BR112019001593B1 - DRUM UNIT, CARTRIDGE, ELECTROPHOTOGRAPHIC IMAGE FORMING APPARATUS AND COUPLING ELEMENT - Google Patents

Abstract

The present invention relates to a drum unit including a photosensitive drum in a coupling element. The coupling member includes an engaging member having a drive force receiving portion that is capable of entering a recess of a drive shaft to receive a drive force to rotate the photosensitive drum. The coupling element includes a retaining element configured to retain said engaging element so as to be slidable in at least one radial direction from said drum unit.

Description

Field of Invention

[0001] The present invention relates to an imaging apparatus using an electrophotographic process, a drum unit, a cartridge and a coupling that are usable with the imaging apparatus, or the like.

Fundamentals of the Invention

[0002] In an electrophotographic image forming apparatus, a structure is known in which elements such as a photosensitive drum and a developing roller, which are rotating elements related to image formation, are integrated into a cartridge that is mountable in detachable form with respect to a main assembly of an image forming apparatus (hereinafter, the main assembly of the apparatus). In such a structure, a structure for receiving a driving force from the main apparatus assembly to rotate the photosensitive drum in the cartridge is employed in many apparatus. At present, a structure is known in which a driving force is transmitted through the engagement between a coupling element on the cartridge side and a driving force transmitting part, such as a driving pin, on the main assembly side of the cartridge. device.

[0003] For example, Patent Document 1 describes a cartridge having a coupling member provided at an end portion of a photosensitive drum so as to be tiltable with respect to an axis of rotation of the photosensitive drum.

Summary of the Invention [Problem to be solved by the invention]

[0004] It is another objective of the present invention to develop the conventional technique mentioned above.

[Means to Solve the Problem]

[0005] The typical structure provides a drum unit detachably mountable to a main assembly of an electrophotographic image forming apparatus, the main assembly including a drive shaft provided with a recess, said drum unit comprising (1) a photosensitive drum; and (2) a coupling member provided on said photosensitive drum and including (2 - 1) an engageable member having a driving force receiving part configured to enter the recess for receiving a driving force for rotating said photosensitive drum, (2 - 2) a retaining member configured to retain said engageable member so as to be slidable in at least one radial direction of said drum unit, (2 - 3) a driving member configured to drive said engageable member.

Effects of the Invention

[0006] The conventional technique mentioned above is disclosed.

Brief Description of the Drawings

[0007] Figure 1 is a schematic sectional view of an image forming apparatus 100.

[0008] Figure 2 is a perspective view of an external appearance of a process cartridge 7.

[0009] Figure 3 is a schematic section view of the process cartridge 7.

[0010] Figure 4 is a sectional view of the process cartridge 7.

[0011] Figure 5 is a sectional view of the process cartridge 7.

[0012] Figure 6 shows an external appearance of a main assembly drive shaft 101.

[0013] Figure 7 is a sectional view of the main assembly drive shaft 101.

[0014] Figure 8 is a perspective view of the main assembly drive shaft 101.

[0015] Figure 9 is a sectional view of the coupling 28 and the main assembly drive shaft 101.

[0016] Figure 10 is a cross-sectional view of a coupling unit 28 and the main assembly drive shaft 101, taken along a plane perpendicular to an axis of rotation.

[0017] Figure 11 is a perspective view of a drive side of the drum unit 30.

[0018] Figure 12 is a sectional view of the drive side of the drum unit 30.

[0019] Parts (a) and (b) of Figure 13 are perspective views of a coupling element 65.

[0020] Parts (a) and (b) of Figure 14 are perspective views of an element of the coupling unit 28.

[0021] Figure 15 is a sectional view of the coupling unit 28 taken along a plane perpendicular to the axis of rotation.

[0022] Figure 16 is a perspective view illustrating the assembly of the cartridge 7 to the main assembly of the image forming apparatus 100A.

[0023] Figure 17 is a sectional view illustrating the operation of assembling the cartridge 7 to the main assembly of the image forming apparatus 100A.

[0024] Figure 18 is a sectional view illustrating the operation of assembling the cartridge 7 to the main assembly 100A of the image forming apparatus.

[0025] Figure 19 is a cross-sectional view illustrating the operation of mounting the cartridge 7 to the main assembly 100A of the imaging apparatus.

[0026] Figure 20 is a sectional view illustrating the assembly of the coupling unit 28 to the main assembly drive shaft 101.

[0027] Figure 21 is a sectional view illustrating the assembly of the coupling unit 28 to the main assembly drive shaft 101.

[0028] Figure 22 is a sectional view illustrating the assembly of the coupling unit 28 to the main assembly drive shaft 101.

[0029] Figure 23 is a cross-sectional view of the coupling unit 28 and the main assembly drive shaft 101, taken along a plane perpendicular to the axis of rotation.

[0030] Figure 24 is a cross-sectional view of the coupling unit 28 and the main assembly drive shaft 101, taken along a plane perpendicular to the axis of rotation.

[0031] Parts (a) and (b) of Figure 25 are cross-sectional views of the coupling unit 28 and the main assembly drive shaft 101, taken along a plane perpendicular to the axis of rotation.

[0032] Figure 26 is a cross-sectional view of an engagement element 65 and a drive transmission engagement surface of the main assembly drive shaft 101.

[0033] Figure 27 is a schematic view of a main assembly 4100A of an image forming apparatus.

[0034] Figure 28 shows an external appearance of a 4013 drum cartridge.

[0035] Figure 29 is a sectional view of a drum cartridge 4013.

[0036] Figure 30 shows an external appearance of a developing cartridge 4004.

[0037] Figure 31 is a sectional view of the developing cartridge 4004.

[0038] Figure 32 is a perspective view of a main assembly drive shaft 4101.

[0039] Figure 33 is a sectional view of the main assembly drive shaft 4101.

[0040] Figure 34 is a perspective view of a coupling unit 4028.

[0041] Parts (a) and (b) of Figure 35 are perspective views of a coupling element 4065.

[0042] Parts (a) and (b) of Figure 36 are perspective views of an element of the coupling unit 4028.

[0043] Parts (a) and (b) of Figure 37 are perspective views of the coupling unit 4028 and a toner supply roller 4020.

[0044] Figure 38 is a cross-sectional view of the coupling unit 4028 and the main assembly drive shaft 4101, taken along a plane perpendicular to the axis of rotation.

[0045] Figure 39 is a sectional view of a developing cartridge 4004.

[0046] Figure 40 is a perspective view illustrating the assembly of the developing cartridge 4004 to the main assembly 4100 of the image forming apparatus.

[0047] Figure 41 is a sectional view illustrating the assembly of the developing cartridge 4004 to the main assembly 4100 of the image forming apparatus.

[0048] Figure 42 is a sectional view illustrating the assembly of the developing cartridge 4004 to the main assembly 4100 of the image forming apparatus.

[0049] Figure 43 is a cross-sectional view illustrating the assembly of the developing cartridge 4004 to the main assembly 4100 of the imaging apparatus.

[0050] Figure 44 is a sectional view illustrating the assembly of the coupling unit 4028 to the main assembly drive shaft 4101.

[0051] Figure 45 is a sectional view illustrating the assembly of the coupling unit 4028 to the main assembly drive shaft 4101.

[0052] Figure 46 is a sectional view illustrating the assembly of the coupling unit 4028 to the main assembly drive shaft 4101.

[0053] Figure 47 is a sectional view illustrating the assembly of the coupling unit 4028 to the main assembly drive shaft 4101.

[0054] Parts (a), (b), (c) and (d) of Figure 48 are illustrations of a coupling element.

[0055] Parts (a) and (b) of Figure 49 are sectional views of a coupling unit.

[0056] Parts (a), (b), (c) and (d) of Figure 50 are illustrations of the coupling element.

[0057] Parts (a) and (b) of Figure 51 are sectional views of a coupling unit.

[0058] Parts (a) and (b) of Figure 52 are sectional views of a coupling unit.

[0059] Figure 53 is a sectional view of a coupling unit.

[0060] Figure 54 is a sectional view of a coupling unit.

[0061] Figure 55 is a sectional view of a coupling unit.

[0062] Figure 56 is a sectional view of a coupling unit.

[0063] Figure 57 is a sectional view of a coupling unit.

Detailed Description of the Invention

[0064] In the following, the image forming apparatus and the process cartridge of the present embodiment will be described together with the attached drawings. The image forming apparatus forms an image on a recording material using an electrophotographic image forming process, for example. It includes, for example, an electrophotographic copying apparatus, an electrophotographic printer (e.g., an LED printer, a laser beam printer, etc.), an electrophotographic fax machine and the like. Furthermore, the cartridge is mountable and detachable from the main assembly of the imaging apparatus (main assembly). Among the cartridges, the unitized with the process means acting on the photoreceptor and the photoreceptor is particularly called a process cartridge.

[0065] Furthermore, a unit that includes a photosensitive drum and a coupling element as a unit is called a drum unit.

[0066] In the following embodiments, a color image forming apparatus in relation to which four process cartridges can be mounted and dismounted is taken as an example, in Embodiment 4. However, the number of process cartridges mountable to the imaging apparatus image formation is not limited to that. Likewise, the constituent elements described in the embodiments are not intended to limit the material, arrangement, dimensions, other numerical values, etc. Unless otherwise specified, “up” means upward in the direction of gravity when the imaging apparatus is installed.

<Mode 1> [General Description of Electrophotographic Image Forming Apparatus]

[0067] First, the general structure of an embodiment of an electrophotographic image forming apparatus (image forming apparatus) according to this embodiment will be described in conjunction with Figure 1.

[0068] Figure 1 is a schematic sectional view of an image forming apparatus 100 in accordance with this embodiment.

[0069] As shown in Figure 1, the image forming apparatus 100 includes, as a plurality of image forming sections, first, second, third, fourth image forming units SY, SM, SC and SK for forming images of respective colors, that is, 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.

[0070] In this embodiment, the structures and operations of the process cartridges 7 (7Y, 7M, 7C, 7K) are substantially the same, except that the colors of the images to be formed are different. Therefore, from now on, Y, M, C, and K will be omitted and the explanation will be commonly applied unless otherwise noted.

[0071] In this embodiment, the image forming apparatus 100 has cylinders (hereinafter called photosensitive drums) 1, each having a photosensitive layer, the cylinders being arranged side by side along a direction slightly inclined with respect to a vertical direction as a plurality of image rolling elements. A digitizing unit (exposure device) 3 is arranged below the process cartridge 7. Furthermore, around the drive drum 1, a charging roller 2 or similar functioning as a process medium (process device, process element) acting on the photosensitive layer is disposed.

[0072] The charging roller 2 is a charging means (charging device, charging element) for uniformly charging the surface of the photosensitive drum 1. The digitizing unit (exposure device) 3 is an exposure means (exposure device) , exposure element) to form an electrostatic image (electrostatic latent image) on the photosensitive drum 1 by exposing to a laser based on the image information. Around the photosensitive drum 1, a cleaning blade 6 as a developing device (hereinafter called developing unit) 4 and cleaning means (cleaning device, cleaning element) are provided.

[0073] Furthermore, an intermediate transfer belt 5 as an intermediate transfer element for transferring the toner image from the photosensitive drum 1 to the recording material (sheet, recording medium) 12 is provided so as to face the four photosensitive drums 1.

[0074] The developing unit 4 of this embodiment uses a one-component non-magnetic developer (hereinafter called toner) as a developer and employs a contact developing system in which a developing roller 17 as a developer-equipped element enters in contact with the photosensitive drum 1.

[0075] With the structure described above, 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 process medium acting on the photosensitive drum 1, the process cartridge includes a charging roller 2 for loading the photosensitive drum 1 and a cleaning blade 6 for cleaning the remaining toner without being transferred to the photosensitive drum 1. The toner residual untransferred residue remaining in the photosensitive drum 1 that has not been transferred to the sheet 12 is collected by the cleaning blade 6. Furthermore, the residual toner collected by the cleaning blade 6 is accommodated in a removed developer accommodation part (hereinafter called of a waste toner accommodation part) 14a from the opening 14b. The waste toner accommodation part 14a and the cleaning blade 6 are unitized to form a cleaning unit (photosensitive body unit, imaging element unit) 13.

[0076] Furthermore, the developing unit 4 and the cleaning unit 13 are unitized (made into a cartridge) to form a process cartridge 7. The image forming apparatus 100 is provided in the main assembly frame with guides ( positioning means) such as a mounting guide and a positioning element (not shown). The process cartridge 7 is guided by the guide mentioned above, and is configured to be mountable and detachable from the imaging apparatus main assembly (electrophotographic imaging apparatus main assembly) 100A.

[0077] The toners of the respective colors of yellow (Y), magenta (M), cyan (C) and black (K) are accommodated in the 7 process cartridges for the respective colors.

[0078] The intermediate transfer belt 5 contacts the photosensitive drum 1 of each process cartridge and rotates (moves) in the direction indicated by an arrow B in Figure 1. The intermediate transfer belt 5 is wound around a plurality of support elements (a drive roller 51, an opposing secondary transfer 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 means are juxtaposed so as to face each photosensitive drum 1. A secondary transfer roller 9 as a secondary transfer means is disposed in a position facing the opposite secondary transfer roller 52 on the outer peripheral surface side of the intermediate transfer belt 5.

[0079] At the time of image formation, the surface of the photosensitive drum 1 is first uniformly loaded by the loading roller 2. Then, the surface of the photosensitive drum 1 thus loaded is scanned and exposed to the laser beam corresponding to the emitted image information from the digitizing unit 3. Therefore, 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.

[0080] The photosensitive drum is a rotating element (image rolling element) that rotates in a state of carrying an image (developer image, toner image) formed with a developer (toner) on its surface.

[0081] The toner image formed on the photosensitive drum 1 is transferred (primary transfer) to the intermediate transfer belt 5 by the operation of the primary transfer roller 8.

[0082] For example, when forming a color image, the process described above is carried out sequentially on the four process cartridges 7 (7Y, 7M, 7C, 7K). The toner images of the respective colors formed in the photosensitive drums 1 of the respective process cartridges 7 are sequentially transferred primarily so as to be superimposed on the intermediate transfer belt 5. Subsequently, in synchronism with the movement of the intermediate transfer belt 5, the material recorder 12 is fed into the secondary transfer part. The four-color toner images on the intermediate transfer belt 5 are generally transferred to the recording material 12 transported to the secondary transfer part consisting of the intermediate transfer belt 5 and the secondary transfer roller 9.

[0083] The recording material 12 to which the toner image has been transferred is transported to a clamping device 10 as a fixing means. By applying heat and pressure to the recording material 12 in the clamping device 10, the toner image is fixed to the recording material 12. Furthermore, the residual primary transfer toner remaining in the photosensitive drum 1 after the primary transfer process is removed by the cleaning blade 6 and collected as waste toner. Furthermore, the residual secondary transfer toner remaining on the intermediate transfer belt 5 after the secondary transfer step is removed by the intermediate transfer belt cleaning device 11.

[0084] The image forming apparatus 100 is also capable of forming monochromatic or multicolor images using single or some (not all) desired image forming units.

[Process Cartridge General Description]

[0085] With reference to Figures 2, 3 and 4, the process cartridge 7 (cartridge 7) mounted in the main assembly of the image forming apparatus 100A of this embodiment will be described.

[0086] The cartridge 7a containing the yellow toner, the cartridge 7b containing the magenta toner, the cartridge 7c containing the cyan toner and the cartridge 7d containing the black toner have the same structure. Therefore, in the following description, each of the cartridges 7a, 7b, 7c, 7d will simply be called a cartridge 7. The respective cartridge components will also be described in the same way.

[0087] Figure 2 is an external perspective view of the process cartridge 7. Here, as shown in Figure 2, the direction of the rotation axis of the photosensitive drum 1 is defined as a Z direction (arrow Z1, arrow Z2), horizontal direction in Figure 1 as X direction (arrow X1, arrow X2), vertical direction is Y direction (arrow Y1, arrow Y2).

[0088] Figure 3 is a schematic cross-sectional view of the process cartridge 7 viewed in the Z direction in a state (attitude) in which the photosensitive drum 1 and the developing roller 17 are in contact with each other, which is mounted to the image forming apparatus 100.

[0089] The process cartridge 7 comprises two units, i.e., a cleaning unit 13 including the photosensitive drum 1, the loading roller 2 and the cleaning blade 6 as a unit, and a developing unit 4 including an element development roller such as development roller 17.

[0090] The developing unit 4 has a developing frame 18 for supporting various elements in the developing unit 4. The developing unit 4 includes the developing roller 17 as a developer element that is rotatable in the direction of arrow D ( counterclockwise) in contact with the photosensitive drum 1. The developing roller 17 is rotatably supported by the developing frame 18 through the developing bearings 19 (19R, 19L) on both end parts in relation to the longitudinal direction (direction of the axis of rotation) of them. Here, developing bearings 19 (19R, 19L) are mounted on respective sides of the developing frame 18 respectively.

[0091] Furthermore, the developing unit 4 is provided with a developer accommodating chamber (then toner accommodating chamber) 18a and a developing chamber 18b in which the developing roller 17 is provided.

[0092] In the developing chamber 18b, a toner supply roller 20 is provided as a developer supply element that contacts the developing roller 17 and rotates in the direction of arrow E, and a developing blade 21 as a developing regulating element for regulating the toner layer of the developing roller 17. The developing blade 21 is fixed and integrated with the fixing element 22 by welding or similar.

[0093] A stirring element 23 for agitating the contained toner and for transporting the toner to the toner supply roller 20 is provided in the toner accommodation chamber 18a of the developing frame 18.

[0094] The developing unit 4 is rotatably coupled to the cleaning unit 13 around the fitting shafts 24 (24R, 24L) fitted into the holes 19Ra, 19La provided in the bearing elements 19R, 19L. Furthermore, in the developing unit 4, the developing roller 17 is driven by the pressure spring 25 (25R, 25L) in a direction of contacting the photosensitive drum 1. Therefore, at the time of image formation using the cartridge process 7, the developing unit 4 turns (rotates) in the direction of an arrow F around the fitting axis 24, so that the photosensitive drum 1 and the developing roller 17 are in contact with each other.

[0095] The cleaning unit 13 has a cleaning frame 14 as a structure for supporting various elements in the cleaning unit 13.

[0096] Figures 4 and 5 are cross-sectional views along an imaginary plane along an axis of rotation of the photosensitive drum 1 of the process cartridge 7.

[0097] In Figure 4, the side (relative to the Z1 direction) on which the coupling unit (coupling element) 28 receives the driving force from the main assembly of the image forming apparatus is called the side of drive of process cartridge 7. In Figure 5, the side opposite the drive side (relative to the Z2 direction) is called the non-drive side (front side) of process cartridge 7.

[0098] When the cartridge 7 is mounted on the mounting part of the main assembly of the image forming apparatus, the drive side of the cartridge 7 is placed on the back side, and the non-drive side placed on the front part of the cartridge assembly 7.

[0099] At the end opposite the coupling unit 28 (the end part on the non-drive side of the process cartridge), an electrode (electrode part) is provided in contact with the inner surface of the photosensitive drum 1, and this electrode works as the electrical ground when contacting the main assembly.

[0100] The coupling unit 28 is mounted on one end of the photosensitive drum 1, and a flange element on the non-drive side 29 is mounted on the other end of the photosensitive drum 1 to constitute a photosensitive drum unit 30. The photosensitive drum 30 receives a driving force from a main assembly drive shaft 101 provided in the main assembly of the image forming apparatus 100A through coupling unit 28 (the driving force is transmitted from the main assembly drive shaft 100A). main set 101). As will be described in detail below, upon mounting the cartridge 7 to the main assembly 100A, the coupling unit 28 is able to engage the drive shaft of the main assembly 101. Upon disassembly of the cartridge 7 from the main assembly 100A, the unit coupling 28 is capable of disengaging from the main assembly drive shaft 101.

[0101] The coupling unit 28 is configured to be coupled and uncoupled from the main assembly drive shaft 101.

[0102] The coupling unit 28 includes a flange element (flange element on the drive side) mounted on the end part on the drive side of the photosensitive drum 1.

[0103] As shown in Figure 4, the Z1 side of the coupling unit 28 has a cylindrical shape (cylindrical part 71a). The cylindrical part 71a projects towards the Z1 side (outside in the axial direction) beyond the end part of the photosensitive drum 1. In the cylindrical part 71a, a part on the Z1 side, close to the free end, is a part of support 71c. The support part 71c is rotatably supported by the bearing part provided in a drum unit bearing element 39R. In other words, the support part 71c is supported by the bearing part of the drum unit bearing element 39R, so that the photosensitive drum unit 30 can rotate.

[0104] Similarly, in Figure 5, the non-drive side flange element 29 provided on the non-drive side of the photosensitive drum unit 30 is rotatably supported by a drum unit bearing element 39L. The flange element on the non-drive side 29 has a cylindrical part (cylindrical part) projecting from the end part of the photosensitive drum 1, and the outer peripheral surface of this cylindrical part 29a is rotatably supported by the drive bearing element of 39L drum.

[0105] The drum unit bearing element 39R is disposed on the drive side of the process cartridge 7, and the drum unit bearing element 39L is disposed on the non-drive side of the process cartridge 7.

[0106] As shown in Figure 4, when the process cartridge 7 is mounted on the main apparatus assembly 100A, the drum unit bearing element 39R abuts the rear cartridge positioning section 108 provided on the main forming apparatus assembly. of 100A image. Furthermore, the drum unit bearing member 39L abuts the cartridge positioning portion on the front side 110 of the main assembly of the image forming apparatus 100A. Thereby, the cartridge 7 is positioned in the image forming apparatus 100A.

[0107] In the Z direction of this embodiment, as shown in Figure 4, the position in which the drum unit bearing element 39R supports the support part 71c is made close to the position in which the drum unit bearing element 39R is positioned in the rear side cartridge positioning part 108. By doing this, it is possible to suppress tilting of the coupling unit 28 when the process cartridge 7 is mounted in the main apparatus assembly 100A.

[0108] The supporting part 71c is arranged so that the position in which the rolling element 39R supports the supporting part 71c and the position in which the rolling element 39R is positioned in the rear side cartridge positioning part 108 may be close to each other. That is, the supporting part 71c is arranged on the free end side (the Z1 direction side) of the outer peripheral surface 71a of the cylindrical part 71 provided in the coupling unit 28.

[0109] Similarly, in the Z direction, as shown in Figure 5, the position in which the drum unit support element 39L rotatably supports the flange element on the non-drive side 29 is arranged in a position close to the position in which the drum unit support element 39L is positioned in the cartridge positioning part on the near side 110. Thereby, the tilt of the flange element on the non-drive side 29 is suppressed.

[0110] The drum unit bearing elements 39R and 39L are mounted on the sides of the cleaning frame 14, respectively, and support the photosensitive drum unit 30. Hereby, the photosensitive drum unit 30 is supported so as to be rotating with respect to the cleaning frame 14.

[0111] Furthermore, a loading roller 2 and a cleaning blade 6 are mounted on the cleaning frame 14, and they are arranged so as to be in contact with the surface of the photosensitive drum 1. Furthermore, the roller bearings load roller 15 (15R, 15L) are mounted on the cleaning frame 14. The loading roller bearing 15 is a bearing for supporting the loading roller shaft 2.

[0112] Here, the loading roller bearings 15 (15R, 15L) are mounted so as to be movable in the direction of arrow C shown in Figure 3. A rotation axis 2a of the loading roller 2 is rotatably mounted on the loading roller 15 (15R, 15L). The loading roller bearing 15 is driven towards the photosensitive drum 1 by a pressure spring 16 as a driving means. As a result, the charging roller 2 rests against the photosensitive drum 1 and is rotated by the photosensitive drum 1.

[0113] The cleaning frame 14 is provided with a cleaning blade 6 as a cleaning means for removing toner remaining on the surface of the photosensitive drum 1. The cleaning blade 6 is formed by unitizing a blade-shaped rubber (elastic element ) 6a that rests against the photosensitive drum 1 to remove the toner in the photosensitive drum 1 and a metal support plate 6b that supports the blade-type rubber (elastic element) 6a. In this embodiment, the supporting metal plate 6b is fixed to the cleaning frame 14 with screws.

[0114] As previously described, the cleaning frame 14 has an opening 14b for collecting residual transfer toner collected by the cleaning blade 6. The opening 14b is provided with a blow-out prevention sheet 26 that is in contact with the drum photosensitive drum 1 and seals between the photosensitive drum 1 and the opening 14b so as to suppress toner leakage in the upward direction of the opening 14b.

[0115] In this way, by employing the structure in which the components related to image formation are unitized in a mountable cartridge in a way that can be decoupled from the main assembly of the device, ease of maintenance is improved. In other words, the user can easily maintain the device by changing the process cartridge. Therefore, it is possible to provide a device for which the maintenance operation can be carried out not only by a technician but also by a user.

[Main Assembly Drive Shaft Structure]

[0116] With reference to Figures 5, 6, 7, 8, 9 and 10, the drive shaft structures of the main assembly 101 will be described.

[0117] Figure 6 is an external view of the main assembly drive shaft.

[0118] Figure 7 is a cross-sectional view taken along the axis of rotation (axis of rotation) of the main assembly drive shaft 101 mounted on the main assembly of the image forming apparatus.

[0119] Figure 8 is a perspective view of the main assembly drive shaft.

[0120] Figure 9 is a cross-sectional view of the coupling unit 28 and the main assembly drive shaft 101, taken along the axis of rotation (axis of rotation).

[0121] Figure 10 is a cross-sectional view of the coupling element 28 and the main assembly drive shaft 101, taken along a plane perpendicular to the axis of rotation.

[0122] As shown in Figure 6, the main assembly drive shaft 101 is provided with a gear part 101e, a shaft part 101f, a rough guide part 101g and a support part 101d.

[0123] A motor (not shown) as a drive source is provided in the main assembly of the image forming apparatus 100A. From the motor, the gear part 101e receives the rotational drive force so that the main assembly drive shaft 101 rotates. Furthermore, the main assembly drive shaft 101 includes a rotating projection shaft portion 101f that projects toward the side of the cartridge from the gear portion 101e along its axis of rotation. The rotational drive force received from the motor is transmitted to the cartridge side 7 through the slot-shaped drive transmission slot 101a (recessed part, drive passage part) provided in the shaft part 101f. Furthermore, the shaft portion 101f has a semi-spherical shape 101c at its free end portion.

[0124] The main assembly drive transmission slot 101a is formed so that a part of a coupling part 65a of the coupling unit 28, which will be described as a hearing, can then enter. Specifically, it is provided with a main assembly drive transmitting surface 101b as a surface that contacts the drive force receiving surface (drive force receiving part) 65b of the coupling unit 28 to transmit the drive force.

[0125] Furthermore, as shown in Figure 6, the main assembly drive transmission surface 101b is not a flat surface, but a twisted shape around the axis of rotation of the main assembly drive shaft 101. The direction of twist is such that the downstream side in the Z1 direction of the main assembly drive shaft 101 is upstream of the downstream side in its Z2 direction, relative to the direction of rotation of the main assembly drive shaft 101. In this embodiment, the amount of twist along the direction of the axis of rotation of the cylinder of the engaging part 65a is set to approximately 1 degree per 1 mm. The reason why the main assembly drive transmission surface 101b is twisted will be described below.

[0126] Furthermore, the main assembly drive transmission slot 101a is provided on the steering side surface Z2 with a removal cone on the main assembly side 101i. The removal cone on the side of the main assembly 101i is a narrowing (inclined surface, inclined part) to help the engaging part 65a disengage from the drive transmission groove 101a when disassembling the process cartridge 7 from the main apparatus assembly 100A. Its details will be described below.

[0127] Here, when the drive force is transmitted from the drive transmission groove 101a to the engaging part 65a, it is desirable that the main assembly drive transmission surface 101b and the drive force receiving surface (part receiving drive force) 65b are safely in contact with each other. Therefore, in order to prevent the surface other than the main assembly drive transmission surface 101b from contacting the engaging part 65a, the main assembly drive transmission groove 101a has a gap (G) in relative to the engagement part 65a in the direction of the axis of rotation, in the circumferential direction and in the radial direction (Figures 9 and 10).

[0128] Furthermore, in the axial direction of the main assembly drive shaft 101, the center 101h of the semi-spherical 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 set drive transmission groove 101a are projected onto the geometric axis of the main set drive shaft 101 onto the geometric axis of the main set drive shaft 101, the projection area of the center 101h on the geometric axis is within the projection area of the main assembly drive transmission slot 101a.

[0129] Here, the main assembly drive shaft and the geometric axis (axis of rotation, axis of rotation) of the drum unit mean an imaginary straight line extending so as to pass through the center of rotation of the shaft. Furthermore, the axial direction (direction of the axis of rotation) means 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.

[0130] Furthermore, “X and Y overlap in the A direction” means that since X and Y are projected in a straight line extending parallel to the A direction, it means that at least a part of the projection area of overlaps at least one part of the projection area of Y, on the straight line.

[0131] In the case of projecting something onto a line, the projected direction is a direction perpendicular to the line unless otherwise specified. For example, “project A on axis” means “project A in a direction perpendicular to the axis on axis”.

[0132] The rough guide part 101g of the main assembly drive shaft 101 is provided between the shaft part 101f and the gear part 101e in the axial direction (Figure 6). As shown in Figure 9, the rough guide part 101g has a narrowed shape at the free end part on the side of the shaft part 101f, and the outer diameter D6 of the rough guide part 101g is, as shown in Figure 7, smaller than the than the inner diameter D2 of the inner surface 71b of the cylindrical part 71 of the coupling unit 28. The outer diameter D6 of the rough guide part 101g is larger than the outer diameter D5 of the shaft part 101f as shown in Figure 6. Thus, When the cartridge 7 is inserted into the main assembly of the image forming apparatus 100A, the main assembly drive shaft 101 is guided to be along the coupling unit 28 so as to reduce axial misalignment between the center of rotation of the cylindrical part 71 and the center of rotation of the shaft part 101f. Therefore, the rough guide part 101g can be considered as an insertion guide.

[0133] The rough guide part 101g is defined to have a dimensional relationship such that it does not touch the inner peripheral surface 71b, after the assembly of the cartridge 7 to the main assembly of the image forming apparatus 100A is complete.

[0134] As shown in Figure 7, the support part 101d of the main assembly drive shaft 101 is disposed on the opposite side of the rough guide part 101g through the gear part 101e. The support portion 101d is rotatably supported by a bearing member 102 provided in the main assembly of the image forming apparatus 100A.

[0135] Furthermore, as shown in Figure 7, the main assembly drive shaft 101 is driven toward the side of the cartridge 7 by a spring element 103 of the main assembly of the image forming apparatus 100A. However, the moving amount (play) of the main assembly drive shaft 101 in the Z direction is approximately 1 mm which is sufficiently smaller than the width, measured in the Z direction, of the drive force receiving surface 65ba which will be described. Next.

[0136] As described above, the main assembly drive shaft 101 is provided with the main assembly drive transmission slot 101a, and the coupling unit 28 is provided with the coupling part 65a, to transmit the assembly drive main 100A for cartridge 7 (drum unit 30).

[0137] As will be described in detail below, the coupling part 65a is driven by a driving element which is an elastically expandable and contractile compression spring. Accordingly, the engaging part 65a is configured to be movable at least externally in the radial direction of the drum unit 30 when the cartridge 7 is mounted in the main apparatus assembly 100A. Therefore, as the cartridge 7 is inserted into the main apparatus assembly 100A, the engagement part 65a enters the drive transmission groove 101a, and the engagement part 65a and the main assembly drive transmission groove 101a can engage one into the other.

[0138] In the following description, the radial direction of the drum unit 30 can simply be called the radial direction. The radial direction of the drum unit 30 is the radial direction of the photosensitive drum 1 and also the radial direction of the coupling unit 28.

[Coupling Element Structure]

[0139] With reference to Figures 11, 12, 13, 14 and 15, the coupling unit 28 of this embodiment will be described in detail.

[0140] Figure 11 is a perspective view of the drive side of the drum unit 30, in which the coupling unit 28 is mounted to the photosensitive drum 1.

[0141] Figure 12 is a cross-sectional view of the drive side of the drum unit 30.

[0142] Figure 13 is a perspective view of the engagement element 65, where part (a) of Figure 13 is a perspective view seen from the upper left part, and part (b) of Figure 13 is a Perspective view seen from the top right.

[0143] Figure 14 is a perspective view of elements that constitute the coupling unit 28.

[0144] Figure 15 is a cross-sectional view of the coupling unit 28.

[0145] As shown in Figure 11, the coupling unit 28 is provided with three engagement parts 65a engageable with the main assembly drive shaft 101. As shown in Figure 10, the engagement part 65a enters the groove part 101a of the main set drive shaft 101 so that the drive force receiving surface 65b of the engagement part 65a and the drive transmitting surface 101b of the main set drive shaft 101 come into contact with each other, and the force drive is transmitted from the main assembly drive shaft 101 to the coupling unit 28.

[0146] Figure 12 is a cross-sectional view of the state in which the coupling unit 28 is mounted on the photosensitive drum 1. The engaging element 65 including the engaging part 65a is supported in a state of being driven by the driving element 66 to the inner side in the radial direction of the coupling unit 28, in the coupling unit 28.

[0147] In the following, the structure of the coupling unit 28 will be specifically described. As shown in the sectional view of Figure 12 and the perspective view of Figure 14, the coupling unit 28 includes the flange member 71, a flange cover member 72, the coupling member 65 and the drive member 66.

[0148] The flange element 71 is mounted on the inner periphery of the photosensitive drum 1 and fixed to the photosensitive drum 1. The flange element 71 has a substantially cylindrical shape and is provided with a hollow part. The flange element 71 is open externally in the axial direction of the drum unit.

[0149] The flange cover element 72 is mounted on the inner surface of the hollow part of the flange element 71. The flange cover element 72 closes the inside (underside) of the flange element 71 in the axial direction of the drum unit .

[0150] The flange cover element 72 is attached to the photosensitive drum 1 by means of the flange element 71.

[0151] The structure is such that the engagement element 65 is kept movable (sliding) on the flange cap element 72 and is movable (sliding) relative to the flange cap element 72. The pushing element 66 is a elastic (spring element), and the structure is such that it drives the engaging element 65 inwards at least in the radial direction of the drum unit.

[0152] In this embodiment, the flange element 71, the flange cover element 72, the engagement element 65 and the thrust element 66 are formed as separate bodies (separate elements). In this example, the engagement member 65 is constituted to be movable along the radial direction of the coupling unit (substantially parallel to the radial direction). Furthermore, the engaging element 65 and the pushing element 66 are arranged along the radial direction. That is, the structure is such that both the engaging element 65 and the driving element 66 are arranged on an imaginary line parallel to the radial direction of the coupling unit.

[0153] As shown in Figure 11, three engagement elements 65 are arranged at regular intervals in the circumferential direction of the coupling unit 28 (at intervals of 120 degrees, substantially equally spaced). Furthermore, as shown in Figure 13, the engaging member 65 has an engaging part 65a projecting inwardly in the radial direction and a driving force receiving surface 65b formed on the engaging part 65a. The engagement member 65 also has a drive shaft abutment surface (drive axle abutment portion) 65c which is formed adjacent to the drive force receiving surface 65b and which is formed in an arc shape so as to contact the outer circumferential surface 101f of the main assembly drive shaft. The drive force receiving surface 65b is a drive force receiving part that receives the drive force from the main assembly drive shaft 101, contacting the drive groove 101a. The engagement part 65a is a projection part (projection part) that projects (projects) from the surface of the engagement element 65.

[0154] Engagement element 65 is a drive force receiving element provided with a drive force receiving part (drive force receiving surface 65b), and is also a support element for supporting the drive surface receiving drive force 65b.

[0155] The engagement element 65 is provided with a first guided surface (surface to be guided) 65d and a second guided surface (surface to be guided) 65e to be guided (guided) in the radial direction in the coupling unit. The first guided surface 65d is a position regulating part for regulating the position of the engaging element 65 in the circumferential direction, and is arranged on the side closest to the engaging part 65a. The second guided surface 65e is a position regulating part for regulating the position of the engaging element 65 in the circumferential direction and is arranged on a side away from the engaging part 65a.

[0156] The first guided surface 65d and the second guided surface 65e are parts guided by a flange cover element 72, which will be described below. The first guided surface 65d and the second guided surface 65e are constrained parts, the positions of which are regulated by the flange cover member 72, in the direction of rotation (circumferential direction) of the drum unit. The first guided surface 65d is a guided part on the upstream side (the restricted part of the upstream side) located on a downstream side of the engagement member 65 in the direction of rotation of the coupling unit. The second guided surface 65e is a downstream guided part (the downstream regulated part) positioned on the upstream side of the engagement member 65 in the direction of rotation.

[0157] The first guided surface 65d and the second guided surface 65e are substantially parallel to each other.

[0158] Furthermore, a third guided surface 65f and a fourth guided surface 65g for regulating the position of the engagement element 65 in the axial direction are provided. The third guided surface 65f and the fourth guided surface 65g are guided parts to be guided by the flange cover element 72, which will be described hereinafter. The third guided surface 65f and the second guided surface 65g are regulated parts, 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 the outer guided part (and the outer restricted part) located outside the engagement member 65 in the axial direction of the drum unit. The fourth guided surface 65 g is a downstream guided part (and a downstream regulated part) located on the downstream side of the engagement member 65 in the axial direction.

[0159] The third guided surface 65f and the fourth guided surface 65e are substantially parallel to each other.

[0160] Furthermore, the engaging element 65 is provided with a contact surface (a driven part, driven surface) 65h (Figure 10) for receiving a pushing force by the driving element 66. The engaging element 65 is also provided with a position regulating projection 65i for restricting the position of the engagement member 65 when abutting against the flange cover member 72 by the pushing force of the pushing member 66. In particular, the structure is such that the regulating surface position position of the pushing force (engaged part) 65j formed in the position restraining projection is brought into contact with the flange cover element 72. The position regulating projection 65i is provided on both sides of the engaging element 65 with a contact surface 65h in relation to the thrust element 66 interposed between them.

[0161] The engagement member 65 has a tapered insertion surface 65k on the outer side (the Z1 direction side) of the photosensitive drum unit 30 in the Z direction. The tapered insertion surface 65k is an inclined portion facing outward in the direction axial. The narrowed insertion surface 65k is a mounting force receiving part that receives a force to retract the engaging member 65 in the radial direction when the cartridge is mounted. Furthermore, the engaging member 65 has a tapered part 65l as a dismounting force receiving part on the inner side (the Z2 direction side) of the photosensitive drum unit 30 in the Z direction. The tapered removal surface 65l is a disassembly force receiving part that receives a force to retract the engagement member 65 in the radial direction when the cartridge is disassembled.

[0162] The flange cover member 72 is provided with a coupling hole portion 72a for allowing the main assembly drive shaft 101 to pass therethrough and a mounting hole portion 72b for supporting the coupling member 65 of so as to be movable in the radial direction. The engagement portion 65a of the engagement member 65 is exposed through the coupling hole portion 72a in order to engage the engagement member with the main assembly drive shaft. The mounting hole 72b is provided with a first guide surface 72d abutting the first guided surface 65d which is the surface for regulating the position of the engaging element 65 in the circumferential direction, and is provided with a second guide surface 72e which is in contact with the second guided surface 65e. Furthermore, the mounting hole 72b is provided with a third guide surface 72f which contacts the third guide surface 65f which is a surface which restricts the position of the engagement element 65 in the axial direction, and is provided with a fourth guiding surface 72 g in contact with the fourth guided surface 65 g which is a surface opposite the third guided surface.

[0163] The first guide surface 72d, the second guide surface 72e, the third guide surface 72f, and the fourth guide surface 72g are guide parts for guiding the engagement element 65, and also restraining parts (parts of position constraint) to constrain the position of the engagement element.

[0164] The first guide surface 72d is an upstream guide (upstream restraint part) that guides the upstream side of the engagement element 65 in the direction of rotation of the drum unit and regulates the position. Similarly, the second guide surface 72e is a downstream guide (downstream regulating part) that guides the downstream side of the engagement member 65.

[0165] The engaging element 65 and the pushing element 66 are arranged in a space between the first guide surface 72d and the second guide surface 72e.

[0166] Furthermore, the third guide surface 72f is an external guide part (external regulating part) that guides the outside of the engaging element 65 in the axial direction of the drum unit and regulates the position. Similarly, the fourth guide surface 72 g is an internal guide part (internal restraint part) that guides the inside of the engagement element 65 in the axial direction and regulates the position.

[0167] The flange cover element 72 is a guide element that guides the engagement element 65 using these guide parts (the first guide surface 72d, the second guide surface 72e, the third guide surface 72f and the fourth guide surface 72g). The flange cap member 72 is a retaining member that keeps the engagement member 65 movable (in a guided manner).

[0168] 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.

[0169] The engagement element 65 is a movable element that is movably held by the flange cover element 72 and is also a sliding element that slides relative to the flange cover element 72.

[0170] Furthermore, in order to regulate the position of the engaging element 65 against the pushing force of the pushing element 66, the flange cover element 72 is provided with the restraining surface (engaging part) 72j.

[0171] The restraining surface (engaging part) 72j restricts the engaging element 65 from moving inwardly in the radial direction by contacting the pushing force position regulating surface (radially projecting part) 65j. That is, the restraining surface (locking part) 72j locks a locking element 65 against the pushing force of the pushing element 66. In a state in which the cartridge 7 is not mounted in the main apparatus assembly (a spontaneous state in which no force is applied to the cartridge 7), the locking element 65 is driven towards the restraining surface 72j by the pushing force of the pushing element 66.

[0172] Furthermore, the flange cover element 72 is provided with a mating surface 72k for mating with the inner peripheral surface of the flange element 71 and a position adjusting groove 72l for adjusting the position in the direction of rotation. relative to the flange member 71. Furthermore, the flange cover member 72 is in contact with the semi-spherical shape 101c of the main assembly drive shaft 101 including the conical surface 72m so as to position the main assembly drive shaft 101 in relation to the flange cover element 72.

[0173] Here, the positioning part does not need to be a conical recess like the 72m conical surface. Whether the position of the photosensitive drum unit 30 relative to the main drive shaft 101 can be determined when the radial positioning part and the longitudinal positioning part come into contact with the free end (semi-closed shape 101c) of the joint drive shaft main 101, the form can be any. For example, a recess part (undercut part) including a narrow part is preferred as it goes towards the bottom. As an example of such a shape, a cone shape that is not a polygonal cone, such as a pyramid (a square pyramid, etc.) can also be used. However, as long as the conical shape is symmetrical with respect to the axis of the coupling unit 28 like the conical shaped part 72m of this embodiment, the position of the coupling unit 28 can be maintained with particularly high accuracy.

[0174] Here, the conical shaped part 72m may have a region for contact with the main assembly drive shaft 101, and therefore the region that is not in contact may be of any shape. For example, the bottom of the conical-shaped portion 72m is not necessarily in contact with the main assembly drive shaft 101, and therefore the conical-shaped portion 72m may not have a bottom surface.

[0175] The flange element 71 is provided with a fitting part 71d relative to the photosensitive drum, and a flange part 71e formed at the axial end part of the fitting part. Furthermore, the flange member 71 includes a cylindrical portion 71a that extends further in the axial direction of the flange portion 71e. The cylindrical part 71a is formed with an inner peripheral surface 71b through which the main assembly drive shaft 101 passes, and with a supporting part 71c supported by the rolling element. As shown in Figure 14, the flange part 71e has a shape that projects outwardly from the fitting part 71d in the radial direction. When assembling the photosensitive drum 1 of the coupling unit 28, the end surface of the photosensitive drum 1 is abutted against the end surface of the flange part 71e, thereby determining the positions of the photosensitive drum 1 and the coupling unit 28 in the Z direction

[0176] As shown in Figure 12, the fitting part 71d of the flange element 71 is press-fitted into the inner diameter part of the photosensitive drum cylinder 1. Advancing the flange element 71 in the axial direction to the flange part 71e of the flange member 71 abuts against the end surface of the photosensitive drum and presses the fitting portion 71d onto the photosensitive drum 1, the coupling unit 28 is precisely positioned relative to the photosensitive drum 1. More specifically, the inner diameter of the cylinder of the photosensitive drum 1 and the outer shape of the fitting part 71d are dimensioned so as to be in a close-fitting relationship.

[0177] As described above, after mounting the flange element 71 to the photosensitive drum 1, the flange element 71 and the photosensitive drum 1 are fixed by a clamping method. More specifically, a portion where the cylinder end portion of the photosensitive drum 1 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 71. Here, fastening refers to joining a plurality of parts together by partial plastic deformation.

[0178] Here, the clamping fixing method is an example of a means for firmly fixing the flange element 71 to the photosensitive drum 1, and another fixing means such as fixing the inner diameter of the drum and the fitting part 71d by membership can be used.

[0179] As described above, the cylindrical part 71a of the flange element 71 is provided with the support part 71c on the free end side (the Z1 direction side) of the outer peripheral surface thereof (Figures 4 and 9). In other words, the coupling unit has a supporting part 71c that has a cylindrical outer shape on the Z1 direction side (outer side in the axial direction) relative to the engaging element. By employing such a form, the engaging part 65a is not exposed on the outer surface of the cartridge 7. For this reason, the engaging part 65a of the engaging element 65 can be protected by the drum unit bearing element 39R and the support 71c. Through this, it is possible to prevent the user from accidentally touching the engaging part 65a or prevent something from hitting the engaging part 65a directly when the cartridge 7 falls. Furthermore, as shown in Figure 14, the inner peripheral surface 71b of the cylindrical part 71 is provided with a conical shape 71g at the free end of the front end (Z1 direction). The conical shape 71g is an inclined part (inclined surface) for guiding the main assembly drive shaft 101 inserted into the cylindrical part 71.

[0180] The driving element 66 is an elastically expandable compression helical spring, and applies a reaction force in a direction in which the compression spring extends, against the external force in the compression direction of the compression spring. Here, the pushing element 66 can apply a pushing force to the engaging element 65 radially inwardly and therefore, in addition to the helical compression spring as in this embodiment, a leaf spring or a pushing element (elastic element, spring) such as a helical torsion spring can be used, for example.

[0181] It is also possible to arrange for the driving element 66 to be integrated with the engaging element 65 or the flange cover element 72. In this example, however, the driving element 66 is formed separately from the engaging element 65 and the flange cover element 72. By doing so, the selection latitude of the driving element 66 is increased, and a suitable driving element 66 can be easily selected. For example, it is easier to select the driving element 66 that provides an appropriate pushing force (elastic force) to drive the engaging element 65.

[0182] With respect to the coupling unit 28 constituted as described above, the supporting structure of the coupling element 65 will be described in detail. Figure 15 is a sectional view taken perpendicular to the axial direction of the coupling unit.

[0183] The first guided surface 65d and the second guided surface 65e of the engagement element 65 contact and guide the first guide surface 72d and the second guide surface 72e of the flange cover element 72, respectively. As shown in Figure 12, the third guided surface 65f and the fourth guided surface 65g of the engagement member 65 contact 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 engagement member 65 is guided and supported so as to be movable at least in the radial direction with respect to the flange cover member 72. That is, a vector along the direction in which the engagement member coupling 65 moves has at least one component in the radial direction of the drum unit. In this embodiment, the engagement member 65 is movable in parallel with a substantially radial direction.

[0184] The engaging element 65 is driven inwardly in the radial direction of the coupling unit 28 by the driving element 66. The driving element 66 is compressed into a state of being between the contact surface 65h of the engaging element 65 and the inner peripheral surface of the flange element 71, and therefore exerts a pushing force in a direction in which the pushing element 66 expands, thereby driving the engaging element 65.

[0185] The position of the engagement element 65 is restricted by the contact between the position restriction surface 65j and the restriction surface 72j of the flange cover element 72 against the pushing force.

[0186] The engagement member 65 is supported by the flange cover member 72 in a state in which the engagement portion 65a thereof is exposed through the hole 72a of the flange cover member 72. Furthermore, similarly, the surface of drive shaft abutment 65c having an arc shape in the engagement member 65 is exposed through hole 72a of the flange cover member 72. The engagement portion 65a of the engagement member 65 projects inwardly in the radial direction from of the inner peripheral surface of the bore portion 72a of the flange cover member 72.

[0187] The amount by which the engagement part 65a projects relative to the drive shaft abutment surface 65c of the engagement element 65 is sufficient for the engagement part 65a to safely enter the groove 101a of the drive shaft. This amount of projection is sufficient for the drive force receiving surface 65b formed on the engaging part 65a to have the force corresponding to the load torque of the photosensitive drum unit 30 which is the element to be rotated. That is, it will be sufficient if the drive force receiving surface 65b of the engagement part 65a can stably transmit the drive force from the main assembly drive shaft 101. In the case of this embodiment, the projection amount of the coupling 65a is selected so that the distance measured from the inner surface of the flange cover element 72 to the free end of the coupling part 65a along the radial direction of the coupling unit is 1 mm to 3 mm.

[0188] Furthermore, similarly, the drive shaft abutment surface 65c of the engagement element 65 also projects inwardly in the radial direction from the inner peripheral surface of the bore portion (hollow portion) 72a of the cap element. flange 72. The projection amount (exposure amount) by which the drive shaft abutment surface 65c projects from the inner peripheral surface of the bore portion 72a is such that the drive shaft abutment surface 65c protrudes securely from the inner peripheral surface of the hole part 72a even when the dimensions of the respective parts vary. In the case of this embodiment, the amount of projection of the drive shaft abutment surface 65c projecting from the inner peripheral surface of the hole 72a is preferably 0.3 mm to 1 mm. That is, the distance from the inner surface of the flange cover element 72 to the drive shaft abutment surface 65c measured along the radial direction of the coupling unit is 0.3 mm to 1 mm.

[0189] As described above, the engagement portion 65a and the drive shaft abutment surface 65c of the engagement member 65 are exposed through hole 72a and can engage and abut the drive shaft of the main assembly 101. The structure in which engagement element 65 is engaged with the main assembly drive shaft 101 and the drive transmission is performed, will be described below.

[Assembly of Cartridge to Main Assembly of Image Forming Apparatus]

[0190] With reference to Figures 16, 17, 18 and 19, the assembly and disassembly of the process cartridge 7 in relation to the main assembly of the image forming apparatus will be described.

[0191] Figure 16 is a perspective view illustrating the assembly of the cartridge 7 to the main assembly of the image forming apparatus 100A.

[0192] Figures 17, 18 and 19 are cross-sectional views illustrating the operation of assembling the cartridge 7 to the main assembly of the image forming apparatus 100A.

[0193] The main assembly of the image forming apparatus 100A of this embodiment employs a structure capable of mounting the cartridge in a substantially horizontal direction. Specifically, the main assembly of the imaging apparatus 100A has an internal space in which a cartridge can be mounted. The main assembly of the imaging apparatus has a cartridge port 104 (front port) for inserting the cartridge into the space on the front of the main assembly 100A (the side near the user that is in use).

[0194] As shown in Figure 16, the cartridge door 104 of the main assembly of the image forming apparatus 100A is provided for opening and closing. When the cartridge door 104 is opened, the lower cartridge guide rail 105 for guiding the cartridge 7 is provided on the space-defining lower surface, and the upper cartridge guide rail 106 is provided on the upper surface. The cartridge 7 is guided into the mounting position by the upper and lower guide rails (105, 106) provided above and below the space. The cartridge 7 is inserted into the mounting position substantially along the axis of the photosensitive drum unit 30.

[0195] With reference to Figures 17, 18 and 19, the operations of assembling and disassembling the cartridge to the main assembly of the image forming apparatus 100A will be described below.

[0196] As shown in Figure 17, the drum unit bearing element 39R or the photosensitive drum 1 does not contact the intermediate transfer belt 5 at the beginning of insertion of the cartridge 7. In other words, the size relationship is such that the photosensitive drum 1 and the intermediate transfer belt 5 do not come into contact with each other in a state in which the end part on the rear side in relation to the cartridge insertion direction 7 is supported by the cartridge guide rail lower 105.

[0197] As shown in Figure 18, the main assembly of the image forming apparatus 100A includes a rear side lower cartridge guide 107 that projects upward relative to the direction of gravity of the lower cartridge guide rail 105 toward the rear side in the insertion direction of the lower cartridge guide rail 105. The lower cartridge guide on the rear side 107 is provided with a tapered surface 107a on the front side relative to the cartridge insertion direction 7. Along with the insertion, the cartridge 7 moves on the narrowed surface 107a and is guided into the mounting position.

[0198] The position and shape of the lower cartridge guide on the rear side 107 can be any if a portion of the cartridge does not rub against the image forming area 5A of the intermediate transfer belt 5 when the cartridge is inserted into the main assembly of the 100A device. Here, the image forming area 5A is a region in which a toner image to be transferred to the recording material 12 is transported on the intermediate transfer belt 5. Furthermore, in this embodiment, parts of the cartridges in the mounting attitude , the bearing element of the unit 39R provided on the rear side in relation to the insertion direction of the cartridge 7 projects mainly upward in relation to the direction of gravity. Therefore, it will be sufficient if the arrangement and shape of each element are appropriately selected so that the trace (hereinafter called the insertion trace) of the end of the drum unit bearing element 39R farthest in the insertion direction at the time of Cartridge insertion does not interfere with imaging area 5A.

[0199] Next, the cartridge 7 is further inserted into the rear side of the main assembly of the image forming apparatus 100A from the state in which it is located in the lower cartridge guide on the rear side 107. Then, the cartridge bearing element drum unit 39R abuts the rear cartridge positioning part 108 provided in the main assembly of the image forming apparatus 100A. At this time, the cartridge 7 (the photosensitive drum unit 30) is tilted by approximately 0.5 to 2 degrees relative to the state in which the cartridge 7 (photosensitive drum unit 30) is completely assembled into the main assembly of the forming apparatus. image 100A (part (d) of Figure 17). That is, in the insertion direction of the cartridge 7, the downstream side of the cartridge 7 (photosensitive drum unit 30) is at a higher level than the upstream side.

[0200] Figure 19 is an illustration of the state of the main apparatus and cartridge assembly when the cartridge door 104 is closed. The image forming apparatus 100A has a front side lower cartridge guide 109 on the front side, relative to the insertion direction, of the lower cartridge guide rail 105. The front side lower cartridge guide 109 is configured to move. up and down in interrelation with the opening and closing of the cartridge door (front door) 104.

[0201] When the cartridge door 104 is closed by the user, the lower cartridge guide on the front side 109 is raised. Then, the drum unit bearing element 39L and the cartridge positioning part on the near side 110 of the main assembly of the image forming apparatus 100A come into contact with each other, so that the cartridge 7 is positioned in relative to the main assembly of the image forming apparatus 100A.

[0202] With the operation described above, the assembly of the cartridge 7 to the main assembly of the image forming apparatus 100A is complete.

[0203] Furthermore, disassembly of the cartridge 7 from the main assembly of the image forming apparatus 100A is performed in the reverse order of the insertion operation described above. As the oblique mounting structure is employed as described above, it is possible to suppress friction between the photosensitive drum and the intermediate transfer belt when the cartridge 7 is mounted on the main assembly of the apparatus 100A. For this reason, it is possible to suppress the occurrence of small scratches (scratches) on the surface of the photosensitive drum or the surface of the intermediate transfer belt.

[0204] Furthermore, the structure of this embodiment can simplify the structure of the main assembly of the imaging apparatus 100A compared to the structure in which the entire cartridge is lifted after the cartridge is moved horizontally and mounted on the main assembly of the apparatus.

[Process of Engaging the Coupling Element with the Main Drive Shaft]

[0205] With reference to Figures 20, 21, 22, 23, 24, 25 and 26, the process of engaging the coupling unit 28 and the main assembly drive shaft 101 will be described in detail.

[0206] Figures 20, 21 and 22 are cross-sectional views illustrating an assembly operation of the coupling unit 28 to the main assembly drive shaft 101.

[0207] Figures 23 and 24 are cross-sectional views illustrating the operation of assembling the coupling unit 28 to the main shaft of the drive assembly 101 when the drive shaft of the main assembly 101 rotates from a state in which the phases of the drive transmission of the main assembly 101a and the engagement part 65 (the drive force receiving surface 65b) are not aligned, for the state in which the phases are aligned.

[0208] Figure 25 is a cross-sectional view that illustrates the relationship of forces acting on the coupling element.

[0209] Figure 26 is an axial cross-sectional view illustrating the drive transmission engagement surfaces of the engagement member and the main assembly drive shaft.

[0210] Furthermore, Figures 21 and 23 illustrate a state in which the phases of the drive transmission groove of the main assembly 101a and the engagement part 65 (drive force receiving surface 65b) are not aligned.

[0211] Cartridge 7 is inserted into the main apparatus assembly 100A as described above. Then, together with the cartridge assembly operation, the coupling unit abuts the semi-spherical shape 101c formed at the free end of the main assembly drive shaft 101 and an inclined surface formed at the end of the rough guide portion 101g of the drive shaft. main set. Thereby, the main assembly drive shaft 101 is guided to the inner surface 71b of the flange element 71 of the coupling unit.

[0212] Figure 20 shows a state in which the main assembly drive shaft 101, thus guided, is in contact with the engagement element 65 of the coupling unit. The semi-spherical shape 101c of the main assembly drive shaft abuts against the narrowed insertion surface 65k formed in the engagement member 65.

[0213] From this state, a force is further applied in one direction to mount the cartridge 7 further. Then, the force in the cartridge mounting direction acts in a direction in which the engaging element 65 is retracted outwardly in the radial direction by the narrowed insertion surface 65k. Therefore, with the free end of the main assembly drive shaft 101 in contact with the narrowed insertion surface 65k, it is possible to move the cartridge 7 further towards the rear side of the apparatus main assembly.

[0214] Figures 21 and 23 show a state in which the cartridge 7 is moved to the rear side in this manner and the assembly of the cartridge 7 to the main apparatus assembly 100A is complete. In this state, the semi-spherical shape 101c of the main assembly drive shaft abuts against the conical surface 72m of the coupling unit, and the main assembly drive shaft 101 is positioned in the axial direction and the radial direction relative to the coupling unit 28 .

[0215] As mentioned above, the engagement element 65 is guided by the first, second, third and fourth guiding surface of the flange cover element 72 on the first, second, third and fourth guiding surface of the engagement element 65, so which it retracts in the radial direction until the free end of the engagement part contacts the outer peripheral surface of the shaft part 101f of the main assembly drive shaft. At this time, as shown in Figure 23, the restraining surface 65j against the pushing force of the engagement element 65 is separated from the restraining surface 72j of the flange cap member. Furthermore, the drive member 66 is more compressed and contracted compared to the state shown in Figure 15, in which the main assembly drive shaft 101 is not inserted into the coupling unit 28.

[0216] Then, at the time of starting the main assembly of the imaging apparatus or at the beginning of the image forming operation, the main assembly drive shaft 101 rotates. Then, as shown in Figure 22 and Figure 24, the engagement portion 65a of the engagement element enters the groove 101a of the main assembly drive shaft. Thereby, the engagement element 65 moves radially inward until the abutment surface of the drive shaft 65c of the engagement element comes into contact with the outer peripheral surface of the shaft portion 101f of the drive shaft of the main assembly. Here, in Figure 24, the position restraining surface 65j of the engagement member is also in contact with the restraining surface 72j of the flange cap member.

[0217] However, in order to more reliably approximate the abutment surface of the drive shaft 65c of the engagement element with the outer peripheral surface of the shaft portion 101f of the drive shaft of the main assembly, it is desirable to select a dimensional relationship such that a predetermined gap is always formed between the position restraining surface 65j and the restraining surface 72j. That is, so that a gap is positively generated between the position restraining surface 65j and the restraining surface 72j in a state where the drive shaft abutment surface 65c of the engagement element is in contact with the outer circumferential surface of the shaft part 101f of the main assembly drive shaft, even when dimensional variation occurs.

[0218] In addition, as the main set drive shaft 101 rotates from the state of Figure 24, the drive transmission surface 101b of the main set drive shaft and the drive force receiving surface 65b of the part coupling elements are brought into contact with each other so that the drive transmission to the photosensitive drum 1 is allowed, as shown in Figure 25. As described above, the engagement part 65a of the coupling element engages with the drive shaft of the assembly main 101.

[0219] In Figure 22, the coupling part 65a is arranged so that, in the Z direction, the distance L1 from the front end surface of the cylindrical part 71 to the front end surface of the coupling part 65a and the length L2 of the surface receiving drive force 65b satisfy L1 > L2.

[0220] As shown in Figure 22, a conical shaped part 72m is arranged so that the center 101h of the semi-spherical shape 101c falls within the range L2 of the driving force receiving surface 65b of the engagement element 65 in the Z direction. If the engagement part 65a and the center 101h are projected onto the axis of the drum unit 30, the center 101h is disposed within the projection region L2 of the driving force receiving surface 65b of the engagement part 65a. By establishing this arrangement relationship, the following effects can be provided.

[0221] As shown in Figure 4, Figure 5 and Figure 19, the drum unit bearing element 39R and the drum unit bearing element 39L abut against the rear side cartridge positioning part 108 and the cartridge positioning on the rear side 110, respectively. By this, the position of the cartridge 7 relative to the main assembly of the image forming apparatus 100A is determined. Here, the relative position between the main assembly drive shaft 101 and the coupling unit 28 is affected by part tolerances. More specifically, the position shifts due to the influence of the component tolerances of the drum unit bearing element 39R to the coupling unit 28 and the component tolerances of the rear side cartridge positioning unit 108 to the assembly drive shaft. main 101.

[0222] As shown in Figure 6 and Figure 22, the semi-spherical shape 101c of the main assembly drive shaft 101 abuts against the inverted conical shape 533a, and the supporting part 101d and the semi-spherical shape 101c establish the structure supported on both sides. extremities. That is, viewed from the coupling unit 28, the main assembly drive shaft 101 is inclined about the center 101h of the semi-spherical shape 101c. The same position of center 101h in the direction of the Z axis is the position that is least affected by this tilt. The driving force receiving surface 65b is arranged in the same position as the center 101h in the direction of the Z axis, so that the influence of position displacement can be minimized. That is, the position in which the photosensitive drum 1 can be stably driven is determined.

[0223] Here, in this embodiment, a projection for receiving a driving force is provided on the side of the engaging element 65, but it is possible that a groove for receiving drive by engaging elements is provided, and a movable projection that can engage with the groove moving in the radial direction on the drive shaft side of the main assembly 101 is provided. However, compared with the cartridge 7, the main assembly of the imaging apparatus 100A is required to have greater durability. From the point of view of increasing the durability of the main assembly of the image forming apparatus 100A, it is preferred to provide the movable part (the engaging part 65) that moves in the radial direction, on the coupling unit 28 side of the cartridge. 7 as in this modality.

[Coupling Unit Drive by Main Assembly Drive Shaft]

[0224] With reference to Figure 25 and Figure 26, a structure will be described to transmit the rotation drive force to the coupling unit 28.

[0225] First, the support structure for the engagement element 65 during coupling drive will be described in detail. As shown in Figure 25, when the main assembly drive shaft 101 is rotatably driven in the direction of arrow R, the drive transmission surface 101b formed in the groove 101a of the main assembly drive shaft abuts against the force receiving surface. drive 65b formed on the engagement portion 65a of the engagement member to provide a force F in the direction normal to the drive force receiving surface 65b. When the driving force F acts on the driving force receiving surface, the first guiding surface 65d of the engagement element and the first guiding surface 72d of the flange cover are brought into contact with each other by this force. Furthermore, more preferably, the abutting surface of the drive shaft 65c of the engagement element abuts against the outer peripheral surface of the shaft part 101f of the drive shaft of the main assembly. Thereby, the engagement element 65 is strongly supported between the flange cover element 72 and the main assembly drive shaft 101.

[0226] Next, the force produced for the engagement element 65 and the support structure of the engagement element 65 using this force will be described.

[0227] The drive force receiving surface 65b is inclined with respect to the direction of movement S of the engagement element 65 so that it faces outward at least in the radial direction. That is, the normal vector of the driving force receiving surface 65b (a vector that extends perpendicular to the driving force receiving surface 65b toward the side toward which the driving force receiving surface 65b faces) is an external component in the radial direction of the coupling unit.

[0228] In other words, the radially inner side of the actuating force receiving surface 65b (the free end side of the engagement part 65a) is on the upstream side of the actuating force receiving surface 65b in the radial direction ( the rear end side of the engagement part 65a) in the direction of rotation of the drum unit.

[0229] When the actuation force F is applied vertically to the actuation force receiving surface 65b of the coupling part, the direction in which the actuation force F is produced is inclined inwardly in the radial direction with respect to the circumferential direction ( circumferential direction) of the coupling unit. That is, by drawing an imaginary circle passing through the actuating force receiving surface 65b concentrically with the coupling unit, the actuating force F is inclined so as to be directed radially inwardly with respect to the tangent of this imaginary circle.

[0230] Therefore, the driving force F is divided into a force F1 which is a tangential component along the tangent of the imaginary circle (circumferential direction component, rotation direction component) and a force F2 which is a component in the direction radial direction directed inward in the radial direction.

[0231] The drive force receiving surface 65b of the engagement element is driven radially inwardly by the force F2 applied to the drive force receiving surface 65b. It is possible to prevent the drive force receiving surface 65b from moving radially outwards, and therefore it is also possible to prevent the drive force receiving surface 65b from disestablishing the state of contact with the drive transmitting surface 101b of the main assembly drive shaft.

[0232] Furthermore, the direction of movement S in which the engagement element is guided radially inwardly relative to the flange cap element is inclined by an angle with respect to the direction of the force F acting in the normal direction of the receiving surface of drive force. Thereby, as shown in part (b) of Figure 25, the force F acting on the driving force receiving surface has a component FS that acts in the direction of movement S of the engagement element. This force FS prevents movement of the engagement element 65 to the opposite side in the direction of movement S and it is therefore possible to prevent the drive force receiving surface 65b of the engagement element from being disengaged from the drive transmitting surface 101b from the main assembly drive shaft to the outside. Simply put in a different way, the direction of the drive force receiving surface 65b is inclined to a direction in which the drive force receiving surface 65b bites the drive transmitting surface 101b of the main assembly drive shaft, relative to the direction of movement of the coupling element 65.

[0233] Furthermore, more preferably, the abutment surface of the drive shaft 65c of the engagement element may come into contact with the outer peripheral surface of the shaft part 101f of the drive shaft of the main assembly.

[0234] As shown in Figure 25, the drive shaft abutment surface 65c is provided on the side opposite to the drive force direction F relative to the drive force receiving surface 65b. Therefore, the rotational moment M produced in the engagement element 65 is supported by the driving shaft abutment surface 65c by the force F acting on the drive force receiving surface, so that the engagement element 65 can be more firmly supported. The engagement surface of the drive shaft 65c of the engagement member projects radially into the inner circumferential surface of the hole 72a of the flange cap member. With this, even when there are variations in the dimensions and assembly accuracy of each part, the abutting surface of the driveshaft 65c can be reliably brought into contact with the outer peripheral surface of the driveshaft 101f. That is, it is preferred that at least a part of the drive shaft abutting surface 65c is disposed on the upstream side of the drive force receiving surface 65b in the direction of rotation of the drum unit.

[0235] In this way, the engagement element 65 is strongly supported between the flange cover element 72 and the main assembly drive shaft 101. Therefore, it is possible to prevent disengagement of the engagement element 65 from the main assembly drive shaft. main assembly 101 and stably transmit the driving force from the main assembly driving shaft 101 to the engagement element 65. It is possible to improve the driving stability of the photosensitive drum 1 and improve the image quality.

[0236] Next, the inclination of the engagement part in the axial direction of the drive force receiving surface 65b will be described. Figure 26 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, Figure 25 is a cross-sectional view taken along the direction of the force arrow F in Figure 25. Here, the main assembly drive transmission surface 101b formed in the drive transmission groove 101a of the assembly drive shaft main assembly 101 and the driving force receiving surface 65b formed on the engaging part 65a of the engaging element come into contact with each other, and the driving force of the drive shaft of the main assembly 101 is transmitted to the engaging element 65.

[0237] As previously described, the main assembly drive transmission surface 101b has a twisted shape around the axis of the coupling unit 28, and in Figure 26, the main assembly drive transmission surface 101b is inclined relative to to the axis of rotation of the main assembly drive shaft 101. The drive force receiving surface 65b of the engagement part also has the same twisted shape so as to come into contact with the main assembly drive transmission surface 101b, and therefore, the drive force receiving surface 65b is inclined with respect to the axis of rotation of the main assembly drive shaft 101. More particularly, the outer side of the drive force receiving surface 65b in the axial direction of the Drum unit is arranged on the upstream side in the direction of rotation of the drum unit than on the inner side.

[0238] Therefore, the force F in the normal direction applied from the drive transmitting surface of the main assembly 101b to the drive force receiving surface 65b has a force F3 as a component in the direction of the axis of rotation. That is, the force F3 for driving the coupling member 65 and the coupling unit 28 outward in the longitudinal direction of the photosensitive drum is generated. Hereby, it is possible to prevent a force from being applied to the main assembly drive shaft 101 in a direction in which the coupling unit 28 is disassembled in the axial direction. As shown in Figure 21, a force is produced to drive the semi-spherical shape 101c formed at the free end of the main assembly drive shaft in a direction to abut against the conical shaped portion 72m formed in the flange cover member. By this, the semi-spherical shape 101c of the main assembly drive shaft rests securely against the conically shaped part 72m of the flange cover element, and it becomes possible to more precisely position the main assembly drive shaft 101 relative to the unit. coupling 28.

[0239] The actuation force received by the actuation force receiving surface 65b is transmitted from the engagement element 65 to the flange cover element 72. That is, the actuation force is transmitted from the first guided surface 65d of the engagement element engagement 65 to the first guide surface 72d of the flange cover element 72. The first guide surface 72d is the transmitted part to which the driving force is transmitted, and the flange cover element 72 is the transmitted element. Furthermore, the first guide surface 72d is also a bearing part to prevent the engagement part 65a from moving to the downstream side in the direction of rotation of the drum unit when a driving force is applied to the engagement member 65 Furthermore, the first guided surface 65d is a transmission part for transmitting the driving force to the flange cover member 72.

[0240] The first guide surface 72d is inclined with respect to the drive force receiving surface 65b. Accordingly, the driving force F applied perpendicular to the driving force receiving surface 65d has a component directed inwardly in the radial direction along the first guide surface 72d.

[0241] Due to the driving force component F, the engaging part 65a is guided along the first guide surface 72d towards the radially inner side of the coupling unit 28. That is, the first guide surface 72d drives the engaging part 65a and the drive force receiving surface 65b toward the inside in the radial direction (that is, the rear side of the drive transmission groove 101a) when the drive force F is transmitted.

[0242] In Figure 25, the structure is such that when the tangent of the first guide surface 72d and the tangent of the drive receiving surface 65d are extended, the two tangent lines intersect outside in the radial direction than the first surface guide 72d and the drive receiving surface 65d.

[0243] Furthermore, in the rotational direction R of the drum unit, the radially inner side of the first guide surface 72d is disposed on the downstream side of the radially outer side (Figure 25).

[0244] The driving force transmitted from the engagement element 65 to the flange cover element 72 is transmitted to the photosensitive drum 1 by means of the flange element 71. As a result, the photosensitive drum 1 rotates in conjunction with the unit coupling 28.

[0245] That is, as shown in Figure 14, the flange cover element 72 is provided with position regulating grooves 72l (engagement parts, recessed parts) for engaging with the projections provided on the flange element 71. Furthermore , it is also provided with a mating surface 72k to be engaged with the inner periphery of the flange element 71. The driving force is transmitted to the flange element 71 through these faces 72k and the position regulating groove 72l. The flange element 71 is mounted to the photosensitive drum 1 and therefore the driving force is finally transmitted from the flange element 71 to the photosensitive drum 1.

[0246] Here, a projection is provided on the flange element 71, and a recessed portion (position restriction groove 72l) for engaging with the flange cover element 72 is provided, but is not limited to such a structure. For example, a recess may be provided in the flange member 71, and the flange cover member 72 is provided with a projection that engages with the flange cover member 72 so that driving force can be transmitted from the flange member 72. flange 72 to flange element 71.

[0247] Here, as described above, since the drive force receiving surface 65b is a twisted surface, when the drive force F is applied to the drive force receiving surface 65b, the drum unit 30 is thrust outward in the axial direction. That is, the structure is such that when a driving force is applied from the main assembly drive shaft 101 to the drive force receiving surface 65b, the drum unit 30 and the main assembly drive shaft 101 are attracted for each other. Here, the drive 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 inclined in a direction to produce the driving force Fc2 when receiving the driving force F described above, and the shape of the surface may be a flat surface or a curved surface, e.g. example.

[0248] Furthermore, as shown in Figures 10 and 12, the flange element 71 is provided with the contact surface in contact with the driving element (thrust part of driving element) 71f, which receives, when the element coupling element 65 receives a radially inward pushing force from the driving element 66, a reaction force, that is, a radially outward force. The contact surface 71f is a pressure force receiving part (pushing force receiving part) pressed and driven by the pushing element. It is a driving element supporting part for supporting the driving element.

[0249] As shown in Figure 12, the contact surface 71f of the flange element 71 is arranged in a position such that, in the longitudinal direction of the photosensitive drum 1, at least a part of the contact surface 71f overlaps with a part of the photosensitive drum 1 in the longitudinal direction. That is, when the contact surface 71f and the photosensitive drum 1 are projected perpendicular to the axis of the photosensitive drum, at least parts of their mutual projection areas overlap each other. In other words, at least a part of the contact surface 71f is provided inside the photosensitive drum 1. In particular, in this embodiment, the entire contact surface 71f is inside the photosensitive drum 1. This is for the following reasons.

[0250] The contact surface 71f of the flange element 71 is arranged in a thin-walled part of the flange element, because of the requirement for space in the radial direction. The radially outward thrust force of the thrust element 66 applied to the contact surface 71f is received by the photosensitive drum 1 made of an aluminum alloy having generally higher strength than the flange element, so that deformation of the element of flange 71 in the vicinity of the contact surface 71f can be suppressed. By suppressing the deformation of this flange element 71, the deformation of the supporting part 71c formed on the flange element 71 for rotatably supporting the photosensitive drum 1 is suppressed, so that the photosensitive drum 1 can be rotatably supported with high precision.

[0251] At least a part of the driving element 66 is arranged within the photosensitive drum 1 to place at least a part of the contact surface 71f within the photosensitive drum 1.

[0252] More strictly, at least a part of a contact part (drive part) of the drive element 66 that is in contact with the contact surface 71f is inside the photosensitive drum 1. In particular, in this embodiment, the entire drive element 66 is inside the photosensitive drum 1.

[0253] Furthermore, at least a part of the engaging element 65, the engaging part 65a, and the driving force receiving surface 65b are also within the photosensitive drum 1. That is, especially in this embodiment, the entire coupling 65 is inside the photosensitive drum 1.

[0254] A movable engagement element 65 and an elastically deformable pushing element 66 are inside the photosensitive drum 1, so that it is difficult for the user's hands to touch them. It is also suitable for protecting the engaging element 65 and the driving element 66.

[0255] In addition, by placing at least a part of the engagement element 65 within the photosensitive drum, the following effects are also provided.

[0256] That is, if the engagement element 65 is inside the photosensitive drum 1, the shaft part 101f in which the drive transmission groove 101a is formed also enters the inside of the photosensitive drum 1 when the cartridge 7 is mounted in the main set device (Figures 8 and 9). The drive transmission shaft 101 is supported in two locations and therefore the length between the support part 101d and a shaft part 101f is preferably to suppress the tilt of the drive transmission shaft 101 relative to the drum unit. . By moving the shaft part 101f into the photosensitive drum 1, it is easy to ensure the distance between the bearing part 101d and the shaft part 101f while keeping the main assembly of the device small.

[Main Assembly Drive Shaft Coupling Unit Removal]

[0257] With reference to Figure 10, Figure 20, Figure 21 and Figure 22, the operation of removing the coupling unit 28 from the main assembly drive shaft 101 will be described.

[0258] As shown in Figure 10, at the moment when the rotation drive of the main set drive shaft 101 is stopped, the drive force receiving surface 65b and the main set drive force transmitting surface 101b are in contact with each other. In this state, the engagement part 65a enters the main assembly drive transmission groove 101a.

[0259] When removal of the cartridge 7 from the main assembly of the imaging apparatus 100A is initiated, the tapered removal surface 65l of the engagement portion 65a abuts against the removed taper on the side of the main assembly 101i, as shown in Figure 22. The removal neck surface 65l abuts the removal neck on the side of the main assembly 101i, so that the drive member 66 begins to contract, and the engagement member 65 moves outward in the radial direction along with the neck. removal tool on the side of the main assembly 101i.

[0260] Furthermore, when the coupling unit 28 is pulled from the main assembly drive shaft 101, the state is the same as in Figure 21, and the driving element 66 is contracted, so that the engaging part 65a moves to the outer diameter of the shaft portion 101f of the main assembly drive shaft 101. As the engagement portion 65a moves to the outer diameter of the shaft portion 101f, the coupling unit 28 can be removed of the main assembly drive shaft 101.

[0261] Furthermore, when the coupling unit 28 is withdrawn from the main assembly drive shaft 101, the engagement element 65 returns to the position where the restraining portion 65j of the engagement member and the restraining portion 72j of the coupling element Flange cover are in contact with each other in that the position in the pushing direction is restricted, as shown in Figure 20, Figure 15.

[0262] With the above operation, the coupling unit 28 is removed from the main assembly drive shaft 101.

[0263] Here, as mentioned above, the drive force receiving surface 65b has a twisted shape around the axis of rotation of the flange element 71. The direction of twist is such that the outside (z1 direction side) of the drive force receiving surface 65b is on the upstream side of the inner side (Z2 direction side) relative to the rotation direction of the photosensitive drum 1.

[0264] In this state, when attempting to remove the coupling unit 28 from the main assembly drive shaft 101, a drive force receiving surface 65b is formed in a direction that prevents this removal operation. That is, as shown in Figure 26, the exterior (z1 direction side) of the drive force receiving surface 65b is on the upstream side of the interior (Z2 direction side) with respect to the direction of rotation and therefore if the coupling unit 28 is pulled from the main assembly drive shaft 101 in the removal operation, the removal load is greater than the insertion load.

[0265] Conversely, the main assembly drive shaft 101 can be rotated inversely from the moment the rotational drive of the main assembly drive shaft 101 is stopped and the removal of the cartridge 7 from the main assembly of the imaging 100A is started. In this way, after the state in which the driving force receiving surface 65b is in contact with the driving transmitting surface 101b is released, the cartridge 7 is removed from the main assembly of the image forming apparatus 100A and therefore removal charge can be reduced.

[0266] As a method of reverse rotation, in interrelationship with the operation of opening the cartridge door 104, the main assembly drive shaft 101 may be reversely rotated by a linkage mechanism or the like or the power source motor. Main assembly drive shaft drive 101 can be reversely rotated.

[0267] In the embodiment described above, the operation and effect of the present invention will be summarized.

[0268] In this embodiment, a coupling element 65 is provided which is movable in the radial direction within the coupling unit 28 and therefore it is possible to satisfactorily mount and dismount the cartridge 7 and transmit the drive through the coupling unit 28 without using a mechanism for retracting the main assembly drive shaft 101 in the axial direction.

[0269] The engagement part 65a formed in the engagement element 65 projects radially inwards from the bore part 72a of the coupling unit 28. In this way, it is possible to protect the engagement part 65a in the cartridge 7 constituted to be detachable from the main 100A device assembly.

[0270] Furthermore, the drive force receiving surface 65b formed on the engaging part extends radially inwardly. Therefore, after the engaging part has entered the groove part 101a of the main assembly drive shaft, the drive force receiving surface 65b and the drive transmission surface 101b formed in the groove part 101a come into contact with each other. with the other, thus allowing a satisfactory drive transmission.

[0271] Furthermore, the direction of the driving force F that the driving force receiving surface 65b receives in the normal direction during the driving of the coupling unit 28 is inclined inwardly in the radial direction of the photosensitive drum 1 relative to the direction tangential of the circle centered on the axis of rotation of the photosensitive drum 1. Furthermore, the direction of the driving force F is inclined with respect to the direction in which the engaging element 65 is movably guided, and the angle formed by it is a acute angle. Therefore, after the engaging part has entered the groove part 101a of the drive shaft of the main assembly, the drive force receiving surface 65b and the drive transmission surface 101b formed in the groove part 101a come into contact with each other. with the other, thus allowing a satisfactory drive transmission.

[0272] Furthermore, the direction of the driving force F that the driving force receiving surface 65b receives in the normal direction during the driving of the coupling unit 28 is inclined inwardly in the radial direction of the photosensitive drum 1 relative to the direction tangential of the virtual circle centered on the axis of rotation of the photosensitive drum 1. Furthermore, the direction of the driving force F is inclined with respect to the direction in which the engaging element 65 is movably guided, and the angle formed between them is an acute angle. This prevents a force from being exerted radially outwardly on the engagement member 65, thereby preventing the drive force receiving surface 65b from disengaging from the drive transmitting surface 101b and, additionally, the drive force from the main assembly drive shaft. 101 can be stably transmitted to the engagement element 65. Consequently, the driving stability of the photosensitive drum 1 is improved and therefore the image quality is improved.

[0273] Furthermore, the engagement element 65 is provided with a drive shaft abutment surface 65c abutting the outer peripheral surface of the shaft portion 101f of the main assembly drive shaft. Therefore, the rotational moment M produced in the engagement element 65 is supported by the drive shaft abutment surface 65c so that the engagement element 65 is more firmly supported, and the stability of the drive can be improved.

[0274] Furthermore, the direction of the driving force F received by the driving force receiving surface 65b in the normal direction is inclined outward in the longitudinal direction of the photosensitive drum 1 relative to the direction of the rotation axis of the photosensitive drum 1 In this way, it is possible to prevent a force from being applied to the main assembly drive shaft 101 in a direction in which the coupling unit 28 is disassembled in the axial direction.

[0275] Furthermore, in the engaging part 65a, a tapered insertion surface 65k is provided at one end on the outer side in the longitudinal direction of the photosensitive drum 1, and at the other end on the opposite side, a tapered removal surface 65l is provided . Thereby, when the cartridge is assembled or disassembled, by placing the narrowed insertion surface 65k or the narrowed removal surface 65l in contact with the groove portion 101a of the drive shaft of the main assembly, the cartridge 7 can be assembled and disassembled. without obstruction.

[0276] Furthermore, at least a part of the contact surface 71f with the thrust element provided on the flange element 71 is arranged in a position overlapping the photosensitive drum 1 in the longitudinal direction. The engaging element 65 receives a pushing force radially inwardly from the pushing element 66 and, on the other hand, the contact part 71f receives a force, in the radial direction, which is a reaction force of the pushing force. By arranging such a contact surface 71f inside the photosensitive drum 1, the deformation of the supporting part 71c formed in the flange element 71 is suppressed, and the photosensitive drum 1 can be rotatably supported with high precision.

<Mode 2>

[0277] With reference to Figures 27 to 47, Embodiment 2 will be described. The elements corresponding to those in the previous embodiment are denoted by the same names, and the description of the same points described above may be omitted in some cases. The description will mainly be made about points other than the elements mentioned above.

[0278] The coupling unit described in each of the previous embodiments is an element to which a drive force is transmitted to rotate the photosensitive drum 1. However, it is possible to use the coupling unit described above to rotate an element that does not the photosensitive drum 1.

[0279] As an example of such a case, in this embodiment, a coupling unit 4028 receives the driving force to rotate the developing roller and the toner supply roller.

[0280] The photosensitive drum 1, the developer roller 4017, and the toner supply roller 4020 are all rotating elements configured to rotate in a state in which a developer (toner) is conveyed on its surface.

[General Arrangement of Electrophotographic Image Forming Apparatus]

[0281] Referring first to Figure 27, the general structure of an embodiment of an electrophotographic image forming apparatus (image forming apparatus) according to this embodiment will be described.

[0282] Figure 27 is a schematic sectional view of the image forming apparatus 4100A of this embodiment.

[0283] As shown in Figure 27, the image forming apparatus 4100A includes, as a plurality of image forming sections, the first, second, third and fourth image forming unit SY, SM, SC and SK for forming images of respective colors, i.e. 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 line in a substantially horizontal direction.

[0284] In this embodiment, the structures and operations of the drum cartridges 4013 (4013Y, 4013M, 4013C and 4013K) are substantially the same as the drum cartridges 4013, except that the colors of the images to be formed are different from each other. The structures and operations of the 4004 developing cartridges (4004Y, 4004M, 4004C and 4004K) are substantially the same as those of the 4004 drum cartridges, with the difference that the colors of the images to be formed differ from each other. Therefore, from now on, Y, M, C, and K will be omitted and the explanation will be commonly applied unless otherwise noted.

[0285] In this embodiment, the image forming apparatus 4100A has cylinders (hereinafter called photosensitive drums) 1, each having a photosensitive layer, the cylinders being arranged side by side along a direction slightly inclined with respect to a vertical direction as a plurality of image rolling elements. A digitizing unit (exposure device) 4013 is disposed below the drum cartridge 4013 and the developing cartridge 4004 relative to the direction of the gravitational force. Furthermore, around the photoconductive drum 1, a charging roller 2 or similar functioning as a process means (process device, process element) acting on the photosensitive layer, is arranged.

[0286] The charging roller 2 is a charging means (charging device, charging element) for uniformly charging the surface of the photosensitive drum 1. The digitizing unit (exposure device) 3 is an exposure means (exposure device) , exposure element) to form an electrostatic image (electrostatic latent image) on the photosensitive drum 1 by exposing to a laser based on the image information. Around the photosensitive drum 1, a cleaning line 6 as cleaning means (cleaning device, cleaning element) and a developing cartridge 4004 are provided.

[0287] Furthermore, an intermediate transfer belt 5 as an intermediate transfer element for transferring the toner image from the photosensitive drum 1 to the recording material (sheet, recording medium) 12 is provided so as to face the four photosensitive drums 1.

[0288] In the developing cartridge 4004 of this embodiment, a contact developing method is employed in which a one-component non-magnetic developer (hereinafter called a toner) is used as a developer and a developing roller 4017 as a developer transport comes into contact with the photosensitive drum 1.

[0289] With the structure described above, 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 the actuable process medium in the photosensitive drum 1, the drum cartridge 4013 is provided with the loading roller 2 for loading the photosensitive drum 1, the cleaning blade 6 for removing the remaining toner without being transferred to the photosensitive drum 1. The residual untransferred toner remaining in the photosensitive drum 1 that has not been transferred to the sheet 12 is collected by the cleaning blade 6. Furthermore, the residual toner collected by the cleaning blade 6 is accommodated in a removed developer accommodation part (in then called a waste toner accommodation part) 4014a from the opening 4014b. The waste toner container 4014a and the cleaning blade 6 are integrated into a drum cartridge (photosensitive element unit, drum unit, image roller element unit) 4013.

[0290] The image forming apparatus 4100A is provided in the main assembly frame with guides (positioning means), such as a mounting guide and a positioning element (not shown). The developer cartridge 4004 and the drum cartridge 4013 are guided by the guides described above and are mountable and detachable from the imaging apparatus main assembly 4100A.

[0291] Toners of respective colors of yellow (Y), magenta (M), cyan (C) and black (K) are accommodated in developing cartridges 4004 for the respective colors.

[0292] The intermediate transfer belt 5 contacts the photosensitive drum 1 of each drum cartridge 4013 and rotates (moves) in the direction of arrow B in Figure 1. The intermediate transfer belt 5 is wound around a plurality of support elements 51 (a drive roller 51, an opposing secondary transfer 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 means are juxtaposed so as to face each photosensitive drum 1. A secondary transfer roller 9 as a secondary transfer means is disposed in a position facing the opposite secondary transfer roller 52 on the outer peripheral surface side of the intermediate transfer belt 5.

[0293] At the time of image formation, the surface of the photosensitive drum 1 is first uniformly loaded by the loading roller 2. Then, the surface of the photosensitive drum 1 thus loaded is scanned and exposed to the laser beam corresponding to the emitted image information from the digitizing unit 3. Thereby, 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 image of toner formed in the photosensitive drum 1 is transferred (primary transfer) to the intermediate transfer belt 5 by the operation of the primary transfer roller 8.

[0294] For example, when a color image is formed, the process described above is performed sequentially on the four drum cartridges 4013 (4013Y, 4013M, 4013C, 4013K) and on the four development cartridges 4004 (4004Y, 4004M, 4004C, 4004K ). The toner images of the respective colors formed on the photosensitive drums 1 of the respective drum cartridges 4013 are sequentially transferred primarily 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 transported to the secondary transfer part. The four-color toner images on the intermediate transfer belt 5 are generally transferred to the recording material 12 and transported to the secondary transfer part consisting of the intermediate transfer belt 5 and the secondary transfer roller 9.

[0295] The recording material 12 to which the toner image has been transferred is transported to a clamping device 10 as a clamping means. By applying heat and pressure to the recording material 12 in the clamping device 10, the toner image is fixed to the recording material 12. Furthermore, the residual primary transfer toner remaining in the photosensitive drum 1 after the primary transfer process is removed by the cleaning blade 6 and collected as waste toner. Furthermore, the residual secondary transfer toner remaining on the intermediate transfer belt 5 after the secondary transfer step is removed by the intermediate transfer belt cleaning device 11.

[0296] The image forming apparatus 4100A is also capable of forming monochromatic or multicolor images using single or some (not all) desired image forming units.

[Process Cartridge General Arrangement]

[0297] With reference to Figures 28, 29, 30 and 31, the description will be given as the general arrangements of the drum cartridges 4013 (4013Y, 4013M, 4013C, 4013K) and the developing cartridges 4004 (4004Y, 4004M, 4004C, 4004K) mountable to the main assembly of the image forming apparatus 4100A of this embodiment.

[0298] The 4013Y drum cartridge, the 4013M drum cartridge, the 4013C drum cartridge and the 4013K drum cartridge have the same structures. Furthermore, the 4004Y developing cartridge containing the yellow toner, the 4004M developing cartridge containing the magenta toner, the 4004C developing cartridge containing the cyan toner, and the 4004K developing cartridge containing the black toner have the same structures. Therefore, in the following description, each of the 4013Y, 4013M, 4013C, and 4013K drum cartridges will be commonly called a 4013 drum cartridge, and each of the 4004Y, 4004M, 4004C, and 4004K developing cartridge will be commonly called a 4004 developing cartridge. The respective components of the cartridge will also normally be described in the same manner.

[0299] Figure 28 is an external perspective view of the drum cartridge 4013. Here, as shown in Figure 28, the direction of the rotation axis of the photosensitive drum 1 is defined as a Z direction (arrow Z1, arrow Z2), the horizontal direction in Figure 27 as the X direction (arrow X1, arrow X2), the vertical direction is a Y direction (arrow Y1, arrow Y2) in Figure 27.

[0300] The drum unit bearing elements 4039R and 4039L are mounted on the sides of the cleaning frame 4014, respectively, and support the photosensitive drum unit 4030. Thus, the photosensitive drum unit 4030 is supported so as to be rotatable. in relation to the cleaning table 4014.

[0301] Furthermore, a loading roller 2 and a cleaning blade 6 are mounted on the cleaning frame 4014, and they are arranged to be in contact with the surface of the photosensitive drum 1. A loading roller bearing 15 is mounted to the cleaning frame 4014. The loading roller bearing 15 is a bearing for supporting the loading roller shaft 2.

[0302] Here, the loading roller bearings 15 (15R, 15L) are mounted so as to be movable in the direction of arrow C shown in Figure 29. A rotation axis 2a of the loading roller 2 is rotatably mounted to the loading roller 15 (15R, 15L). The loading roller bearing 15 is driven towards the photosensitive drum 1 by a pressure spring 16 as a driving means. As a result, the charging roller 2 rests against the photosensitive drum 1 and is rotated by the photosensitive drum 1.

[0303] The cleaning board 4014 is provided with a cleaning blade 6 as a cleaning means for removing toner remaining on the surface of the photosensitive drum 1. The cleaning blade 6 is formed by unitizing a blade-shaped rubber ( elastic element) 6a that rests against the photosensitive drum 1 to remove the toner in the photosensitive drum 1 and a metal support plate 6b that supports the blade-like rubber (elastic element) 6a. In this embodiment, the supporting metal plate 6b is fixed to the cleaning frame 4014 with screws.

[0304] As previously described, the cleaning frame 4014 has an opening 4014b for collecting residual transfer toner collected by the cleaning blade 6. The opening 4014b is provided with a blow-out prevention sheet 26 that is in contact with the drum photosensitive drum 1 and seal between the photosensitive drum 1 and opening 4014b to prevent toner from leaking into the top of opening 4014b.

[0305] Figure 30 is an external perspective view of the developing cartridge 4004.

[0306] Developing cartridge 4004 includes a developing frame 4018 for supporting various elements. In the developing cartridge 4004, a developing roller 4017 is provided as a developer support element that rotates in the direction of arrow D (counterclockwise direction) shown in Figure 31 in contact with the photosensitive drum 1. The developing roller 4017 is rotatably supported by the developing frame 4018 through the developing bearings 4019 (4019R, 4019L) on both end parts in relation to the longitudinal direction (direction of the axis of rotation) thereof. Here, developing bearings 4019 (4019R, 4019L) are mounted on the respective sides of the developing frame 4018, respectively.

[0307] Furthermore, as shown in Figure 31, the developing cartridge 4004 includes a developer-accommodating chamber (hereinafter referred to as a toner-accommodating chamber) 4018a and a developing chamber 4018b in which the developing roller 4017 is provided.

[0308] In the developing chamber 4018b, a toner supply roller 4020 is provided as a developer supply element that contacts the developing roller 4017 and rotates in the direction of arrow E, and a developing blade 21 as a developer adjusting element for regulating the toner layer of the developing roller 4017. The developing blade 21 is fixed and integrated with the fixing element 22 by welding or the like.

[0309] A stirring element 23 for agitating the contained toner and for transporting the toner to the toner supply roller 4020 is provided in the toner accommodation chamber 4018a of the developing frame 4018.

[Main Assembly Drive Shaft Structure]

[0310] With reference to Figures 32 and 33, the structure of the main assembly drive shaft 4101 will be described.

[0311] Figure 32 is an external view of the main assembly drive shaft 4101.

[0312] Figure 33 is a cross-sectional view taken along the axis of rotation (axis of rotation) of the main assembly drive shaft 4101 mounted on the main assembly of the image forming apparatus.

[0313] As shown in Figure 32, the main assembly drive shaft 4101 comprises a gear element 4101e, an intermediate element 4101p, an output element 4101q, and a drive transmission element 4101r.

[0314] A motor (not shown) as a drive source is provided in the main assembly of the image forming apparatus 4100A. From this motor, the gear element 4101e is provided with a rotational drive force, and the drive force is transmitted in order to the intermediate element 4101p, the output element 4101q, and the drive transmission element 4101r, from way that the main assembly drive shaft 4101 rotates. The gear element 4101e, the intermediate element 4101p and the output element 4101q constitute an Oldham coupling mechanism, movement which is possible in the X direction and Y direction within a certain distance. Therefore, the drive transmission element 4101r provided through the Oldham coupling on the cartridge side of the drive shaft of the main assembly 4101 can also move within a certain distance in the X direction and Y direction. 4101r is provided with a rotating shaft part 4101f, and the rotary drive force received from the motor is transmitted to the side of the developing cartridge 4004 through a groove-shaped drive transmission slot 4101a (a recessed part , a drive passage part) provided in shaft part 4101f. Furthermore, the shaft portion 4101f has a conical shaped portion 4101c at its free end.

[0315] The main assembly drive transmission slot 4101a is such that a part of an engagement part 4065a, which will be described below, can enter. Specifically, it is provided with a main assembly drive transmitting surface 4101b as a surface that contacts the drive force receiving surface (drive force receiving part) 4065b of the coupling unit 4028 to transmit the drive force.

[0316] Furthermore, as shown in Figure 32, the main assembly drive transmission surface 4101b is not a flat surface, but a twisted shape around the axis of rotation of the main assembly drive shaft 4101. twist is such that the downstream side in the Z1 direction of the main assembly drive shaft 4101 is upstream of the downstream side in its Z2 direction, relative to the direction of rotation of the main assembly drive shaft 4101. In this embodiment, the amount of twist along the direction of the cylinder rotation axis of the coupling part 4065a is set to approximately 1 degree per 1 mm. The reason why the 4101b main assembly drive transmission surface is twisted will be described below.

[0317] Furthermore, a disassembly neck on the side of the main assembly 4101i is provided on a side surface downstream with respect to the Z2 direction of the main assembly drive transmission groove 4101a. The disassembly tapered part on the main assembly side 4101i has a taper (slanted surface, inclined part) to assist the engagement part 4065a in being disengaged from the drive transmission groove 4101a when disassembling the developing cartridge 4004 from the main apparatus assembly. 4100A.

[0318] As shown in Figure 33, a supported part 4101d provided in the gear element 4101e is rotatably supported (axially supported) by a bearing element 4102 provided in the main assembly of the image forming apparatus 4100A. The output element 4101q is rotatably supported by a coupling bracket 4101s. Furthermore, the drive transmission element 4101r is supported by the output element 4101q so as to be moved in the Z direction, and is driven toward the developing cartridge 4004 (the Z2 direction) by the spring element 4103. However, the moving amount (play) of the drive transmission element 4101q in the Z direction is approximately 1 mm, which is sufficiently smaller than the width of a drive force receiving surface 4073a which will be described below, in the Z direction.

[0319] Furthermore, the coupling bracket 4101s is driven in the substantially Y2 direction by the drive spring 4101t. Therefore, as will be described below, when assembling the developing cartridge 4004, the drive transmission element 4101r is in a position offset in the direction substantially Y2 with respect to the axis line of the gear element 4101e.

[0320] As described above, the drive transmission element 4101r is provided with the main assembly drive transmission groove 4101a, and the coupling unit 4028 is provided with the engagement (projection, protrusion) part 4065a, so that the drive is transmitted from the main apparatus assembly 4100A to the developing cartridge 4004.

[0321] As will be described in detail below, the engaging part 4065 is formed in the engaging element (sliding element, moving element, driving force receiving element) 4065 which is movable in the state of being driven by the driving element . Therefore, the engaging part 4065a is configured to be externally movable at least in the radial direction when the developing cartridge 4004 is mounted on the main body of the apparatus 4100A. Thereby, as the developing cartridge 4004 is inserted into the main body of the apparatus 4100A, the engagement portion 4065a enters the drive transmission groove 4101a, and the engagement portion 4065a and the main assembly drive transmission groove 4101a can engage each other.

[Coupling Unit Structure]

[0322] Next, with reference to Figures 34, 35, 36, 37, 38 and 39, the coupling unit 4028 of the present embodiment will be described in detail. Figure 34 is a perspective view in which the coupling unit 4028 is coupled to the toner supply roller 4020.

[0323] Figure 35 is a perspective view of the engagement element 4065, part (a) of Figure 35 is a perspective view seen from the upper left, and part (b) of Figure 35 is an enlarged view. perspective seen from the top right.

[0324] Figure 36 is a perspective view of elements constituting the coupling unit 4028.

[0325] Figure 37 is a perspective view of the coupling unit 4028 and the toner supply roller 4020.

[0326] Figure 38 is a cross-sectional view illustrating a state in which the coupling unit 4028 is engaged with the drive transmission element 4101r.

[0327] Figure 39 is a sectional view of the developing cartridge 4004.

[0328] The coupling unit 4028 of this embodiment is different from the coupling unit 28 of Embodiment 1 in that the element to be driven is the toner supply roller 4020, but, except for this, it has similar structures.

[0329] As shown in Figure 34, the coupling unit 4028 is provided with three engagement parts 4065a that engage with the drive transmission element 4101r. The engagement part 4065a fits into the groove part 4101a of the drive transmission element 4101r, as shown in Figure 38, and the drive transmission is performed.

[0330] In the following, the structure of the coupling unit (coupling element) 4028 will be specifically described. As shown in the perspective view of Figure 36 and the cross-sectional view of Figure 38, the coupling assembly 4028 includes a coupling cover element 4071, a coupling support element 4072, an engagement element 4065, and a coupling element 4065. impulsion 4066.

[0331] The coupling cover element 4071 is a cylindrical element including a hollow part, and the coupling support element 4072 is disposed in the internal space of the coupling cover element 4071.

[0332] The coupling support element 4072 is a retaining element that holds the coupling element 4065 in a sliding manner.

[0333] As shown in Figure 38, the engagement member 4065 including an engagement portion 4065a is supported within the coupling unit 4028, in the state of being driven by the driving member 4066 in a direction radially inwardly towards the coupling unit 4028 .

[0334] As shown in Figure 35, the coupling element 4065 is provided with a first guided surface 4065d and a second guided surface 4065e, so as to be movably guided radially in the coupling unit. Furthermore, a third guided surface 4065f and a fourth guided surface 4065g are provided in order to regulate the position of the engaging element 4065 in the axial direction.

[0335] As in Embodiment 1, the first to fourth guided surfaces (4065d, 4065e, 4065f, 4065g) are the parts guided by the coupling support element 4072 and the position constraint part (part to be constrained in position). The coupling support member 4072 has first to fourth guide surfaces corresponding to the first to fourth guided surfaces as in Embodiment 1.

[0336] The engaging element 4065 has a contact surface (a driven part, a pressed part) 4065h for receiving the pushing force by the pushing element 4066. Furthermore, the engaging element 4065 has a position constraint projection 4065i to constrain the position of the engagement member 4065 being brought into contact by the coupling support member 4072 by the pushing force of the pushing member 66, and includes a pushing force position restraining surface 4065j formed in the thrust restraining projection. position. As in Embodiment 1, the pushing force position restraining surface 4065j is an engaged part that is retained and locked in radial internal movement by the coupling support member 4072.

[0337] Engagement member 4065 also has a narrowed insertion surface 4065k.

[0338] The coupling support element 4072 is provided with a coupling hole portion 4072a for passing the drive transmission element 4101r and a mounting hole portion 4072b for supporting the engagement element 4065 movably in the radial direction .

[0339] As shown in Figure 36, the coupling cover element 4071 has a cylindrical shape, and is mounted on the outer peripheral surface 4072k of the coupling support element 4072.

[0340] Drive element 4066 is an elastically expandable and contractile element (helical compression spring), which 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.

[0341] The coupling element 4065 is driven at least toward the inner side (radially inward) of the coupling unit 4028 by the driving element 4066. The driving element 4066 is compressed into a state that lies 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 a direction in which the pushing member 4066 expands, it drives the engaging member 65.

[0342] The engagement member 4065 is supported by the coupling support member 4072 in a state in which the engagement portion 4065a of the engagement member 4065 is exposed through the bore portion 4072a of the coupling support member 4072. Furthermore Similarly, the drive shaft contact surface 4065c formed in an arc shape on the coupling member 4065 is exposed through the bore portion 4072a of the coupling support member 4072.

[0343] The engagement portion 4065a of the engagement member 4065 projects inwardly in the radial direction from the inner peripheral surface of the bore portion 4072a of the coupling support member 4072. The amount of projection is an amount sufficient for the portion 4065a fits securely into groove 4101a on the drive shaft. This projection amount is a suitable amount for the drive force receiving surface 4065b formed on the engaging part 4065a to have the resistance corresponding to the loading torque of the toner supply roller 4020, which is the element to be rotated. This projection amount only needs to be such that the engagement part 4065a can stably transmit the driving force from the main assembly drive shaft 4101.

[0344] In the case of this embodiment, the projection amount of the engagement part 4065a is preferably 1 mm to 3 mm. That is, the distance from the inner surface of the coupling support element 4072 to the free end of the coupling part 4065a measured along the radial direction of the coupling element is 1 mm to 3 mm.

[0345] Furthermore, similarly, the contact surface of the drive shaft 4065c of the engagement element 4065 projects further inwardly in the radial direction beyond the inner circumferential surface of the bore portion 4072a of the flange cover element 4072. In the case In this embodiment, the amount of projection is preferably 0.3 mm to 1 mm, so that the contact surface of the drive shaft 4065c projects reliably from the inner peripheral surface of the bore part 4072a even when the dimensions of each part vary.

[0346] In addition, as shown in Figure 37, the coupling support 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 toner 4020 and the coupling unit 4028 rotate integrally due to the rotation stop formed in the hole part 4072h and the shaft part 4020a. That is, in this embodiment, unlike Embodiment 1, the coupling unit 4028 is fixed to the shaft (shaft part 4020a) of the rotating element (toner supply roller). The coupling unit 4028 is located coaxially with the toner supply roller 4020.

[0347] Here, the distance from the axis (center) of the coupling unit 4028 to the drive force receiving part (drive force receiving surface 4065b) is greater than the radius of the shaft part 4020a. By doing this, the force applied to the drive 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.

[0348] As shown in Figure 39, the toner supply roller 4020 has a gear 4098 on the opposite side (non-drive side) to the drive side to which the coupling unit 4028 is mounted. This gear meshes with gear 4099 mounted on the shaft of the developing roller 4017.

[0349] When the toner supply roller 4020 is rotated by the drive force transmitted from the coupling unit 4028, the developing roller 4017 also rotates by the two gears.

[Assembling the Cartridge to the Main Assembly of the Image Forming Apparatus]

[0350] With reference to Figures 154 and 155, the assembly and disassembly of the developing cartridge 4004 in relation to the main assembly of the image forming apparatus will be described.

[0351] Figure 40 is a perspective view illustrating the assembly of the developing cartridge 4004 to the main assembly of the image forming apparatus 4100A.

[0352] Figures 41, 42 and 43 are cross-sectional views illustrating the operation of assembling the developing cartridge 4004 to the main assembly of the image forming apparatus 4100A.

[0353] The main assembly of the image forming apparatus 4100A of this embodiment employs a structure in which the developing cartridge 4004 and the drum cartridge 4013 can be mounted in a horizontal direction. Specifically, the main assembly of the image forming apparatus 4100A includes a space in which the developing cartridge 4004 and the drum cartridge 4013 can be mounted. Cartridge door 4104 (front door) to allow insertion of developing cartridge 4004 and drum cartridge 4013 into the space is provided on the front side of the main assembly of image forming apparatus 4100A (the side that the user uses).

[0354] As shown in Figure 40, the cartridge door 4104 of the main assembly of the image forming apparatus 4100A is provided for opening and closing. When the cartridge door 4104 is opened, the lower cartridge guide rail 4105 for guiding the developing cartridge 4004 is provided at the bottom of the space, and the upper cartridge guide rail 4106 is arranged on the upper surface. The developing cartridge 4004 is guided into the mounting position by the upper and lower guide rails (4105, 4106) provided above and below the space. The developing cartridge 4004 is inserted into the mounting position substantially along the axis of the developing roller 4020.

[0355] With reference to Figures 41, 42 and 43, the assembly and disassembly operations of the developing cartridge 4004 to the main assembly of the image forming apparatus 4100A will be described below.

[0356] As shown in Figure 41, the developing cartridge 4004 is inserted in the state that the lower part of the end part on the rear side in the insertion direction is supported and guided by the lower cartridge guide rail 4105, and the upper side from the end part thereof on the rear side in the insertion direction is guided by the upper cartridge guide rail 4016. There is a dimensional relationship such that the intermediate transfer belt 5 does not come into contact with the development frame 4018 or the development roller 4019.

[0357] As shown in Figure 42, the developing cartridge 4004 is inserted horizontally while being supported by the lower cartridge guide rail 4105, and is inserted until it touches the rear cartridge positioning part 4108 provided in the main assembly of the forming apparatus of image 4100A.

[0358] When the developing cartridge 4004 is assembled in this manner, the drive transmission element 4101r of the main assembly of the image forming apparatus 4100A is engaged with the coupling unit 4028 while being driven substantially in the Y2 direction.

[0359] Figure 43 is an illustration of the state of the main assembly of the image forming apparatus 4100A and the developing cartridge 4004 in a state in which the cartridge door 4104 is closed. The lower cartridge guide rail 4105 of the main assembly of the image forming apparatus 4100A is configured to move up and down in interrelation with the opening and closing of the cartridge door (front door) 4104.

[0360] When the user closes the cartridge door 4104, the lower cartridge guide rail 4105 is raised. Then, both end parts of the developing cartridge 4004 come into contact with the cartridge positioning parts (4108, 4110) of the main assembly of the image forming apparatus 4100A, and the developing cartridge 4004 is positioned relative to the assembly. of the 4100A image forming apparatus. Furthermore, the drive transmission element 4101r of the main assembly of the image forming apparatus 4100A also follows the developing cartridge 4004 so as to move upward.

[0361] By the operation described above, the assembly of the developing cartridge 4004 to the main assembly of the image forming apparatus 4100A is complete.

[0362] Furthermore, the operation of disassembling the developing cartridge 4004 from the main assembly of the imaging apparatus 4100A is performed in the reverse order of the insertion operation described above.

[Process of Attaching the Coupling Unit to the Main Assembly Drive Shaft]

[0363] With reference to Figures 44, 45, 46 and 47, the engagement process of the coupling element 4028 and the main assembly drive shaft 4101 will be described in detail.

[0364] Figures 44, 45, 46 and 47 are cross-sectional views illustrating the assembly operation of the coupling element 4028 on the drive shaft of the main assembly 4101.

[0365] Figure 44 is an illustration of a state in which the coupling element 4028 begins to engage with the drive transmission element 4101r. Furthermore, Figure 47 shows a state in which the developing cartridge 4004 is mounted on the imaging apparatus main assembly 4100A. Particularly, Figure 47 shows a state in which the lower cartridge guide rail 4105 is lifted when the cartridge door 4104 closes, and the developing cartridge 4004 is positioned relative to the main assembly of the imaging apparatus 4100A.

[0366] Here, Figures 45 and 46 are illustrations of the assembly process of the coupling unit 4028 and the drive transmission element 4101r between the positions shown in Figure 44 and Figure 47. The drive transmission element 4101r is driven substantially in the Y2 direction by the bias spring 4101t and the shaft of the drive transmission element 4101r is urged to a position offset substantially in the Y2 direction from the shaft of the coupling unit 4028.

[0367] As described with reference to Figure 40, the developing cartridge 4004 is inserted horizontally while being supported by the lower cartridge guide rail 4105 of the imaging apparatus main assembly 4100A.

[0368] Figure 44 is an illustration of a state before the drive transmission element 4101r is engaged with the coupling unit 4028. As described above, in this state, the shaft of the drive transmission element 4101r and the drive shaft of coupling 4028 are deviated from each other. Accordingly, the conical shaped part 4101c of the drive transmission element 4101r is brought into contact with the narrowed surface 4072p formed in an inlet of the bore part 4072a of the coupling of the support element 4072 of the coupling unit 4028.

[0369] As shown in Figure 45, the coupling unit 4028 is further inserted towards the rear side of the drive transmission element 4101r from the position of Figure 44. Then the narrowed insertion surface 4065k of the coupling element 4065 guides the tapered portion 4101c of the drive transmission element 4101r such that the axis of the coupling unit 4028 and the axis of the drive transmission element 4101r become substantially aligned.

[0370] As shown in Figure 46, the coupling unit 4028 is further inserted towards the rear side of the drive transmission element 4101r from the position of Figure 45. Then, the coupling unit 4028 is inserted into the drive element drive transmission 4101r to the narrowed disassembly surface 4073e of the engagement element 4065 go to the rear side in the Z direction past the disassembly narrowing on the main assembly side 4101i of the drive transmission element 4101r.

[0371] The coupling unit 4028 is further inserted into the drive transmission element 4101r. Then, the conical recess 4072m, which is a positioning part formed in the coupling support element 4072 of the coupling unit 4028, and the conical shaped part 4101c of the drive transmission element 4101r are brought into contact with each other.

[0372] Thereafter, as described above, the developing cartridge 4004 is lifted by the lower cartridge guide rail 4105 so that the developing cartridge 4004 is positioned in place relative to the main assembly of the image forming apparatus 4100A (shown in Figure 43). At this time, as shown in Figure 47, the drive transmission element 4101r also rises as the developing cartridge 4004 moves upward.

[0373] As described above, as the developing cartridge 4004 is mounted on the apparatus main assembly 4100A, the main assembly drive transmission slot 4101a and the engagement portion 4065a can be engaged together. Therefore, it is not necessary to move the main assembly drive shaft 4101 to engage with the coupling unit 4028. That is, there is no need to provide a mechanism for moving the main assembly drive shaft 4101 so as to engage with the coupling unit 4028. coupling 4028, on the main apparatus assembly 4100A of the image forming apparatus.

[0374] That is, it is not necessary to provide a mechanism to move the main assembly drive shaft 4101 in order to engage with the coupling unit 4028 after mounting the development cartridge 4004 to the main assembly of the image forming apparatus 4100A .

[0375] When the development cartridge 4004 is mounted to the main assembly of the apparatus 4100A, the coupling part 4065 of the coupling unit 4028 comes into contact with the main assembly drive shaft 4101 to retreat radially outwards. The engagement portion 4073 is configured to engage the groove (main assembly drive transmission groove 4101a) of the main assembly drive shaft 4101 by moving radially inwardly.

[0376] Here, it is also possible to provide a groove for receiving the drive in the coupling element, and a movable part engageable with the groove, moving in the radial direction is provided on the side of the main assembly drive shaft 4101. However , compared with the developing cartridge 4004, the main assembly of the image forming apparatus 4100A is required to have greater durability. It is preferred to provide the moving part (the engaging part 4065) that moves in the radial direction, as in this embodiment, on the side of the coupling unit 4028 of the developing cartridge 4004, from the point of view of increasing the durability of the main assembly. of the 4100A image formation apparatus.

[0377] The engagement element 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 apparatus) 4004. Therefore, the coupling unit 4028 in this embodiment also has the same operations and effects as the coupling unit 28 described in Embodiment 1 according to the present invention. The coupling unit structure shown in this embodiment can be used as a coupling unit for rotating the photosensitive drum 1.

[0378] Here, the coupling unit structure shown in this embodiment can be used as a coupling unit for rotating the photosensitive drum 1.

<Mode 3>

[0379] With reference to Figures 48 to 50, Modality 3 will be described. In this example, compared to the previous embodiment, the shape of the engagement part of the engagement element is different. The explanation will mainly be given as to the form of this coupling part.

[0380] Here, as in Embodiment 1, the docking unit provided in the drum cartridge will be described as an example, but it can also be used for a docking unit provided in a developing cartridge.

[Engagement Part of Coupling Element]

[0381] Part (a) of Figure 48 and Part (b) of Figure 48 are perspective views of the engagement element 5065 in this embodiment, and Part (c) of Figure 48 is a front view thereof. Figure 49 is a sectional view of the coupling unit. Figure 49 is a view illustrating a state in which a driving force is applied from the main assembly drive shaft 101 to the coupling unit 5028, and is an enlarged partial view of the coupling unit 5028. More particularly, Figure 49 is a sectional view taken along a plane perpendicular to the axis of the coupling unit 5028 (drum unit axis).

[0382] As shown in Figures 48 and 49, as in the case of Embodiment 1, the coupling element 5065 is provided with a coupling part 5065a projecting inwardly in the radial direction of the photosensitive drum 1. The free end side of this Engagement part 5065a is rounded and widens (projects) toward the upstream side in the direction of rotation of the drum unit.

[0383] More particularly, the engaging part 5065a is provided with a projection (enlarged part) 5065m having a semicircular shape that projects in the circumferential direction towards the side on which the abutment surface of the drive shaft 5065c is formed, and a recess 5065n is provided on the part of the coupling part 5065a in relation to the projection 5065m. That is, projection 5065m is a part that projects (widens) to the upstream side in the direction of rotation of the drum unit relative to recess 5065n. In contrast, undercut 5065n is a part that is undercut toward the downstream side in the direction of rotation relative to projection 5065m.

[0384] Figure 49 shows a state in which a drive force F is applied from the drive transmission surface 101b of the drive shaft of the main assembly 101 to the engagement part 5065a having such shape. A recess 5065n is formed in the base part of the engagement part 5065a projecting from the engagement member 5065 and therefore the corner part on the input side 101j on the drive transmission surface side 101b can enter the recess. 5065n in the groove 101a of the main assembly drive shaft 101. Through this, the engaging part 5065a receives a drive force F acting in a direction normal to the drive transmission surface 101b, and the drive transmission is performed.

[0385] That is, the drive force receiving part 5065r for receiving the drive force from the drive transmission surface 101b is facing at least radially outward from the coupling unit. Therefore, the drive force F received by the drive force receiving part 5065r from the drive transmission surface 101b is applied towards the inner side in the radial direction of the coupling unit. The engagement portion 5065a and the actuation force receiving portion 5065r are driven inwards at least in the radial direction (i.e. the rear side of the actuation transmission slot 101a).

[0386] As a result, the engagement part 5065a and the drive force receiving part 5065r can stably engage with the drive transmission slot 101a.

[0387] The shape of the engagement portion 5065a will be described in more detail. As shown in Figure 49, when a tangent line T parallel to the direction of movement S of the coupling element 5065 is drawn to projection 5065m, the tangent line T and projection 5065m have an apex 5065p as a contact point. The apex 5065p projects from the base portion 5065q of the hook portion 5065a and a position spaced apart by a distance L3 along the direction of movement S of the hook member 5065.

[0388] Between the apex 5065p and the base part 5065q, a recess 5065n recessed from the tangent line T is formed. When the corner part 101j of the drive shaft enters the recess 5065n, the engagement part 5065a can receive the drive force F in the contact part (drive force receiving part 5065r) with the drive transmission surface 101b arranged in the recessed part 5065n.

[0389] The surface on which the driving force receiving part 5065r is provided (the curved surface between the apex 5065p and the base part 5065q) is inclined with respect to the direction of movement of the engaging element 5065 and faces the outside at least in the radial direction of the coupling unit. That is, the normal vector of the drive force receiving part 5065r (a vector extending perpendicular to the drive force receiving part 5065r in the direction in which the drive force receiving part 5065r faces) has a component radially external. As shown in parts (a) and (b) of Figure 49, the driving force F is a force that acts perpendicular to the driving transmitting surface 101b and the driving force receiving part 5065r. Therefore, the driving force F has an inwardly directed component in the radial direction.

[0390] In addition, the driving force F is a force that is applied in a direction inclined by an angle with respect to the direction of movement S of the coupling element 5065. Therefore, as shown in part (b) of Figure 49, the driving force F has a force FS as a component of the direction of movement S of the coupling element. This force FS prevents the engagement member 5065 from moving toward the opposite side in the direction of movement S and prevents the drive force receiving portion 5065r of the engagement member from being disengaged from the drive transmission surface 101b of the drive shaft. drive the main assembly to the outside.

[0391] Here, in Figure 49, as an example of the shape of the projection (widened part) 5065m, a circular shape has been shown, but the shape of the projection is not limited to that, and it is sufficient that the engagement part 5065a is formed so as to produce the force FS from the driving force F. That is, it will be sufficient if in relation to the tangent line T, an apex 5065p serving as a point of contact were formed at a position projecting from the part of base 5065q of the coupling part, and a recessed part 5065n recessed from the tangential line T were formed between the apex 5065p and the base part 5065q.

[0392] It will be sufficient if the transverse shape of the projection (enlarged part) 5065m was engaged with the drive transmission slot 101a. For example, a substantially circular polygon (such as a pentagon) can also be used as an enlarged part. The shape of the cross section may be elliptical or similar. Such an example will be explained in Figure 55 of Mode 4.

[0393] Here, as mentioned above, in this embodiment, it is desirable that a contact part (drive force receiving part) 5065r for contacting the drive transmission surface 101b be arranged between an apex 5065p and a part base 5065q of the projection (extended part) 5065m.

[0394] As described above, in order for the drive transmission surface 101b to reliably contact the contact part 5065r, it is preferred that at least the engagement element 5065 can move more than the distance from the center to the surface in transverse fashion. of the 5065m projection. That is, it is preferred that the engagement element 5065 is movable beyond the radius of the transverse shape of the projection 5065m. Even more preferably, it can move with a margin beyond the 5065m projection width (i.e., greater than the diameter).

[0395] Here, if the amount of movement of the engagement element 5065 is small, the projection 5065m comes into contact with the drive transmission groove 101a on a freer end side of the projection 5065m than the apex 5065p. In this case, when the projection 5065m receives the driving force, there is a possibility that a force in a direction away from the driving transmission groove 101a will be applied to the engagement element 5065. Therefore, in order to ensure the engagement state between the engagement element 5065 and the drive transmission groove 101a, it is preferred that the pushing force of the drive element to drive the engagement element 5065 is increased or the frictional force generated between the projection 5065m and the drive transmission groove drive 101a is increased. Taking these measures, it is difficult for the engagement member 6065 to retract from the drive transmission groove 101a.

[0396] Next, with respect to Figure 50 and Figure 51, a modified example of Embodiment 3 will be described. As shown in Figure 50, the entire engagement portion 6065a is an enlarged portion formed into a substantially circular shape. It is formed in such a simple way that it is possible to easily manage the dimensional accuracy of the 6065a coupling part.

[0397] The engagement part 6065a also has an apex 6065p as a point of contact with a tangential line T parallel to the direction of movement S of the engagement element 6065. Furthermore, the apex 6065p projects from the base part 6065q of the engaging part at a position separated by the distance L4 along the direction of movement S. And, between the apex 6065p and the base part 6065q of the engaging part, a recessed part 6065n recessed from the tangent line T is provided. Between the apex 6065p and the base part 6065q of the engagement part, a contact part (a drive force receiving part 6065r) for contacting the drive transmission surface 101b is also provided. This contact part (drive force receiving part) 6065r is facing in a direction to generate a force FS as a component produced in the opposite direction to the direction of movement S of the engagement element with respect to the drive force F. As a As a result, it is possible to prevent the engagement element 6065 from being disengaged from the drive transmission surface 101b of the main assembly drive shaft to the outside.

[0398] The surface (the curved surface between the apex 6065p and the base part 6065q of the engagement part) on which the abutment part (actuation force receiving part) 6065r is provided is inclined with respect to the direction of movement S of the engagement element 6065. To be more specific, the tangent of the actuation force receiving part 6065r is inclined with respect to the movement direction S.

[0399] The drive force receiving part 6065r is facing outwards at least in the radial direction of the coupling unit. That is, the normal vector of the driving force receiving part 6065r facing the side in which the driving force receiving part 6065r is facing has at least one radially external component of the coupling unit.

[0400] Here, the cross-sectional shape of the engagement part (enlarged part) projection 6065a is not necessarily rounded, but may be a suitable protuberance for engaging with the drive transmission groove 101a. For example, a substantially circular polygon (such as a pentagon) is also suitable as an enlarged part. The shape of the cross section may be elliptical or similar.

[0401] Furthermore, so that the abutment part (drive force receiving part) 6065r arranged between the apex 6065p and the base part 6065q safely comes into contact with the drive transmission surface 101b, it is preferred that the momentum of the coupling element 6065 satisfies the following condition. That is, it is preferred that the engagement member 6065 is movable beyond the distance from the center to the surface in the cross section of the engagement portion 6065a. That is, it is preferred that the engagement element 6065 (engagement part 6065a) is movable beyond the radius of the cross-sectional shape of the engagement part 6065a.

[0402] More preferably, the engaging portion 6065a is movable beyond the width (i.e., the diameter) of the cross-sectional shape of the engaging portion of the engaging element 6065a.

<Mode 4>

[0403] With reference to Figures 52 to 57, Embodiment 4 will be described. In this embodiment, the structures corresponding to the engagement element and the impulsion element are integrated and formed with the resin. Here, as in Embodiment 1 and Embodiment 3, the coupling unit provided in the drum cartridge will be described as an example, but it can also be used for a coupling unit provided in a developing cartridge.

[0404] Parts (a) and (b) of Figure 52 are cross-sectional views of the drum unit. Part (a) of Figure 52 shows a state in which the engaging part 565a is engaged with the drive transmission groove 101a to receive a drive force. Part (b) of Figure 52 shows a state before the engagement part 565a and the drive transmission slot 101a are engaged.

[0405] Like Embodiment 1 and Embodiment 3, a flange element 571 is mounted inside the photosensitive drum 1. This flange element 571 is a coupling unit (coupling element) in this embodiment.

[0406] A support part 565 for movably supporting the actuation force receiving part 565r is integrally formed with the flange element 571 in the flange element 571. Three support parts 565 are provided in the flange element 571. Each of these brackets 565 is provided with extensions 565t, an enlarged portion (engagement portion 565a) provided at the free end of the extension portion; a connecting part 565s for connecting the extension part 565t and the coupling part 565a together.

[0407] The extension part 565t is connected to the inner periphery of the flange element 571. That is, the fixed end 565t of the extension part 565t is provided on the inner periphery of the flange element 571. The extension part 565t extends to from the fixed end 565t towards the interior of the hollow portion of the flange member 571. Details will be described below, but the extension portion 565t is an elastic portion capable of being elastically deformed.

[0408] Furthermore, the free end side (i.e., the side where the connecting part 565s is provided) of the extension part 565t is located on a side further downstream in the direction of rotation R of the drum unit ( coupling) than the fixed end 565t1 of the extension part 575t. That is, the extension part 565t extends from the fixed end 565t1 in the direction of the free end at least on the downstream side in the direction of rotation R. The free end of the extension part 575t (i.e., the connection part 565s and the engagement part 565a) is located radially inwardly from the fixed end 565t1 of the extension part 575t.

[0409] The engagement part 565a is a flared part provided at the end of the extension part 565t and is a part for entering the drive transmission groove 101a of the main assembly drive shaft 101. The engagement part 565a is connected by a connecting part 575s provided at the free end of the extension part 575t. The connecting part 575s is a part formed by flexing the free end side of the extension part 565t. The coupling part 565a and the connecting part 565 are projections (projections) projecting in a direction intersecting the extension direction of the extension part 565t.

[0410] The engaging part 565a is provided with a driving force receiving part 565r. As shown in part (a) of Figure 52, the drive force receiving part 565r contacts the drive transmission groove 101a to receive the drive force. When the driving force receiving part 565r receives the driving force, this driving force is transmitted to the flange element 571 through the fixed end 565t1 of the supporting part 565. The flange element 571 is fixed to the photosensitive drum 1 and therefore the flange element 571 and the photosensitive drum 1 are integrally rotated.

[0411] The extension part 575t and the engagement part 565a are formed integrally with the flange member 570. The extension part 575t and the engagement part 565a are parts of the support part 565 that movably support the receiving drive force 565r.

[0412] As described previously, the extension part 565t can be elastically deformed. That is, as shown in part (b) of Figure 52, during the process of inserting the cartridge 7 into the main assembly of the apparatus, the engaging part 565a comes into contact with the outer circumferential surface of the main assembly drive shaft 101. Then, the extension part 565a is elastically deformed so that the engaging part 565a moves outwards at least in the radial direction of the coupling unit.

[0413] Here, the extension part 565t is deformed to lean with its own fixed end 565t as a fulcrum. As a result, the engagement portion 565a moves in a direction that crosses the extension direction of the extension portion 565t.

[0414] After the cartridge 7 is inserted into the main assembly of the apparatus, when the drive shaft of the main assembly 101 is rotatably driven, the engagement part 565a enters the interior of the drive transmission groove 101a, at the moment when the phases of the engagement part 565a and the drive transmission slot 101a coincide with each other.

[0415] That is, by elastically deforming at least a part of the extension part 565t, the engagement part 565a is driven into the drive transmission slot 101a. The extension part 565t can be considered as a pushing part for driving the engaging part 565a inwardly at least in the radial direction.

[0416] That is, the engagement part 565a is driven towards the inside of the drive transmission slot 101a by the elastic force (thrust force) of the extension part 565t. The extension part 565t has a function corresponding to the pushing element 72 in Embodiment 1. That is, the supporting part 565 is a part that also serves as the pushing element 72 and the function of the engaging element 65 in Embodiment 1.

[0417] At least a part of the support part 565 and at least a part of the drive force receiving part 565r provided in the support part 565 are arranged inside the photosensitive drum 1 (Figure 52). That is, the same as the driving element 72 and the engaging element 65 in Embodiment 1.

[0418] Here, inside the photosensitive drum 1, the flange element 571 is held in the photosensitive drum 1 and therefore the flange element 571 is not easily deformed. Particularly, if at least a part of the fixed end 565t of the support part 565 is disposed within the photosensitive drum 1, such a structure is preferred from the point of view of suppressing deformation of the flange element 571, even if a driving force is transmitted to the flange member 571 via the fixed end 565t.

[0419] Here, the extension part is made of resin, but the elastic force or resistance of the extension part can be increased by inserting an elastic metal (for example, leaf spring) into the resin that constitutes the extension part extension.

[0420] When the engagement part 565a enters the inside of the drive transmission groove 101a, the drive force receiving part 565r provided in the engagement part 565a receives a force from the inside of the drive transmission groove 101a. Here, in order to ensure the state of engagement between the drive transmission shaft 101a and the engagement part 565a when the drive transmission shaft 101a is driven, it is preferred that more than half of the engagement part 565a enter into the interior of the drive transmission shaft with coupling part 565a.

[0421] Therefore, it is preferred that the engagement part 565a is movable beyond the cross-sectional radius of the engagement part 565a (the distance from the center of the engagement part to the surface). Still preferably, the engagement portion 565a can move over the cross-sectional diameter of the engagement portion 565a (not less than the cross-sectional width of the engagement portion 565a, not less than twice the distance from the center of the engagement portion 565a). coupling part to the surface).

[0422] Here, Figure 53 shows a state in which the driving force receiving part 565r receives the driving force F. A straight line LN1 is drawn in the normal direction of the driving force receiving part 565r. The straight line LN1 extends towards the side towards which the driving force receiving part 565r is facing and is also a straight line along the vector indicating the driving force F.

[0423] The fixed end 565t1 of the extension part 565t is disposed further upstream in the rotation direction R than the straight line LN1. That is, a support part 565 is provided through a straight line L1.

[0424] In this case, when the driving force receiving part 565r receives the driving force F, a moment M1 in the same direction as the direction of rotation of the drum unit (counterclockwise direction in the drawing) is produced in the part length 565t with the fixed end 565t as a fulcrum. This moment M1 acts so that the supporting part 565 approaches the drive shaft of the main assembly 101. That is, the moment M1 acts to drive the engaging part 565a to the rear of the drive transmission groove 101a. Through this, it is possible to stabilize the engagement state between the engagement part 565a and the drive transmission groove 101a. In this embodiment, the support part 565 can be molded as a part of the flange element 571 using a mold, and therefore, the manufacture of the flange element 571 including the support part 565 is facilitated.

[0425] Next, with reference to Figures 54 to 58, a modified example of Embodiment 4 will be described. Figures 54 to 58 are sectional views of the coupling unit (flange element).

[0426] First, in the modification shown in Figure 54, the extended parts (665t, 665s) are folded and have the first extension part 665s and the second extension part 665t extending in different directions. The boundary between the first extension part 665ts and the second extension part 665t is a folded part. The first extension portion 665s in this modified example corresponds to the connecting portion 565s shown in Figure 52. That is, the extended portion of the connecting portion 565s (Figure 52) is the first extension portion 665s (Figure 54), and the first extension part 665s is also the connecting part connecting the second extension part 665t and the coupling part 665a. On the contrary, it is also possible to consider the connecting part 565 shown in Figure 52 as the first extension part and the extension part 565t as the second extension part.

[0427] The engagement part 665a shown in Figure 54 is an enlarged part provided at the free end of the extension part (the first extension part 665s). The first extension part 665s and the coupling part 665a can be considered as projection parts (projection parts) that project in a direction intersecting with the second extension part 665t.

[0428] The first extension part 665s of this modification is longer than the connecting part 565s shown in Figure 52. Correspondingly, therefore, the flange element 671 of the present modification becomes thinner (the thickness becomes smaller ).

[0429] Next, Figure 55 shows another modified example. As shown in Figure 55, the shape of the flared part (hook part) is different. As described in Embodiment 3, the flared portion may have a polygonal or similar shape. In Figure 55, the cross-sectional shape of the engaging portion 765a is substantially hexagonal. Such a transverse shape can also be considered as a substantially circular shape. Here, also in the modified examples (Figures 56 and 57) shown below, the transverse shape of the coupling part (flared part) can be polygonal.

[0430] Another modification is shown in Figure 56. In the structure shown in Figure 56, the extension part 865t is not directly connected to the flared part (the engagement part 865a). However, the center of the engagement part 865a is offset from the extended line of the extension part 865t, and the engagement part 865a is a projecting part that projects in the direction intersecting with the extension part 865t. In this modification, the position of the fixed end 856t1 of the extension part 865t is different from the structure shown in Figure 52. That is, the fixed end 865t1 is on the downstream side in the direction of rotation R relative to the straight line L1 extending in normal direction of the drive force receiving part 865r.

[0431] With such a structure, when the supporting part 865 receives the driving force, a moment in the clockwise direction in Figure can be applied to the supporting part 865 with the fixed end 865t1 as a fulcrum. This moment acts to move engagement portion 865a away from drive transmission slot 101a.

[0432] In this case, in order to prevent the engagement between the engagement part 865a and the drive transmission groove 101a from being broken, it is desirable to increase the elastic force of the extension part 865t (that is, by making the extension part 865t difficult to deform). Or, it is preferred that a large friction force is produced between the engaging part 865a and the drive transmission groove 101a.

[0433] With reference to Figure 57, a further modification will be described. With the structure of Figure 56 described above, the engaging part is arranged in a position offset from the extended line of the extension part. In contrast, in this modified example shown in Figure 57, the center of the engagement portion 965a is disposed on a line extended from the extension portion 965t.

[0434] The engagement part 965a is a projecting part provided at the free end of the extension part 965t and projects (raised) to the entire circumferential direction of the extension part 965t.

[0435] In this modified example shown in Figure 57, the fixed end 965t1 of the support part 965 is disposed on a more downstream side in the direction of rotation R, compared to the above-described structure shown in Figure 56. Therefore, when the drive force receiving part of the engagement part 965a receives the drive force, a moment may be applied to the support part 965 in a direction that tends to separate the engagement part 965a from the drive transmission groove 101a.

[0436] Therefore, in order to ensure the state of engagement between the engagement part 965a and the drive transmission groove 101a, it is preferred that, as described above, measures are taken to further increase the elastic force of the extension part 965t or to increase the surface friction coefficient of the coupling part 965a.

[0437] However, when the elastic force of the extension part 965t is increased with the result that the extension part 965t does not easily bend, the force required to mount the cartridge 7 in the apparatus main assembly is increased. That is, to mount the 7 cartridge, it is necessary to flex the 965t extension part, and the load for this is added. Therefore, taking into account the mountability of the cartridge 7, it is preferable that a necessary and sufficient spring force is selected for the extension part 965t.

[ INDUSTRIAL APPLICABILITY ]

[0438] According to the present invention, a drum unit mountable and detachable from a main assembly of an electrophotographic image forming apparatus is provided.

Claims (47)

1. Drum unit (30) for a cartridge (7), comprising: (1) a photosensitive drum (1); and (2) a coupling member (28) provided on said photosensitive drum (1) and including (2 - 1) an engageable member (65) having a driving force receiving portion (65b) configured to enter said recess to receive a driving force to rotate said photosensitive drum (1), (2 - 2) a retaining element (72) configured to slidingly retain said engageable element (65), (2 - 3) a drive (66) configured to drive said engageable element (65), said drum unit (30) being characterized by the fact that said engageable element (65) is provided with a projecting part (65a) which includes said part receiving drive force (65b), wherein the projected part (65a) is disposed within the photosensitive drum (1) and the projected part (65a) projects inwardly in at least one radial direction from the drum unit (30 ). 2. Drum unit (30), according to claim 1, characterized in that said driving element (66) drives said engageable element (65) inwardly in the radial direction of said drum unit (30). 3. Drum unit (30) according to claim 1 or 2, characterized in that said retaining element (72) is provided with a locking part for restricting the movement of said engageable element (65) in the radial direction of the said drum unit (30). 4. Drum unit (30), according to claim 3, characterized in that said engageable element (65) is driven towards said locking part by said driving element (66). 5. Drum unit (30), according to any one of claims 1 to 4, characterized in that said drive force receiving part (65b) is inclined with respect to a direction of movement of said engageable element (65) . 6. Drum unit (30) according to any one of claims 1 to 5, characterized in that said drive force receiving part (65b) faces outwardly in the radial direction of said drum unit (30). 7. Drum unit (30) according to any one of claims 1 to 6, characterized in that said retaining element (72) has a hollow part, and said engageable element (65) is driven towards an interior of said hollow part. 8. Drum unit (30) according to any one of claims 1 to 6, characterized in that said retaining element (72) has a hollow part, and said driving force receiving part (65b) is exposed to an interior of said hollow part. 9. Drum unit (30), according to any one of claims 1 to 8, characterized in that at least a part of said engageable element (65) is located within said photosensitive drum (1). 10. Drum unit (30), according to any one of claims 1 to 9, characterized in that said drive element (66) is an elastic element. 11. Drum unit (30), according to any one of claims 1 to 10, characterized in that at least a part of said drive element (66) is located within said photosensitive drum (1). 12. Drum unit (30) according to any one of claims 1 to 11, characterized in that said retaining element (72) includes a receiving part for receiving driving force from said engageable element (65) . 13. Drum unit (30), according to claim 12, characterized in that said receiving part also functions as a guide to guide said engageable element (65). 14. Drum unit (30), according to any one of claims 1 to 13, characterized in that said retention element (72) is fixed to said photosensitive drum (1). 15. Drum unit (30), according to any one of claims 1 to 14, characterized in that said retaining element (72) is provided with a guide for guiding said engageable element (65). 16. Drum unit (30), according to claim 15, characterized in that said guide orients an upstream side of said engageable element (65) in relation to the direction of rotational movement of said photosensitive drum (1). 17. Drum unit (30), according to claim 15, characterized in that said guide orients downstream of said engageable element (65) in relation to the direction of rotational movement of said photosensitive drum (1). 18. Drum unit (30) according to claim 15, characterized in that said guide is provided with an upstream guide for guiding the upstream side of said engageable element (65) with respect to the direction of rotational movement of the said photosensitive drum (1) and a downstream guide for guiding the downstream side of said engageable element (65) with respect to the direction of rotational movement. 19. Drum unit (30), according to claim 18, characterized in that said upstream guide and said downstream guide are arranged so as to be substantially parallel to each other. 20. Drum unit (30) according to any one of claims 1 to 14, characterized in that said retaining element (72) is provided with two guides that are substantially parallel to each other, and said engageable element (65) is guided by two guides. 21. Drum unit (30) according to any one of claims 1 to 20, characterized in that said driving element (66) and said engageable element (65) are arranged along the radial direction of said drum unit (30). 22. Cartridge (7) detachably mountable to the main assembly of the electrophotographic image forming apparatus, said cartridge (7) characterized by comprising a drum unit (30) as defined in any one of claims 1 to 21, a frame to rotatably support said drum unit (30). 23. Cartridge (7; 4004) comprising: (1) a rotating element (1; 4017, 4020) configured to rotate while transporting a developer and a surface thereof; and (2) a coupling member (28; 4028) including an engageable member (65) having a driving force receiving part (65b; 4065b) configured to receive a driving force for rotating said rotating member (1; 4017, 4020), said cartridge being characterized by the fact that said coupling element (28; 4028) further includes a retaining element (72; 4072) configured to slideably retain said engageable element (65; 4065) so that said engageable element is sliding relative to said retaining element (72; 4072) in at least one direction radially from said coupling element (28; 4028), and a pushing element (66; 4066) configured to driving said engageable element (65; 4065), wherein said engageable element (65; 4065) including a projection is provided with said driving force receiving part (65b; 4065b). 24. Cartridge (7; 4004), according to claim 23, characterized in that said driving element (66; 4066) drives said engageable element (65; 4065) inwards in the radial direction of said coupling element (28 ; 4028). 25. Cartridge (7; 4004), according to claim 23 or 24, characterized in that said retaining element (72; 4072) is provided with a locking part to restrict the movement of said engageable element (65; 4065) in the radial direction of said coupling element (28; 4028). 26. Cartridge (7; 4004), according to claim 25, characterized in that said engageable element (65; 4065) is driven towards said locking part by said pushing element (66; 4066). 27. Cartridge (7; 4004), according to any one of claims 23 to 26, characterized in that said drive force receiving part (65b; 4065b) is inclined with respect to a direction of movement of said engageable element (65 ; 4065). 28. Cartridge (7; 4004), according to any one of claims 23 to 27, characterized in that said drive force receiving part (65b; 4065b) faces outwardly in the radial direction of said drum unit (30 ). 29. Cartridge (7; 4004), according to any one of claims 23 to 28, characterized in that said retention element (72; 4072) has a hollow part, and said engageable element (65; 4065) is driven towards an interior of said hollow part. 30. Cartridge (7; 4004), according to any one of claims 23 to 28, characterized in that said retention element (72; 4072) has a hollow part, and said actuating force receiving part (65b; 4065b) be exposed to an interior of said hollow part. 31. Cartridge (7; 4004), according to any one of claims 23 to 30, characterized in that said push element (66; 4066) is an elastic element. 32. Cartridge (7; 4004), according to any one of claims 23 to 31, characterized in that said retaining element (72; 4072) includes a receiving part for receiving the driving force from said engageable element ( 65; 4065). 33. Cartridge (7; 4004), according to claim 32, characterized in that said receiving part also functions as a guide to guide said engagement element (65; 4065). 34. Cartridge (7; 4004), according to any one of claims 23 to 32, characterized in that said retention element (72; 4072) is provided with a guide for guiding said engageable element (65; 4065). 35. Cartridge (7; 4004), according to claim 34, characterized in that said guide orients an upstream side of said engageable element (65; 4065) in relation to the direction of rotational movement of said rotating element (1; 4017, 4020). 36. Cartridge (7; 4004), according to claim 34, characterized in that said guide orients a downstream side of said engageable element (65; 4065) in relation to the direction of rotational movement of said rotating element (1; 4017, 4020). 37. Cartridge (7; 4004), according to claim 34, characterized in that said guide is provided with an upstream guide for guiding the upstream side of said engageable element (65; 4065) with respect to the direction of movement of rotation of said rotating element (1; 4017, 4020) and a downstream guide for guiding the downstream side of said engageable element (65; 4065) with respect to the direction of rotational movement. 38. Cartridge (7; 4004), according to claim 37, characterized in that said upstream guide and said downstream guide are arranged so as to be substantially parallel to each other. 39. Cartridge (7; 4004), according to any one of claims 23 to 32, characterized in that said retention element (72; 4072) is provided with two guides that are substantially parallel to each other, and said engageable element ( 65; 4065) is sliding in relation to said two guides. 40. Cartridge (7; 4004), according to any one of claims 23 to 39, characterized in that said driving element (66; 4066) and said engaging element (65; 4065) are arranged along the radial direction of the said coupling element (28; 4028). 41. Cartridge (7; 4004), according to any one of claims 23 to 40, characterized in that said rotating element (1; 4017, 4020) is a photosensitive drum (1). 42. Cartridge (7; 4004), according to any one of claims 23 to 40, characterized in that said rotating element (1; 4017, 4020) is a developing roller. 43. Cartridge (7; 4004), according to claim 42, characterized in that it additionally comprises a supply roller for supplying the developer to said developing roller. 44. Cartridge (7; 4004), according to claim 43, characterized in that said developing roller is configured to receive a driving force from the coupling element (28; 4028) through said supply roller. Cartridge (7; 4004) according to any one of claims 23 to 40, characterized in that said rotating element (1; 4017, 4020) is a supply roller for supplying a developer to said developing roller. 46. Cartridge (7; 4004), according to any one of claims 23 to 45, characterized in that said rotating element (1; 4017, 4020) includes an axis to which said coupling element (28; 4028) is mounted . 47. Electrophotographic image forming apparatus, characterized in that it comprises a cartridge (7; 4004) as defined in any one of claims 22 to 46, and a main assembly including a drive shaft configured to couple said coupling element (28; 4028), wherein said cartridge (7; 4004) is detachably mountable to said main assembly.