and drive transmission is performed.

[0348] Hereinafter, the structure of the coupling unit (coupling member) 4028 will be described in detail. Fig.36 Perspective drawing and Fig.38 As shown in the cross-sectional view of , the coupling unit 4028 includes a coupling cover member 4071 , a coupling holder member 4072 , an engaging member 4065 , and a pressing member 4066 .

[0349] The coupling cover member 4071 is a cylindrical member including a hollow portion, and the coupling holder member 4072 is provided in an inner space of the coupling cover member 4071 .

[0350] The coupling holder member 4072 is a holding member that holds the engaging member 4065 so as to be slidable.

[0351] like Fig.38 As shown, the engaging member 4065 including the engaging portion 4065 a is supported within the coupling unit 4028 in a state where it is urged in a radially inward direction of the coupling unit 4028 by the urging member 4066 .

[0352] like Fig.35As shown, the engaging member 4065 is provided with a first guided surface 4065d and a second guided surface 4065e so as to be radially movably guided in the coupling unit. In addition, a third guided surface 4065f and a fourth guide surface 4065g are provided so as to control the position of the engaging member 4065 in the axial direction.

[0353] As in Embodiment 1, the first to fourth guided surfaces (4065d, 4065e, 4065f, 4065g) are guided portions and position restricted portions (position restricted portions) guided by the coupling holder member 4072. As in Embodiment 1, the coupling holder member 4072 has first to fourth guide surfaces corresponding to the first to fourth guided surfaces.

[0354] The engaging member 4065 has a contact surface (pushed portion, pressed portion) 4065h for receiving the pushing force of the pushing member 4066. Moreover, the engaging member 4065 has a position limiting protrusion 4065i, which is used to limit the position of the engaging member 4065 by contacting the coupling retainer member 4072 with the pushing force of the pushing member 66, and the engaging member includes a pushing force position limiting surface 4065j formed in the position limiting protrusion. As in Embodiment 1, the pushing force position limiting surface 4065j is an engaged portion that is limited and locked by the coupling retainer member 4072 in radially inward movement.

[0355] The engaging member 4065 also has an insert tapered surface 4065k.

[0356] The coupling holder member 4072 is provided with a coupling hole portion 4072a for passing the drive transmission member 4101r and a mounting hole portion 4072b for movably supporting the engagement member 4065 in the radial direction.

[0357] like Fig.36 As shown, the coupling cover member 4071 has a cylindrical shape, and it is mounted to the outer peripheral surface 4072 k of the coupling holder member 4072 .

[0358] The pressing member 4066 is an elastic member (compression coil spring) that is elastically expandable and contractible, and applies a reaction force in a direction in which the compression spring expands against an external force in a direction in which the compression spring contracts.

[0359] The engaging member 4065 is pushed at least toward the inner side (radially inward) of the coupling unit 4028 by the pushing member 4066. The pushing member 4066 is compressed in a state of being sandwiched between the contact surface 4065h of the engaging member 4065 and the inner peripheral surface of the coupling cover member 4071, and therefore, by applying a pushing force in the direction in which the pushing member 4066 expands, it pushes the engaging member 4065.

[0360] The engaging member 4065 is supported by the coupling holder member 4072 in a state where the engaging portion 4065a of the engaging member 4065 is exposed through the hole portion 4072a of the coupling holder member 4072. In addition, similarly, the drive shaft contact surface 4065c formed in an arc shape on the engaging member 4065 is exposed through the hole portion 4072a of the coupling holder member 4072.

[0361] The engaging portion 4065a of the engaging member 4065 protrudes inwardly in the radial direction from the inner peripheral surface of the hole portion 4072a of the coupling holder member 4072. The protruding amount is an amount sufficient to allow the engaging portion 4065a to reliably enter the groove 4101a of the drive shaft. The protruding amount is an amount suitable for the driving force receiving surface 4065b formed in the engaging portion 4065a to have a strength corresponding to the load torque of the toner supply roller 4020 as a member to be rotated. The protruding amount is only required to enable the engaging portion 4065a to stably transmit the driving force from the main assembly drive shaft 4101.

[0362] In the case of this embodiment, the protrusion amount of the engagement portion 4065a is preferably 1 mm to 3 mm. That is, the distance from the inner surface of the coupling holder member 4072 to the free end of the engagement portion 4065a measured along the radial direction of the coupling member is 1 mm to 3 mm.

[0363] In addition, similarly, the drive shaft contact surface 4065c of the engagement member 4065 protrudes further inward in the radial direction beyond the inner peripheral surface of the hole portion 4072a of the flange cover member 4072. In the case of this embodiment, the protrusion amount is preferably 0.3 mm to 1 mm so that the drive shaft contact surface 4065c surely protrudes from the inner peripheral surface of the hole portion 4072a even when the size of each portion varies.

[0364] In addition, if Fig.37 As shown, the coupling holder member 4072 is provided with a hole portion 4072h for passing the shaft portion (shaft) 4020a of the toner supply roller 4020. The toner supply roller 4020 and the coupling unit 4028 rotate integrally due to the rotation stop shape formed on the hole portion 4072h and the shaft portion 4020a. That is, in this embodiment, unlike Embodiment 1, the coupling unit 4028 is fixed to the shaft (shaft portion 4020a) of the rotatable member (toner supply roller). The coupling unit 4028 is coaxially arranged with the toner supply roller 4020.

[0365] Here, the distance from the axis (center) of the coupling unit 4028 to the driving force receiving portion (driving force receiving surface 4065b) is longer than the radius of the shaft portion 4020a. By doing so, the force applied to the driving force receiving surface 4065b can be reduced compared to the load torque required to rotate the shaft portion 4020a of the toner supply roller 4020.

[0366] like Fig.39 As shown, the toner supply roller 4020 has a gear 4098 on the side opposite to the driving side (non-driving side) to which the coupling unit 4028 is mounted. This gear meshes with a gear 4099 mounted on the shaft of the developing roller 4017.

[0367] When the toner supply roller 4020 is rotated by the driving force transmitted from the coupling unit 4028, the developing roller 4017 is also rotated through the two gears.

[0368] [Installing the cartridge into the imaging device main assembly]

[0369] refer to Figure 40-43 , the installation and removal of the developing box 4004 relative to the main component of the imaging device will be described.

[0370] Fig.40 41 is a perspective view showing the mounting of the developing cartridge 4004 to the main assembly 4100A of the image forming apparatus.

[0371] Fig.41 , Fig.42 and Fig.43 41 is a sectional view showing the mounting operation of the developing cartridge 4004 to the main assembly 4100A of the image forming apparatus.

[0372] The image forming apparatus main assembly 4100A of this embodiment adopts a structure in which the developing cartridge 4004 and the drum cartridge 4013 can be installed in a horizontal direction. Specifically, the image forming apparatus main assembly 4100A includes therein a space in which the developing cartridge 4004 and the drum cartridge 4013 can be installed. A cartridge door 4104 (front door) for allowing the developing cartridge 4004 and the drum cartridge 4013 to be inserted into the space is provided at the front side (the side on which the user stands for use) of the image forming apparatus main assembly 4100A.

[0373] like Fig.40 As shown, the box door 4104 of the imaging device main assembly 4100A is arranged to be able to open and close. When the box door 4104 is opened, the lower box guide rail 4105 for guiding the developer box 4004 is arranged on the bottom of the space, and the upper box guide rail 4106 is arranged on the upper surface. The developer box 4004 is guided to the installation position by the upper guide rail and the lower guide rail (4105, 4106) arranged above and below the space. The developer box 4004 is basically inserted into the installation position along the axis of the developer roller 4020.

[0374] refer to Fig.41 , Fig.42 and Fig.43 , the operations of installing the developing box 4004 into the main assembly 4100A of the image forming apparatus and removing the developing box therefrom will be described below.

[0375] like Fig.41 As shown, the developing cartridge 4004 is inserted in a state where the lower portion of the end portion located on the rear side in the insertion direction is supported and guided by the lower cartridge guide 4105, and the upper side portion of the end portion of the developing cartridge located on the rear side in the insertion direction is guided by the upper cartridge guide 4016. There is a dimensional relationship so that the intermediate transfer belt 5 does not contact the developing frame 4018 or the developing support 4019.

[0376] like Fig.42 As shown, the developing box 4004 is horizontally inserted while being supported by the lower box guide 4105, and is inserted until it abuts against the rear box positioning portion 4108 provided in the main component 4100A of the imaging device.

[0377] When the developing cartridge 4004 is mounted in this manner, the drive transmitting member 4101r of the image forming apparatus main assembly 4100A engages with the coupling unit 4028 while being urged substantially in the Y2 direction.

[0378] Fig.43 4104 and 4106. It is a diagram of the state of the image forming apparatus main assembly 4100A and the developing cartridge 4004 in a state in which the cartridge door 4104 is closed. The lower cartridge guide 4105 of the image forming apparatus main assembly 4100A is configured to move up and down in association with the opening and closing of the cartridge door (front door) 4104.

[0379] When the user closes the cartridge door 4104, the lower cartridge guide rail 4105 rises. Subsequently, both end portions of the developing cartridge 4004 contact the cartridge positioning portions (4108, 4110) of the imaging device main assembly 4100A, and the developing cartridge 4004 is positioned relative to the imaging device main assembly 4100A. In addition, the drive transmission member 4101r of the imaging device main assembly 4100A also follows the developing cartridge 4004 so as to move upward.

[0380] Through the above operations, the installation of the developing box 4004 to the main component 4100A of the imaging device is completed.

[0381] Furthermore, the operation of removing the developing cartridge 4004 from the image forming apparatus main assembly 4100A is performed in the reverse order of the above-described insertion operation.

[0382] [Joining process of the coupling unit and the main assembly drive shaft]

[0383] refer to Fig.44 , Fig.45 , Fig.46 and Fig.47 , the engagement process of the connecting member 4028 and the main component driving shaft 4101 will be described in detail.

[0384] Fig.44 , Fig.45 , Fig.46 and Fig.47 41 is a sectional view showing the operation of mounting the coupling member 4028 on the main assembly drive shaft 4101.

[0385] Fig.44 4028 is a diagram showing a state where the coupling member 4028 begins to engage with the drive transmission member 4101r. Fig.47 4 shows a state where the developing cartridge 4004 is mounted to the main assembly 4100A of the imaging device. Specifically, Fig.47 The state in which the lower cartridge guide 4105 is raised and the developing cartridge 4004 is positioned relative to the main assembly 4100A of the imaging apparatus is shown when the cartridge door 4104 is closed.

[0386] here, Fig.45 and Fig.46 The connection unit 4028 and the drive transmission member 4101r are connected to each other. Fig.44 and Fig.47 The drive transmission member 4101r is urged substantially in the direction Y2 by the urging spring 4101t, and the axis of the drive transmission member 4101r is urged to a position offset substantially in the Y2 direction from the axis of the coupling unit 4028.

[0387] If already referenced Fig.40 As described, the developing box 4004 is horizontally inserted while being supported by the lower box guide 4105 of the main assembly 4100A of the imaging device.

[0388] Fig.44 4028. As described above, in this state, the axis of the drive transmission member 4101r and the axis of the coupling unit 4028 are deviated from each other. Therefore, the tapered portion 4101c of the drive transmission member 4101r contacts the tapered surface 4072p formed at the entrance of the hole portion 4072a of the coupling holder member 4072 of the coupling unit 4028.

[0389] like Fig.45 As shown, the connection unit 4028 is Fig.44The position of the coupling unit 4028 is further inserted toward the rear side of the drive transfer member 4101r. Subsequently, the insertion tapered surface 4065k of the engagement member 4065 guides the tapered portion 4101c of the drive transfer member 4101r so that the axis of the coupling unit 4028 and the axis of the drive transfer member 4101r become substantially aligned.

[0390] like Fig.46 As shown, the connection unit 4028 is Fig.45 Subsequently, the coupling unit 4028 is inserted into the drive transmission member 4101r until the disassembly tapered surface 4073e of the coupling member 4065 exceeds the main component side disassembly tapered portion 4101i of the drive transmission member 4101r in the Z direction to reach the rear side.

[0391] The coupling unit 4028 is further inserted into the drive transmission member 4101r. Then, the tapered recess 4072m as a positioning portion formed in the coupling holder member 4072 of the coupling unit 4028 and the tapered portion 4101c of the drive transmission member 4101r come into contact with each other.

[0392] Thereafter, as described above, the developing cartridge 4004 is lifted by the lower cartridge guide rail 4105 so that the developing cartridge 4004 is relatively close to the main assembly 4100A ( Fig.43 As shown in the figure, the Fig.47 As shown, when the developing box 4004 moves upward, the drive transmission member 4101r also rises.

[0393] As described above, when the developing cartridge 4004 is mounted to the apparatus main assembly 4100A, the main assembly drive transmission groove 4101a and the engaging portion 4065a can engage with each other. Therefore, it is not necessary to move the main assembly drive shaft 4101 to engage with the coupling unit 4028. That is, in the apparatus main assembly 4100A of the image forming apparatus, it is not necessary to provide a mechanism for moving the main assembly drive shaft 4101 so as to engage with the coupling unit 4028.

[0394] That is, after the developing cartridge 4004 is mounted to the image forming apparatus main assembly 4100A, it is not necessary to provide a mechanism for moving the main assembly drive shaft 4101 so as to engage with the coupling unit 4028.

[0395] When the developing cartridge 4004 is mounted to the apparatus main assembly 4100A, the engaging portion 4065 of the coupling unit 4028 contacts the main assembly drive shaft 4101 to contract radially outward. The engaging portion 4065 is configured to engage with the groove (main assembly drive transmission groove 4101a) of the main assembly drive shaft 4101 by moving radially inward.

[0396] Here, it is also possible to provide a groove for receiving a drive on the coupling member, and to provide a movable portion that can engage with the groove by moving in the radial direction on the main assembly drive shaft 4101 side. However, the image forming apparatus main assembly 4100A is required to have higher durability than the developing cartridge 4004. From the viewpoint of improving the durability of the image forming apparatus main assembly 4100A, it is preferable to provide a movable portion (engaging portion 4065) that moves in the radial direction as in this embodiment on the coupling unit 4028 side of the developing cartridge 4004.

[0397] The coupling member 4065 provided in the coupling unit 4028 of the present embodiment has substantially the same configuration as that provided in the coupling unit 28 described in Embodiment 1. That is, the coupling unit 4028 of the present embodiment is a modification of the configuration in which the coupling unit 28 described in Embodiment 1 is applied to the developing cartridge (developing device) 4004. Therefore, the coupling unit 4028 in the present embodiment also has the same operation and effect as the coupling unit 28 described in Embodiment 1 according to the present invention. The structure of the coupling unit shown in this embodiment can be used as a coupling unit for rotating the photosensitive drum 1.

[0398] Here, the structure of the coupling unit shown in this embodiment can be used as a coupling unit for rotating the photosensitive drum 1 .

[0399] <Example 3>

[0400] refer to Figures 48 to 50 , Embodiment 3 will be described. In this example, the shape of the engaging portion of the engaging member is different from that of the previous embodiment. The shape of the engaging portion will be mainly described.

[0401] Here, as in Embodiment 1, a coupling unit provided in a drum cartridge will be described as an example, but it can also be applied to a coupling unit provided in a developing cartridge.

[0402] [Jointing portion of joining member]

[0403] Fig.48 Part (a) and Fig.48 Part (b) is a perspective view of the engaging member 5065 in this embodiment, and Fig.48 Part (c) is its front view. Fig.49 is a cross-sectional view of the connection unit. Fig.49 1 is a view showing a state in which a driving force is applied from the main assembly driving shaft 101 to the coupling unit 5028, and is a partially enlarged sectional view of the coupling unit 5028. More specifically, Fig.49 It is a cross-sectional view taken along a plane perpendicular to the axis of the coupling unit 5028 (the axis of the drum unit).

[0404] like Fig.48 and Fig.49 As shown, as in the case of Embodiment 1, the engaging member 5065 is provided with an engaging portion 5065a protruding inwardly in the radial direction of the photosensitive drum 1. The free end side of the engaging portion 5065a is rounded and bulges (protrudes) toward the upstream side in the rotation direction of the drum unit.

[0405] More specifically, the engaging portion 5065a is provided with a protrusion (raised portion) 5065m having a semicircular shape protruding in the circumferential direction toward the side forming the drive shaft abutment surface 5065c, and a recess 5065n is provided at a portion of the engaging portion 5065a opposite to the protrusion 5065m. That is, the protrusion 5065m is a portion protruding (raised) toward the upstream side in the rotation direction of the drum unit relative to the recess 5065n. On the contrary, the recess 5065n is a portion recessed toward the downstream side in the rotation direction relative to the protrusion 5065m.

[0406] Fig.49 101a shows a state in which a driving force F is applied to the engaging portion 5065a having such a shape from the drive transmission surface 101b of the main assembly drive shaft 101. A recess 5065n is formed at a base portion of the engaging portion 5065a protruding from the engaging member 5065, and therefore, an inlet side corner portion 101j on the drive transmission surface 101b side can enter the groove 5065n in the groove 101a of the main assembly drive shaft 101. Thus, the engaging portion 5065a receives the driving force F acting in a direction perpendicular to the drive transmission surface 101b, and drive transmission is performed.

[0407] That is, the driving force receiving portion 5065r for receiving the driving force from the driving transmission surface 101b faces at least the radial outer side of the coupling unit. Therefore, the driving force F received by the driving force receiving portion 5065r from the driving transmission surface 101b is applied toward the inner side in the radial direction of the coupling unit. The engaging portion 5065a and the driving force receiving portion 5065r are pushed toward the inner side in at least the radial direction (i.e., the rear side of the driving transmission groove 101a).

[0408] Therefore, the engaging portion 5065a and the driving force receiving portion 5065r can be stably engaged with the drive transmission groove 101a.

[0409] The shape of the engaging portion 5065a will be described in more detail. Fig.49 As shown, when the tangent line T parallel to the moving direction S of the engaging member 5065 is pulled to the protrusion 5065m, the tangent line T and the protrusion 5065m have a vertex 5065p as a contact point. The vertex 5065p protrudes from the base portion 5065q of the engaging portion 5065a and is separated from the base portion by a distance L3 along the moving direction S of the engaging member 5065.

[0410] Between the vertex 5065p and the base portion 5065q, a recess 5065n is formed that is recessed from the tangent line T. When the corner portion 101j of the drive shaft enters the recess 5065n, the engagement portion 5065a can receive the driving force F at a contact portion (driving force receiving portion 5065r) that contacts the drive transmission surface 101b provided in the recess 5065n.

[0411] The surface on which the driving force receiving portion 5065r is provided (the curved surface between the vertex 5065p and the base portion 5065q) is inclined relative to the moving direction of the coupling member 5065 and faces outward at least in the radial direction of the coupling unit. That is, the normal vector of the driving force receiving portion 5065r (the vector extending perpendicular to the driving force receiving portion 5065r in the direction in which the driving force receiving portion 5065r faces) has a radially outward component. Moreover, as Fig.49 As shown in parts (a) and (b) of FIG. 5 , the driving force F is a force acting perpendicularly to the drive transmission surface 101b and the driving force receiving portion 5065r. Therefore, the driving force F has a component directed inwardly in the radial direction.

[0412] In addition, the driving force F is a force applied in a direction inclined at an angle θ with respect to the moving direction S of the engaging member 5065. Fig.49 As shown in part (b) of the drawing, the driving force F has a force FS as a component of the engaging member in the moving direction S. This force FS prevents the engaging member 5065 from moving toward the opposite side in the moving direction S and prevents the driving force receiving portion 5065r of the engaging member from being disengaged from the drive transmission surface 101b of the main assembly drive shaft to the outside.

[0413] Here, in Fig.49 , as an example of the shape of the protrusion (raised portion) 5065m, a circular shape has been shown, but the shape of the protrusion is not limited thereto, and it is sufficient that the engaging portion 5065a is formed so as to generate the force FS from the driving force F. That is, it is sufficient as long as the vertex 5065p serving as a contact point is formed at a position protruding from the base portion 5065q of the engaging portion with respect to the tangent line T, and the concave portion 5065n recessed from the tangent line T is formed between the vertex 5065p and the base portion 5065q.

[0414] It is sufficient as long as the cross-sectional shape of the protrusion (raised portion) 5065m engages with the drive transmission groove 101a. For example, a substantially circular polygon (e.g., a pentagon) can also be used as the raised portion. The shape of the cross section can be an ellipse, etc. Fig.55 Such an example will be described in .

[0415] Here, as described above, in this embodiment, it is desirable that the contact portion (driving force receiving portion) 5065r for contacting with the drive transmission surface 101b is provided between the apex 5065p and the base portion 5065q of the projection (raised portion) 5065m.

[0416] As described above, in order to make the drive transmission surface 101b reliably contact the contact portion 5065r, it is preferred that at least the engaging member 5065 can move beyond the distance from the center to the surface in the cross-sectional shape of the protrusion 5065m. That is, it is preferred that the engaging member 5065 can move beyond the radius of the cross-sectional shape of the protrusion 5065m. Further preferably, it can move with a margin exceeding the width of the protrusion 5065m (i.e., greater than the diameter).

[0417] Here, if the movement amount of the coupling member 5065 is small, the protrusion 5065m contacts the drive transfer groove 101a at a position closer to the free end side of the protrusion 5065m than the vertex 5065p. In this case, when the protrusion 5065m receives the driving force, there is a possibility that a force in a direction away from the drive transfer groove 101a is applied to the coupling member 5065. Therefore, in order to ensure the engagement state between the coupling member 5065 and the drive transfer groove 101a, it is preferred that the pushing force of the pushing member for pushing the coupling member 5065 is increased or the friction force generated between the protrusion 5065m and the drive transfer groove 101a is increased. By taking these measures, the coupling member 6065 is difficult to retract from the drive transfer groove 101a.

[0418] Next, refer to Fig.50 and Fig.51 , a modified example of Embodiment 3 will be described. Fig.50 As shown, the entire engaging portion 6065a is a raised portion formed in a substantially circular shape. It is formed in such a simple shape that the dimensional accuracy of the engaging portion 6065a can be easily managed.

[0419] The engaging portion 6065a also has a vertex 6065p as a contact point with a tangent line T parallel to the moving direction S of the engaging member 6065. In addition, the vertex 6065p protrudes from the base portion 6065q of the engaging portion at a position separated by a distance L4 along the moving direction S. Moreover, between the vertex 6065p and the base portion 6065q of the engaging portion, a recessed portion 6065n recessed from the tangent line T is provided. Between the vertex 6065p and the base portion 6065q of the engaging portion, a contact portion (driving force receiving portion 6065r) for contacting the drive transmission surface 101b is also provided. The direction in which the contact portion (driving force receiving portion) 6065r faces causes a force FS to be generated, which is a component generated relative to the driving force F in a direction opposite to the moving direction S of the engaging member. Therefore, it is possible to prevent the engaging member 6065 from being separated from the drive transmission surface 101b of the main component drive shaft to the outside.

[0420] The surface on which the abutment portion (driving force receiving portion) 6065r is provided (the curved surface between the vertex 6065p and the base portion 6065q of the engaging portion) is inclined relative to the moving direction S of the engaging member 6065. More specifically, the tangent line of the driving force receiving portion 6065r is inclined relative to the moving direction S.

[0421] Moreover, the driving force receiving portion 6065r faces outward at least in the radial direction of the coupling unit. That is, the normal vector of the driving force receiving portion 6065r facing the side facing the driving force receiving portion 6065r has at least a radially outward component of the coupling unit.

[0422] Here, the cross-sectional shape of the engagement portion (raised portion) protrusion 6065a is not necessarily circular, but may be a protrusion suitable for engaging with the drive transfer groove 101a. For example, a substantially circular polygon (e.g., a pentagon) is also suitable as the protrusion. The cross-sectional shape may be an ellipse, etc.

[0423] In addition, in order to ensure that the abutting portion (driving force receiving portion) 6065r arranged between the vertex 6065p and the base portion 6065q contacts the drive transmission surface 101b, it is preferred that the movement amount of the engaging member 6065 satisfies the following conditions. That is, it is preferred that the engaging member 6065 can move beyond the distance from the center to the surface in the cross section of the engaging portion 6065a. That is, it is preferred that the engaging member 6065 (engaging portion 6065a) can move beyond the radius of the cross-sectional shape of the engaging portion 6065a.

[0424] More preferably, the engagement portion 6065a can move beyond the width (ie, diameter) of the cross-sectional shape of the engagement member engagement portion 6065a.

[0425] <Example 4>

[0426] refer to Figure 52 to Figure 57 , Embodiment 4 will be described. In this embodiment, the structures corresponding to the engaging member and the pushing member are integrated and formed with resin. Here, in the same manner as Embodiments 1 and 3, the coupling unit provided in the drum cartridge will be described as an example, but it can also be used for the coupling unit provided in the developing cartridge.

[0427] Fig.52 Parts (a) and (b) are sectional views of the drum unit. Fig.52 Part (a) shows a state in which the engaging portion 565a is engaged with the drive transmission groove 101a to receive the driving force. Fig.52 Part (b) shows the state before the engagement portion 565a and the drive transmission groove 101a are engaged.

[0428] Similar to Embodiment 1 and Embodiment 3, the flange member 571 is installed inside the photosensitive drum 1. The flange member 571 is a coupling unit (coupling member) in this embodiment.

[0429] A support portion 565 for movably supporting the driving force receiving portion 565r is formed integrally with the flange member 571 on the flange member 571. Three support portions 565 are provided on the flange member 571. Each of these support members 565 is provided with an extension portion 565t, a raised portion (engagement portion 565a) provided at a free end portion of the extension portion; and a connection portion 565s for connecting the extension portion 565t and the engagement portion 565a to each other.

[0430] The extension portion 565t is connected to the inner periphery of the flange member 571. That is, the fixed end portion 565t1 of the extension portion 565t is disposed on the inner periphery of the flange member 571. Also, the extension portion 565t extends from the fixed end portion 565t1 toward the inside of the hollow portion of the flange member 571. The details will be described below, but the extension portion 565t is an elastic portion that can be elastically deformed.

[0431] Furthermore, the free end side of the extended portion 565t (i.e., the side where the connecting portion 565s is provided) is located on the more downstream side in the rotation direction R of the drum unit (coupling unit) than the fixed end 565t1 of the extended portion 565t. That is, the extended portion 565t extends from the fixed end 565t1 toward the free end located at least on the downstream side in the rotation direction R. The free end of the extended portion 565t (i.e., the connecting portion 565s and the engaging portion 565a) is located radially inward of the fixed end 565t1 of the extended portion 565t.

[0432] The engaging portion 565a is a raised portion provided at the end of the extending portion 565t, and is a portion for entering the drive transmission groove 101a of the main assembly drive shaft 101. The engaging portion 565a is connected by a connecting portion 565s provided at the free end of the extending portion 565t. The connecting portion 565s is a portion formed by bending the free end side of the extending portion 565t. The engaging portion 565a and the connecting portion 565s are protrusions (protrusions) protruding in a direction intersecting the extending direction of the extending portion 565t.

[0433] The engaging portion 565a is provided with a driving force receiving portion 565r. Fig.52 As shown in part (a) of the support portion 565, the driving force receiving portion 565r contacts the driving transmission groove 101a to receive the driving force. When the driving force receiving portion 565r receives the driving force, the driving force is transmitted to the flange member 571 through the fixed end portion 565t1 of the support portion 565. The flange member 571 is fixed to the photosensitive drum 1, and thus the flange member 571 and the photosensitive drum 1 rotate integrally.

[0434] The extending portion 565t and the engaging portion 565a are integrally formed with the flange member 570. The extending portion 565t and the engaging portion 565a are portions of the supporting portion 565 that movably support the driving force receiving portion 565r.

[0435] As mentioned above, the extension portion 565t can be elastically deformed. Fig.52 As shown in part (b) of the drawing, during the process of inserting the cartridge 7 into the main assembly of the apparatus, the engaging portion 565a contacts the outer peripheral surface of the main assembly drive shaft 101. Subsequently, the extending portion 565a is elastically deformed so that the engaging portion 565a moves outward at least in the radial direction of the coupling unit.

[0436] Here, the extending portion 565t is deformed so as to be inclined with the fixed end portion 565t1 of itself as a fulcrum. Therefore, the engaging portion 565a moves in a direction intersecting with the extending direction of the extending portion 565t.

[0437] After the box 7 is inserted into the main component of the device, when the main component driving shaft 101 is rotationally driven, the engaging portion 565a enters the interior of the drive transmission groove 101a when the phases of the engaging portion 565a and the drive transmission groove 101a match each other.

[0438] That is, by elastically deforming at least a portion of the extension portion 565t, the engagement portion 565a is pressed inside the drive transmission groove 101a. The extension portion 565t may be regarded as a pressing portion for pressing the engagement portion 565a inward at least in the radial direction.

[0439] That is, the coupling portion 565a is pushed toward the inside of the drive transmission groove 101a by the elastic force (pushing force) of the extension portion 565t. The extension portion 565t has a function corresponding to the pushing member 72 in Example 1. That is, the supporting portion 565 is a portion that also serves the functions of the pushing member 72 and the coupling member 65 in Example 1.

[0440] At least a portion of the supporting portion 565 and at least a portion of the driving force receiving portion 565r provided on the supporting portion 565 are provided inside the photosensitive drum 1 ( Fig.52 ). This is the same as the pressing member 72 and the engaging member 65 in the first embodiment.

[0441] Here, inside the photosensitive drum 1, the flange member 571 is held on the photosensitive drum 1, and therefore, the flange member 571 is not easily deformed. Specifically, if at least a portion of the fixed end portion 565t of the support portion 565 is disposed inside the photosensitive drum 1, this structure is preferred from the viewpoint of suppressing deformation of the flange member 571 even if the driving force is transmitted to the flange member 571 through the fixed end portion 565t.

[0442] Here, the extension portion is made of resin, but by inserting an elastic metal (for example, a leaf spring) into the resin constituting the extension portion, the elastic force or strength of the extension portion can be increased.

[0443] When the engaging portion 565a enters the interior of the drive transmission groove 101a, the driving force receiving portion 565r provided in the engaging portion 565a receives the force from the interior of the drive transmission groove 101a. Here, in order to ensure the engaging state between the drive transmission shaft 101a and the engaging portion 565a when the drive transmission shaft 101a is driven, it is preferred that more than half of the engaging portion 565a enters the interior of the drive transmission shaft.

[0444] Therefore, it is preferred that the engaging portion 565a can move beyond the radius of the cross section of the engaging portion 565a (the distance from the center of the engaging portion to the surface). Further preferably, the engaging portion 565a can move beyond the diameter of the cross section of the engaging portion 565a (not less than the width of the cross section of the engaging portion 565a and not less than twice the distance from the center of the engaging portion to the surface).

[0445] here, Fig.53 The driving force receiving portion 565r receives the driving force F. A straight line LN1 is drawn in the normal direction of the driving force receiving portion 565r. The straight line LN1 extends toward the side that the driving force receiving portion 565r faces and is also a straight line along the vector indicating the driving force F.

[0446] Furthermore, the fixed end portion 565t1 of the extended portion 565t is provided upstream of the straight line LN1 in the rotation direction R. That is, the support portion 565 is provided across the straight line L1.

[0447] In this case, when the driving force receiving portion 565r receives the driving force F, a moment M1 in the same direction as the rotation direction of the drum unit (counterclockwise in the figure) is generated in the extension portion 565t with the fixed end 565t1 as a fulcrum. The moment M1 acts to make the support portion 565 approach the main component drive shaft 101. That is, the moment M1 is used to push the engaging portion 565a toward the rear of the drive transmission groove 101a. Thus, the engaging state between the engaging portion 565a and the drive transmission groove 101a can be stabilized. In this embodiment, the supporting portion 565 can be molded as a part of the flange member 571 using a mold, and therefore, it is easy to manufacture the flange member 571 including the supporting portion 565.

[0448] In the following, reference Figure 54 to Figure 57 , a modified example of Embodiment 4 will be described. Figure 54 to Figure 57 It is a cross-sectional view of the connection unit (flange member).

[0449] First, in Fig.54 In the modification shown, the extension portion (665t, 665s) is bent and has a first extension portion 665s and a second extension portion 665t extending in different directions. The boundary between the first extension portion 665ts and the second extension portion 665t is a bent portion. The first extension portion 665s in this modification example corresponds to Fig.52 That is, the connecting portion 565s ( Fig.52 ) is the first extension portion 665s ( Fig.54 ), and the first extension portion 665s is also a connecting portion connecting the second extension portion 665t and the bonding portion 665a. Fig.52 The illustrated connecting portion 565s is considered a first extension portion and the extending portion 565t is considered a second extension portion.

[0450] Fig.54 The engaging portion 665a shown is a raised portion provided at the free end of the extending portion (first extending portion 665s). The first extending portion 665s and the engaging portion 665a can be regarded as protruding portions (convex portions) protruding in a direction intersecting with the second extending portion 665t.

[0451] The modified first extension portion 665s is Fig.52 The connecting portion 565s shown is long. Therefore, accordingly, the flange member 671 of the present modification is thinned (the thickness is reduced).

[0452] Next, Fig.55 Another modification example is shown. Fig.55 As shown in the figure, the shape of the raised portion (engagement portion) is different. As described in Example 3, the raised portion can be a polygon, etc. Fig.55 In the embodiment, the cross-sectional shape of the engagement portion 765a is substantially hexagonal. This cross-sectional shape can also be regarded as a substantially circular shape. Here, the modified example ( Fig.56 and Fig.57 ) in which the cross-sectional shape of the joining portion (raised portion) may be a polygon.

[0453] Another modification in Fig.56 In Fig.56 In the structure shown, the extension portion 865t is not bent but directly connected to the raised portion (engagement portion 865a). However, the center of the engagement portion 865a is offset from the extension line of the extension portion 865t, and the engagement portion 865a is a protruding portion protruding in a direction intersecting the extension portion 865t. In this modification, the position of the fixed end portion 856t1 of the extension portion 865t is different from that of the Fig.52 That is, the fixed end portion 865t1 is located on the downstream side in the rotation direction R with respect to the straight line L1 extending in the normal direction of the driving force receiving portion 865r.

[0454] With this structure, when the support portion 865 receives a driving force, a moment in the clockwise direction in the figure can be applied to the support portion 865 with the fixed end 865t1 as a fulcrum. This moment acts to move the engagement portion 865a away from the drive transmission groove 101a.

[0455] In this case, in order to prevent the engagement between the engagement portion 865a and the drive transmission groove 101a from being broken, it is desirable to increase the elastic force of the extension portion 865t (i.e., to make the extension portion 865t difficult to deform). Alternatively, preferably, a large friction force is generated between the engagement portion 865a and the drive transmission groove 101a.

[0456] refer to Fig.57 , further modifications will be described. Fig.56 In the structure, the joint portion is arranged at a position deviating from the extension line of the extension portion. Fig.57 In the illustrated modified example, the center of the engaging portion 965a is disposed on an extension line of the extending portion 965t.

[0457] The engaging portion 965a is a protruding portion provided at a free end portion of the extending portion 965t and protrudes (rises) toward the entire circumferential direction of the extending portion 965t.

[0458] exist Fig.57 In the modified example shown, Fig.56 Compared to the above-mentioned structure shown in FIG. 1 , the fixed end 965t1 of the support portion 965 is disposed on a more downstream side in the rotation direction R. Therefore, when the driving force receiving portion of the engaging portion 965a receives the driving force, a torque can be applied to the support portion 965 in a direction tending to separate the engaging portion 965a from the drive transmission groove 101a.

[0459] Therefore, in order to ensure the engagement state between the engagement portion 965a and the drive transmission groove 101a, it is preferable to take measures to further increase the elastic force of the extension portion 965t or increase the friction coefficient of the surface of the engagement portion 965a as described above.

[0460] However, when the elastic force of the extension portion 965t increases and as a result the extension portion 965t is not easily bent, the force required to install the cartridge 7 in the apparatus main assembly increases. That is, in order to install the cartridge 7, it is necessary to deflect the extension portion 965t, and the load for this increases. Therefore, in consideration of the mountability of the cartridge 7, it is preferable to select a necessary and sufficient elastic force for the extension portion 965t.

[0461] [Industrial Applicability]

[0462] According to the present invention, there is provided a drum unit which is attachable to and detachable from a main assembly of an electrophotographic image forming apparatus.

Claims

1. A drum unit, the drum unit being detachably mountable to a main assembly of an electrophotographic image forming apparatus, the main assembly comprising a drive shaft provided with a recess, the drum unit comprising: (1) Photosensitive drum; as well as (2) a connecting member, which is arranged on the photosensitive drum and includes (2-1) an engageable member, the engageable member having a driving force receiving portion configured to enter the recess to receive a driving force for rotating the photosensitive drum, (2-2) a retaining member, the retaining member being configured to retain the engageable member so that it can slide at least in the radial direction of the drum unit, and (2-3) a pushing member, the pushing member being configured to push the engageable member.

Images