Cartridge, drum unit and image forming apparatus

Abstract

Developing conventional technology [Solution] The cartridge has a photosensitive drum and a coupling. The coupling has a main body and a movable member movable relative to the main body. The movable member has an engaging portion and is configured to move relative to the main body to insert the engaging portion between a driving force applying member and a braking force applying member. The movable member is configured to receive a driving force from the driving force applying member for rotating the photosensitive drum, and a braking force from the braking force applying member for applying a load to the rotation of the photosensitive drum.

Description

[Technical Field]

[0001] The present invention relates to an electrophotographic image forming apparatus such as a copying machine or a printer that employs an electrophotographic system, a cartridge used in the electrophotographic image forming apparatus, and a drum unit used in the electrophotographic image forming apparatus or the cartridge.

[0002] Here, an electrophotographic image forming apparatus (hereinafter also referred to as "image forming apparatus") is an apparatus that forms an image on a recording medium using an electrophotographic image forming method. Examples of image forming apparatuses include copying machines, facsimile machines, printers (laser beam printers, LED printers, etc.), and combination machines (multifunction printers) of these.

[0003] A cartridge is detachably attached to the main body of an image forming apparatus. An example of a cartridge is a process cartridge, which integrates a photosensitive member and at least one process means that acts on the photosensitive member.

[0004] The drum unit is a unit having a photosensitive drum, and is used in cartridges and image forming apparatuses. [Background technology]

[0005] In a conventional image forming apparatus using an electrophotographic process, an electrophotographic photosensitive member (hereinafter referred to as a photosensitive drum) and a process means acting on the photosensitive drum are integrated into a cartridge. The cartridge is detachably mountable to the main body of the image forming apparatus.

[0006] This cartridge system allows users to perform maintenance on the image forming apparatus themselves without the need for a service technician, significantly improving maintainability, and is therefore widely used in image forming apparatuses.

[0007] In a configuration in which a cartridge is detachably attached to an image forming apparatus main body (apparatus main body), the apparatus main body and the cartridge are connected using a coupling, so that a driving force is input from the apparatus main body to the cartridge (see Patent Document 1).

[0008] The amount of torque required to drive the cartridge varies depending on the cartridge configuration.

[0009] Patent Document 2 proposes a cartridge configuration that includes a load generating member that applies a load to the rotation of the photosensitive drum. The load generating member stabilizes the rotation of the photosensitive drum by increasing the torque of the photosensitive drum (see Patent Document 2). [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Publication No. 8-328449 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-202690 Summary of the Invention [Problem to be solved by the invention]

[0011] The object is to further develop the above-mentioned conventional technology. [Means for solving the problem]

[0012] Representative configurations disclosed in this application include: A cartridge detachably mountable to a main body of an image forming apparatus, the cartridge comprising a driving force applying member and a braking force applying member, A photosensitive drum; a coupling operatively connected to the photoreceptor drum so as to be capable of transmitting a driving force toward the photoreceptor drum; and The coupling is The main body and a movable member movable relative to a main body of the coupling; and the movable member has an engaging portion, and is configured to move relative to the main body of the coupling to cause the engaging portion to enter between the driving force applying member and the braking force applying member, The movable member is a cartridge configured to receive the driving force from the driving force applying member and to receive a braking force from the braking force applying member for applying a load to the rotation of the coupling.

[0013] Another exemplary configuration disclosed herein is: A cartridge detachably mountable to a main body of an image forming apparatus, the cartridge comprising: a driving force applying member; and a braking force applying member configured to apply a load to rotation of the driving force applying member and movable relative to the driving force applying member, A photosensitive drum; a coupling operatively connected to the photoreceptor drum so as to be capable of transmitting a driving force toward the photoreceptor drum; and The coupling is a cartridge that has an engaging portion configured to engage with the braking force application member and is configured to receive the driving force from the driving force application member via the braking force application member.

[0014] Another exemplary configuration disclosed herein is: In the cartridge, A photosensitive drum; a casing having a first end and a second end opposite to the first end in an axial direction of the photosensitive drum, the casing rotatably supporting the photosensitive drum; a coupling operatively connected to the photoreceptor drum for transmitting a driving force toward the photoreceptor drum, the coupling being located near a first end of the casing; and The coupling is The main body and a movable part that is movable between a first position and a second position relative to the main body of the coupling, the movable part being configured to be located closer to the second end of the casing in the axial direction of the photosensitive drum when located at the second position than when located at the first position; a protrusion configured to move in a circumferential direction of the coupling relative to a main body of the coupling in response to movement of the movable portion from the first position to the second position; A cartridge having

[0015] Another exemplary configuration disclosed herein is: In the cartridge, A photosensitive drum; a casing having a first end and a second end opposite to the first end in an axial direction of the photosensitive drum, the casing rotatably supporting the photosensitive drum; a coupling operatively connected to the photoreceptor drum for transmitting a driving force toward the photoreceptor drum, the coupling being located near a first end of the casing; and The coupling is The main body and a movable part that is movable between a first position and a second position relative to a main body of the coupling, the movable part being configured to be closer to the second end of the casing in the axial direction of the coupling when positioned at the second position than when positioned at the first position; a protrusion configured to move relative to a main body of the coupling in a direction away from an axis of the coupling in response to movement of the movable part from the first position to the second position; It is a cartridge having the above.

[0016] Another exemplary configuration disclosed herein is: In the cartridge, A photosensitive drum; a casing having a first end and a second end opposite to the first end in an axial direction of the photosensitive drum, the casing rotatably supporting the photosensitive drum; a coupling operatively connected to the photoreceptor drum so as to be capable of transmitting a driving force toward the photoreceptor drum; and The coupling is The first wall and a second wall provided radially inward of the coupling relative to the first wall; a groove formed by the first wall and the second wall; a recessed portion provided in the second wall; an inclined portion located near the recessed portion, at least a portion of which is located farther from the axis of the coupling than the recessed portion in the radial direction; Equipped with one side of the recessed portion is open in a circumferential direction of the coupling, and at least a part of the inclined portion is disposed on the other side of the recessed portion in the circumferential direction, The inclined portion is inclined so as to move away from the second end of the casing in the axial direction of the photosensitive drum as it moves away from the recessed portion in the circumferential direction.

[0017] Another exemplary configuration disclosed herein is: In the cartridge, A photosensitive drum; a casing having a first end and a second end opposite to the first end in an axial direction of the photosensitive drum, the casing rotatably supporting the photosensitive drum; a coupling operatively connected to the photoreceptor drum for transmitting a driving force toward the photoreceptor drum, the coupling being located near a first end of the casing; and The coupling is a base portion extending in the axial direction of the coupling; a first protrusion having a cylindrical shape protruding outward in the radial direction of the coupling from the base portion; a second projection having a cylindrical shape that projects outward in the radial direction of the coupling from the base portion; Equipped with In a radial direction of the coupling, a distance from an axis of the coupling to an outermost edge of the first projection is shorter than a distance from the axis of the coupling to an outermost edge of the second projection, When viewed along the axial direction of the coupling, a direction in which the first protrusion extends from the base portion is different from a direction in which the second protrusion extends from the base portion, In the cartridge, the first protrusion is disposed farther from the second end of the casing than the second protrusion in the axial direction of the coupling.

[0018] Another exemplary configuration disclosed herein is: In the image forming apparatus, a main body of the image forming apparatus; Any of the cartridges described above; The image forming apparatus has the above.

[0019] Another exemplary configuration disclosed herein is: A drum unit used in a cartridge detachably attached to a main body of an image forming apparatus, the drum unit including a driving force applying member and a braking force applying member, A photosensitive drum; a coupling operatively connected to the photoreceptor drum so as to be capable of transmitting a driving force toward the photoreceptor drum; and The coupling is The main body and a movable member movable relative to a main body of the coupling; and the movable member has an engaging portion, and is configured to move relative to the main body of the coupling to cause the engaging portion to enter between the driving force applying member and the braking force applying member, The movable member is configured to receive the driving force from the driving force applying member and to receive a braking force from the braking force applying member for applying a load to the rotation of the coupling.

[0020] Another exemplary configuration disclosed herein is: A drum unit used in a cartridge detachable from a main body of an image forming apparatus, the drum unit comprising: a driving force applying member; and a braking force applying member configured to apply a load to rotation of the driving force applying member and movable relative to the driving force applying member, A photosensitive drum; a coupling operatively connected to the photoreceptor drum so as to be capable of transmitting a driving force toward the photoreceptor drum; and The coupling is a drum unit having an engaging portion configured to engage with the braking force applying member and configured to receive the driving force from the driving force applying member via the braking force applying member.

[0021] Another exemplary configuration disclosed herein is: In a drum unit used in a cartridge, a photoreceptor drum having a first end and a second end opposite the first end; a coupling operatively connected to the photoreceptor drum to transmit a driving force toward the photoreceptor drum, the coupling being located near a first end of the photoreceptor drum; and The coupling is The main body and a movable part that is movable between a first position and a second position relative to the main body of the coupling, the movable part being configured to be located closer to a second end of the photosensitive drum in the axial direction of the photosensitive drum when located at the second position than when located at the first position; a protrusion configured to move in a circumferential direction of the coupling relative to a main body of the coupling in response to movement of the movable portion from the first position to the second position; The drum unit has:

[0022] Another exemplary configuration disclosed herein is: In a drum unit used in a cartridge, a photoreceptor drum having a first end and a second end opposite the first end; a coupling operatively connected to the photoreceptor drum to transmit a driving force toward the photoreceptor drum, the coupling being located near a first end of the photoreceptor drum; and The coupling is The main body and a movable part that is movable between a first position and a second position relative to a main body of the coupling, the movable part being configured to be closer to a second end of the photosensitive drum in the axial direction of the coupling when positioned at the second position than when positioned at the first position; a protrusion configured to move relative to a main body of the coupling in a direction away from an axis of the coupling in response to movement of the movable part from the first position to the second position; The drum unit has:

[0023] Another exemplary configuration disclosed herein is: In a drum unit used in a cartridge, a photoreceptor drum having a first end and a second end opposite the first end; a coupling operatively connected to the photoreceptor drum so as to be capable of transmitting a driving force toward the photoreceptor drum; and The coupling is The first wall and a second wall provided radially inward of the coupling relative to the first wall; a groove formed by the first wall and the second wall; a recessed portion provided in the second wall; an inclined portion located near the recessed portion, at least a portion of which is located farther from the axis of the coupling than the recessed portion in the radial direction; Equipped with one side of the recessed portion is open in a circumferential direction of the coupling, and at least a part of the inclined portion is disposed on the other side of the recessed portion in the circumferential direction, The inclined portion is a drum unit that is inclined so as to move away from the recessed portion in the circumferential direction and also away from the second end of the photosensitive drum in the axial direction of the photosensitive drum.

[0024] Representative configurations disclosed in this application include: In a drum unit used in a cartridge, a photoreceptor drum having a first end and a second end opposite the first end; a coupling operatively connected to the photoreceptor drum to transmit a driving force toward the photoreceptor drum, the coupling being located near a first end of the photoreceptor drum; and The coupling is a base portion extending in the axial direction of the coupling; a first protrusion having a cylindrical shape protruding outward in the radial direction of the coupling from the base portion; a second projection having a cylindrical shape that projects outward in the radial direction of the coupling from the base portion; Equipped with In a radial direction of the coupling, a distance from an axis of the coupling to an outermost edge of the first projection is shorter than a distance from the axis of the coupling to an outermost edge of the second projection, When viewed along the axial direction of the coupling, a direction in which the first protrusion extends from the base portion is different from a direction in which the second protrusion extends from the base portion, In the drum unit, the first protrusion is disposed farther from the second end of the photosensitive drum than the second protrusion in the axial direction of the coupling. [Effects of the Invention]

[0025] It can develop conventional technology. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 10 is a perspective view of a drum coupling 143. [Figure 2] FIG. 1 is a schematic cross-sectional view of an image forming apparatus. [Figure 3] FIG. 2 is a cross-sectional view of the process cartridge. [Figure 4] FIG. 2 is a cross-sectional view of the image forming apparatus. [Figure 5] FIG. 2 is a cross-sectional view of the image forming apparatus. [Figure 6] FIG. 2 is a cross-sectional view of the image forming apparatus. [Figure 7] FIG. [Figure 8] FIG. 2 is a perspective view of a memory element pressing unit and a cartridge pressing unit. [Figure 9] FIG. 2 is a partial perspective view of the image forming apparatus. [Figure 10] FIG. 2 is a side view (partial cross-sectional view) of the process cartridge. [Figure 11] FIG. 2 is a cross-sectional view of the image forming apparatus. [Figure 12] FIG. [Figure 13] FIG. 2 is an assembled perspective view of the process cartridge. [Figure 14] FIG. 2 is a perspective view of the process cartridge. [Figure 15] FIG. 2 is an assembled perspective view of the process cartridge. [Figure 16] FIG. 2 is an assembled perspective view of the process cartridge. [Figure 17] FIG. 10 is a view of the spacing member R alone. [Figure 18] FIG. 10 is a view showing the force applying member R alone. [Figure 19] FIG. 10 is a partial cross-sectional view of the spacing member R after assembly. [Figure 20] FIG. 10 is an enlarged view of the area around the spacing member R. [Figure 21] FIG. 10 is an enlarged view of the area around the spacing member R. [Figure 22] FIG. 2 is a bottom view of the drive side of the process cartridge. [Figure 23] 5A and 5B are diagrams illustrating the operation of a development unit in the image forming apparatus main body. [Figure 24] 5A and 5B are diagrams illustrating the operation of a development unit in the image forming apparatus main body. [Figure 25] 5A and 5B are diagrams illustrating the operation of a development unit in the image forming apparatus main body. [Figure 26] 5A and 5B are diagrams illustrating the operation of a development unit in the image forming apparatus main body. [Figure 27] 5A and 5B are diagrams illustrating the operation of a development unit in the image forming apparatus main body. [Figure 28] FIG. 10 is a view showing the spacing member L alone. [Figure 29] FIG. 10 is a view showing a force applying member L alone. [Figure 30] FIG. 10 is an assembled perspective view after the development pressure spring and the spacing member L are assembled. [Figure 31] FIG. 10 is a partial cross-sectional view of the spacing member L after assembly. [Figure 32] 10 is an enlarged view of the periphery of a spacing member L and a force applying member L. FIG. [Figure 33] FIG. 4 is an enlarged view of the periphery of a spacing member. [Figure 34] FIG. 2 is a side view of the process cartridge mounted inside the image forming apparatus main body, as viewed from the drive side. [Figure 35] FIG. 2 is a diagram illustrating a process cartridge in the main body of the image forming apparatus. [Figure 36] 5A and 5B are diagrams illustrating the operation of a development unit in the image forming apparatus main body. [Figure 37]5A and 5B are diagrams illustrating the operation of a development unit in the image forming apparatus main body. [Figure 38] 5A and 5B are diagrams illustrating the operation of a development unit in the image forming apparatus main body. [Figure 39] 5A and 5B are diagrams illustrating the operation of a development unit in the image forming apparatus main body. [Figure 40] 10 is a diagram showing the arrangement of a spacing member R and a force applying member. FIG. [Figure 41] FIG. 10 is a diagram illustrating the arrangement of a spacing member and a force applying member. [Figure 42] 1 is a side view of the process cartridge 100 mounted inside the image forming apparatus main body, as viewed from the drive side. [Figure 43] FIG. 2 is an exploded perspective view of a drive transmission unit 203. [Figure 44] FIG. 2 is a cross-sectional view of a drive transmission unit 203. [Figure 45] FIG. 2 is a perspective view of a drive transmission unit 203. [Figure 46] FIG. 2 is a cross-sectional perspective view of the device body including the drive transmission unit 203. [Figure 47] FIG. 2 is a front view of the drive transmission unit 203 and the drum coupling 143. [Figure 48] FIG. 10 is a development view illustrating engagement of the drum coupling. [Figure 49] FIG. 10 is a development view illustrating engagement of the drum coupling. [Figure 50] FIG. 10 is a development view illustrating engagement of the drum coupling. [Figure 51] FIG. 4 is a cross-sectional view illustrating engagement of the drum coupling. [Figure 52] FIG. 10 is a perspective view illustrating a modified example of the drum coupling. [Figure 53] FIG. 10 is a development view illustrating engagement of the drum coupling. [Figure 54] FIG. 10 is a development view illustrating engagement of the drum coupling. [Figure 55] FIG. 2 is a perspective view of the drum unit showing the drum coupling. [Figure 56]FIG. 10 is a view of the drum unit to show the drum coupling. [Figure 57] FIG. 2 is a perspective view of the drum unit showing the drum coupling. [Figure 58] FIG. [Figure 59] FIG. 2 is a perspective view showing components of a drive transmission unit. [Figure 60] FIG. 2 is a perspective view of a drive transmission unit and a drum unit. [Figure 61] FIG. 2 is a perspective view of a drive transmission unit and a drum unit. [Figure 62] FIG. 2 is a perspective view of a drive transmission unit and a drum unit. [Figure 63] FIG. 2 is a perspective view of a drive transmission unit and a drum unit. [Figure 64] FIG. 2 is a perspective view of a drive transmission unit and a drum unit. [Figure 65] FIG. 2 is a perspective view of a drive transmission unit and a drum unit. [Figure 66] FIG. 2 is a perspective view of a drive transmission unit and a drum unit. [Figure 67] FIG. 2 is a perspective view of a drive transmission unit and a drum unit. [Figure 68] FIG. 2 is a perspective view of a drive transmission unit and a drum unit. [Figure 69] FIG. 2 is a perspective view of a drive transmission unit and a drum unit. [Figure 70] FIG. 2 is a perspective view of a drive transmission unit and a drum unit. [Figure 71] FIG. 2 is a perspective view of a drive transmission unit and a drum unit. [Figure 72] FIG. 2 is a perspective view of a drive transmission unit and a drum unit. [Figure 73] FIG. 10 is a perspective view showing a modified example of the drum coupling. [Figure 74] 10A and 10B are a perspective view and a front view showing a modified example of the drum coupling. [Figure 75] FIG. 2 is a perspective view of the drum unit. [Figure 76]FIG. 10 is a development view illustrating engagement of the drum coupling. [Figure 77] FIG. 2 is a perspective view of a drum unit and a front view of a coupling. [Figure 78] FIG. 2 is a perspective view of a drum unit and a drive transmission unit. [Figure 79] 2A and 2B are a side view, a perspective view, and a front view of a coupling; [Figure 80] FIG. [Figure 81] 1A and 1B are a side view and a perspective view of a coupling; [Figure 82] FIG. 1 is a schematic cross-sectional view of an image forming apparatus. [Figure 83] FIG. 2 is a schematic cross-sectional view of the process cartridge. [Figure 84] FIG. 2 is a schematic perspective view of the process cartridge. [Figure 85] FIG. 2 is a schematic perspective view of the process cartridge. [Figure 86] 2 is a schematic cross-sectional view of the process cartridge taken along the center of the rotation axis of the photosensitive drum. FIG. [Figure 87] FIG. 10 is an exploded perspective view of a drive transmission unit 811. [Figure 88] 10 is a cross-sectional view taken along the center of the rotation axis of a drive transmission unit 811 attached to the image forming apparatus main body. [Figure 89] FIG. 10 is a schematic perspective view of a drum coupling 770 of another embodiment. [Figure 90] FIG. 10 is a schematic perspective view for explaining the mounting of a cartridge 701 into an image forming apparatus main body 800. [Figure 91] 10 is a schematic cross-sectional view for explaining the operation of mounting the cartridge 701 into the image forming apparatus main body 800. FIG. [Figure 92] 10 is a schematic cross-sectional view for explaining the mounting operation of the drum coupling 770 to the main body drive transmission unit 811. FIG. [Figure 93] 10 is a schematic cross-sectional view for explaining the mounting operation of the drum coupling 770 to the main body drive transmission unit 811. FIG. [Figure 94]FIG. 10 is a perspective view illustrating a process cartridge according to another embodiment. [Figure 95] FIG. 2 is a cross-sectional view of the drum unit. [Figure 96] FIG. [Figure 97] FIG. 2(a) is a perspective view of a coupling, and FIG. [Figure 98] FIG. [Figure 99] FIG. 4 is a perspective view showing an engaged state of the coupling and the brake engaging member. [Figure 100] FIG. [Figure 101] FIG. [Figure 102] 2A and 2B are a front view, a perspective view, and a side view of a coupling; [Figure 103] FIG. 4 is a perspective view showing an engaged state of the coupling and the brake engaging member. [Figure 104] 2A and 2B are a perspective view and a side view of a drum unit; [Figure 105] FIG. 2 is a perspective view of a drum unit and a front view of a coupling. [Figure 106] FIG. 2 is a cross-sectional view of the drum unit. [Figure 107] FIG. 2 is a perspective view of the drum unit. [Figure 108] FIG. [Figure 109] FIG. 2 is a perspective view of the drum unit. [Figure 110] FIG. 2 is a cross-sectional view of the drum unit and the drive transmission unit. [Figure 111] FIG. 11 is a perspective view of a drum coupling 1100. [Figure 112] FIG. 11 is an enlarged perspective view of a drum coupling 1100. [Figure 113] FIG. 11 is a front view of the drum coupling 1100. [Figure 114] FIG. 11 is a perspective view showing a modified example of the drum coupling 1100. [Figure 115] FIG. 12 is an exploded perspective view of a drum coupling 1206. [Figure 116] FIG. 12 is a cross-sectional view of a drum coupling 1206. [Figure 117] FIG. 12 is a perspective view showing the operation of the drum coupling 1206. [Figure 118] 12A and 12B are perspective and cross-sectional views showing the operation of a drum coupling 1206. [Figure 119] 12A and 12B are perspective and cross-sectional views showing the operation of a drum coupling 1206. [Figure 120] 12A and 12B are perspective and cross-sectional views showing the operation of a drum coupling 1206. [Figure 121] 1A and 1B are a perspective view and an exploded perspective view of a drive transmission unit 203. FIG. [Figure 122] 10A and 10B are a side view and a cross-sectional view of a drive transmission unit 203. FIG. [Figure 123] FIG. 13 is an exploded perspective view of a drum coupling 1342. [Figure 124] 13A and 13B are front and perspective views of a drum coupling 1342. [Figure 125] 13 is a perspective view showing an engagement operation between the drum coupling 1342 and the drive transmission unit 203. FIG. [Figure 126] 10 is a cross-sectional view showing the engagement operation of the drum coupling 1342 and the drive transmission unit 203. FIG. [Figure 127] 10 is a cross-sectional view showing the engagement operation of the drum coupling 1342 and the drive transmission unit 203. FIG. [Figure 128] 13 is a perspective view showing an engagement operation between the drum coupling 1342 and the drive transmission unit 203. FIG. [Figure 129] 10 is a cross-sectional view showing the engagement operation of the drum coupling 1342 and the drive transmission unit 203. FIG. [Figure 130] 10 is a cross-sectional view showing the engagement operation of the drum coupling 1342 and the drive transmission unit 203. FIG. [Figure 131] FIG. 13 is a front view of the drum coupling 1342. [Figure 132] FIG. 12 is a perspective view showing the internal structure of a drum coupling 1206. [Figure 133]10A and 10B are a perspective view and a front view of a second brake engaging member 208. FIG. [Figure 134] FIG. 15 is an exploded perspective view of a drum coupling 1545. [Figure 135] 15A and 15B are a front view and a cross-sectional view of an engaging member 1543 as seen from the driving side. [Figure 136] 15A and 15B are a perspective view, a front view, and a cross-sectional view showing the engagement between an engagement member 1543 and a flange member 1544. [Figure 137] 10A and 10B are perspective views of a drum coupling 1545 and a drive transmission unit 203 before engagement and an engagement view. [Figure 138] 10A and 10B are cross-sectional views of a drum coupling 1545 and a drive transmission unit 203 before and during engagement. [Figure 139] 10 is a perspective view showing the drive transmission between a second brake engaging member 208 and a drum drive coupling 180. FIG. [Figure 140] 10A and 10B are a side view and a cross-sectional view of a second brake engaging member 208 and a drive transmission unit 203. FIG. [Figure 141] 10A and 10B are diagrams showing a deformed state of a second brake engaging member 208. FIG. [Figure 142] FIG. 10 is a cross-sectional perspective view of a drum coupling 1545 and a drive transmission unit 203. [Figure 143] 10 is a cross-sectional view of a drum coupling 1545 and a drive transmission unit 203. FIG. [Figure 144] FIG. 15 is a perspective view of another form of drum coupling 1546. [Figure 145] FIG. [Figure 146] FIG. [Figure 147] 10(a) and 10(b) are perspective views of a drum coupling, and FIG. 10(c) is a view showing the engagement state of a drive transmission unit and an engagement member. [Figure 148] FIG. [Figure 149] 1A is a side view of the drum coupling, and FIG. 1B is a perspective view of the drum coupling. [Figure 150]1A is a front view of the drum coupling, and FIG. 1B is a perspective view of the drum coupling. DETAILED DESCRIPTION OF THE INVENTION

[0027] <<Example 1>> Hereinafter, the present invention will be described in detail by way of example with reference to the drawings and examples. However, the functions, materials, shapes, relative positions, etc. of the components described in the examples are not intended to limit the scope of the present invention unless otherwise specified.

[0028] The first embodiment will be described below with reference to the drawings.

[0029] In the following embodiment, an image forming apparatus to which four process cartridges are detachably attached is exemplified as the image forming apparatus.

[0030] The number of process cartridges to be mounted in the image forming apparatus is not limited to this, but may be set appropriately as needed.

[0031] In the embodiment described below, a laser beam printer is exemplified as one aspect of the image forming apparatus.

[0032] [Schematic configuration of image forming device] 2 is a schematic cross-sectional view of the image forming apparatus M. FIG.

[0033] This image forming apparatus M is a four-color full-color laser printer that uses an electrophotographic process, and forms a color image on a recording medium S. The image forming apparatus M is of a process cartridge type, and a process cartridge is removably attached to an image forming apparatus main body (apparatus main body, electrophotographic image forming apparatus main body) 170, and a color image is formed on the recording medium S.

[0034] Here, the side of the image forming apparatus M where the front door 11 is provided is referred to as the front side (front face), and the side opposite the front side is referred to as the back side (rear face). Also, when looking at the image forming apparatus M from the front, the right side is referred to as the drive side, and the left side is referred to as the non-drive side.

[0035] 2 is a cross-sectional view of the image forming apparatus M as seen from the non-drive side, with the front side being the non-drive side of the image forming apparatus M, the right side being the front of the image forming apparatus M, and the back side being the drive side of the image forming apparatus M.

[0036] The drive side of the process cartridge 100 is the side on which a drum coupling (photosensitive member coupling) (described later) is arranged in the axial direction of the photosensitive drum. The drive side of the process cartridge 100 is also the side on which a development coupling (described later) is arranged in the axial direction of the development roller (developing member).

[0037] The axial direction of the photosensitive drum is a direction parallel to the rotation axis of the photosensitive drum, which will be described later. Similarly, the axial direction of the developing roller is a direction parallel to the rotation axis of the developing roller, which will be described later. In this embodiment, the axial direction of the photosensitive drum and the axial direction of the developing roller are substantially parallel, so the axial direction of the photosensitive drum and the axial direction of the developing roller are considered to be substantially the same.

[0038] In the image forming apparatus main body 170, four process cartridges 100 (100Y, 100M, 100C, 100K) including a first process cartridge 100Y, a second process cartridge 100M, a third process cartridge 100C, and a fourth process cartridge 100K are arranged in a substantially horizontal direction.

[0039] The first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) each have the same electrophotographic process mechanism, but each has a different color developer (hereinafter referred to as toner). A rotational driving force is transmitted to the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) from a driving output portion (details of which will be described later) of the image forming apparatus main body 170.

[0040] Moreover, bias voltages (charging bias, developing bias, etc.) are supplied to each of the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) from the image forming apparatus main body 170 (not shown).

[0041] 3, each of the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) of this embodiment has a photosensitive drum 104 and a drum holding unit 108 equipped with charging means as process means that acts on the photosensitive drum 104. In addition, each of the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) has a developing unit 109 equipped with developing means that develops the electrostatic latent image on the photosensitive drum 104.

[0042] The drum holding unit 108 and the developing unit 109 are coupled to each other. A more specific configuration of the process cartridge 100 will be described later.

[0043] The first process cartridge 100Y accommodates yellow (Y) toner in a developing frame 125, and forms a yellow toner image on the surface of the photosensitive drum 104.

[0044] The second process cartridge 100M accommodates magenta (M) toner in the developing frame 125, and forms a magenta toner image on the surface of the photosensitive drum 104.

[0045] The third process cartridge 100C accommodates cyan (C) toner in the developing frame 125, and forms a cyan toner image on the surface of the photosensitive drum 104.

[0046] The fourth process cartridge 100K accommodates black (K) toner in the developing frame 125, and forms a black toner image on the surface of the photosensitive drum 104. A laser scanner unit 14 serving as an exposure means is provided above the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K). This laser scanner unit 14 outputs a laser beam U corresponding to image information. The laser beam U passes through an exposure window 110 of the process cartridge 100 and scans and exposes the surface of the photosensitive drum 104.

[0047] An intermediate transfer unit 12 serving as a transfer member is provided below the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K). The intermediate transfer unit 12 has a drive roller 12e, a turn roller 12c, and a tension roller 12b, and a flexible transfer belt 12a is stretched across them.

[0048] The lower surface of the photosensitive drum 104 of each of the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) contacts the upper surface of the transfer belt 12a. This contact area is the primary transfer area. A primary transfer roller 12d is provided on the inner side of the transfer belt 12a, facing the photosensitive drum 104.

[0049] A secondary transfer roller 6 is brought into contact with the turn roller 12c via the transfer belt 12a. The contact area between the transfer belt 12a and the secondary transfer roller 6 is the secondary transfer portion.

[0050] A feeding unit 4 is provided below the intermediate transfer unit 12. This feeding unit 4 has a paper feed tray 4a that stores a stack of recording media S, and a paper feed roller 4b.

[0051] 2, a fixing device 7 and a paper discharge device 8 are provided in the upper left portion of the image forming apparatus main body 170. A paper discharge tray 13 is provided on the top surface of the image forming apparatus main body 170.

[0052] The toner image is fixed onto the recording medium S by a fixing means provided in the fixing device 7 , and the recording medium S is discharged onto the paper discharge tray 13 .

[0053] [Image formation operation] The operation for forming a full color image is as follows.

[0054] The photosensitive drum 104 of each of the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) is rotated at a predetermined speed (in the direction of arrow A in FIG. 3).

[0055] The transfer belt 12a is also rotated in the forward direction (the direction of arrow C in FIG. 2) of the rotation of the photosensitive drum at a speed corresponding to the speed of the photosensitive drum 104.

[0056] The laser scanner unit 14 is also driven. In synchronization with the driving of the laser scanner unit 14, the charging roller 105 in each process cartridge uniformly charges the surface of the photosensitive drum 104 to a predetermined polarity and potential. The laser scanner unit 14 scans and exposes the surface of each photosensitive drum 104 with laser light U in accordance with an image signal for each color.

[0057] As a result, an electrostatic latent image corresponding to the image signal for the corresponding color is formed on the surface of each photosensitive drum 104. The formed electrostatic latent image is developed by the developing roller 106, which is driven to rotate at a predetermined speed. That is, the developing roller 106 is in contact with the photosensitive drum 104, and toner moves from the developing roller 106 to the latent image on the photosensitive drum 104, thereby developing the latent image into a toner image. Note that this embodiment employs a contact development method, in which the developing roller 106 and the photosensitive drum 104 are in contact with each other. However, a non-contact development method may also be employed, in which a small gap is provided between the developing roller 106 and the photosensitive drum 104 and toner is jetted from the developing roller 106 to the photosensitive drum 104.

[0058] Through the electrophotographic image forming process described above, a yellow toner image corresponding to the yellow component of the full-color image is formed on the photosensitive drum 104 of the first process cartridge 100Y. The toner image is then primarily transferred onto the transfer belt 12a. A portion of the photosensitive drum 104 is exposed to the outside of the cartridge and is in contact with the transfer belt 12a. At this contact point, the toner image on the surface of the photosensitive drum 104 is transferred to the transfer belt 12a.

[0059] Similarly, a magenta toner image corresponding to the magenta component of the full-color image is formed on the photosensitive drum 104 of the second process cartridge 100M. Then, this toner image is primarily transferred onto the transfer belt 12a, superimposed on the yellow toner image already transferred onto the transfer belt 12a.

[0060] Similarly, a cyan toner image corresponding to the cyan component of the full-color image is formed on the photosensitive drum 104 of the third process cartridge 100C. Then, this toner image is primarily transferred onto the transfer belt 12a, superimposed on the yellow and magenta toner images already transferred onto the transfer belt 12a.

[0061] Similarly, a black toner image corresponding to the black component of the full-color image is formed on the photosensitive drum 104 of the fourth process cartridge 100K. Then, this toner image is primarily transferred onto the transfer belt 12a, superimposed on the yellow, magenta, and cyan toner images already transferred onto the transfer belt 12a.

[0062] In this way, an unfixed full-color toner image of four colors, yellow, magenta, cyan, and black, is formed on the transfer belt 12a.

[0063] Meanwhile, the recording media S are separated and fed one by one at a predetermined control timing, and the recording media S are introduced into a secondary transfer section, which is a contact point between the secondary transfer roller 6 and the transfer belt 12a, at a predetermined control timing.

[0064] As a result, the four-color superimposed toner image on the transfer belt 12a is transferred onto the surface of the recording medium S in a batch in sequence while the recording medium S is being transported to the secondary transfer portion.

[0065] The structure of the image forming apparatus main body will be described in more detail below.

[0066] [Process cartridge installation / removal configuration overview] The tray (hereinafter referred to as the tray) 171 that supports the process cartridge will be described in further detail with reference to Figure 42 and Figures 4 to 7. Figure 4 is a cross-sectional view of the image forming apparatus M with the front door 11 open and the tray 171 positioned inside the image forming apparatus main body 170. Figure 5 is a cross-sectional view of the image forming apparatus M with the front door 11 open and the tray 171 positioned outside the image forming apparatus main body 170, and the process cartridge 100 housed inside the tray. Figure 6 is a cross-sectional view of the image forming apparatus M with the front door 11 open and the tray 171 positioned outside the image forming apparatus main body 170, and the process cartridge 100 removed from the tray. Figure 7(a) is a partial detailed view of the tray 171 as seen from the drive side in the state of Figure 4. Figure 7(b) is a partial detailed view of the tray 171 as seen from the non-drive side in the state of Figure 4.

[0067] 4 and 5, the tray 171 is movable relative to the image forming apparatus main body 170 in the direction of arrow X1 (pushing direction) and the direction of arrow X2 (pulling direction). That is, the tray 171 is provided so as to be able to be pulled out and pushed into the image forming apparatus main body 170, and is configured so as to be able to move in a substantially horizontal direction when the image forming apparatus main body 170 is installed on a horizontal surface. Here, the state in which the tray 171 is located outside the image forming apparatus main body 170 (the state in FIG. 5) is referred to as the outer position. Furthermore, the state in which the tray 171 is located inside the image forming apparatus main body 170 with the front door 11 open and the photosensitive drum 104 and the transfer belt 12a are separated (the state in FIG. 4) is referred to as the inner position.

[0068] The tray 171 also has an attachment portion 171a at its outer position, into which the process cartridge 100 can be removably attached, as shown in FIG. 6. Each process cartridge 100 attached to the attachment portion 171a at the outer position of the tray 171 is supported on the tray 171 by a drive-side cartridge cover member 116 and a non-moving-side cartridge cover member 117, as shown in FIG. 7. The process cartridge 100, while positioned in the attachment portion 171a, moves toward the inside of the image forming apparatus main body 170 as the tray 171 moves. At this time, a gap is maintained between the transfer belt 12a and the photosensitive drum 104. The tray 171 can move the process cartridge 100 toward the inside of the image forming apparatus main body 170 without the photosensitive drum 104 coming into contact with the transfer belt 12a (details will be described later).

[0069] As described above, the tray 171 allows multiple process cartridges 100 to be moved together to a position inside the image forming apparatus main body 170 where image formation is possible, and also allows them to be pulled out together to the outside of the image forming apparatus main body 170.

[0070] [Positioning of the Process Cartridge in the Main Body of the Electrophotographic Image Forming Apparatus] The positioning of the process cartridge 100 relative to the image forming apparatus main body 170 will be described in more detail with reference to FIG.

[0071] As shown in Fig. 7, tray 171 is provided with positioning portions 171VR and 171VL for holding cartridge 100. Positioning portions 171VR have linear portions 171VR1 and 171VR2, respectively. The center of the photosensitive drum is determined by contacting arc portions 116VR1 and 116VR2 of cartridge cover member 116 shown in Fig. 7 with linear portions 171VR1 and 171VR2.

[0072] 7 has a rotation determining protrusion 171KR, which fits into the rotation determining recess 116KR of the cartridge cover member 116 shown in FIG.

[0073] Incidentally, a positioning portion 171VL and a rotation determining protrusion 171KL are arranged at a position (non-drive side) opposite the positioning portion 171VR across the intermediate transfer belt 12a in the longitudinal direction of the process cartridge 100. In other words, even on the non-drive side, the position of the process cartridge 100 is determined by the engagement of the arc portions 117VL1 and 117VL2 of the cartridge cover member 117 with the positioning portion 171VL and the engagement of the rotation determining recess 117KL with the rotation determining protrusion 171KL.

[0074] In this way, the process cartridge 100 is correctly positioned relative to the tray 171.

[0075] Then, as shown in FIG. 5, the process cartridge 100 integrated with the tray 171 is moved in the direction of the arrow X1 and inserted to the position shown in FIG.

[0076] Then, by closing the front door 11 in the direction of arrow R, the process cartridge 100 is pressed by a cartridge pressing mechanism (not shown) described later, and is fixed to the image forming apparatus main body 170 together with the tray 171. In addition, in conjunction with the operation of the cartridge pressing mechanism, the transfer belt 12a comes into contact with the photosensitive member 104. This state enables an image to be formed (FIG. 2).

[0077] In this embodiment, the positioning portions 171VR and 171V are made of metal sheet metal because they also serve as reinforcement to maintain rigidity during the draw-out operation of the tray 171, but the present invention is not limited to this.

[0078] [Cartridge pressing mechanism] Next, the cartridge pressing mechanism will be described in detail with reference to FIG.

[0079] 8(a) shows only the process cartridge 100, tray 171, cartridge pressing mechanisms 190 and 191, and intermediate transfer unit 12 in the state shown in FIG. 4. FIG. 8(b) shows only the process cartridge 100, tray 171, cartridge pressing mechanisms 190 and 191, and intermediate transfer unit 12 in the state shown in FIG.

[0080] During image formation, the process cartridge 100 receives a driving force, and also receives a reaction force in the direction of arrow Z1 from the primary transfer roller 12d (FIG. 2). Therefore, in order to maintain a stable position of the process cartridge without lifting from the positioning portions 171VR and 171VL during image formation, it is necessary to press the process cartridge in the direction Z2.

[0081] In order to achieve this, in this embodiment, the image forming apparatus main body 170 is provided with cartridge pressing mechanisms (190, 191).

[0082] The cartridge pressing mechanism (190, 191) is composed of a storage element pressing unit 190 on the non-driving side and a cartridge pressing unit 191 on the driving side. This will be explained in more detail below.

[0083] By closing the front door 11 shown in FIG. 4, the storage element pressing unit 190 and the cartridge pressing unit 191 shown in FIG. 8 move down in the direction of the arrow Z2.

[0084] The memory element pressing unit 190 mainly has a main body side electrical contact (not shown) that comes into contact with the electrical contact of a memory element (not shown) provided in the process cartridge 100. By linking it with the front door 11 using a link mechanism (not shown), the memory element 140 and the main body side electrical contact can be brought into contact or not into contact with each other.

[0085] That is, when the front door 11 is closed, the contacts come into contact with each other, and when the front door 11 is opened, the contacts are separated from each other.

[0086] In this way, when the process cartridge 100 moves together with the tray 171 inside the image forming apparatus main body, the electrical contacts do not rub against each other, and the contacts are retracted from the insertion / removal path of the process cartridge 100, so that the insertion / removal of the tray 171 is not hindered.

[0087] This storage element pressing unit 190 also plays a role in pressing the process cartridge 100 against the above-mentioned positioning portion 171VR.

[0088] Similarly to the memory element pressing unit 190, the cartridge pressing unit 121 also descends in the direction of arrow Z2 in conjunction with the closing of the front door 11, and serves to press the process cartridge 100 against the positioning portion 171VL described above.

[0089] Furthermore, although the details will be described later, the cartridge pressing mechanisms (190, 191) also simultaneously play a role in pressing down force application members 152L, 152R of the process cartridge 100, which will be described later.

[0090] [Drive transmission mechanism] Next, the drive transmission mechanism of the main body in this embodiment will be described with reference to FIGS. 9 and 10 (for convenience, the tray 171 is omitted from the drawings).

[0091] Figure 9(a) is a perspective view in which the process cartridge 100 and the tray 171 are omitted from the state of Figure 4 or Figure 5. Figure 9(b) is a perspective view in which the process cartridge 100, the front door 11, and the tray 171 are omitted.

[0092] FIG. 10 is a side view of the process cartridge 100 as seen from the drive side.

[0093] The process cartridge in this embodiment has a developing coupling portion 32a and a drum coupling (photosensitive member coupling) 143, as shown in FIG.

[0094] When the front door 11 is closed (as shown in Figure 9(b)), the main body side drum drive coupling 180, which transmits drive force to the process cartridge 100, and the main body side developing drive coupling 185 are configured to protrude in the direction of arrow Y1 by a link mechanism not shown.

[0095] Furthermore, when the front door 11 is opened (the state shown in FIG. 9(a)), the drum drive coupling 180 and the developing device drive coupling 185 are retracted in the direction of the arrow Y2.

[0096] By retracting the respective couplings from the insertion / removal loci (X1 direction, X2 direction) of the process cartridge, the insertion / removal of the tray 171 is not hindered.

[0097] When the front door 11 is closed and the image forming apparatus main body 170 starts to operate, the drum drive coupling 180 described above engages with the drum coupling (coupling member, cartridge side coupling) 143. In response to this, the main body side developing drive coupling 185 engages with the developing coupling portion 32a. As a result, driving force is transmitted to the process cartridge 100. The transmission of driving force to the process cartridge 100 is not limited to two points as described above, and a mechanism may be provided in which driving force is input only to the drum coupling and transmitted to the developing roller.

[0098] [Intermediate transfer unit configuration] Next, the intermediate transfer unit 12 of the image forming apparatus main body in this embodiment will be described with reference to FIG.

[0099] In this embodiment, when the front door 11 is closed, the intermediate transfer unit 12 rises in the direction of arrow R2 by a link mechanism (not shown) and moves to the position where the image is formed (the position where the photosensitive drum 104 and the intermediate transfer belt 12a come into contact).

[0100] Furthermore, when the front door 11 is opened, the intermediate transfer unit 12 descends in the direction of arrow R1, and the photosensitive drum 2 and the intermediate transfer belt 12a are separated from each other.

[0101] That is, when the process cartridge 100 is set on the tray 171, the photosensitive drum 104 and the intermediate transfer belt 12a come into contact with or separate from each other depending on the opening and closing operation of the front door 11.

[0102] The contact and separation operation is configured such that the intermediate transfer unit 12 moves up and down along a rotational locus centered on a central point PV1 shown in FIG.

[0103] The intermediate transfer belt 12a is driven by a force from a gear (not shown) that is arranged coaxially with PVI. Therefore, by using the position PV1 as the rotation center, the intermediate transfer unit 12 can be raised and lowered without moving the gear center. This eliminates the need to move the gear center, making it possible to maintain the gear position with high precision.

[0104] With the above configuration, when the process cartridge 100 is set in the tray 171, the photosensitive drum 104 and the intermediate transfer belt 12a do not slide when inserting or removing the tray 11, preventing scratches on the photosensitive drum 104 and image degradation due to charge memory.

[0105] [Developer separation control unit] Next, the separation mechanism of the image forming apparatus main body in this embodiment will be described with reference to FIGS. 8, 11 and 12. FIG.

[0106] Fig. 11 is a cross-sectional view of the image forming apparatus M taken along the drive side end surface of the process cartridge 100. Fig. 12 is a perspective view of the developer separation control unit as seen obliquely from above.

[0107] In this embodiment, the developer separation control unit 195 engages with a part of the developer unit 109 to control the separation and contact operation of the developer unit 109 with respect to the photosensitive drum 104. The developer separation control unit 195 is located below the image forming apparatus main body 170 as shown in FIG.

[0108] Specifically, the developer separation control unit 195 is disposed vertically below the developer input coupling portion 32a and the drum coupling 143 (below in the direction of arrow Z2).

[0109] The developer separation control unit 195 is disposed in the longitudinal direction (Y1, Y2 direction) of the photosensitive drum 104 of the intermediate transfer belt 12. That is, the developer separation control unit 195 has a developer separation control unit 195R disposed on the driving side and a developer separation control unit 195L disposed on the non-driving side.

[0110] As described above, by disposing the development separation control unit 195 in the dead space of the image forming apparatus main body 170, the main body can be made compact.

[0111] The developer separation control unit 195R has four separation control members 196R corresponding to the process cartridges 100 (100Y, 100M, 100C, 100K). The four separation control members have approximately the same shape. The developer separation control unit 195R is always fixed to the image forming apparatus main body. However, the separation control members 196R are configured to be movable in the W41 and W42 directions by a control mechanism (not shown). The detailed configuration will be described later.

[0112] The developer separation control unit 195L has four separation control members 196L corresponding to the process cartridges 100 (100Y, 100M, 100C, 100K). The four separation control members have approximately the same shape. The developer separation control unit 195L is always fixed to the image forming apparatus main body. However, the separation control members 196L are configured to be movable in the W41 and W42 directions by a control mechanism (not shown). The detailed configuration will be described later.

[0113] In addition, in order for the development separation control unit 195 to engage with a part of the development unit 109 and control the separation and abutment operation of the development unit 109, a part of the development control unit 196 and a part of the development unit 109 must overlap in the vertical direction (Z1 and Z2 directions).

[0114] Therefore, after the development unit 109 of the process cartridge 100 is inserted in the X1 direction, a part of the development unit (the force applying member 152 in this embodiment) needs to protrude in order to overlap in the vertical direction (Z1 and Z2 directions) as described above. Details will be described later.

[0115] If the developer separation control unit 195 itself is raised in order to engage it, as with the intermediate transfer unit 12, problems arise such as an increase in the operating force of the interlocking front door 11 and a complicated drive train.

[0116] Addressing this issue is one of the reasons why the present embodiment employs a system in which the developer separation control unit 195 is fixed to the image forming apparatus main body 170 and a part of the developing unit 109 (the force applying member 152) protrudes downward (Z2) within the image forming apparatus main body 170. In addition, the mechanism for protruding the force applying member 152 utilizes the mechanisms of the memory element pressing unit 190 and the cartridge pressing unit 191 described above as they are, so there are no issues as described above and an increase in the cost of the apparatus main body can be suppressed.

[0117] The entire developing separation control unit 195 is fixed to the image forming apparatus main body 170. However, as will be described later, a part of it is movable in order to engage with a force applying member 152 and apply an operation so that the developing unit 109 is in a separated state or a contact state with the photosensitive drum 104. Details will be described later.

[0118] [Overall structure of the process cartridge] The structure of the process cartridge will be described with reference to FIGS.

[0119] Figure 13 is an assembled perspective view of the process cartridge 100 as seen from the drive side, which is one side in the axial direction of the photosensitive drum 104. Figure 14 is a perspective view of the process cartridge 100 as seen from the drive side.

[0120] In this embodiment, the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) have the same electrophotographic process mechanism, but differ in the color of the toner contained therein and the amount of toner filled therein.

[0121] The process cartridge 100 includes photosensitive drums 104 (4Y, 4M, 4C, 4K) and process means that act on the photosensitive drums 104. As process means, the cartridge 100 includes a charging roller 105 that is a charging means (charging member) that charges the photosensitive drum 104. The cartridge 100 also includes a developing roller 106 that is a developing means (developing member) that develops the latent image formed on the photosensitive drum 104 as another process means.

[0122] Another possible process means is a cleaning means (such as a cleaning blade) for removing residual toner remaining on the surface of the photosensitive drum 104. However, the image forming apparatus of this embodiment employs a configuration in which no cleaning means that comes into contact with the photosensitive drum 104 is provided.

[0123] The process cartridge 100 is divided into a drum holding unit 108 (108Y, 108M, 108C, 108K) and a developing unit 109 (109Y, 109M, 109C, 109K).

[0124] [Drum holding unit configuration] 3 and 13, the drum holding unit 108 is composed of a photosensitive drum 104, a charging roller 105, a drum frame 115 which is a first frame, etc. The photosensitive drum 104 is integrated with a coupling 143 and a drum flange 142 as a drum unit 103 (see FIG. 1(a); details will be described later).

[0125] The drum unit 103 is rotatably supported by a driving side cartridge cover member 116 and a non-moving side cartridge cover member 117 provided at both ends of the longitudinal direction of the process cartridge 100. The driving side cartridge cover member 116 and the non-moving side cartridge cover member 117 will be described later.

[0126] 13 and 14, a drum coupling 143 for transmitting a driving force to the photosensitive drum 104 is provided near one end in the longitudinal direction of the photosensitive drum 104. As described above, the coupling 143 engages with a main body-side drum drive coupling 180 (see FIG. 9) serving as a drum drive output unit of the image forming apparatus main body 170. The driving force of a drive motor (not shown) of the image forming apparatus main body 170 is transmitted to the photosensitive drum 104, causing it to rotate in the direction of arrow A. The photosensitive drum 104 also has a drum flange 142 near the other end (second end) in the longitudinal direction.

[0127] A shaft 143j (see FIG. 1) of the coupling 143 is supported by the drive-side cartridge cover 116, and the drum flange 142 is supported by a shaft fixed to the non-drive-side cartridge cover 117. This allows the drum unit 103 to be rotatably supported within the cartridge. In other words, both ends of the photosensitive drum 104 are rotatably supported by both ends of the cartridge casing (i.e., the cartridge covers 116 and 117) via the coupling 143 and the drum flange 142.

[0128] The charging roller 105 is supported by a drum frame 115 so as to be in contact with the photosensitive drum 104 and to be rotated by the photosensitive drum 104.

[0129] Of the two longitudinal (axial) sides of the drum unit 103, the side where the coupling 143 is located is the drive side, and the side where the drum flange 142 is located is the non-drive side. In other words, of the two axial ends of the photosensitive drum 104, the coupling 143 is fixed near the drive side end, and the drum flange 142 is fixed near the end opposite the drive side. One of the two axial ends of the photosensitive drum 104 may be referred to as the first end and the other as the second end. Figure 80 shows the end 104a of the photosensitive drum on the drum drive side and the end 104b on the non-drive side.

[0130] As with the drum unit 103, the side of the cartridge 100 where the coupling 143 is located is called the drive side, and the side opposite the drive side is called the non-drive side. For example, Figures 10 and 19 are views showing the drive side of the cartridge. Also, Figure 16 is a view showing the non-drive side of the cartridge.

[0131] 13 and 14, the drive side cartridge cover 116 is a component located at the drive side end of the casing of the cartridge 100, and the non-drive side cartridge cover 117 is a component located at the non-drive side end of the casing. The drum coupling 143 supported by the drive side cartridge cover 116 can be considered to be located near the non-drive side end of the casing of the cartridge 100. One of the two ends of the cartridge 100 may be referred to as a first end, and the other as a second end.

[0132] [Developing unit configuration] 3 and 13, the developing unit 109 is made up of a developing roller 106, a toner transport roller (toner supply roller) 107, a developing blade 130, and a developing frame 125. The developing frame 125 is made up of a lower frame 125a and a lid member 125b. The lower frame 125a and the lid member 125b are joined together by ultrasonic welding or the like.

[0133] The developing frame 125, which is a second frame (second casing), has a toner storage portion 129 that stores toner to be supplied to the developing roller 106. The developing frame 125 also rotatably supports the developing roller 106 and the toner transport roller 107 via a drive-side bearing 126 and a non-drive-side bearing 127, which will be described later, and holds a developing blade 130 that regulates the thickness of the toner layer on the circumferential surface of the developing roller 106.

[0134] The developing blade 130 is made by attaching an elastic member 130b, which is a sheet metal about 0.1 mm thick, to a support member 130a, which is a metal material with an L-shaped cross section, by welding or the like. The developing blade 130 is attached to the developing frame 125 at two points, near one end and the other end, in the longitudinal direction, with fixing screws 130c. The developing roller 106 is made up of a metal core 106c and a rubber portion 106d.

[0135] The developing roller 106 is rotatably supported by a drive-side bearing 126 and a non-drive-side bearing 127 attached to both longitudinal ends of a developing frame 125. The developing frame 125, the drive-side bearing 126, and the non-drive-side bearing 127 are part of the frame (casing) of the cartridge. In a broad sense, the bearings 126 and 127 may be considered part of the developing frame 125, or the bearings 126 and 127 and the developing frame 125 may be collectively referred to as the developing frame.

[0136] The developing roller 106 is a roller that carries toner for developing the latent image on the photosensitive drum 104. The toner transport roller 107 transports and supplies the toner contained in the toner container 129 toward the developing roller 106. The toner transport roller 107 is in contact with the developing roller 106.

[0137] 13 and 14, a development input coupling portion (development coupling) 32a for transmitting a driving force to the development unit 109 is provided on one side in the longitudinal direction of the development unit 109. The development input coupling portion 32a engages with a main body side development drive coupling 185 (see FIG. 9) serving as a development drive output portion of the image forming apparatus main body 170, and the driving force of a drive motor (not shown) of the image forming apparatus main body 170 is input to the development unit 109.

[0138] The driving force input to the developing unit 109 is transmitted by a drive train (not shown) provided inside the developing unit 109, thereby rotating the developing roller 106 in the direction of arrow D in Fig. 3. Similarly, the driving force received by the development input coupling 32a also rotates the toner transport roller 107, supplying toner to the developing roller 106.

[0139] A developing unit cover member 128 that supports and covers the developing input coupling portion 32a and a drive train (not shown) is provided on one longitudinal side of the developing unit 109. The outer diameter of the developing roller 106 is set to be smaller than the outer diameter of the photosensitive drum 104. In this embodiment, the outer diameter of the photosensitive drum 104 is set in the range of Φ18 to Φ22, and the outer diameter of the developing roller 106 is set in the range of Φ8 to Φ14. Setting the outer diameters within this range enables efficient arrangement.

[0140] [Assembling the drum support unit and developing unit] 13, the assembly of the drum holding unit 108 and the developing unit 109 will be described. The drum holding unit 108 and the developing unit 109 are connected by a driving side cartridge cover member 116 and a non-moving side cartridge cover member 117 provided at both ends of the process cartridge 100 in the longitudinal direction.

[0141] A developing unit support hole 116a is provided in a driving side cartridge cover member 116 provided on one longitudinal side (driving side) of the process cartridge 100 to swingably (movably) support the developing unit 109. Similarly, a non-driving side cartridge cover member 117 provided on the other longitudinal side (non-driving side) of the process cartridge 100 is provided with a developing unit support hole 117a to swingably support the developing unit 109.

[0142] Furthermore, the drive side cartridge cover member 116 and the non-moving side cartridge cover member 117 are provided with drum support holes 116b, 117b for rotatably supporting the photosensitive drum 104. Here, on the drive side, the outer diameter portion of the cylindrical portion 128b of the developing cover member 128 is fitted into the developing unit support hole 116a of the drive side cartridge cover member 116. On the non-drive side, the outer diameter portion of the cylindrical portion (not shown) of the non-drive side bearing 127 is fitted into the developing unit support hole 117a of the non-moving side cartridge cover member 117.

[0143] Furthermore, both longitudinal ends of the photosensitive drum 104 are fitted into drum support holes 116b of the driving-side cartridge cover member 116 and drum support holes 117b of the non-moving-side cartridge cover member 117. The driving-side cartridge cover member 116 and the non-moving-side cartridge cover member 117 are then fixed to the drum frame 115 of the drum holding unit 108 with screws, adhesive, or the like (not shown). As a result, the developing unit 109 is rotatably supported by the driving-side cartridge cover member 116 and the non-moving-side cartridge cover member 117. The developing unit 109 is movable (rotatable) relative to the drum holding unit 108, and this movement allows the developing roller 106 to move relative to the photosensitive drum 104. The developing roller 106 can be positioned to act on the photosensitive drum 104 during image formation.

[0144] The drum frame 115 and the cover members 116 and 117 are part of the frame (casing) of the cartridge. More specifically, they are the frame of the drum holding unit 108. Furthermore, because the cover members 116 and 117 are fixed to one end and the other end of the drum frame 115, respectively, the cover members 116 and 117 are sometimes considered to be part of the drum frame 115. Alternatively, the cover members 116 and 117 and the drum frame 115 may be collectively referred to as the drum frame.

[0145] In addition, one of the frame (115, 116, 117) of the drum holding unit 108 and the frame (125, 126, 127) of the developing unit may be referred to as a first frame (first casing), and the other as a second frame (second casing). In addition, the frame (115, 116, 117) of the drum holding unit 108 and the frame (125, 126, 127) of the developing unit may not be particularly distinguished from each other, and both may be collectively referred to as a cartridge frame (cartridge casing).

[0146] The drum holding unit 108 and the developing unit 109 are assembled by the above steps and integrally formed as the process cartridge 100, as shown in FIG.

[0147] The axis connecting the center of the developing unit support hole 116a of the driving side cartridge cover member 116 and the center of the developing unit support hole 117a of the non-moving side cartridge cover member 117 is referred to as the swing axis K. Here, the cylindrical portion 128b of the driving side developing unit cover member 128 is coaxial with the developing input coupling 74. In other words, the developing unit 109 is configured to receive driving force from the image forming apparatus main body 170 at this swing axis K. The developing unit 109 is also supported rotatably about the swing axis K.

[0148] [Configuration of the separation and contact mechanism] The structure for separating and contacting the photosensitive drum 104 of the process cartridge 100 and the developing roller 106 of the developing unit 109 in this embodiment will be described in detail. The process cartridge has a separation and contact mechanism 150R on the drive side and a separation and contact mechanism 150L on the non-drive side. Figure 15 shows an assembled perspective view of the drive side of the developing unit 109 including the separation and contact mechanism 150R. Figure 16 shows an assembled perspective view of the non-drive side of the developing unit 109 including the separation and contact mechanism 150L. Regarding the separation and contact mechanisms, the drive side separation and contact mechanism 150R will first be described in detail, followed by a description of the non-drive side separation and contact mechanism 150L.

[0149] As the separation and contact mechanism has almost the same functions on the drive side and non-drive side, the reference numerals of each component on the drive side have an R at the end. On the non-drive side, the reference numerals of each component are the same as those on the drive side, with an L at the end.

[0150] The separation and contact mechanism 150R includes a separation maintaining member 151R as a restricting member, a force applying member 152R as a pressing member, and a tension spring 153.

[0151] The separation and contact mechanism 150L includes a separation maintaining member 151L as a restricting member, a force applying member 152L as a pressing member, and a tension spring 153.

[0152] [Detailed explanation of spacing member R] Here, the spacing member 151R will be described in detail with reference to FIG.

[0153] FIG. 17(a) is a front view of the spacing member 151R as viewed from the longitudinal direction of the drive side of the process cartridge 100. FIGS. 17(b) and 17(c) are perspective views of the spacing member 151R. FIG. 17(d) is a view of the spacing member 151R as viewed in the direction of arrow Z2 in FIG. 17(a) (vertically upward in the image formation state). The spacing member 151R has an annular support receiving portion 151Ra and a spacing portion 151Rb that protrudes from the support receiving portion 151Ra in the radial direction of the support receiving portion 151Ra. The tip of the spacing portion 151Rb has a spacing surface 151Rc that is arc-shaped about the spacing member pivot axis H and is inclined at an angle θ1 with respect to a line HA parallel to the spacing member pivot axis H. The angle θ1 is set to satisfy equation (1). 0°≦θ1≦45° (1)

[0154] The spacing member 151R also has a second regulated surface 151Rk adjacent to the spacing surface 151Rc. The spacing member 151R further has a second pressed portion 151Rd that protrudes in the Z2 direction beyond the support receiving portion 151Ra, and has an arc-shaped second pressed surface 151Re that protrudes from the second pressed portion 151Rd in the direction of the spacing member pivot axis H of the support receiving portion 151Ra.

[0155] Furthermore, the spacing member 151R has a main body 151Rf connected to the support receiving portion 151Ra, and the main body 151Rf has a spring hook portion 151Rg that protrudes from the support receiving portion 151Ra in the direction of the spacing member oscillation axis H. Furthermore, the main body 151Rf has a rotation prevention portion 151Rm that protrudes in the Z2 direction, and a rotation prevention surface 151Rn is provided in a direction facing the second pressed surface 151Re.

[0156] [Detailed explanation of force application member R] Here, the force application member 152R will be described in detail with reference to FIG.

[0157] FIG. 18(a) is a front view of the force applying member 152R as viewed from the longitudinal direction of the process cartridge 100, and FIGS. 18(b) and 18(c) are perspective views of the force applying member 152R as a single unit.

[0158] The force applying member 152R has an elongated support receiving portion 152Ra. The longitudinal direction of the elongated support receiving portion 152Ra is indicated by arrow LH, with arrow LH1 pointing upward and arrow LH2 pointing downward. Furthermore, the direction in which the elongated support receiving portion 152Ra is formed is indicated by arrow HB. The force applying member 152R has a protruding portion 152Rh formed downstream of the elongated support receiving portion 152Ra in the direction of arrow LH2. The elongated support receiving portion 152Ra and the protruding portion 152Rh are connected by a main body portion 152Rb. Meanwhile, the force applying member 152R has a pushed portion 152Re that protrudes in the direction of arrow LH1 and substantially perpendicular to the direction of arrow LH1. The pushed portion 152Re has an arc-shaped pushed surface 152Rf downstream in the direction of arrow LH1 and a push-in restricting surface 152Rg upstream. Furthermore, the force-applying member 152R has a first storage state restricting surface 152Rv extending from the main body portion 152Rb upstream of the protrusion portion 152 in the direction of arrow LH2, and a second storage state restricting surface 152Rw adjacent to the first storage state restricting surface 152Rv and approximately parallel to the first pressing surface 152Rq.

[0159] The protrusion 152Rh has a first force receiving portion 152Rk and a second force receiving portion 152Rn that are disposed at the end in the direction of arrow LH2 and face each other in a direction substantially perpendicular to the direction of arrow LH2. The first force receiving portion 152Rk and the second force receiving portion 152Rn have a first force receiving surface 152Rm and a second force receiving surface 152Rp that extend in the HB direction and have an arc-shaped shape. The protrusion 152Rh also has a spring hook portion 152Rs and a locking portion 152Rt that protrude in the HL direction, and the locking portion 152Rt has a locking surface 152Ru that faces the same direction as the first force receiving surface 152Rp.

[0160] Furthermore, the force applying member 152R is part of the main body 152Rb and is arranged upstream of the second force receiving portion 152Rn in the direction of arrow LH2, and has a first pressing surface 152Rq facing the same direction as the second force receiving surface 152Rp. The force applying member 152R also has a second pressing surface 152Rr that is perpendicular to the first storage state restricting surface 152Rv and arranged opposite to the first pressing surface 152Rq.

[0161] When the process cartridge 100 is mounted in the image forming apparatus main body 170, the LH1 direction is approximately the same as the Z1 direction, the LH2 direction is approximately the same as the Z2 direction, and the HB direction is approximately the same as the longitudinal direction of the process cartridge 100.

[0162] [Assembly of separation and contact mechanism R] Next, the assembly of the spacing and contact mechanism will be described with reference to Figures 10, 15 to 19. Figure 19 is a perspective view of the process cartridge 100 after the spacing member 151R has been assembled, as seen from the drive side.

[0163] 15, the developing unit 109 is fitted with the outer diameter portion of the cylindrical portion 128b of the developing unit cover member 128 in the developing unit support hole portion 116a of the drive-side cartridge cover member 116. This allows the developing unit 109 to be supported rotatably with respect to the photosensitive drum 104 about the swing axis K. In addition, the developing unit cover member 128 has a cylindrical first support portion 128c and a second support portion 128k that protrude in the direction of the swing axis K.

[0164] The outer diameter of the first support portion 128c fits into the inner diameter of the support receiving portion 151Ra of the spacing maintaining member 151R, thereby rotatably supporting the spacing maintaining member 151R. Here, the center of oscillation of the spacing maintaining member 151R assembled to the developing device covering member 128 is defined as a spacing maintaining member oscillation axis H. The developing device covering member 128 has a first retaining portion 128d that protrudes in the direction of the spacing maintaining member oscillation axis H. As shown in FIG. 15 , movement of the spacing maintaining member 151R assembled to the developing device covering member 128 in the direction of the spacing maintaining member oscillation axis H is restricted by the first retaining portion 128d coming into contact with the spacing maintaining member 151R.

[0165] The outer diameter of the second support portion 128k fits into the inner wall of the elongated support receiving portion 152Ra of the force application member 152R, supporting the force application member 152R rotatably and movably in the elongated direction. The center of oscillation of the force application member 152R attached to the developing device covering member 128 is defined as a force application member oscillation axis HC. As shown in FIG. 15, movement of the force application member 152R attached to the developing device covering member 128 in the direction of the force application member oscillation axis HC is restricted by the second retaining portion 128m coming into contact with the spacing maintaining member 151R.

[0166] 10 is a cross-sectional view in which a part of the driving-side cartridge cover member 116 and a part of the developing device covering member 128 are partially omitted along the partial cross-sectional line CS so as to show the fitting portion between the elongated round support receiving portion 151Ra of the force applying member 152R and the cylindrical portion 128b of the developing device covering member 128. The spacing contact mechanism 150R is provided with a tension spring 153 as a biasing means for biasing the spacing maintaining member 151R to rotate in the direction of arrow B1 in the figure around the spacing maintaining member swing axis H, and for biasing the force applying member 152R in the direction of arrow B3.

[0167] The direction of arrow B3 is substantially parallel to the longitudinal direction LH2 (see FIG. 18) of the elongated support receiving portion 152Ra of the force application member 152R. The tension spring 153 is assembled between a spring hook 151Rg provided on the spacing member 151R and a spring hook 152Rs provided on the force application member 152R. The tension spring 153 applies a force to the spring hook 151Rg of the spacing member 151R in the direction of arrow F2 in FIG. 10, thereby applying a biasing force that rotates the spacing member 151R in the direction of arrow B1. Furthermore, the tension spring 153 applies a force to the spring hook 152Rs of the force application member 152R in the direction of arrow F1, thereby applying a biasing force that moves the force application member 152R in the direction of arrow B3.

[0168] The line connecting the spring hook 151Rg of the spacing maintaining member 151R and the spring hook 152Rs of the force maintaining member 152R is designated as GS. The line connecting the spring hook 152Rs of the force applying member 152R and the force applying member oscillation axis HC is designated as HS. Here, the angle θ2 formed by the line GS and the line HS is set to satisfy the following equation (2), with the clockwise direction about the spring hook 152Rs of the force applying member 152R as the positive direction. As a result, the force applying member 152R is biased to rotate in the direction of arrow BA around the force applying member oscillation axis HC. 0°≦θ2≦90° (2)

[0169] 15, the developing drive input gear 132 is arranged such that the inner diameter of the cylindrical portion 128b of the developing cover member 128 fits into the outer diameter of the cylindrical portion 32b of the developing drive input gear 132, and in addition, the support portion 126a of the drive-side bearing 126 fits into the cylindrical portion (not shown) of the developing drive input gear 132. This allows the developing roller gear 131, the toner conveying roller gear 133, and other gears to transmit driving force.

[0170] In this embodiment, the attachment positions of the spacing member 151R and the force application member 152R are as follows. As shown in FIG. 15 , in the direction of the swing axis K, the spacing member 151R is arranged on the side (outer side in the longitudinal direction) where the driving-side cartridge cover member 116 is arranged, sandwiching the developing device cover member 128 therebetween. The force application member 152R is arranged on the side (inner side in the longitudinal direction) where the developing device drive input gear 13 is arranged. However, the arrangement positions are not limited to this, and the arrangement positions of the spacing member 151R and the force application member 152R may be interchanged, or the spacing member 151R and the force application member 152R may be arranged on one side in the direction of the swing axis K with the developing device cover member 128 as the reference. Furthermore, the arrangement order of the spacing member 151R and the force application member 152R may be interchanged.

[0171] The developing unit cover member 128 is fixed to the developing frame 125 via the drive-side bearing 126 to form the developing unit 109. Note that the fixing method in this embodiment is by fixing with a fixing screw 145 and an adhesive (not shown) as shown in Fig. 15, but the fixing method is not limited to this and may be a joining method such as welding by heat or pouring in and hardening a resin.

[0172] 20 is an enlarged cross-sectional view of the separation maintaining portion 151R and its periphery in FIG. 10, with portions of the tension spring 153 and separation maintaining member 151R partially omitted along the partial cross-sectional line CS4. The first regulating surface 152Rv of the force applying member 152R contacts the first regulating surface 128h of the developing device covering member 128 due to the biasing force of the tension spring 153 in the direction F1 in the drawing. Furthermore, the second regulating surface 152Rw of the force applying member 152R contacts the second regulating surface 128q of the developing device covering member 128, thereby positioning the force applying member 152R. This position is referred to as the stored position (reference position) of the force applying member 152R. Furthermore, the spacing maintaining member 151R rotates in the B1 direction around the spacing maintaining member pivot axis H due to the biasing force in the F2 direction of the tension spring 153, and the second pressed portion 151Rd of the spacing maintaining member 151R comes into contact with the second pressing surface 152Rr of the force applying member 152R, thereby stopping the rotation. This position is referred to as the spacing maintaining position (restricted position) of the spacing maintaining member 151R.

[0173] Furthermore, for the sake of explanation, FIG. 21 is an enlarged view of the area around the spacing member 151R in FIG. 10, with the tension spring 153 omitted. Consider the case where a process cartridge 100 having the spacing contact mechanism 150R described in this embodiment is dropped in the direction JA in FIG. 21 during transportation. At this time, the spacing member 151R is subjected to a force due to its own weight that rotates it in the direction of arrow B2 about the spacing member pivot axis H. When the spacing member 151R begins to rotate in the direction B2 for the reasons described above, the rotation prevention surface 151Rn of the spacing member 151R abuts against the locking surface 152Ru of the force applying member 152R, and the spacing member 151R is subjected to a force in the direction F3 in the figure that prevents it from rotating in the direction B2. This prevents the spacing member 151R from rotating in the direction B2 during transportation, preventing the spacing between the photosensitive drum 104 and the developing unit 109 from being damaged.

[0174] In this embodiment, the tension spring 153 is used as the biasing means for biasing the spacing maintaining member 151R to the spacing maintaining position and the force applying member 152R to the storage position, but the biasing means is not limited to this. For example, a torsion coil spring, a leaf spring, or the like may be used as the biasing means for biasing the force applying member 152R to the storage position and the spacing maintaining member 151R to the spacing maintaining position. The biasing means may be made of any material, such as metal or mold, that has elasticity and is capable of biasing the spacing maintaining member 151R and the force applying member 152R.

[0175] As described above, the developing unit 109 equipped with the separation and contact mechanism 150R is integrally connected to the drum holding unit 108 by the drive side cartridge cover member 116 as described above (the state shown in FIG. 19).

[0176] FIG. 22 shows a view from the direction of arrow J in FIG. 19. As shown in FIG. 15, the drive-side cartridge cover 116 of this embodiment has an abutment surface 116c. The abutment surface 116c is inclined at an angle θ3 with respect to the pivot axis K, as shown in FIG. 22. Note that the angle θ3 is preferably the same as the angle θ1 forming the spacing maintaining surface 151Rc of the spacing maintaining member 151R described above, but is not limited to this. Furthermore, as shown in FIGS. 15 and 19, when the drive-side cartridge cover member 116 is assembled to the developing unit 109 and the drum holding unit 108, the abutment surface 116c faces the spacing maintaining surface 151Rc of the spacing maintaining member 151R positioned at the spacing maintaining position. The abutment surface 116c comes into contact with the spacing maintaining surface 151Rc due to the biasing force of the development pressure spring 134, which will be described later. When the engagement surface 116Rc and the spacing maintaining surface 151Rc come into contact with each other, the posture of the developing unit 109 is positioned with a gap P1 between the developing roller 106 of the developing unit 109 and the photosensitive drum 104. This state in which the developing roller 106 (developing member) is separated from the photosensitive drum 104 by the gap P1 due to the spacing maintaining member 151R is referred to as the spacing position (retracted position) of the developing unit 109 (see FIG. 42(a)).

[0177] The separated state and the contact state of the process cartridge 100 will now be described in detail with reference to FIG.

[0178] Figure 42 is a side view of the process cartridge 100 as seen from the drive side when it is installed inside the image forming apparatus main body 170. Figure 42(a) shows a state in which the developing unit 109 is separated from the photosensitive drum 104. Figure 42(b) shows a state in which the developing unit 109 is in contact with the photosensitive drum 104.

[0179] First, with the spacing maintaining member 151R positioned at the spacing maintaining position and the developing unit 109 positioned at the separated position, the pressed portion 152Re of the force applying member 152R is pressed in the ZA direction. This causes the protruding portion 152Rh of the force applying member 152R to protrude from the process cartridge 100. As described above, the second pressed surface 151Re of the spacing maintaining member 151R is in contact with the second pressing surface 152Rr of the force applying member 152R by the tension spring 153. Therefore, when the second force receiving portion 152Rn is pressed in the direction of arrow W42, the force applying member 152R rotates in the direction of arrow BB about the force applying member pivot axis HC, causing the spacing maintaining member 151R to rotate in the direction of arrow B2. When the spacing maintaining member 151R rotates in the direction of arrow B2, the spacing maintaining surface 151Rc moves away from the contact surface 116c, and the developing unit 109 becomes rotatable from the separated position in the direction of arrow V2 around the swing axis K. In other words, the developing unit 109 rotates in the direction V2 from the separated position, and the developing roller 106 of the developing unit 109 comes into contact with the photosensitive drum 104. Here, the position of the developing unit 109 where the developing roller 106 and the photosensitive drum 104 come into contact is referred to as the contact position (developing position) (the state shown in FIG. 42(b)). Note that the position where the spacing maintaining surface 151Rc of the spacing maintaining member 151R moves away from the contact surface 116c is referred to as the separation release position (permissible position). When the developing unit 109 is located at the contact position, the second regulating surface 151Rk of the spacing member 151R contacts the second regulating surface 116d of the driving side cartridge cover 116, thereby maintaining the spacing member 151R at the separation release position.

[0180] The drive-side bearing 126 also has a first pressed surface 126c that is a surface perpendicular to the pivot axis K. Because the drive-side bearing 126 is fixed to the developing unit 109, when the developing unit 109 is in the contact position, it presses the first force receiving portion 152Rk of the force applying member 152R in the direction of arrow V41. As a result, the first pressing surface 152Rq comes into contact with the first pressed surface 126c, causing the developing unit 109 to rotate around the pivot axis K in the direction of arrow V1 and move to the separated position (the state shown in FIG. 42(a)). Here, when the developing unit 109 moves from the contact position to the separated position, the direction in which the first force receiving surface 126c moves is indicated by arrow W41 in FIGS. 42(a) and 42(b). The opposite direction to arrow W41 is arrow W42, and arrows W41 and W42 are substantially horizontal (X1 and X2 directions). As described above, the second force receiving surface 152Rp of the force applying member 152R assembled to the developing unit 109 is located upstream, in the direction of arrow W41, of the first force receiving surface 126c of the drive-side bearing 126. Furthermore, the first force receiving surface 126c and the second force receiving surface 151Re of the spacing member 151R are positioned so as to at least partially overlap in the W1 and W2 directions.

[0181] The detailed operation of the separation / contact mechanism 150R inside the image forming apparatus main body 170 will be described next.

[0182] [Installing the process cartridge into the image forming apparatus] 12, 23, and 24, an engagement operation between the separation and contact mechanism 150R of the process cartridge 100 and the developer separation control unit 195 of the image forming apparatus main body 170 when the process cartridge 100 is mounted in the image forming apparatus main body 170 will be described. For the purpose of explanation, these figures are cross-sectional views in which part of the developing device cover member 128 and part of the driving side cartridge cover member 116 are partially omitted along partial cross-sectional lines CS1 and CS2, respectively.

[0183] 23 is a view seen from the drive side of the process cartridge 100 when the process cartridge 100 is mounted on a cartridge tray 171 (not shown) of the image forming apparatus M and the cartridge tray 171 is inserted into the first mounting position. In this figure, only the process cartridge 100, the cartridge pressing unit 121, and the separation control member 196R are shown.

[0184] As described above, the image forming apparatus main body 170 of this embodiment has a separation control member 196R corresponding to each process cartridge 100. When the process cartridge 100 is positioned at the first inner position or the second inner position, the separation control member 196R is positioned closer to the underside of the image forming apparatus main body 170 than the separation maintaining member 151R. The separation control member 196R protrudes toward the process cartridge 100 and has a first force application surface 196Ra and a second force application surface 196Rb that face each other with a space 196Rd between them. The first force application surface 196Ra and the second force application surface 196Rb are connected via a connecting portion 196Rc on the underside of the image forming apparatus main body 170. The separation control member 196R is rotatably supported by the control plate metal 197 around a rotation center 196Re. The separation member 196R is constantly biased in the E1 direction by a biasing spring. Furthermore, the control metal plate 197 is configured to be movable in the W41 and W42 directions by a control mechanism (not shown), so that the separation control member 196R is configured to be movable in the W41 and W42 directions.

[0185] As described above, in conjunction with the transition of the front door 11 of the image forming apparatus main body 170 from the open state to the closed state, the cartridge pressing unit 121 descends in the direction of arrow ZA, and the first force application portion 121a abuts against the pressed surface 152Rf of the force application member 152R. When the cartridge pressing unit 121 subsequently descends to a predetermined position, which is the second installation position, the protruding portion 152Rh of the force application member 152R protrudes downward in the Z2 direction of the process cartridge 100 (the state shown in FIG. 24). This position is referred to as the protruding position of the force application member 152R. Upon completion of this operation, as shown in FIG. 24, a gap T4 is formed between the first force application surface 196Ra of the separation control member 196R and the first force receiving surface 152Rp of the force application member 152R, and a gap T3 is formed between the second force application surface 196Rb and the second force receiving surface 152Rp. The separation control member 152R is then positioned in the second installation position, where the separation control member 196R does not act on the force application member 152R. This position of the separation control member 196R is referred to as the home position. At this time, the first force receiving surface 152Rp of the force application member 152R and the first force application surface 196Ra of the separation control member 196R are arranged so as to partially overlap in the W1-W2 direction. Similarly, the second force receiving surface 152Rp of the force application member 152R and the second force application surface 196Rb of the separation control member 196R are arranged so as to partially overlap in the W1-W2 direction.

[0186] [Developing unit contact operation] Next, the operation of the separation / contact mechanism 150R to bring the photosensitive drum 104 and the developing roller 106 into contact with each other will be described in detail with reference to Figures 24 to 26. For the purpose of explanation, these figures are cross-sectional views in which part of the developing device cover member 128, part of the driving side cartridge cover member 116, and part of the driving side bearing 126 are partially omitted along partial cross-sectional lines CS1, CS2, and CS3, respectively.

[0187] In the configuration of this embodiment, the development input coupling 32 receives a driving force in the direction of arrow V2 in FIG. 24 from the image forming apparatus main body 170, causing the development roller 106 to rotate. In other words, the development unit 109 having the development input coupling 32 receives a torque in the direction of arrow V2 from the image forming apparatus main body 170 about the swing axis K. As shown in FIG. 24, when the development unit 109 is in the separated position and the spacing maintaining member 151R is in the separated position, the development unit 109 receives this torque and a biasing force from the development pressure spring 134, which will be described later. Even in this case, the spacing maintaining surface 151Rc of the spacing maintaining member 151R abuts against the abutting surface 116c of the drive-side cartridge cover member 116, and the attitude of the development unit 109 is maintained in the separated position.

[0188] In this embodiment, the separation control member 196R is configured to be movable from its home position in the direction of arrow W42 in FIG. 24. When the separation control member 196R moves in the W42 direction, the second force applying surface 196Rb of the separation control member 196R abuts against the second force receiving surface 152Rp of the force applying member 152R, causing the force applying member 152R to rotate in the direction BB around the force applying member pivot axis HC. Furthermore, as the force applying member 152R rotates, the second pressing surface 152Rr of the force applying member 152R abuts against the second pressed surface 151Re of the separation maintaining member 151R, causing the separation maintaining member 151R to rotate in the direction B2. The separation maintaining member 151R is then rotated by the force applying member 152R to a separation release position where the separation maintaining surface 151Rc and the abutting surface 116c are separated. Here, the position of the separation control member 196R shown in FIG. 25, which moves the separation maintaining member 151R to the separation release position, is referred to as a first position.

[0189] In this way, the separation control member 196R moves the separation maintaining member 151R to the separation release position. Then, the developing unit 109 rotates in the V2 direction due to the torque received from the image forming apparatus main body 170 and the developing pressure spring 134 (described later), and moves to the contact position where the developing roller 106 and the photosensitive drum 104 contact each other (the state shown in FIG. 25 ). At this time, the separation maintaining member 151R, which is biased in the direction of arrow B1 by the tension spring 153, is maintained at the separation release position by the second regulated surface 151Rk contacting the second regulating surface 116d of the driving-side cartridge cover member 116. The separation control member 196R then moves in the W41 direction to return to the home position. At this time, the force application member 152R rotates in the BA direction due to the tension spring 153, and the first pressing surface 152Rq of the force application member 152R and the first pressing surface 126c of the drive-side bearing 126 come into contact with each other (the state shown in FIG. 26).

[0190] As a result, the gaps T3 and T4 are formed again, and the force application member 152R is positioned so that the separation control member 196R does not act on the force application member 152R. The transition from the state in Figure 25 to the state in Figure 26 occurs without any time lapse.

[0191] As described above, in the configuration of this embodiment, the separation control member 196R moves from the home position to the first position, which rotates the force application member 152R and moves the separation maintaining member 151R from the separation maintaining position to the separation release position. This allows the development unit 109 to move from the separation position to the contact position where the development roller 9 and photosensitive drum 104 contact each other. The position of the separation control member 196R in FIG. 26 is the same as that in FIG. 24.

[0192] [Developing unit separation operation] Next, the operation of moving the developing unit 109 from the contact position to the separated position by the separation contact mechanism 150R will be described in detail with reference to Figures 26 and 27. For the purpose of explanation, these figures are cross-sectional views in which part of the developing unit cover member 128, part of the driving side cartridge cover member 116, and part of the driving side bearing 126 are partially omitted along the partial cross-sectional line CS.

[0193] In this embodiment, the separation control member 196R is configured to be movable in the direction of arrow W41 in FIG. 26 from its home position. When the separation control member 196R moves in the W41 direction, the first force application surface 196Rb and the first force receiving surface 152Rm of the force application member 152R come into contact with each other, causing the force application member 152R to rotate in the direction of arrow BB around the force application member pivot axis HC. The first pressing surface 152Rq of the force application member 152R comes into contact with the first pressed surface 126c of the drive-side bearing 126, causing the development unit 109 to rotate in the direction of arrow V1 around the pivot axis K from the contact position (the state shown in FIG. 27). At this time, the pressed surface 152Rf of the force application member 152R is arc-shaped, and the center of this arc is positioned to coincide with the pivot axis K. As a result, when the developing unit 109 moves from the abutting position to the separated position, the force that the pressed surface 152Rf of the force applying member 152R receives from the cartridge pressing unit 121 is directed in the direction of the swing axis K. Therefore, the developing unit 109 can be operated so as not to interfere with rotation in the direction of arrow V1. The second regulated surface 151Rk of the spacing maintaining member 151R and the second regulating surface 116d of the driving-side cartridge cover member 116 separate from each other, and the spacing maintaining member 151R rotates in the direction of arrow B1 due to the biasing force of the tension spring 153. As a result, the spacing maintaining member 151R rotates until the second pressed surface 151Re abuts against the second pressing surface 152Rr of the force applying member 152R, and upon abutment, the spacing maintaining member 151R moves to the separated position. When the developing unit 109 is moved from the abutment position toward the separated position by the separation control member 196R and the separation maintaining member 151R is located at the separated position, a gap T5 is formed between the separation maintaining surface 151Rc and the abutment surface 116c as shown in Fig. 27. Here, the position shown in Fig. 27 where the developing unit 109 is rotated from the abutment position toward the separated position and the separation maintaining member 151R can move to the separated position is referred to as the second position of the separation control member 196R.

[0194] Thereafter, the separation control member 196R moves in the direction of arrow W42, returning from the second position to the home position. Then, while the separation maintaining member 151R maintains the separation maintaining position, the developing unit 109 rotates in the direction of arrow V2 due to torque received from the image forming apparatus main body 170 and the developing pressure spring 134 (described later), and the separation maintaining surface 151Rc and the contact surface 116c come into contact. In other words, the separation position of the developing unit 109 is maintained by the separation maintaining member 151R, and the developing roller 106 and the photosensitive drum 104 are separated by the gap P1 (the state shown in FIGS. 24 and 42(a)). This re-establishes the aforementioned gaps T3 and T4, and the separation control member 196R is positioned so that it does not act on the force applying member 152R (the state shown in FIG. 24). The transition from the state shown in FIG. 27 to the state shown in FIG. 24 occurs immediately.

[0195] As described above, in this embodiment, when the separation control member 196R moves from the home position to the second position, the separation maintaining member 151R moves from the separation release position to the separation maintaining position. When the separation control member 196R returns from the second position to the home position, the developing unit 109 is maintained in the separated position by the separation maintaining member 151R.

[0196] [Detailed explanation of the spacing member L] Here, the spacing member 151L will be described in detail with reference to FIG.

[0197] Figure 28(a) is a front view of the spacing member 151L as viewed from the longitudinal direction of the drive side of the process cartridge 100, and Figures 28(b) and 28(c) are perspective views of the spacing member 151L. The spacing member 151L has an annular support receiving portion 151La, and a spacing portion 151Lb that protrudes from the support receiving portion 151La in the radial direction of the support receiving portion 151La. The tip of the spacing portion 151Lb has an arc-shaped spacing surface 151Lc centered on the spacing member pivot axis H.

[0198] The spacing member 151L also has a second regulated surface 151Lk adjacent to the spacing surface 151Lc. The spacing member 151L also has a second pressed portion 151Ld that protrudes in the Z2 direction beyond the support receiving portion 151La, and a second pressed surface 151Le that has an arc shape and protrudes from the second pressed portion 151Ld in the direction of the spacing member pivot axis H of the support receiving portion 151La.

[0199] Furthermore, the spacing member 151L has a main body 151Lf connected to the support receiving portion 151La, and the main body 151Lf has a spring hook portion 151Lg that protrudes from the support receiving portion 151La in the direction of the spacing member oscillation axis H. The main body 151Lf also has a rotation prevention portion 151m that protrudes in the Z2 direction, and a rotation prevention surface 151Ln is provided in a direction facing the second pressed surface 151Le.

[0200] [Detailed explanation of the force applying member L] Here, the force application member 152L will be described in detail with reference to FIG.

[0201] 29(a) is a front view of the force applying member 152L as viewed from the longitudinal direction of the process cartridge 100, and FIG. 29(b) and FIG. 29(c) are perspective views of the force applying member 152L as a single unit.

[0202] The force applying member 152L has an elongated support receiving portion 152La. Here, the longitudinal direction of the elongated shape of the elongated support receiving portion 152La is indicated by arrow LH, with arrow LH1 pointing upward and arrow LH2 pointing downward. Furthermore, the direction in which the elongated support receiving portion 152La is formed is indicated by HD. The force applying member 152L has a protrusion 152Lh formed on the downstream side of the elongated support receiving portion 152La in the direction of arrow LH2. The elongated support receiving portion 152La and the protrusion 152Lh are connected by a main body portion 152Lb. Meanwhile, the force applying member 152L has a pushed portion 152Le that protrudes in the direction of arrow LH1 and substantially perpendicular to the direction of arrow LH1. The force applying member 152L has an arc-shaped pushed surface 152Lf downstream in the direction of arrow LH1 and a push-in restricting surface 152Lg upstream. Furthermore, the force applying member 152L has a first storage state restricting surface 152Lv which is part of the elongated round support receiving portion 152La and is located downstream in the direction of the arrow LH2.

[0203] The protrusion 152Lh has a first force receiving portion 152Lk and a second force receiving portion 152Ln that are disposed at the end in the direction of arrow LH2 and face each other in a direction substantially perpendicular to the direction of arrow LH2. The first force receiving portion 152Lk and the second force receiving portion 152Ln have a first force receiving surface 152Lm and a second force receiving surface 152Lp, respectively, that extend in the HD direction and have an arc-shaped. The protrusion 152Lh also has a spring hook portion 152Ls and a locking portion 152Lt that protrude in the HB direction, and the locking portion 152Lt has a locking surface 152Lu that faces the same direction as the second force receiving surface 152Lp.

[0204] The force application member 152L is part of the main body 152Lb, is arranged upstream of the second force receiving portion 152Ln in the direction of arrow LH2, and has a first pressing surface 152Lq facing the same direction as the second force receiving surface 152Lp. The force application member 152L is also part of the main body 152Lb, is arranged upstream of the first force receiving portion 152Lk in the direction of arrow LH2, and has a first pressing surface 152Lr facing the same direction as the first force receiving surface 152Lm.

[0205] When the process cartridge 100 is mounted in the image forming apparatus main body 170, the LH1 direction is approximately the same as the Z1 direction, the LH2 direction is approximately the same as the Z2 direction, and the HB direction is approximately the same as the longitudinal direction of the process cartridge 100.

[0206] [Assembly of separation and contact mechanism L] Next, the assembly of the spacing mechanism will be described with reference to Figures 16 and 29 to 35. Figure 30 is a perspective view of the process cartridge 100, as seen from the drive side, after the spacing member 151L has been assembled. As mentioned above, as shown in Figure 16, the developing unit 109 has the outer diameter portion of the cylindrical portion 127a of the non-drive side bearing 127 fitted into the developing unit support hole 117a of the non-drive side cartridge cover member 117. This allows the developing unit 109 to be supported rotatably with respect to the photosensitive drum 104 about the pivot axis K. The non-drive side bearing 127 also has cylindrical first and second support portions 127b and 127e that protrude in the direction of the pivot axis K.

[0207] The outer diameter of first support portion 127b fits into the inner diameter of support receiver 151La of spacing maintaining member 151L, rotatably supporting spacing maintaining member 151L. Here, the center of oscillation of spacing maintaining member 151L assembled to non-drive-side bearing 127 is defined as spacing maintaining member oscillation axis H. Non-drive-side bearing 127 has first retaining portion 127c that protrudes in the direction of spacing maintaining member oscillation axis H. As shown in FIG. 16 , movement of spacing maintaining member 151L assembled to non-drive-side bearing 127 in the direction of spacing maintaining member oscillation axis H is restricted by first retaining portion 127c coming into contact with spacing maintaining member 151L.

[0208] The outer diameter of the second support portion 127e fits into the inner wall of the elongated support receiving portion 152La of the force application member 152L, supporting the force application member 152L rotatably and movably in the elongated direction. The center of oscillation of the force application member 152L assembled to the non-drive-side bearing 127 is defined as the force application member oscillation axis HC. As shown in FIG. 16, movement of the force application member 152L assembled to the non-drive-side bearing 127 in the direction of the force application member oscillation axis HE is restricted by the second retaining portion 127f coming into contact with the spacing member 151L.

[0209] Figure 31 shows the process cartridge 100 after the spacing member 151L is installed, as viewed from the direction of the developing unit pivot axis H. This is a cross-sectional view, partially cut away along the partial cross-sectional line CS, of the non-drive-side cartridge cover member 117, so as to show the fitting portion between the elongated support receiving portion 151La of the force applying member 152L and the cylindrical portion 127e of the non-drive-side bearing 127. The spacing contact mechanism 150L biases the spacing member 151L to rotate in the direction of arrow B1 about the spacing member pivot axis H, and includes a tension spring 153 as a biasing means for biasing the force applying member 152L in the direction of arrow B3. The direction of arrow B3 is substantially parallel to the elongated longitudinal direction LH2 of the elongated support receiving portion 152La of the force applying member 152L (see Figure 29). The tension spring 153 is assembled between a spring hook 151Lg provided on the spacing member 151L and a spring hook 152Ls provided on the force application member 152L. The tension spring 153 applies a force to the spring hook 151Lg of the spacing member 151L in the direction of arrow F2 in Figure 31, thereby applying a biasing force that rotates the spacing member in the direction of arrow B1. Furthermore, the tension spring 153 applies a force to the spring hook 152Ls of the force application member 152L in the direction of arrow F1, thereby applying a biasing force that moves the force application member 152L in the direction of arrow B3.

[0210] The line connecting the spring hook 151Lg of the spacing maintaining member 151L and the spring hook 152Ls of the force maintaining member 152L is designated as GS. The line connecting the spring hook 152Ls of the force applying member 152L and the force applying member oscillation axis HE is designated as HS. The angle θ3 formed by the line GS and the line HE is set to satisfy the following equation (3), with the counterclockwise direction about the spring hook 152Ls of the force applying member 152L as the positive angle. As a result, the force applying member 152L is biased to rotate in the direction BA in the figure around the force applying member oscillation axis HE as the rotation center. 0°≦θ3≦90° (3)

[0211] In this embodiment, the attachment positions of the spacing member 151L and the force application member 152L are as follows: As shown in Figure 29, in the direction of the swing axis K, the spacing member 151L and the force application member 152L are arranged on the side of the non-drive-side bearing 127 where the non-drive-side cartridge cover member 117 is arranged (outer side in the longitudinal direction). However, the arrangement positions are not limited to this, and the spacing member 151L and the force application member 152L may be arranged on the developing frame 125 side of the non-drive-side bearing 127 (inner side in the longitudinal direction), or the spacing member 151L and the force application member 152L may be arranged with the non-drive-side bearing 127 sandwiched between them. Furthermore, the arrangement order of the spacing member 151L and the force application member 152L may be reversed.

[0212] The non-drive side bearing 127 is fixed to the developing frame 125 to form the developing unit 109. Note that the fixing method in this embodiment is by fixing with a fixing screw 145 and an adhesive (not shown) as shown in Figure 16, but the fixing method is not limited to this and may be a joining method such as welding by heat or pouring in and hardening a resin.

[0213] 32(a) and 32(b) are cross-sectional views in which the non-drive-side cartridge cover member 117, the tension spring 153, and a portion of the spacing member 151L are partially omitted along the partial cross-sectional line CS. For the purpose of explanation, FIGS. 32(a) and 32(b) respectively show enlarged views of the force application member pivot axis HE of the force application member 152L and the periphery of the spacing member 151L in FIG.

[0214] The force application member 152L is positioned by the first restricting surface 152Lv of the force application member 152L contacting the second support portion 127e of the non-drive-side bearing 127 due to the biasing force of the tension spring 153 in the direction of arrow F1. As shown in FIG. 32(b), the first pressing surface 152Lq of the force application member 152L contacts the first pressed surface 127h of the non-drive-side bearing 127. This position is referred to as the stored position (reference position) of the force application member 152L. Furthermore, the biasing force of the tension spring 153 in the direction of arrow F2 causes the spacing member 151L to rotate in the direction of arrow B1 about the spacing member pivot axis H, and the contact surface 151Lp of the spacing member 151L contacts the second pressing surface 152Lr of the force application member 152L, thereby positioning the spacing member 151L. This position is referred to as the spacing position (restricting position) of the spacing member 151L. When the force-applying member 152L moves to the protruding position described later, the second pressed surface 151Le of the spacing maintaining member 151L comes into contact with the second pressing surface 152Lr of the force-applying member 152L, thereby enabling the spacing maintaining member 152L to be positioned at the spacing maintaining position.

[0215] Furthermore, for the sake of explanation, Figure 33 is an enlarged view of the area around the spacing member 151L in Figure 31, with the tension spring 153 omitted. Consider the case where a process cartridge 100 having a spacing mechanism 150L is dropped in the direction of arrow JA in Figure 33 during transportation. At this time, the spacing member 151L is subjected to a force due to its own weight that rotates it in the direction of arrow B2 around the spacing member pivot axis H. When the spacing member 151L begins to rotate in the direction of arrow B2 for the reasons described above, the rotation prevention surface 151Ln of the spacing member 151L abuts against the locking surface 152Lu of the force applying member 152L, and the spacing member 151L is subjected to a force in the direction of arrow F4 that inhibits rotation in the direction of arrow B2. This prevents the spacing member 151L from rotating in the direction of arrow B2 during transportation, thereby preventing the spacing between the photosensitive drum 104 and the developing unit 109 from being lost.

[0216] In this embodiment, the tension spring 153 is used as the biasing means for biasing the spacing maintaining member 151L to the spacing maintaining position and the force applying member 152L to the storage position, but the biasing means is not limited to this. For example, a torsion coil spring, a leaf spring, or the like may be used as the biasing means for biasing the force applying member 152L to the storage position and the spacing maintaining member 151L to the spacing maintaining position. The biasing means may be made of any material, such as metal or mold, that has elasticity and is capable of biasing the spacing maintaining member 151L and the force applying member 152L.

[0217] As described above, the developing unit 109 equipped with the spacing and contact mechanism 150L is integrally coupled to the drum holding unit 108 by the non-drive-side cartridge cover member 117 as described above (the state shown in FIG. 30). As shown in FIG. 16, the non-drive-side cartridge cover 117 of this embodiment has a contact surface 117c. The contact surface 117c is a surface parallel to the pivot axis K. Furthermore, as shown in FIGS. 16 and 30, when the non-drive-side cartridge cover member 117 is assembled to the developing unit 109 and the drum holding unit 108, the contact surface 117c faces a spacing maintaining surface 151Lc of the spacing maintaining member 151L that is positioned at the spacing maintaining position.

[0218] Here, the process cartridge 100 has a developing pressure spring 134 as an urging member for abutting the developing roller 106 against the photosensitive drum 104. The developing pressure spring 134 is assembled between a spring hook portion 117e of the non-drive-side cartridge cover member 117 and a spring hook portion 127k of the non-drive-side bearing 127. The urging force of the developing pressure spring 134 brings a spacing maintaining surface 151Lc of the spacing maintaining member 151L into contact with an abutment surface 117c of the non-drive-side cartridge cover member 117. When the abutment surface 117cc and the spacing maintaining surface 151Lc abut against each other, the developing unit 109 is positioned such that a gap P1 is left between the developing roller 106 of the developing unit 109 and the photosensitive drum 104. The state in which the developing roller 106 is separated from the photosensitive drum 104 by the gap P1 by the spacing member 151L is referred to as the separated position (retracted position) of the developing unit 109 (see FIG. 35(a)).

[0219] The separated state and contact state of the process cartridge 100 will now be described in detail with reference to Figure 35. Figure 35 is a side view of the process cartridge 100 as seen from the non-drive side when it is installed inside the image forming apparatus main body 170. Figure 35(a) shows the state in which the developing unit 109 is separated from the photosensitive drum 104. Figure 35(b) shows the state in which the developing unit 109 is contacted against the photosensitive drum 104.

[0220] First, when the spacing member 151L is positioned at the spacing position and the developing unit 109 is positioned at the separated position, the pressed portion 152Le of the force applying member 152L is pressed in the direction of arrow ZA. This causes the protruding portion 152Lh of the force applying member 152L to protrude from the process cartridge 100 (the state shown in FIG. 34(a)). This position is referred to as the protruding position of the force applying member 152L. As described above, the second pressed surface 151Le of the spacing member 151L abuts against the second pressing surface 152Lr of the force applying member 152L by the tension spring 153. Therefore, when the second force receiving portion 152Ln is pressed in the direction of arrow W42, the force applying member 152L rotates in the direction of arrow BD around the force applying member pivot axis HE, causing the spacing member 151L to rotate in the direction of arrow B5. When the spacing member 151L rotates in the direction of arrow B5, the spacing surface 151Lc moves away from the contact surface 117c, and the developing unit 109 becomes rotatable from the separated position around the swing axis K in the direction of arrow V2.

[0221] That is, the developing unit 109 rotates in the V2 direction from the separated position, and the developing roller 106 of the developing unit 109 comes into contact with the photosensitive drum 104. Here, the position of the developing unit 109 where the developing roller 106 comes into contact with the photosensitive drum 104 is referred to as the contact position (developing position) (the state shown in FIG. 34(b)). Note that the position where the separation maintaining surface 151Lc of the separation maintaining member 151L is separated from the contact surface 117c is referred to as the separation release position (permitted position). When the developing unit 109 is located at the contact position, the second regulating surface 151Lk of the separation maintaining member 151L comes into contact with the second regulating surface 117d of the driving side cartridge cover 116, thereby maintaining the separation maintaining member 151L in the separation release position.

[0222] Furthermore, the non-drive-side bearing 127 of this embodiment has a first pressed surface 127h that is a surface perpendicular to the pivot axis K. Because the non-drive-side bearing 127 is fixed to the developing unit 109, when the developing unit 109 is in the abutting position, it presses the first force receiving portion 152Lk of the force applying member 152L in the direction of arrow V41. Then, the first pressing surface 152Lq abuts against the first pressed surface 127h, causing the developing unit 109 to rotate around the pivot axis K in the direction of arrow V1 and move to the separated position (the state shown in FIG. 34(a)). Here, when the developing unit 109 moves from the abutting position to the separated position, the direction in which the first pressed surface 127h moves is indicated by arrow W41 in FIGS. 34(a) and 34(b). The opposite direction to arrow W41 is arrow W42, and both arrows W41 and W42 are substantially horizontal (the X1 and X2 directions). As described above, the second force receiving surface 152Lp of the force applying member 152L assembled to the developing unit 109 is located upstream, in the direction of arrow W41, of the first pressed surface 127h of the non-drive-side bearing 127. Furthermore, the first pressed surface 127h and the second force receiving surface 151Le of the spacing member 151L are positioned so as to at least partially overlap in the W1 and W2 directions.

[0223] The operation of the separation / contact mechanism 150L inside the image forming apparatus main body 170 will be described next.

[0224] [Installing the process cartridge into the image forming apparatus] Next, using Figures 35 and 36, we will explain the engagement operation between the separation and contact mechanism 150R of the process cartridge 100 and the developer separation control unit 196 of the image forming apparatus main body 170 when the process cartridge 100 is mounted in the image forming apparatus main body 170. For the sake of explanation, these figures are cross-sectional views in which a portion of the developer cover member 128 and a portion of the non-drive-side cartridge cover member 117 are partially omitted along the partial cross-sectional line CS. Figure 35 is a view seen from the drive side of the process cartridge 100 when the process cartridge 100 is mounted in a cartridge tray 171 (not shown) of the image forming apparatus M and the cartridge tray 171 is inserted to the first mounting position. In this figure, only the process cartridge 100, the cartridge pressing unit 121, and the separation control member 196L are shown.

[0225] As described above, the image forming apparatus main body 170 of this embodiment has a separation control member 196L corresponding to each process cartridge 100. When the process cartridge 100 is positioned at the first inner position or the second inner position, the separation control member 196L is positioned closer to the underside of the image forming apparatus main body 170 than the separation maintaining member 151L. The separation control member 196L protrudes toward the process cartridge 100 and has a first force application surface 196La and a second force application surface 196Lb that face each other across a space 196Rd. The first force application surface 196Ra and the second force application surface 196Rb are connected via a connecting portion 196Rc on the underside of the image forming apparatus main body 170. The separation control member 196R is rotatably supported by the control plate metal 197 around a rotation center 196Re. The separation member 196R is constantly biased in the E1 direction by a biasing spring. Furthermore, the control metal plate 197 is configured to be movable in the W41 and W42 directions by a control mechanism (not shown), so that the separation control member 196R is configured to be movable in the W41 and W42 directions.

[0226] As described above, in conjunction with the transition of the front door 11 of the image forming apparatus main body 170 from the open state to the closed state, the cartridge pressing unit 121 descends in the direction of arrow ZA, and the first force application portion 121a abuts against the pressed surface 152Lf of the force application member 152L. When the cartridge pressing unit 121 subsequently descends to a predetermined position, which is the second installation position, the 152Lh of the force application member 152L moves to a protruding position protruding downward in the Z2 direction of the process cartridge 100 (the state shown in FIG. 36 ). Upon completion of this operation, as shown in FIG. 36 , a gap T4 is formed between the first force application surface 196La of the separation control member 196L and the first force receiving surface 152Lp of the force application member 152L, and a gap T3 is formed between the second force application surface 196Lb and the second force receiving surface 152Lp. The separation control member 196L is then positioned in the second installation position, where it does not act on the force application member 152L. This position of the separation control member 196L is referred to as the home position. At this time, the first force receiving surface 152Lp of the force applying member 152L and the first force applying surface 196La of the separation control member 196L are arranged to partially overlap in the W1-W2 direction. Similarly, the second force receiving surface 152Lp of the force applying member 152L and the second force applying surface 196Lb of the separation control member 196L are arranged to partially overlap in the W1-W2 direction.

[0227] [Developing unit contact operation] Next, the operation of the separation / contact mechanism 150L to bring the photosensitive drum 104 and the developing roller 106 into contact with each other will be described in detail with reference to Figures 36 to 38. For the purpose of explanation, these figures are cross-sectional views in which part of the developing device cover member 128, part of the non-driven side cartridge cover member 117, and part of the non-driven side bearing 127 are partially omitted along the partial cross-sectional line CS.

[0228] As explained above, the development input coupling 32 receives a driving force in the direction of arrow V2 in Figure 24 from the image forming apparatus main body 170, causing the development roller 106 to rotate. In other words, the development unit 109 having the development input coupling 32 receives a torque in the direction of arrow V2 from the image forming apparatus main body 170 about the swing axis K. Furthermore, the development unit 109 also receives a biasing force in the direction of arrow V2 from the biasing force of the development pressure spring 134 mentioned above.

[0229] 36, when the developing unit 109 is in the separated position and the spacing maintaining member 151L is in the separated position, the developing unit 109 receives this torque and the urging force of the developing pressure spring 134. Even in this case, the spacing maintaining surface 151Lc of the spacing maintaining member 151L abuts against the abutment surface 117c of the non-driven side cartridge cover member 117, and the attitude of the developing unit 109 is maintained in the separated position (the state in FIG. 36).

[0230] In this embodiment, the separation control member 196L is configured to be movable from its home position in the direction of arrow W41 in FIG. 36 . When the separation control member 196L moves in the W41 direction, the second force applying surface 196Lb of the separation control member 196L abuts against the second force receiving surface 152Lp of the force applying member 152L, causing the force applying member 152L to rotate in the direction BD around the force applying member oscillation axis HD. Furthermore, as the force applying member 152L rotates, the second pressing surface 152Lr of the force applying member 152L abuts against the second pressed surface 151Le of the separation maintaining member 151L, causing the separation maintaining member 151L to rotate in the direction B5. The separation maintaining member 151L is then rotated by the force applying member 152L to a separation release position where the separation maintaining surface 151Lc and the abutment surface 117c are separated. Here, the position of the separation control member 196L shown in FIG. 37, where the separation maintaining member 151L is moved to the separation release position, is referred to as a first position.

[0231] In this way, the separation control member 196L moves the separation maintaining member 151L to the separation release position. Then, the developing unit 109 rotates in the V2 direction due to the torque received from the image forming apparatus main body 170 and the biasing force of the developing pressure spring 134, and moves to the abutment position where the developing roller 106 and the photosensitive drum 104 abut (the state shown in FIG. 37). At this time, the separation maintaining member 151L, which is biased in the direction of arrow B4 by the tension spring 153, is maintained at the separation release position by the second regulated surface 151Lk abutting against the second regulating surface 117d of the non-drive-side cartridge cover member 117. Thereafter, the separation control member 196L moves in the W42 direction and returns to the home position. At this time, the force application member 152L rotates in the BC direction due to the tension spring 153, and the first pressing surface 152Lq of the force application member 152L and the first pressed surface 127h of the non-drive-side bearing 127 transition to a state in which they are in contact (the state shown in Figure 38). This re-creates the gaps T3 and T4 described above, and the separation control member 196L is positioned so that it does not act on the force application member 152L. The transition from the state shown in Figure 37 to the state shown in Figure 38 occurs immediately. The position of the separation control member 196L in Figure 38 is the same as that in the state shown in Figure 36.

[0232] As described above, in the configuration of this embodiment, the movement of the separation control member 196L from the home position to the first position rotates the force applying member 152L, thereby moving the separation maintaining member 151L from the separation maintaining position to the separation release position, which allows the development unit 109 to move from the separation position to the contact position where the development roller 9 and the photosensitive drum 104 contact each other.

[0233] [Developing unit separation operation] Next, the operation of moving the developing unit 109 from the contact position to the separated position will be described in detail with reference to Figures 38 and 39. For the purpose of explanation, Figure 39 is a cross-sectional view in which part of the developing device cover member 128, part of the non-driven side cartridge cover member 117, and part of the non-driven side bearing 127 are partially omitted along the partial cross-sectional line CS.

[0234] In this embodiment, the separation control member 196L is configured to be movable in the direction of arrow W42 in FIG. 38 from its home position. When the separation control member 196L moves in the W42 direction, the first force application surface 196Lb and the first force receiving surface 152Lm of the force application member 152L come into contact with each other, causing the force application member 152L to rotate in the direction of arrow BC around the force application member oscillation axis HD. Because the first pressing surface 152Lq of the force application member 152L comes into contact with the first pressed surface 127h of the non-drive-side bearing 127, the developing unit 109 rotates from the contact position in the direction of arrow V1 around the oscillation axis K (the state shown in FIG. 39). At this time, the pressed surface 152Lf of the force application member 152L is arc-shaped, and the center of this arc is positioned to coincide with the oscillation axis K. As a result, when the developing unit 109 moves from the abutting position to the separated position, the force that the pressed surface 152Lf of the force applying member 152L receives from the cartridge pressing unit 121 is directed in the direction of the swing axis K. Therefore, the developing unit 109 can be operated so as not to impede rotation in the direction of arrow V1. The second regulated surface 151Lk of the spacing maintaining member 151L and the second regulating surface 117d of the non-drive-side cartridge cover member 117 separate from each other, and the spacing maintaining member 151L rotates in the direction of arrow B4 due to the biasing force of the tension spring 153. As a result, the spacing maintaining member 151L rotates until the second pressed surface 151Le abuts against the second pressing surface 152LR of the force applying member 152L, and upon abutment, the spacing maintaining member 151L moves to the separated position. When the developing unit 109 is moved from the abutment position toward the separated position by the separation control member 196L and the separation maintaining member 151L is positioned at the separated position, a gap T5 is formed between the separation maintaining surface 151Lc and the abutment surface 117c as shown in Figure 39. Here, the position at which the developing unit 109 is rotated from the abutment position toward the separated position and the separation maintaining member 151L can move to the separated position is referred to as the second position of the separation control member 196L.

[0235] Thereafter, the separation control member 196L moves in the direction of arrow W41, returning from the second position to the home position. Then, while the separation maintaining member 151L maintains the separation maintaining position, the developing unit 109 rotates in the direction of arrow V2 due to the torque received from the image forming apparatus main body 170 and the biasing force of the developing pressure spring 134, and the separation maintaining surface 151Lc and the contact surface 117c come into contact. In other words, the separation maintaining member 151L maintains the separation position of the developing unit 109, and the developing roller 106 and the photosensitive drum 104 are separated by the gap P1 (the state shown in FIGS. 36 and 34(a)). This re-establishes the aforementioned gaps T3 and T4, and the separation control member 196L is positioned so that it does not act on the force applying member 152L (the state shown in FIG. 36). The transition from the state shown in FIG. 39 to the state shown in FIG. 36 occurs immediately.

[0236] As described above, in the configuration of this embodiment, when the separation control member 196L moves from the home position to the second position, the separation maintaining member 151L moves from the separation release position to the separation maintaining position. When the separation control member 196L returns from the second position to the home position, the developing unit 109 is maintained in the separated position by the separation maintaining member 151L.

[0237] Up to this point, the operation of the spacing mechanism located on the drive side of the process cartridge 100 and the operation of the spacing mechanism located on the non-drive side have been described separately, but in this embodiment, these mechanisms operate in conjunction with each other. That is, when the developing unit 109 is positioned at the separated position by the spacing maintaining member R, this occurs substantially simultaneously with the developing unit 109 being positioned at the separated position by the spacing maintaining member L. The same is true for the abutment position. Specifically, the separation control member 121R and the separation control member 121L described in FIGS. 23 to 27 and 35 to 39 move integrally via a connecting mechanism (not shown). As a result, the timing at which the spacing maintaining member 151R located on the drive side is positioned at the separated position and the timing at which the spacing maintaining member 151L located on the non-drive side is positioned at the separated position are substantially simultaneous, and the timing at which the spacing maintaining member 151R is positioned at the separation maintaining position and the timing at which the spacing maintaining member 151L is positioned at the separation release position are substantially simultaneous. Note that these timings may differ between the driven side and the non-driven side, but in order to shorten the time from when the user starts a print job to when the printed material is ejected, it is desirable that at least the timings at which they reach the separation release position are simultaneous. Note that in this embodiment, the spacing member pivot axes H of the spacing member 151R and the spacing member 151L are coaxial, but as described above, it is sufficient that they reach the separation release position approximately simultaneously, and this is not limited to this. Similarly, the force application member pivot axis HC of the force application member 152R and the force application member pivot axis HE of the force application member 152L are not coaxial, but as described above, it is sufficient that they reach the separation release position approximately simultaneously, and this is not limited to this.

[0238] As described above, the drive side and non-drive side have similar separation and contact mechanisms that operate approximately simultaneously. This makes it possible to control the amount of separation between the photosensitive drum 104 and the developing roller 9 at both ends in the longitudinal direction, even if the process cartridge 100 is twisted or deformed in the longitudinal direction. This makes it possible to reduce variation in the amount of separation in the longitudinal direction.

[0239] Furthermore, according to this embodiment, the contact state and separation state of the developing roller 106 and the photosensitive drum 104 can be controlled by moving the separation control member 196R(L) in one direction (the direction of arrows W41 and W42) between the home position, the first position, and the second position. Therefore, the developing roller 106 is brought into contact with the photosensitive drum 104 only when image formation is being performed, and the developing roller 106 can be maintained separated from the photosensitive drum 104 when image formation is not being performed. Therefore, even if the developing roller 106 and the photosensitive drum 104 are left for a long period of time without image formation, stable image formation can be performed without deformation of the developing roller 106 and the photosensitive drum 104.

[0240] Furthermore, according to this embodiment, the force application member 152R(L) that acts on the spacing member 151R(L) to rotate it can be positioned in the storage position by the biasing force of the tension spring 153 or the like. Therefore, when the process cartridge 100 is present outside the image forming apparatus main body 170, the force application member 152R(L) does not protrude from the outermost shape of the process cartridge 100, and the process cartridge 100 itself can be made compact.

[0241] Similarly, the force application member 152R(L) can be positioned in the storage position by the biasing force of the tension spring 153 or the like. Therefore, when the process cartridge 100 is mounted in the image forming apparatus main body 170, the mounting can be completed by moving the process cartridge 100 in only one direction. Therefore, there is no need to move the process cartridge 100 (tray 171) in the vertical direction. Therefore, no extra space is required in the image forming apparatus main body 170, and the main body can be made more compact.

[0242] Furthermore, according to this embodiment, when the separation control member 196R(L) is located at the home position, no load is applied to the separation control member 196R(L) from the process cartridge 100. Therefore, the rigidity required for the separation control member 196R(L) and the mechanism that operates the separation control member 196R(L) can be reduced, allowing for miniaturization. Furthermore, the load on the sliding parts of the mechanism that operates the separation control member 196R(L) is also reduced, making it possible to suppress wear on the sliding parts and the generation of abnormal noise.

[0243] Furthermore, according to this embodiment, the developing unit 109 can maintain the spaced position using only the spacing member 151R(L) of the process cartridge 100. Therefore, by reducing the number of parts that cause variations in the spacing between the developing roller 106 and the photosensitive drum 104, component tolerances can be reduced, and the spacing can be minimized. Because the spacing can be reduced, when the process cartridge 100 is installed in the image forming apparatus main body 170, the area in which the developing unit 109 exists as it moves between the contact position and the spaced position is reduced, thereby achieving a more compact image forming apparatus. Additionally, because the space for the developer accommodating portion 29 of the developing unit 109 when it moves between the contact position and the spaced position can be increased, a compact, high-capacity process cartridge 100 can be installed in the image forming apparatus main body 170.

[0244] Furthermore, according to this embodiment, the force application member 152R(L) can be positioned in the storage position when the process cartridge 100 is installed, and the developing unit 109 can maintain the separated position using only the separation member 151R(L) of the process cartridge 100. Therefore, when the process cartridge 100 is installed in the image forming apparatus main body 170, installation can be completed by moving the process cartridge 100 in only one direction. Therefore, the process cartridge 100 (tray 171) does not need to be moved vertically. Therefore, no extra space is required in the image forming apparatus main body 170, and the main body can be made more compact. Furthermore, because the separation amount can be reduced, when the process cartridge 100 is installed in the image forming apparatus main body 170, the area in which the developing unit 109 exists is reduced when the developing unit 109 moves to the abutting position and the separated position, thereby making it possible to make the image forming apparatus more compact. In addition, since the space for the developer accommodating section 29 of the developing unit 109 that moves between the abutment position and the separation position can be increased, a compact, large-capacity process cartridge 100 can be placed in the image forming apparatus main body 170.

[0245] [Details of the arrangement of the separation and contact mechanism] Next, the arrangement of the separation / contact mechanisms R and L in this embodiment will be described in detail with reference to FIGS.

[0246] FIG. 40 is an enlarged view of the process cartridge 100 around the spacing member 151R as viewed from the drive side along the pivot axis K (photosensitive drum axial direction) of the developing unit 109. Additionally, for the sake of explanation, a portion of the developing device cover member 128 and a portion of the drive-side cartridge cover member 116 are partially omitted along the partial cross-sectional line CS. FIG. 41 is an enlarged view of the process cartridge 100 around the spacing member 151R as viewed from the non-drive side along the pivot axis K of the developing unit 109 (along the axis in the photosensitive drum axial direction). Additionally, for the sake of explanation, a portion of the developing device cover member 128 and a portion of the drive-side cartridge cover member 116 are partially omitted along the partial cross-sectional line CS. Note that, with regard to the arrangement of the spacing member and the force applying member described below, there is no distinction between the drive side and the non-drive side, except for the parts that will be described in detail later, and both are common, so only the drive side will be described, and the non-drive side will also be described in the same way.

[0247] 40, the rotation center of the photosensitive drum 104 is defined as point M1, the rotation center of the developing roller 106 is defined as point M2, and the line passing through points M1 and M2 is defined as line N. Furthermore, the contact area between the spacing maintaining surface 151Rc of the spacing maintaining member 151R and the abutting surface 116c of the driving-side cartridge cover member 116 is defined as M3, and the contact area between the second pressed surface 151Re of the spacing maintaining member 151R and the second pressing surface 152Rr of the force applying member 152R is defined as M4. Furthermore, the distance between the oscillation axis K of the developing unit 109 and point M2 is defined as distance e1, the distance between the oscillation axis K and area M3 is defined as distance e2, and the distance between the oscillation axis K and point M4 is defined as distance e3.

[0248] In the configuration of this embodiment, when the developing unit 109 is in the separated position and the force applying member 152R(L) is in the protruding position, the following positional relationship exists. That is, when viewed along the axial direction of the swing shaft K (axial direction of the photosensitive drum) shown in FIG. 40, at least a part of the contact area M3 between the spacing maintaining member 151R and the drive-side cartridge cover member is located in an area opposite to the area where the center of the developing coupling 32 (swing shaft K) is located, across a line N passing through the center of the photosensitive drum 104 and the center of the developing roller 106. That is, the spacing maintaining surface 151Rc of the spacing maintaining member 151R is located so that the distance e2 is longer than the distance e1.

[0249] By arranging the spacing maintaining member 151R and the spacing maintaining surface 151Rc in this manner, it is possible to minimize variations in the posture of the separation position of the developing unit 109 when the position of the spacing maintaining surface 151Rc varies due to component tolerances, etc. In other words, it is possible to minimize the effect of variations in the spacing maintaining surface 151Rc on the separation amount (gap) P1 (see FIG. 42(a)) between the developing roller 106 and the photosensitive drum 104, thereby enabling the developing roller 106 to be separated from the photosensitive drum 104 with high precision. In addition, there is no need to provide extra space for retracting the developing unit 109 when it is separated, which leads to a more compact image forming apparatus main body 170.

[0250] In addition, the first force receiving portion 152Rk(Lk) and the second force receiving portion 152Rn(Ln), which are the force receiving portions of the force applying member 152R(L), are arranged on the opposite side of the rotation center of the development coupling 32 across the extension line of the line N.

[0251] As explained above, the force receiving portions 152Rk (Lk) and 152Rn (Ln) are disposed at the longitudinal end portions. Also, as shown in FIG. 15 (FIG. 16), the cylindrical portion 128b (127a), which is a support portion for the developing unit 109, is disposed at the longitudinal end portions. Therefore, by disposing the force receiving portions 152Rk (Lk) and 152Rn (Ln) on the opposite side of the line N from the cylindrical portion 128b (127a) of the developing unit 109 (i.e., the swing axis K), the functional portions can be disposed efficiently. This leads to a reduction in the size of the process cartridge 100 and the image forming apparatus M.

[0252] In addition, the force receiving portions 152Rk and 152Rn are disposed at the longitudinal drive side end. Also, as shown in FIG. 15, a development drive input gear 132 that receives drive from the image forming apparatus main body 170 and drives the development roller 106 is provided at the longitudinal drive side end. As shown in FIG. 40, the force applying members 152Rk and 152Rn are disposed on the opposite side of the extension of line N from the center of rotation K of the development drive input gear 132 (development coupling portion 132a) shown by the dashed line. This arrangement allows for efficient arrangement of functional portions. This, in other words, leads to a reduction in the size of the process cartridge 100 and image forming apparatus M.

[0253] Furthermore, the contact portion between the spacing member 151R and the force applying member 152R is arranged so that the distance e3 is longer than the distance e1. This allows the spacing member 151R and the driving-side cartridge cover member 116 to come into contact with each other with a lighter force. In other words, the developing roller 106 and the photosensitive drum 104 can be spaced apart stably.

[0254] [Detailed explanation of the drive transmission mechanism to the photosensitive drum] A configuration for transmitting a driving force from the image forming apparatus main body to the drum unit 103 (see FIG. 1(a)) of the cartridge 100 and driving (rotating) the drum unit 103 will be described.

[0255] The drum unit 103 shown in Figures 1, 13, and 55 to 58 includes a photosensitive drum, a drum coupling (cartridge-side coupling, coupling member) 143, and a drum flange 142 (see Figure 13). The drum unit 103 is detachably attached to the image forming apparatus main body as part of the cartridge 100. When attached to the apparatus main body, the drum unit 103 is configured to couple with a drive transmission unit 203 (see Figures 43 and 44; details will be described later) provided in the apparatus main body. The drum unit 103 rotates in the direction of arrow A during image formation (see Figures 1, 55 to 57). In this embodiment, when viewing the drive side of the drum unit 103 (the side where the drum coupling 143 is located), i.e., when viewing the drum unit 103 along the direction of arrow M1B, the rotational direction of the drum unit 103 corresponds to the clockwise direction (see Figure 1). In other words, when viewing the front of the drum coupling 143, the rotational direction A of the drum coupling 143 corresponds to the clockwise direction.

[0256] The rotation direction A of the drum unit (drum coupling 143 and photosensitive drum 104) can be explained using the movement of the surface of the photosensitive drum 104 as follows (see FIGS. 2 and 3). Note that, unlike FIG. 1, in FIGS. 2 and 3, the cartridge is viewed from the non-drive side, so the rotation direction A of the drum unit 103 is counterclockwise.

[0257] As shown in FIG. 3, the surface of the photosensitive drum 104 is charged inside the cartridge at a position near the charging roller 105 (around the position where it contacts the charging roller). The surface of the photosensitive drum 104 then moves to a position where it receives the laser light U, and an electrostatic latent image is formed on the surface. The surface of the photosensitive drum 104 then moves to a position near the developing roller 106 (in this embodiment, a position where it contacts the developing roller), and the latent image formed on the surface of the photosensitive drum 104 is developed into a toner image. The surface of the photosensitive drum 104 then moves to a position below the cartridge and exposed to the outside of the cartridge casing. Then, as shown in FIG. 2, the surface of the photosensitive drum 104 exposed from the cartridge casing comes into contact with the intermediate transfer belt 12a provided in the image forming apparatus main body. As a result, the toner image is transferred from the surface of the photosensitive drum 104 to the transfer belt 12a. The surface of the photosensitive drum 104 then returns to the inside of the cartridge and moves again to a position near the charging roller 105.

[0258] In summary, when the coupling 143 receives a driving force and the photosensitive drum 104 rotates, the surface of the photosensitive drum 104 moves from a position close to the charging roller 105 to a position close to the developing roller 106. After that, the surface of the photosensitive drum 104 is exposed to the outside of the cartridge casing, and then returns to the inside of the cartridge casing and moves close to the charging roller 105 again.

[0259] As described above, the cartridge 100 of this embodiment does not have a cleaning device that contacts the photosensitive drum 104 to remove toner from the surface of the photosensitive drum 104 (see FIG. 3). Therefore, the torque required to rotate the drum unit 103 (photosensitive drum 104) inside the cartridge 100 is relatively small. With this configuration, the drum unit 103 is easily affected by its surroundings when it is driven. As a result, the drum unit 103 is subject to external influences and its rotational speed may become unstable. For example, in this embodiment, the developing roller 106, charging roller 105, and transfer belt 12a contact the photosensitive drum 104. If there is a change in the magnitude of the frictional force generated between these and the photosensitive drum 104, the speed of the drum unit 103 may fluctuate.

[0260] Therefore, in this embodiment, a torque of a certain level or more is required when the drum drive coupling 180 of the drive transmission unit 203 (see FIG. 43) provided in the main body of the apparatus rotates the drum unit 103 (photosensitive drum 104) of the cartridge. As a result, the rotation of the drum unit 103 is relatively less susceptible to external influences, and the rotation speed is stabilized.

[0261] First, the drum coupling 143 of the process cartridge 100 will be described with reference to Figure 1(a). Figure 1(a) is a perspective view of the drum coupling.

[0262] The drum coupling 143 of this embodiment is manufactured by injection molding polyacetal resin. It may be made of resin materials such as polycarbonate resin, polybutylene terephthalate resin, or resin materials in which glass fiber, carbon fiber, or the like is blended with these. Alternatively, it may be made of metal materials such as aluminum, iron, or stainless steel, and processed by die-casting, cutting, or the like.

[0263] Next, the shape of the drum coupling 143 will be described with reference to FIGS. 1 and 55 to 58.

[0264] In the following description of the drum coupling 143, the direction from the photosensitive drum 104 toward the drive transmission unit 230 (drum drive coupling 180) along the axial direction (the direction of arrow M1A) is referred to as the outward direction in the axial direction. Also, the direction opposite to the outward direction (the direction of arrow M1B) is referred to as the inward direction in the axial direction.

[0265] In other words, in the drum coupling, the outward axial direction (M1A direction) is the direction from the non-drive-side end 104b of the photosensitive drum 104 toward the drive-side end 104a (leftward in FIG. 80). Alternatively, the outward axial direction (M1A direction) is the direction from the non-drive-side cartridge cover 117 of the cartridge 100 toward the drive-side cartridge cover 116 in FIG. 14.

[0266] The inward axial direction (M1B direction) is the direction from the drive-side end 104a of the photosensitive drum 104 to the non-drive-side end 104b (to the right in FIG. 80). Alternatively, the inward axial direction (M1B direction) is the direction from the drive-side cartridge cover 116 of the cartridge 100 to the non-drive-side cartridge cover 117 in FIG. 14.

[0267] As shown in FIG. 1(b), the drum coupling 143 is attached to one longitudinal end (driving side end) of the photosensitive drum 104. As described above, the shaft 143j shown in FIG. 1 is rotatably supported by the driving side cartridge cover member 116 (see FIG. 15) that supports the photosensitive drum unit 103. The drum unit 103 is configured to rotate in a predetermined rotation direction (the direction of arrow A) during image formation in which the latent image on the photosensitive drum surface is developed.

[0268] The drum coupling 143 is configured to receive a driving force for rotating the photosensitive drum 104 from the main body drive transmission unit 203 of the apparatus main body, and also to receive a braking force for applying a load to the rotation of the photosensitive drum 104.

[0269] The drum coupling 143 has a protrusion that protrudes outward in the axial direction from the surface of the end of the shaft portion 143j (see FIGS. 1 and 52 to 57). This protrusion has a driving force receiving portion 143b as a first side surface (first side portion) that receives driving force from the drive transmission unit 203. In addition, the protrusion of the drum coupling 143 has a braking force receiving portion 143c as a second side surface (second side portion) that receives braking force from the drive transmission unit 203.

[0270] The driving force receiving portion 143b is a side surface (side portion) facing upstream in the rotation direction A of the drum unit, and the braking force receiving portion 143c is a side surface (side portion) facing downstream in the rotation direction A.

[0271] In other words, one of the driving force receiving portion 143b and the braking force receiving portion 143c faces one circumferential side of the drum unit, and the other faces the other circumferential side. In other words, the driving force receiving portion 143b and the braking force receiving portion 143c are side surfaces (side portions) that face in opposite directions in the rotational direction and the circumferential direction.

[0272] Furthermore, the protrusion of the drum coupling 143 has a spiral inclined surface (inclined portion, slope) 143d as its top surface (upper surface, upper portion, upper part). The inclined surface (top surface) 143d is a portion that faces outward in the axial direction (in the direction of arrow MA1). In other words, the inclined surface 143d is a portion that faces away from the non-drive side end of the drum unit (i.e., the end on the side where the drum flange 142 (FIG. 13) is located). In other words, the spiral inclined surface (top surface) 143d of the coupling 143 is a portion that faces away from the side where the photosensitive drum 104 is located.

[0273] The spiral inclined surface 143d is inclined so as to move outward in the axial direction (in the direction of arrow MA1) as it moves toward the upstream side in the rotation direction (upstream side in the direction of arrow A). In other words, the inclined surface 143d moves in a direction away from the non-driven side of the drum unit 103 as it moves toward the upstream side in the rotation direction. In other words, the inclined surface 143d is inclined so as to move away from the photosensitive drum as it moves toward the upstream side in the rotation direction.

[0274] In other words, the spiral inclined surface 143d extends from upstream to downstream in the direction of rotation so as to approach the non-drive side end of the drum unit 103 or the cartridge. In other words, when the distance from the non-drive side end of the cartridge to the spiral inclined surface 143d is measured along the axial direction, the distance becomes shorter as it moves downstream in the direction of rotation.

[0275] Spiral inclined surface 143d has a downstream portion (downstream top surface, downstream inclined surface, downstream inclined portion, downstream guide) 143d1 that is sandwiched between driving force receiving portion 143b and braking force receiving portion 143c in the rotation direction of the drum unit. In addition, inclined surface 143d has an upstream portion (upstream top surface, upstream inclined surface, upstream inclined portion, upstream guide) 143d2. Upstream portion 143d2 of spiral inclined surface 143d is located upstream in the rotation direction of driving force receiving portion 143b and downstream portion 143d1 of spiral inclined surface 143d (see Figures 55 to 58).

[0276] Furthermore, when the length of the inclined surface 143d is measured along the rotation direction of the drum unit, the length of the upstream inclined surface 143d2 is greater than the length of the downstream inclined surface 143d1.

[0277] An upstream portion (upstream inclined surface) 143d2 of the inclined surface 143d is disposed radially inward (closer to the axis L) than the driving force receiving portion 143b. In other words, the upstream portion (upstream top surface, upstream inclined surface) 143d2 of the inclined surface 143d is disposed closer to the axis L (FIG. 1A) than the driving force receiving portion 143b. The axis L (FIG. 1A) is the axis (rotation axis) that serves as the rotation center of the coupling 143 and the photosensitive drum 104.

[0278] Furthermore, the protrusion of the drum coupling 143 is provided with a circular hole portion 143a as an opening for engaging with a positioning boss (positioning portion) 180i of the drum drive coupling 180 to position their respective shafts. The circular hole portion 143a is an opening whose cross section perpendicular to the axis L of the drum coupling 143 is circular, and is arranged along the axis L.

[0279] The protrusion of the drum coupling 143 has a shaft portion 143p (see FIG. 1) formed along the axis L (see FIG. 1(a)), and a circular hole portion 143a is formed inside the shaft portion 143p. The shaft portion 143p is a shaft portion for forming the circular hole portion 143a.

[0280] The shaft portion 143p and the circular hole portion 143a are arranged on the axis L. The circular hole portion 143a forms an open space between the rotation axis L of the drum unit (see FIG. 1(a)) and the inner surface of the drum coupling 143. The diameter of the shaft portion 143p is smaller than that of the above-mentioned shaft portion 143j.

[0281] The above-described drum coupling 143 has a symmetrical shape (axisymmetric shape) with respect to the axis L (see FIG. 1(a)). The driving force receiving portion 143b, the braking force receiving portion 143c, and the spiral inclined surface 143d are each arranged in two locations spaced 180° apart in the circumferential direction, and form a first coupling portion 143r and a second coupling portion 143s (see FIG. 58), respectively.

[0282] Each coupling portion has one driving force receiving portion 143b, one braking force receiving portion 143c, and one spiral inclined surface 143d, and the first coupling portion 143r and the second coupling portion 143s are disposed symmetrically with respect to the axis.

[0283] The driving force receiving portion 143b, the braking force receiving portion 143c, and the spiral inclined surface 143d are arranged around the circular hole portion 143a and the shaft portion 143p. The driving force receiving portion 143b, the braking force receiving portion 143c, and the spiral inclined surface 143d are located farther from the axis L of the drum unit than the circular hole portion 143a and the shaft portion 143p.

[0284] Next, the configuration of the main body side drive transmission unit 203 provided on the apparatus main body side will be described with reference to Figures 43, 44, and 59. The drive transmission unit 203 is a unit that is connected (engaged) with the drum coupling 143 to drive the drum coupling 143 to rotate.

[0285] Figure 43 is an exploded perspective view of the main body side drive transmission unit 203. Figure 59 is an enlarged perspective view of a portion shown in Figure 43. Figure 44 is a cross-sectional view of the main body side drive transmission unit 203.

[0286] The drive gear 201 is rotatably supported by a support shaft 202 fixed to a frame (not shown) of the apparatus main body 170, and rotates when a driving force is transmitted from a motor (not shown). The drum drive coupling 180 has a cylindrical portion 180c and a flange portion 180a provided at its end, and the flange is supported by fitting with a fitting portion 201a of the drive gear 201. The drum drive coupling 180 also has a rotation stopper portion 180b provided on the flange portion 180a, which comes into contact with the rotation stopper portion 201b of the drive gear 201 and receives the driving force when the drum drive coupling 180 rotates. The drive transmission unit 203 has multiple parts inside the cylindrical portion 180c of the drum drive coupling 180.

[0287] The components arranged inside the cylindrical portion 180c are as follows: a brake member 206 supported by the support shaft 202 and prevented from rotating, a brake transmission member 207 connected to the brake member 206 to transmit braking force, first and second brake engagement members 204 and 208 that engage with the brake force receiving surface 143c of the drum coupling 143, and a brake engagement spring 211 and a drum drive coupling spring 210 that are arranged along the axis M1 and generate a biasing force in the direction of the axis M1 (axial direction). The axis M1 is the rotational axis of the main body side drive transmission unit 203.

[0288] The shapes of the components arranged inside the main body drive transmission unit 203 will be described.

[0289] The first brake engaging member 204 is formed of a cylindrical portion 204d, a flange portion 204a, and a coupling engaging portion 204b that protrudes like a claw and engages with the drum coupling 143. A rotation stop recess 204c is formed in a part of the cylindrical portion to engage with a rotation stop protrusion 208c of the second brake engaging member 208, which will be described later.

[0290] The second brake engaging member 208 is provided with a flange portion 208a, a coupling engaging portion 208b that protrudes like a claw and engages with the drum coupling 143, and a rotation stopping protrusion 208c that engages with the rotation stopping recess 204c of the first brake engaging member 204. Since the second brake engaging member 208 is prevented from rotating relative to the first brake engaging member 204, the first and second brake engaging members 204, 208 rotate integrally. In addition, the first and second brake engaging members 204, 208 are connected so as to move integrally in the axial direction as well.

[0291] Therefore, the first and second brake engagement members 204, 208 may be collectively referred to simply as brake engagement members (204, 208).

[0292] The first brake engaging member 204 is an outer brake engaging member disposed on the outer side in the radial direction, and the second brake engaging member 208 is an inner brake engaging member disposed on the inner side in the radial direction.

[0293] The brake transmission member 207 is made up of a flange portion 207a and a shaft portion 207b. The flange portion 207a is provided with a protrusion 207e that engages with a protrusion 204e provided on the flange portion 204a of the first brake engaging member 204. The flange portion 207a of the brake transmission member 207 is disposed between the flange portion 204a of the first brake engaging member 204 and the flange portion 208a of the second brake engaging member 208, and is sandwiched therebetween with a play (gap) G in the axial direction (FIG. 44). When the brake transmission member 207 is in a position relative to the first brake engaging member 204 in the axial direction M1A such that the protrusion 207e (see FIGS. 43 and 59) engages with the protrusion 204e, the brake transmission member 207 and the first and second brake engaging members 204, 208 rotate integrally. On the other hand, when the brake transmission member 207 is at a position relative to the first brake engagement member 204 in the axial direction where the protrusion 207e is not engaged with the convex portion 204e, the brake transmission member 207 does not restrict the rotation of the first and second brake engagement members 204, 208. The first and second brake engagement members 204, 208 are rotatable relative to the brake transmission member 207. The shaft portion 207b has a non-circular cross section and engages with an engagement hole 206c of the brake member 206, which will be described later, allowing the brake transmission member 207 and the brake member 206 to rotate integrally.

[0294] The brake member 206 is divided into a fixed side 206a and a rotating side 206b, but they are integrated in the axial direction by a retaining member (not shown). The fixed side 206a is supported by a support shaft 202 and is fixed in rotation about the axis. On the other hand, the rotating side 206b is rotatable about the support shaft 202, but rotates while receiving a braking force (load) in the rotational direction from the fixed side 206a. The braking force can be generated by any method, such as friction or viscosity.

[0295] As described above, the brake engaging members (204, 208) are connected to the brake member 206 via the brake transmission member 207. Therefore, the rotational torque of the brake engaging members (204, 208) increases due to the load (braking force) generated by the brake member 206. The brake engaging spring 211 is a compression coil spring, and is disposed so as to be sandwiched and compressed between the end face 206d of the brake member 206 and the flange portion 204a of the first brake engaging member 204. As a result, the spring 211 applies a repulsive force (biasing force, elastic force) to each of the end face 206d of the brake member 206 and the flange portion 204a of the first brake engaging member 204.

[0296] The drum drive coupling spring 210 is a compression coil spring, and is disposed so as to be sandwiched and compressed between the end face 206d of the brake member 206 and the flange portion 207a of the brake transmission member 207. As a result, the spring 210 applies a repulsive force (biasing force, elastic force) to each of the end face 206d of the brake member 206 and the flange portion 207a of the brake transmission member 207.

[0297] The brake transmission member 207 receives the repulsive force of the brake engagement spring 211 via the flange 204a of the first brake engagement member 204, and also directly receives the repulsive force of the drum drive coupling spring 210. A protrusion 207f on the end of the brake transmission member 207 in the axial direction M1A abuts against an abutment surface 180f of the drum drive coupling 180 (see Figure 44).

[0298] As a result, the drum drive coupling 180 also receives the forces of the drum drive coupling spring 210 and the brake engagement spring 211 via the brake transmission member 207. The drum drive coupling 180 attempts to move due to the forces of the springs 210, 211. Therefore, the movement of the drum drive coupling 180 in the direction of arrow M1B is restricted (limited) by an axial direction restricting portion 212 (see FIG. 44), so that the drum drive coupling 180 does not come off from the main body side drive transmission unit 203. Specifically, when the drum drive coupling 180 moves a certain distance in the direction of arrow M1B, the flange portion 180a (see FIG. 43) of the drum drive coupling 180 comes into contact with the restricting portion 212 (see FIG. 44). This prevents the drum drive coupling 180 from moving or coming off.

[0299] In this state, when the drum drive coupling 180 receives a force from outside in the direction of the arrow M1A, the springs 210 and 211 are compressed and the drum drive coupling 180 can move in the direction of the arrow M1A.

[0300] Furthermore, when the brake engaging members (204, 208) engage with the coupling 143, the coupling engaging portions 204b, 208b may interfere with the coupling 143 (see Figure 60; details will be described later). In that case, the brake engaging members (204, 208) can move deeper into (retract from) the drive transmission unit 203 while compressing the springs 210, 211 in the direction of arrow M1A (see Figure 61).

[0301] As described above, the brake engaging members (204, 208) are disposed with a gap G between them and the brake transmission member 207 (see FIG. 44). Within the width of the gap G, the brake engaging members (204, 208) can move in the direction of arrow M1A relative to the brake transmission member 207 and retract. Similarly, the brake engaging members (204, 208) can move in the direction of arrow M1A relative to the drum drive coupling 180 within the width of the gap G. When the brake engaging members (204, 208) move in the direction of arrow M1A relative to the brake transmission member 207 and the drum drive coupling 180, the brake engaging spring 211 is compressed.

[0302] The brake engagement members (204, 208) exceed the width of the gap G and come into contact with the brake transmission member 207 which is moving in the direction of arrow M1A, and the brake transmission member 207 also moves in the direction of arrow M1A together with the brake engagement members (204, 208).

[0303] The drum drive coupling 180 also moves in the direction of arrow M1A together with the brake engaging members (204, 208). As shown in Figure 62, the drum drive coupling 180 and the first brake engaging member 204 have protruding engaging portions 180u and 204u, respectively. Therefore, when the brake engaging member 204 moves a certain distance or more in the direction of arrow M1A relative to the drum drive coupling 180, the engaging portion 204u presses the engaging portion 180u, causing the drive coupling 180 to retreat in the direction of arrow M1A. At this time, not only the spring 211 but also the spring 210 is compressed.

[0304] When the brake engagement members (204, 208) move in the direction of arrow M1A relative to the brake transmission member 207, the protrusion 207e of the brake transmission member 207 disengages from the convex portion 204e of the first brake engagement member 204. In other words, the brake engagement members (204, 208) are no longer connected to the brake transmission member 207, and no braking force is transmitted from the brake transmission member 207. The brake members (204, 208) can rotate relative to the brake transmission member 207 without being subjected to the rotational load generated by the brake member 206.

[0305] In other words, by retracting in the direction of arrow M1A, the brake engaging members (204, 208) can move from a position where they receive the rotational load (braking force) from the brake member 206 during rotation to a position where they do not receive this rotational load during rotation. The brake engaging members (204, 208) are configured to reduce their own torque by moving in the direction M1A relative to the brake transmission member 207 and the drum drive coupling 180.

[0306] Figure 45 is a perspective view showing the positional relationship between the drum drive coupling 180 and the brake engagement members (204, 208). Figure 45(a) is a perspective view of only the drum drive coupling 180, and Figure 45(b) is a perspective view showing both the drum drive coupling 180 and the brake engagement members (204, 208). Figures 45(c) and (d) show the reinforcing cylindrical portion 180e of the drum drive coupling 180 not shown (not visible) for the sake of explanation. The phases of the brake engagement members (204, 208) are different between Figures 45(c) and (d).

[0307] As shown in Figure 45(a), the drum drive coupling (driving force applying member) 180 is provided with two drive transmission surfaces 180d spaced 180 degrees apart in the circumferential direction as surfaces (driving force applying portions) that engage with the coupling 143 to transmit driving force. The drum drive coupling has an axisymmetric shape.

[0308] A through hole 180f communicating in the direction of the axis M1 is provided in a portion other than the drive transmission surface 180d. From this through hole 180f, the coupling engagement portions 204b and 208b of the first brake engagement member 204 and the second brake engagement member 208 are exposed in a direction facing the coupling 143 (see Figure 60).

[0309] FIG. 45(b) shows a state in which the coupling engagement portions 204b, 208b of the first brake engagement member 204 and the second brake engagement member 208 are exposed. The drum drive coupling 180 is provided with a reinforcing cylindrical portion 180e to increase the rigidity of the drive transmission surface 180d. FIG. 45(c) shows a diagram in which the reinforcing cylindrical portion 180e is not shown for the sake of explanation. FIG. 45(c) shows a state in which the coupling engagement portions 204b, 208b and the drive transmission surface 180d are in a close phase relationship in the rotational direction A. The size of the through hole 180f is set wider than the width of the coupling engagement portions 204b, 208b in the circumferential direction. Therefore, the coupling engagement portions 204b, 208b can move within a certain range in the rotational direction within the drum drive coupling 180.

[0310] FIG. 45(d) shows a state in which the coupling engagement portions 204b, 208b and the drive transmission surface 180d are in a phase relationship in which they are spaced apart in the rotational direction A.

[0311] Next, a method of connecting the main assembly side drive transmission unit 203 of the drive transmission mechanism and the photosensitive member coupling 143 on the process cartridge 100 side will be described with reference to FIGS.

[0312] [Coupling engagement operation] Next, a process for connecting the main body side drum drive coupling 180 of the image forming apparatus main body 170 and the drum coupling 143 of the process cartridge 100 will be described. 46 shows a cross-sectional view of the periphery of the main body side drum drive coupling 180 of the image forming apparatus main body 170. An outline of the movement of the main body side drum drive coupling 180 will be described using this FIG.

[0313] When the user opens the front door 111 (FIG. 4) of the image forming apparatus main body 170 to replace the process cartridge 100, the drive transmission unit 203 is moved in the direction of arrow M1A along the axis M1 by a link mechanism (not shown) connected to the front door 111. In other words, the drive transmission unit 203 is moved in a direction away from the process cartridge 100 and the drum coupling 143 (see FIG. 60).

[0314] When the user installs the process cartridge 100 and closes the front door 111, the action of the link described above is released. Therefore, the drum drive coupling 180, the brake engagement members 204 and 208, and the brake transmission member 207 attempt to move again in the direction of arrow M1B due to the biasing forces of the drum drive coupling spring 210 and the brake engagement spring 211. At this time, the drum coupling 143 of the process cartridge 100 is waiting in the direction of arrow M1B and interferes with the approaching drive transmission unit 203 (the state shown in Figures 61, 65, and 69). The drum coupling 143 and the drive transmission unit 203 press against each other.

[0315] In these conditions, the drum coupling 143 and the drum drive coupling 180 of the drive transmission unit 203 are normally not engaged.

[0316] In order for the drum coupling 143 and the main body side drum drive coupling 180 to enter a normal engagement state, the drive transmission unit 203 needs to rotate further from the above-mentioned pushing state. In other words, the drive process of the drive transmission unit 203 needs to proceed until the main body side drum drive coupling 180 meshes with the drum coupling 143.

[0317] Furthermore, the process until the engagement is completed can be divided into several cases depending on the phase of the drum coupling 143 and the main body side drum drive coupling 180, and will be explained separately.

[0318] FIG. 47(a) shows the drum coupling 143, and FIG. 47(b) shows the drive transmission unit 203, both viewed from the axial direction.

[0319] The shape of the coupling 143 will be further explained using Figure 47(a). The shape of the coupling is such that shapes with different functions are arranged in the radial direction. The following components are arranged within the range of the radius indicated by R1 in the figure.

[0320] That is, a positioning hole (opening) 143a that engages with a positioning boss (positioning portion) 180i of the drive coupling 180, a visor (visor portion) 143g (see FIG. 47(a) and FIG. 1) that serves as a protruding portion that prevents the drive transmission unit 203 from entering in the axial direction, and a portion of the spiral inclined surface 143d are arranged. A portion of the spiral inclined surface 143d and a portion of the braking force receiving surface 143c are arranged within the range indicated by R1 to R2. The braking force receiving surface 143c cannot be seen from the viewing direction of FIG. 47(a) and is shown in FIG. 1. A driving force receiving portion 143b, a portion of the spiral inclined surface 143d, and a portion of the braking force receiving surface 143c are arranged within the range indicated by R2 to R3.

[0321] On the other hand, the shape of the drive transmission unit 203 is also arranged with shapes having different functions in the radial direction, so the same range as the coupling 143 is indicated in FIG. 47(b) using the same symbols R1 to R3.

[0322] Within the range of the radius indicated by R1 in Figure 47(b), there are arranged the positioning boss 180i that engages with the positioning hole 143a of the drum coupling 143, and the inward protrusion 208e that is part of the coupling engagement portion 208b of the second brake engagement member 208 that comes into contact with the eaves 143g depending on the phase with the drum coupling 143. Within the range indicated by R1 to R2, there is arranged the coupling engagement portion 208b of the second brake engagement member 208. Within the range indicated by R2 to R3, there are arranged the drive transmission surface 180d and the first brake engagement member 204.

[0323] Figure 48 is an exploded view of these parts exploded around the rotation axis M1. The process up to the engagement between the drum coupling 143 and the drive transmission unit 203 will now be described.

[0324] Figure 48 shows the drive transmission unit 203 on the bottom, moving in the direction of arrow M1B and approaching the drum coupling 143 until engagement is complete. In this figure, structures arranged within the range of radius R1 shown in Figure 47 are shown with dashed lines, structures arranged in the range of radii R1 to R2 are shown with solid lines, and structures arranged in the range of radii R2 to R3 are shown with solid lines and hatching.

[0325] The drum coupling 143 has two coupling portions 143s and 143r that are spaced 180° apart, but for simplicity, only the coupling portion 143s will be described below. The description of the coupling portion 143s also applies to the coupling portion 143r.

[0326] Figure 48(a) shows a state in which the drive transmission surface 180d of the drive transmission unit 203 and the second brake engaging member 208 are close to each other. As shown in Figure 48(a), the phase relationship between the tilt start portion 143f of the drum coupling 143 and the inward protrusion 208e of the second brake engaging member 208 is as follows: In other words, the tilt start portion 143f of the drum coupling 143 is located upstream of the protrusion 208e in the rotation direction (arrow A).

[0327] Figure 48(b) shows a state in which the drive transmission unit 203 has further moved in the direction of arrow M1B from Figure 48(a). The spiral inclined surface 143d faces and comes into contact with the inward protrusion 208e of the approaching first brake engagement member 204.

[0328] Figure 48(c) shows a state in which the drive transmission unit 203 has further moved in the direction of arrow M1B. The spiral inclined surface 143d holds back the approaching second brake engaging member 208. This prevents the second brake engaging member 208 from moving in the direction of arrow M1B. Meanwhile, the parts excluding the second brake engaging member 208 (i.e., the drum drive coupling 180 of the drive transmission unit 203, etc.) have moved in the direction of arrow M1B. Within the drive transmission unit 203, the second brake engaging member 208 is in a state of being relatively pushed in the direction of arrow M1A.

[0329] In this state, as described in Figure 44, the second brake engaging member 208 is no longer connected to the brake member 206 and can rotate without receiving any rotational load. At this time, the brake member 206 receives an elastic force F1 in the direction of the rotation axis M1 from the drum drive coupling spring 210 and the brake engaging spring 211, which are disposed inside the drive transmission unit 203. The spiral inclined surface 143d moves the second brake engaging member 208, which is no longer subjected to any rotational load, in the direction of arrow C due to a component of the elastic force F1. In other words, the second brake engaging member 208 moves downstream in the rotational direction A along the spiral inclined surface 143d.

[0330] FIG. 48(d) shows the state immediately after the second brake engaging member 208 has moved downstream in the rotational direction (in the direction of arrow A). The second brake engaging member 208 moves along the spirally inclined surface 143d of the drum coupling 143 and also moves in the M1B direction by the amount of movement of the entire drive transmission unit 203 in the axial direction M1B, so that it moves along the trajectory indicated by arrow D. As a result, the second brake engaging member 208 moves away from the drive coupling 180 toward the downstream side in the rotational direction A until it can engage with the brake force receiving portion 143c (second side surface, second lateral portion) of the drum coupling 143. In other words, the spirally inclined surface 143d serves as a guide for guiding the brake engaging member toward the brake force receiving portion 143c. In this embodiment, the spirally inclined surface (top surface) 143d, which serves as a guide, has a downstream portion 143d1 and an upstream portion 143d2. The downstream portion (downstream slope, downstream top surface, downstream inclined portion) 143d1 is disposed between the braking force receiving portion 143c and the driving force receiving portion 143b. The upstream portion (upstream slope, upstream top surface, upstream inclined portion) 143d2 is located upstream of the driving force receiving portion 143b in the rotation direction (direction A). Therefore, the second brake engaging member 208 can be smoothly guided from the upstream portion 143d2 of the inclined surface 143d through the downstream portion 143d1 to the braking force receiving portion 143c.

[0331] FIG. 48(e) shows a state in which the drum coupling 143 moves (rotates) in the direction of arrow A due to the rotating drive transmission surface 180d, and as a result, the braking force receiving portion 143c comes into contact with the second brake engaging member 208.

[0332] When the drive transmission unit 203 rotates in the direction of arrow A, the drive transmission surface 180d comes into contact with the drive force receiving portion 143b to transmit the drive force. The drive transmission surface 180d is a drive force applying portion that applies the drive force to the drum coupling 143.

[0333] The drum coupling 143, which is rotating upon receiving the driving force from the drive transmission surface 180d, also receives a braking force when the braking force receiving portion 143c comes into contact with (engages with) the second brake engaging member 208.

[0334] 48(a) to 48(e) show only the second brake engaging member 208 of the first and second brake engaging members 204, 208. However, the first brake engaging member 204 (see FIG. 43) is connected to the second brake member 208 so as to move integrally therewith. Therefore, in the process shown in FIGS. 48(a) to 48(e), the first brake engaging member 204 also moves along a trajectory similar to that of the second brake member 208. In the state shown in FIG. 48(e), the first brake engaging member 204 also engages with the brake force receiving portion 143c together with the second brake engaging member 208.

[0335] For the sake of simplicity, Figures 48(a) to (e) only show the process of engaging the brake engaging members (204, 208) with the coupling portion 143s with the drum drive coupling 180. Similar to the coupling portion 143s, the coupling 143r also engages with the brake engaging members (204, 208) and the drum drive coupling 180. The state of engagement of the brake engaging members (204, 208) with the coupling 143r and the drum drive coupling 180 is shown in Figure 76(a).

[0336] Here, to help understand the process described so far, the explanation will be repeated using the perspective views of Figures 60 to 64. In Figures 60 to 64, for the sake of explanation, part of the drum drive coupling 180 is not shown, revealing the internal shape.

[0337] Figure 60 is a perspective view showing the same state as Figure 48(a) described above. That is, it shows a state in which the tilt start portion 143f of the drum coupling 143 is located upstream of the protrusion 208e in the rotation direction (arrow A), and the drive transmission surface 180d of the drive transmission unit 203 and the second brake engaging member 208 are close to each other. Figure 61 shows a state in which the drive transmission unit 203 has moved from this state in the direction of arrow M1B.

[0338] Figure 61 shows a state corresponding to Figure 48(b), in which the spiral inclined surface 143d faces and contacts the inward protrusion 208e of the approaching second brake engaging member 208. The drive transmission unit 203 and the drum coupling 143 are relatively close to each other until they come into contact, but the state inside the drive transmission unit 203 does not change.

[0339] FIG. 62 shows the state in which the drive transmission unit 203 has further moved in the direction of arrow M1B from this state.

[0340] Figure 62 shows a state corresponding to Figure 48(c), in which the spiral inclined surface 143d holds back the approaching second brake engaging member 208. As a result, within the drive transmission unit 203, the second brake engaging member 208 is pressed in the direction of arrow M1A relative to the drum drive coupling 180.

[0341] In this state, as described in Figure 44, the second brake engaging member 208 is released from connection with the brake member 206 and can rotate without receiving any rotational load. At this time, the brake member 206 receives an elastic force F1 in the direction of the rotation axis M1 from the drum drive coupling spring 210 and the brake engaging spring 211 disposed inside the drive transmission unit 203. The spiral inclined surface 143d moves the second brake engaging member 208, which is no longer subjected to any rotational load, in the direction of arrow C due to a component of the elastic force F1. In other words, the second brake engaging member 208 rotates and moves downstream in the rotational direction A along the spiral inclined surface 143d.

[0342] Figure 63 shows the state of the second brake engaging member 208 immediately after it has moved downstream in the rotational direction (in the direction of arrow A), and corresponds to Figure 48(c). The second brake engaging member 208 moves along the spiral inclined surface 143d of the drum coupling 143, and also moves in the M1B direction by the amount of movement of the entire drive transmission unit 203 in the axial direction M1B, and therefore moves along the trajectory of arrow D. As a result, the brake engaging members (204, 208) move away from the drive coupling 180 toward the downstream side in the rotational direction A until they can engage with the second side surface (brake force receiving portion 143c) of the drum coupling 143. When they reach this position, the brake engaging members (204, 208) return to a state in which they can generate braking force.

[0343] Figure 64 shows a state in which the drum coupling 143 moves (rotates) in the direction of arrow A due to the rotating drive transmission surface 180d, and as a result, the brake force receiving portion 143c comes into contact with the second brake engaging member 208. Figure 64 corresponds to Figure 48(d).

[0344] When the drum drive coupling 180 of the drive transmission unit 203 rotates in the direction of arrow A from the state in Figure 64, the drive transmission surface 180d comes into contact with the drive force receiving portion 143b to transmit the drive force. The drum coupling 143, which is rotating by receiving the drive force from the drive transmission surface 180d, also receives a brake force when the brake force receiving portion 143c comes into contact (engages) with the second brake engaging member 208 (see Figure 48(e)).

[0345] In summary, through the processes shown in FIGS. 48(a) to 48(e) and 60 to 64, the brake engagement members (204, 208) move relative to the drum drive coupling 180 and the drum coupling 143 as follows.

[0346] The brake engaging members (204, 208) move from a position where they are close to the drive transmission surface 180d (Figures 48(a) and 60) to a position where the drum coupling 143 is sandwiched between the drive transmission surface 180d and the brake engaging members (204, 208) (Figures 48(d) and 64).

[0347] When the drive transmission surface 180d rotates from the state shown in Figure 48(d) and Figure 64, the drum coupling 143 also rotates together with the drive transmission surface 180d, resulting in the state shown in Figure 48(e). Then, the drum coupling 143 rotates in the direction of arrow A by the drive force received from the drum drive-side coupling 180 while receiving an appropriate load (braking force) from the brake engagement members (204, 208). As a result, the torque required for the drum drive coupling 180 to rotate the drum unit is not too light but is of an appropriate magnitude, thereby stabilizing the rotational drive of the drum unit.

[0348] Next, using Figures 49(a) to (e), another pattern of the engagement process of the drum drive coupling 180 and the brake engagement members (204, 208) with the drum coupling 143 will be described. Note that although the drum coupling 143 has two coupling portions 143s and 143r, for the sake of simplicity, only the coupling portion 143s will be described.

[0349] 49(a), a case will be described in which the phases of the inclination start portion 143f of the drum coupling 143 and the inward protrusion 208e of the second brake engaging member 208 satisfy the following relationship: In other words, this is the case in which the inclination start portion 143f of the drum coupling 143 is located downstream of the inward protrusion 208e in the rotation direction (arrow A).

[0350] FIG. 49(a) shows a state in which the drive transmission surface 180d of the drive transmission unit 203 and the second brake engaging member 208 are close to each other.

[0351] The eaves 143g of the drum coupling 143 is in contact with the inward projection 208e of the second brake engaging member 208 that is approaching in the M1B direction.

[0352] Next, Figure 49(b) shows a state in which the eaves 143g stops (blocks) the advancement of the approaching second brake engaging member 208. Here, the drum drive coupling 180, which is a component of the drive transmission unit 203, does not come into contact with the eaves 143g and therefore cannot stop the advancement in the M1B direction. In other words, the eaves 143g does not interfere because its shape and position in the radial direction differ from those of the drum drive coupling 180. Meanwhile, the second brake engaging member 208 has an inward protrusion 208e at its tip in the M1B direction. Because the inward protrusion 208e protrudes radially inward, it comes into contact with the eaves 143g of the drum coupling 143.

[0353] As a result of only the drum drive coupling 180 moving in the M1B direction, the second brake engaging member 208 moves in the M1A direction relative to the drum drive coupling 180. As described above, this relative movement allows the second brake engaging member 208 to rotate without receiving any rotational load.

[0354] 49(c) shows a state in which the drive transmission unit 203 has started to rotate in the rotation direction A. First, when the drum drive coupling 180 starts to rotate in the direction A, the second brake engaging member 208 is pushed by the drum drive coupling 180 and also starts to rotate in the direction A.

[0355] The spiral inclined surface 143d of the drum coupling 143 moves the second brake engaging member 208 in the direction of arrow C from the point where the inward projection 208e of the second brake engaging member 208 passes the inclination start portion 143f. In other words, the second brake engaging member 208 moves downstream in the rotational direction A and in the direction M1B.

[0356] Figure 49(d) shows the state after the second brake engaging member 208 has moved along the spiral inclined surface 143d of the drum coupling 143 and passed the inclined surface 143d, as in Figure 48(d). At this time, the entire drive transmission unit 203 moves further in the axial direction M1B. As a result, the second brake engaging member 208 also moves in the M1B direction. The first brake engaging member 204 moves along the trajectory of arrow D.

[0357] Subsequent engagement is the same as that described in Figure 48(d), and the subsequent completed engagement state is the state shown in Figure 48(e). In this embodiment, the eaves 143g is connected to the upstream portion (upstream slope, upstream top surface) 143d2 of the spiral inclined surface 143d. The tilt start portion 143f is the boundary between the eaves 143g and the spiral inclined surface 143d. Therefore, the second brake engaging member 208, whose movement was blocked by the eaves 143g, can smoothly transition to a state in which it comes into contact with the spiral inclined surface 143d as the drive transmission unit 203 rotates. However, this configuration is not necessarily limited to this, and there may be a gap between the eaves 143g and the inclined surface 143d.

[0358] 49(a) to (d), only the second brake engaging member 208 of the brake engaging members (204, 208) is shown. However, as described above, the first brake engaging member 204 (see FIG. 43) moves integrally with the second brake engaging member 208 during the processes shown in FIGS. 49(a) to (d).

[0359] Here, to help understand the process explained using Figures 49(a) to (d), the explanation will be added again using the perspective views of Figures 65 to 68. In Figures 65 to 68, for the sake of explanation, part of the drum drive coupling 180 is not shown, revealing the internal shape.

[0360] Figure 65 shows a state in which the drive transmission surface 180d of the drive transmission unit 203 and the second brake engaging member 208 are approaching each other. At this time, the eaves 143g of the drum coupling 143 are in contact with the second brake engaging member 208 approaching in the M1B direction. Figure 65 corresponds to Figure 49(a).

[0361] Next, Figure 66 shows a state in which the drum drive coupling 180 has moved axially to the right (M1B direction) relative to the second brake engaging member 208. In Figure 66, the eaves 143g is stopping (blocking) the advancement of the approaching second brake engaging member 208.

[0362] Figure 66 corresponds to Figure 49(b). The second brake engaging member 208 moves leftward in the axial direction (in the M1A direction) relative to the drum drive coupling 180. As described above, this relative movement allows the second brake engaging member 208 to rotate without receiving any rotational load.

[0363] Next, Figure 67 shows a state in which the drive transmission unit 203 has started to rotate in the rotation direction A. Figure 67 corresponds to Figure 49(c). The spiral inclined surface 143d of the drum coupling 143 moves the second brake engaging member 208 in the direction of arrow C from the point where the second brake engaging member 208 passes through the inclination start portion 143f. Figure 68 corresponds to Figure 49(d). In the state shown in Figure 68, the first brake engaging member 204 moves along the spiral inclined surface 143d of the drum coupling 143, similar to the states shown in Figures 48(d) and 63. Furthermore, the first brake engaging member 204 also moves in the M1B direction by the amount that the entire drive transmission unit 203 moves in the axial direction M1B. As a result, the first brake engaging member 204 moves along the trajectory of arrow D.

[0364] Then, as described above, the entire drive transmission unit 203 continues to rotate, completing the connection and resulting in a state similar to that shown in FIG. 48(e).

[0365] Next, using Figures 50(a) to (d), a description will be given of yet another pattern of the engagement process of the drum drive coupling 180 and the brake engagement members (204, 208) with the drum coupling 143. Note that although the drum coupling 143 has two coupling portions 143s and 143r, for the sake of simplicity, only the coupling portion 143s will be described.

[0366] 50(a), a case will be described in which the phases of the inclination start portion 143f of the drum coupling 143 and the inward protrusion 208e of the second brake engaging member 208 satisfy the following relationship: In other words, a case will be described in which the inclination start portion 143f of the drum coupling 143 is located downstream in the rotation direction (arrow A).

[0367] FIG. 50(a) shows a state in which the drive transmission surface 180d of the drive transmission unit 203 and the second brake engaging member 208 are separated from each other.

[0368] Next, Figure 50(b) shows a state in which the eaves 143g stops the advancement of the approaching second brake engaging member 208. Here, the drum drive coupling 180, which is a component of the drive transmission unit 203, does not come into contact with the eaves 143g and therefore cannot stop the advancement. As a result, the second brake engaging member 208 moves relative to the drum drive coupling 180 in the M1A direction. As described above, this relative movement allows the second brake engaging member 208 to rotate without receiving a rotational load. Here, the eaves 143g does not interfere because its shape and position in the radial direction differ from those of the drum drive coupling 180.

[0369] Next, Figure 50(c) shows a state in which the drive transmission unit 203 has rotated in rotational direction A and come into contact with the second brake engaging member. The second brake engaging member 208 does not start rotating on its own and remains in that position, and the drum drive coupling 180 rotates and comes into contact with the second brake engaging member 208. If the drum drive coupling 180 rotates further thereafter, the second brake engaging member 208 and the drum drive coupling 180 will rotate integrally.

[0370] Figure 50(d) shows the state after further rotation where the second brake engaging member 208 has passed the tilt start portion 143f of the drum coupling 143. In this state, as explained in Figure 48(c), the second brake engaging member 208 moves in the direction of arrow C. The operation thereafter is the same as that described above and will not be explained further.

[0371] 50(a) to (d), only the second brake engaging member 208 of the brake engaging members (204, 208) is shown. However, as described above, the first brake engaging member 204 (see FIG. 43) moves integrally with the second brake engaging member 208 during the processes shown in FIGS. 50(a) to (d).

[0372] Here, to help understand the process explained using Figures 50(a) to (d), the explanation will be repeated using the perspective views of Figures 69 to 72. In Figures 69 to 72, for the sake of explanation, part of the drum drive coupling 180 is not shown, revealing the internal shape.

[0373] FIG. 69 corresponds to FIG. 50(a), and shows a state in which the drive transmission surface 180d of the drive transmission unit 203 and the second brake engaging member 208 are separated by a gap G1.

[0374] Next, Figure 70 corresponds to Figure 50(b) and shows a state in which the entire drive transmission unit 203 has moved in the M1B direction. It shows a state in which the drum drive coupling 180 has moved to the right (M1B direction) of the second brake engaging member 208 in the axial direction, with the eaves 143g stopping the advancement of the approaching second brake engaging member 208. At this time, the second brake engaging member 208 moves leftward (M1A direction) relative to the drum drive coupling 180. As described above, this relative movement allows the second brake engaging member 208 to rotate without receiving a rotational load.

[0375] 71 corresponds to FIG. 50(c), and shows a state in which the drum drive coupling 180 of the drive transmission unit 203 rotates in the rotation direction A and thereby comes into contact with the second brake engaging member 208. FIG.

[0376] The second brake engaging member 208 cannot rotate without receiving a rotational force from the drum drive coupling 180, and therefore does not rotate and remains stopped in its initial position immediately after the drive transmission unit 203 starts to drive. In other words, only the drum drive coupling 180 starts to rotate in direction A first. As a result, Figure 71 shows the state in which the drum drive coupling 180 comes into contact with the second brake engaging member 208.

[0377] Figure 72 corresponds to Figure 50(d) and shows a state in which the drum drive coupling 180 and the second brake engaging member 208 have come into contact with each other, causing not only the drum drive coupling 180 but also the second brake engaging member 208 to start rotating in direction A. More specifically, this is a state in which the second brake engaging member 208 is pushed by the drum drive coupling 180 and rotates in direction A, causing the second brake engaging member 208 to pass over the inclination start portion 143f of the drum coupling 143. In this state, as described in Figure 48(c) and Figure 62, the second brake engaging member 208 is guided by the inclined surface 143d and moves in the direction along the inclination of the inclined surface 143d (the direction of arrow C).

[0378] The subsequent operations are the same as those explained above using Figures 48(c) to 48(e) and Figures 62 to 64, and therefore will not be described here.

[0379] As explained above, when the cartridge 100 is mounted in the image forming apparatus main body, the phase (position) of the drive transmission unit 203 relative to the drum coupling 143 is not fixed (see Figures 48(a), 49(a), 50(a), 60, 65, and 69). However, in any case, the drum coupling 143 can be connected to the drive transmission unit 203. The drive transmission unit 203 has not only the drum drive coupling 180 but also brake engagement members (204, 208), both of which can be engaged with the drum coupling 143.

[0380] Next, the mutual configurations (mutual shapes) of the drive transmission unit 203 and the drum coupling 143 for aligning (aligning) their axes in the process leading up to their coupling will be described with reference to Figure 51. Figure 51 shows cross-sectional views of the drive transmission unit 203 and the drum coupling 143, and Figure 51(a) shows the shapes of the drive transmission unit 203 and the drum coupling 143 in the coupled state in this embodiment. The circular hole portion 143a of the drum coupling 143 engages with the positioning boss 180i of the drum drive coupling 180 to align the axes. A conical guide surface 143h is provided at one end of the circular hole portion 143a. In other words, the guide surface 143h is a portion of the inner surface of the coupling 143 that is conical in shape. This guide surface 143h is provided to guide the amount of misalignment between the drive transmission unit 203 and the drum coupling 143 when they begin to engage each other while still separated in the axial direction M1B, thereby aligning their axes.

[0381] In addition to this embodiment, as shown in FIG. 51(b), the circular hole 143a of the drum coupling 143 may be engaged with the positioning boss 180i without providing a guide surface. Also, as shown in FIG. 6(c), the guide surface 143h may be enlarged to reduce the engagement between the circular hole 143a and the positioning boss 180i. Also, as shown in FIG. 51(d), the diameter of the circular hole 143a may be enlarged. These options can be selected depending on the method and precision of determining the relative positions of the drive transmission unit 203 and the process cartridge 100.

[0382] It is desirable that the circular hole 143a be long enough to accommodate the positioning boss 180i. That is, as shown in FIG. 95, the positioning boss 180i enters at least within the range of an area Pb on the axis L of the drum unit. The circular hole 143a is formed so as to include the entire area Pb. That is, the area Pb around the axis L is open.

[0383] In Figure 95, the area on the axis L occupied by the braking force receiving portion 143c, the spiral inclined surface (top surface) 143d, the eaves 143g, and the driving force receiving portion 143b (not shown) is Pa, and in this embodiment, the area Pa is included within the area Pb.

[0384] The braking force receiving portion 143c, the slope 143d, the eaves 143g, and the driving force receiving portion 143b are formed so that a projection area Pa when projected onto the axis L at least partially overlaps with a projection area Pb of the circular hole portion 143a.

[0385] As described above, according to this embodiment, the coupling 143 of the cartridge 100 receives a driving force from the drive transmission unit 203 of the image forming apparatus main body. In addition, the coupling 143 operates a brake mechanism (brake member 206) inside the drive transmission unit 203 in response to receiving the driving force from the drive transmission unit 203. The drum coupling 143 can receive the braking force via the brake engaging members (204, 208).

[0386] This brake mechanism allows the load required to drive the cartridge to be set within an appropriate range, allowing the cartridge 100 to be driven stably.

[0387] It should be noted that the drum coupling 104 and drive transmission unit 203 of this embodiment can also be used to rotate members other than the photosensitive drum 104, such as a developing roller or a toner transport roller. However, for the following reasons, the drum coupling 104 and drive transmission unit 203 of this embodiment are particularly suitable for use in rotating the photosensitive drum 104.

[0388] While the cartridge 100 of this embodiment has a photosensitive drum 104, it does not have a cleaning device that comes into contact with the photosensitive drum 104. Therefore, the torque of the photosensitive drum 104 is relatively small, and if the photosensitive drum 104 is affected by its surroundings while being rotated, its speed is likely to fluctuate. Therefore, the drive transmission unit 203 rotates the photosensitive drum 104 while applying a certain load to it. In other words, the coupling 143 not only receives the driving force from the drive transmission unit 203 to rotate the photosensitive drum, but also receives a braking force that suppresses the rotation of the photosensitive drum. By simultaneously receiving two forces acting in different rotational directions, the coupling 143 suppresses speed fluctuations in the photosensitive drum 104 (drum unit 103) and stabilizes its rotation.

[0389] Incidentally, even for a cartridge having a cleaning means, driving force can be input from the drive transmission unit 203 of this embodiment via the coupling 143. When the cartridge 100 has a cleaning means (e.g., a cleaning blade) that contacts the surface of the photosensitive drum to remove toner from the photosensitive drum, frictional force is generated between the photosensitive drum and the cleaning means. This frictional force increases the torque of the photosensitive drum 104. However, even in this case, there may be cases where the torque of the photosensitive drum 104 is not sufficient. In such cases, if the coupling 143 can simultaneously receive the driving force and braking force from the drive transmission unit 203, as in this embodiment, the torque required to rotate the photosensitive drum 104 increases, thereby stabilizing the rotation of the photosensitive drum. A cartridge having a cleaning means will be described in Example 2 below.

[0390] In this embodiment, the brake mechanism for applying an appropriate rotational load to the photosensitive drum is located not in the cartridge but in the main body of the image forming apparatus, i.e., in the drive transmission unit 203. This eliminates the need to locate the brake mechanism in the process cartridge, which is a removable unit that is replaced after use. This contributes to the miniaturization and cost reduction of the process cartridge.

[0391] Furthermore, the coupling 143 has a shape that allows it to smoothly engage with both the driving force applying member (drum drive coupling 180) and the braking force applying member (brake engaging members (204, 208)) provided on the drive transmission unit 203. For example, the coupling 143 is provided with a spiral inclined surface 143d (inclined portion, guide, upper surface, upper side portion) and a visor 143f, which makes it easier to smoothly couple with the drive transmission unit 203.

[0392] The shape of the coupling 143 of this embodiment will be explained in detail below with reference to FIG.

[0393] The coupling 143 has two coupling portions 143s and 143r, and each coupling portion has an engagement portion 143i and a guide forming portion 143j. The engagement portion 143i is a portion shaped to engage with a driving force applying member (drum drive coupling 180) or a braking force applying member (brake engaging members (204, 208)). The engagement portion 143i forms a driving force receiving portion 143b, a braking force receiving portion 143c, and a downstream side inclined surface 143d1.

[0394] The driving force receiving portion 143b and the braking force receiving portion 143c engage with the drum drive coupling 180 and the brake member (204, 208), respectively. Although the driving force receiving portion (first side surface, first side portion) 143b and the braking force receiving portion (second side surface, second side portion) 143c are formed in a flat shape, they are not limited to this configuration. They may be configured to receive the driving force or the braking force, respectively, and may be curved or may have a small area. For example, an edge (ridge line) formed by the engaging portion 143i may form the driving force receiving portion (first side surface, first side portion) 143b or the braking force receiving portion (second side surface, second side portion) 143c.

[0395] Alternatively, the driving force receiving portion 143b or the braking force receiving portion 143c may be a portion formed by a plurality of separated regions. In other words, the engaging portion 143i may be a collection of a plurality of shaped portions.

[0396] The driving force receiving portion 143b and the braking force receiving portion 143c are the upstream and downstream sides of the engaging portion 143i, respectively. That is, the driving force receiving portion 143b is the side facing upstream in the rotational direction, and the braking force receiving portion 143c is the side facing downstream in the rotational direction.

[0397] Furthermore, the guide forming portion 143n is a protrusion (extension) extending in the rotational direction toward the engaging portion 143i. The top surface (upper portion) of the guide forming portion 143n is an upstream-side inclined surface (upstream-side top surface, upstream-side inclined portion) 143d2. The upstream-side inclined surface 143d2 is a guide (upstream-side guide, upstream guide) and an inclined portion for guiding the braking force applying member (brake engaging member (204, 208)) toward the engaging portion 143i.

[0398] That is, the guide forming portion 143n is a protrusion for forming the upstream side inclined surface 143d2 which is a guide (upstream side guide).

[0399] The guide forming portion 143n is adjacent to the engaging portion 143i and extends from upstream to downstream in the rotation direction toward the engaging portion 143i. The upstream side inclined surface 143d2 of the guide forming portion 143n is inclined so as to approach the end of the photosensitive drum on the non-driven side as it moves from upstream to downstream in the rotation direction (see FIG. 80).

[0400] 80, the drum coupling 143 is disposed near the first end (driving side end) 104a of the photosensitive drum 104. In other words, the first end 104a of the photosensitive drum 104 is the end that receives the driving force from the drum coupling 143.

[0401] The end of the photosensitive drum 104 opposite the first end 104a is the non-drive-side end (second end) 104b. The distances from this non-drive-side end 104b to the upstream-side slope 143d2 are indicated by D1 and D2. Distance D1 is the distance measured along the axial direction parallel to axis L from the non-drive-side end 104b of the photosensitive drum to the downstream end of slope 143d2. D2 is the distance measured along the axial direction from the non-drive-side end 104b of the photosensitive drum to the upstream end of upstream slope 143d2.

[0402] In this case, distance D1 is shorter than distance D2. That is, when measured along the axial direction from the non-drive side end 104b of the photosensitive drum to the upstream-side inclined surface 143d2, the distance becomes shorter toward the downstream side in the rotation direction.

[0403] That is, the upstream slope 143d2 is inclined so as to approach the end 104b of the photosensitive drum on the non-driven side as it moves downstream in the rotation direction A. Not only the upstream slope 143d2 but also the downstream slope 143d1 is inclined in the same direction.

[0404] Distances D1 and D2 can also be considered as the distance measured axially from the non-drive end of the cartridge casing (ie, non-drive side cartridge cover 117: see FIG. 14) to upstream slope 143d2.

[0405] One of the guide forming portion 143n and the engaging portion 143i may be referred to as a first shape portion, and the other as a second shape portion.

[0406] In this embodiment, the first shape portion and the second shape portion (i.e., the guide forming portion 143n and the engaging portion 143i) are adjacent to each other and connected to each other. Specifically, the downstream side of the guide forming portion 143n in the rotational direction is connected to the engaging portion 143i. However, although the engaging portion 143i and the guide forming portion 143n are adjacent to each other, they may not be connected, and a gap may be formed between them.

[0407] In this embodiment, the top surface (downstream slope) 143d1 of the engaging portion 143i is smoothly connected to the top surface (upstream slope) 143d2 of the guide forming portion 143n, and these together form one slope (top surface) 143d.

[0408] That is, the top surface (downstream inclined surface) 143d2 of the engaging portion 143i is part of a guide that serves to guide the brake engaging members (204, 208) to a position where they can engage with the brake force receiving portion 143c, similar to the upstream inclined surface 143d1.

[0409] The downstream slope (downstream top surface) 143d2 does not necessarily have to be continuous with the upstream slope (upstream top surface) 143d1. Examples of configurations in which the upstream slope 143d2 and the downstream slope 143d1 are discontinuous include those shown in Figures 81(a) and 81(b). Figures 81(a) and 81(b) show modified examples in which a step is provided between the upstream slope 143d2 and the downstream slope 143d1, separating them in the axial direction, and the downstream slope 143d1 is changed to a flat surface. In this way, it is possible for a portion of the spiral slope 143d serving as a guide to be flat or have a step.

[0410] 48(c), 49(c), 50(d), 62, 67, and 72, the brake engaging members (204, 208) come into contact with the inclined surface 143d, and are guided in the direction of arrow C along the inclination of the inclined surface 143. In other words, the brake engaging members (204, 208) move downstream in the rotation direction and in a direction (M1B direction) approaching the non-driven side of the photosensitive drum.

[0411] After being guided by the inclined surface 143d, the brake engaging members (204, 208) further advance in the axial direction (M1B direction) toward a space arranged downstream of the brake force receiving portion (second side surface) 143c of the drum coupling 143 (see Figures 48(d), 49(d), 63, and 68). As a result, the brake engaging members (204, 208) become able to engage with the brake force receiving portion 143c.

[0412] Note that, as the brake engaging members (204, 208) are guided by the inclined surface 143d, the brake engaging members (204, 208) move downstream in the rotational direction A, away from the drum drive coupling 180. As a result, a gap is generated between the drum drive coupling 180 and the brake engaging members (204, 208). The engaging portion 143i of the drum coupling 143 enters this gap, and the driving force receiving portion (side surface) 143b becomes capable of engaging with the drum drive coupling 180 (see FIGS. 48(d), (e), 49(d), 63, 64, and 68).

[0413] The spiral inclined surface 143d also has the function of moving the brake engaging members (204, 208) away from the drum drive coupling 180 so that the drum drive coupling 180 and the driving force receiving portion 143b can be engaged with each other.

[0414] The spiral inclined surface (top surface) 143d has not only a portion (downstream guide, downstream guide, downstream top surface, downstream inclined portion) 143d1 located between the braking force receiving portion 143c and the driving force receiving portion 143b, but also a portion (upstream guide, upstream top surface, upstream inclined portion) 143d2 located upstream of the driving force receiving portion 143b (see Figures 48(a), 47, 56, etc.). By enlarging the area where the inclined surface 143d is located, the top surface 143d can reliably guide the brake engaging members (204, 208).

[0415] In other words, even when the brake engagement members (204, 208) are located upstream of the driving force receiving portion 143b (see Figure 49(a)), the brake engagement members (204, 208) can be moved to the space downstream of the braking force receiving portion 143c by passing through the upstream slope 143d2 (see Figures 49(c) and (d)).

[0416] In this embodiment, the entire slope 143d is an inclined portion. The entire downstream-side top surface 143d1 and the entire upstream-side top surface 143d2 are downward slopes that slope downward toward the downstream side in the rotation direction.

[0417] However, only a portion of the inclined top surface 143d may be inclined. For example, as described above, the upstream side of the top surface may be inclined as the upstream inclined surface 143d2, while the downstream side of the top surface (the downstream top surface 143d2) may not be inclined and may be a flat surface perpendicular to the axis of the drum unit (see FIGS. 81(a) and 81(b)). In the modified drum coupling shown in FIGS. 81(a) and 81(b), the inclination of the upstream inclined surface (upstream top surface) 143d2 may be used to forcefully move the brake engagement members (204, 208), and the inertia (momentum) may be used to cause the brake engagement members (204, 208) to pass over the flat downstream top surface 143d1.

[0418] Also, a configuration is conceivable in which only the upstream top surface (upstream inclined surface 143d2) is used as a guide for guiding the brake engagement members (204, 208), and the downstream top surface (downstream inclined surface 143d1) is not used. In other words, a configuration is conceivable in which there is almost no portion corresponding to the downstream top surface, or the portion is very short compared to the upstream top surface. Such a configuration will be described later using Figure 74.

[0419] It is also conceivable that the downward spiral slope 143d may have a partial upslope. Even in such a case, if the slope 143d can sufficiently guide the brake engagement member (204, 208) downstream in the direction of rotation, the slope 143d can be considered a downward slope. In other words, even if the slope 143d has a partial upslope, it can be considered a downward slope overall. In other words, it can be considered that the distance from the non-drive-side end of the cartridge to the spiral slope 143d becomes shorter as the spiral slope 143d moves downstream in the direction of rotation.

[0420] In such a configuration, it is conceivable that the uphill portion partially located within the spiral slope 143d may be sufficiently short compared to the other downhill portions, or that the inclination of the uphill portion may be gentle, so that the uphill portion has little effect on the downhill portion.

[0421] The spiral inclined surface 143d may have a curved shape or may be divided into multiple separated regions. Furthermore, the width of at least a portion of the inclined surface 143d may be so small that the spiral inclined surface 143d may be considered a ridge (edge) rather than a surface. The spiral inclined surface 143d has a fan-like (spiral) shape when viewed from the front of the drum coupling 143. However, the shape of the guide (top surface, inclined portion) to be provided on the drum coupling 143 is not limited to this. For example, instead of using the fan-like (spiral) inclined surface 143d, a linearly extending rectangular inclined surface may be used. In other words, an inclined portion (guide, top surface) equivalent to the spiral inclined surface 143d may have a different shape, size, extension direction, etc. Some of these examples will be described later using FIG. 54, etc.

[0422] The upstream slope (upstream top surface) 143d2 is configured to have a region that is narrower than the downstream slope (downstream top surface) 143d1 (see FIGS. 47 and 56). Conversely, the downstream slope 143d1 has a region that is wider than the upstream slope 143d2.

[0423] Here, the width of each slope is a length measured along the radial direction. Also, as shown in Fig. 79, at least a portion of the engagement portion 143i is located farther from the axis L of the drum unit in the radial direction of the drum unit than the guide forming portion 143n. In other words, at least a portion of the engagement portion 143i is located radially outward of the guide forming portion 143n.

[0424] The reason for these dimensional and positional relationships is that the driving force receiving portion 143b of the engaging portion 143i is located near the boundary between the guide forming portion 143n and the engaging portion 143i. That is, a portion of the engaging portion 143i protrudes radially outward beyond the guide forming portion 143n so as to form the driving force receiving portion 143b. As a result, the downstream portion 143d1 of the slope (top surface) 143d has a larger width than the upstream portion 143d2.

[0425] The driving force receiving portion 143b has an area that is located radially outward (farther from the axis L) than the upstream inclined surface 143d2. In addition, in the axial direction of the drum unit, the driving force receiving portion 143b is closer to the non-drive-side end of the photosensitive drum than the upstream inclined surface 143d2. Figure 80 shows a state in which the distance D3 measured along the axial direction from the non-drive-side end 104b of the photosensitive drum to the driving force receiving portion 143b is shorter than the distance D1 from the non-drive-side end 104b of the photosensitive drum to the upstream top surface 143d2.

[0426] In other words, at least a part of the upstream inclined surface 143d2 is located farther from the non-drive-side end 104b of the photosensitive drum in the axial direction than the driving force receiving portion 143b. The upstream inclined surface 143d2 is a tip end portion located closer to the tip of the drum coupling 143 than the driving force receiving portion 143b.

[0427] Distances D1 and D3 can also be considered to be the distances measured along the axial direction from the non-drive side end of the cartridge (i.e., the non-drive side cartridge cover 117: see Figure 14) to the upstream slope 143d2 and the drive force receiving portion 143b, respectively.

[0428] The visor 143d is a blocking portion (stopper) that suppresses (blocks) the axial movement of the brake engaging members (204, 208). In other words, the visor 143d blocks the brake engaging members (204, 208) from approaching the drum coupling 143 and entering an area where they cannot engage with the brake force receiving portion 143c. Figures 66 and 49(b), as well as Figures 69 and 50(a), show this blocked state.

[0429] In this embodiment, the eaves (block portion) 143d is located further upstream in the rotation direction than the upstream inclined surface 143d2, and the eaves 143d is continuous with the top surface (upstream inclined surface 143d2) of the guide forming portion 143n (see Figure 56(d)).

[0430] If the brake engaging members (204, 208) enter the space upstream of the driving force receiving portion 143b or the space downstream of the braking force receiving portion 143c together with the drum drive coupling 180, the brake engaging members (204, 208) will be unable to engage with the braking force receiving portion 143c. The visor 143g blocks the movement of the brake engaging members (204, 208) to prevent this from happening.

[0431] In this embodiment, when the drum unit is viewed from the drive side along the axial direction (see FIG. 47(a)), the eaves 143g of the first coupling part 143s are arranged to cover the space upstream of the driving force receiving part 143b. Furthermore, the eaves 143g are arranged to cover the space downstream of the braking force receiving part 143c.

[0432] Furthermore, the eaves 143d are wide enough to cover at least a portion of the downstream portion (downstream slope 143d1) of the spiral slope (top surface) 143d. As a result, the eaves 143g prevent the brake engagement members (204, 208) and the drum drive coupling 180 from unintentionally entering the space upstream of the driving force receiving portion 143b or the space downstream of the braking force receiving portion 143c.

[0433] On the other hand, the eaves 143g are arranged to allow the brake engagement members (204, 208) to enter the space downstream of the brake force receiving portion independently, separate from the drum drive coupling 180 (see Figures 50(d), 49(c), and 48(c)).

[0434] In other words, after passing the eaves 143g, the brake engagement members (204, 208) come into contact with the upstream inclined surface 143d2 and are guided along the inclined surface 143d toward the space downstream of the brake force receiving portion 143c (see Figures 49(c) and 50(d)).

[0435] That is, the eaves 143g releases the blocked state of the brake engaging members (204, 208) when the brake engaging members (204, 208) are able to come into contact with the upstream portion (upstream top surface) 143d2 of the slope (top surface) 143d.

[0436] Eaves 143g are adjacent to upstream slope 143d2 and are located upstream of upstream slope 143d2. In this embodiment, the top surface of eave 143g and upstream slope 143d2 are connected, but there may be cases where eave 143g and upstream slope 143d2 are adjacent to each other but a gap is formed between them.

[0437] Furthermore, although the top surface of eaves 143g is a plane perpendicular to the axis L of the drum unit, this is not limited to this shape. For example, it is also possible to incline the top surface of eaves 143g in the same direction as upstream slope 143d2. In this case, eaves 143g can be considered to form part of upstream slope 143d2. Alternatively, part of guide formation portion 143n can be considered to form eaves 143g.

[0438] In this embodiment, the coupling 143 has two spiral inclined surfaces 143d, two canopies 143g, two driving force receiving portions 143b, and two braking force receiving portions 143c. That is, the coupling 143 has a shape symmetrical with respect to its axis, and has two coupling portions 143s and 143r (see FIG. 58). The coupling portions 143s and 143r each have a spiral inclined surface (inclined portion) 143d as a top surface. Then, the brake engaging members (204, 208) and the drum driving member 180 engage with the coupling portion 143s and the coupling portion 143r, as shown in FIG. 76(a).

[0439] Other examples (modified examples) of the shape of the coupling 143 will be described later.

[0440] The drive transmission unit 203 has a first brake engaging member 204 and a second brake engaging member 208 as braking force applying members (brake engaging members) that apply a braking force to the coupling 143 to apply a load to the rotation of the photosensitive drum. A gap is provided between the first brake engaging member 204 and the second brake engaging member 208, and the second brake engaging member 208, which is disposed radially inward, can bend to move slightly radially outward so as to approach the first brake engaging member 204. When the coupling 143 and the drive transmission unit 203 are disconnected, the second brake engaging member 208 bends, thereby smoothly disengaging from the coupling 143. For example, the second brake engaging member 208 can bend to overcome the eaves 143g and disengage from the coupling 143.

[0441] [Various modified examples of the coupling and cartridge shown in Example 1] In addition, a description will be given of a modified example (deformed shape) in which the drum coupling 143 of the first embodiment described above is partially modified. Even when the eaves 143g described above is not disposed on the drum coupling 143, it can be made to function depending on the conditions.

[0442] FIG. 52 shows a perspective view of the drum coupling 143 without the visor 143g, and FIG. 53 shows an exploded view for explaining the engagement process.

[0443] The shape will be explained using Figure 52. Figure 52 is a diagram showing one end of the drum unit, and shows a state in which a coupling member (drum coupling) 143 is attached to the end of the photosensitive drum 104. The drum coupling 143 has a spiral slope 143d and a push-back surface 143k, which will be described later, but does not have a visor shape.

[0444] Next, the process up to engagement with the drive transmission unit 203 will be described with reference to FIG.

[0445] The development view of Figure 53 is depicted in the same manner as the development view of Figure 48. The drum coupling 143 has two coupling portions 143s and 143r, but for simplicity of explanation, only the coupling portion 143s will be explained. The explanation of the coupling portion 143s also applies to the coupling portion 143r.

[0446] A case will be described in which the phases of the inclination start portion 143f of the drum coupling 143 and the inward protrusion 208e of the second brake engaging member 208 shown in Figure 53(a) satisfy the following relationship: In other words, a case will be described in which the inclination start portion 146f of the drum coupling 143 is located downstream in the rotation direction (arrow A).

[0447] FIG. 53(a) shows a state in which the drive transmission surface 180d of the drive transmission unit 203 and the second brake engaging member 208 are close to each other.

[0448] Next, in Figure 53(b), since there is no overhang, the drum coupling 143 shows a state in which the drum drive coupling 180 and the second brake engaging member 208 advance into the space between the push-back surface 143k and the spiral inclined surface 143d3.

[0449] Figure 53(c) shows a state in which the drive transmission unit 203 has started to rotate in the rotational direction A. When the drum drive coupling 180 and the second brake engaging member 208 rotate, the second brake engaging member 208 moves in the direction of arrow E along the inclined surface due to the effect of the inclination θ1 of the push-back surface 143k or the effect of the inclination θ2 of the second brake engaging member 208. As described in Figure 48, the second brake engaging member 208 can rotate without receiving any rotational load.

[0450] As described above, when the brake engaging members (204, 208) enter an area where they cannot engage with the brake force receiving portion, the push-back surface (push-back portion) 143k applies force to the second brake engaging member 208. As a result, the push-back surface 143k pushes back the brake engaging members (204, 208) toward the inside of the drive transmission unit 203, moving them in the direction of arrow E.

[0451] However, the second brake engaging member 208 is biased in the M1B direction in the figure by the spring 211 shown in Figure 43, and if the component force of the inclination θ2 of the second brake engaging member 208 is smaller than the spring force F1, the second brake engaging member 208 cannot be moved in the direction of arrow E. The component force varies depending on the load torque of the drum holding unit 108 and the angle of each inclined surface (θ1 or θ2). It is advisable to set the magnitude relationship of the forces within a range in which the above-mentioned action is achieved, taking into account the component force and frictional force, etc.

[0452] Figure 53(d) shows the movement of the second brake engaging member 208 that is no longer receiving the rotational load. The drive transmission unit 203 rotates further, and the second brake engaging member 208 passes over the tilt start portion 146f of the drum coupling 146. In this state, the second brake engaging member 208 moves in the direction of arrow C, as explained in Figure 48(c). The operation thereafter is the same as that described above, so a description thereof will be omitted.

[0453] Although not shown in FIGS. 50(a) to (d), the first brake engaging member 204 also moves together with the second brake engaging member 208 during these processes.

[0454] In the drum coupling 143 shown in the first embodiment (see FIG. 1(a)), the eaves 143g prevent the brake engaging members (204, 208) from entering the area where they cannot engage with the brake force receiving portion. In contrast, in the drum coupling 143 of this modified example, when the brake engaging members (204, 208) enter the area where they cannot engage with the brake force receiving portion 143c together with the drum drive coupling 180, the push-back surface (push-back portion) 143k pushes back the brake engaging members (204, 208). The push-back surface 143k is an inclined portion that is inclined in a direction different from that of the spiral inclined surface 143. In other words, spiral slope 143 is a portion that slopes toward the non-drive side of the drum unit as it moves downstream in the direction of rotation, while push-back surface 143k is a portion that slopes toward the outside of the drum unit, i.e., away from end 104b (see Figure 80) of the non-drive side of the photosensitive drum, as it moves downstream in the direction of rotation A. If spiral slope 143 is viewed as a downward slope, push-back surface 143k is an upward slope. Push-back surface 143k is located upstream of spiral slope 143d in the direction of rotation and is adjacent to spiral slope 43k.

[0455] The push-back surface 143k also serves as a guide (second guide) for guiding the brake engagement members (204, 208) toward the spiral inclined surface 143d. The push-back surface 134k is a spiral inclined surface (second spiral inclined surface, second inclined portion) whose inclination direction is opposite to that of the spiral inclined surface 143d.

[0456] Further, a description will be given of yet another modified shape of the drum coupling 143. The inclined portion and the top surface (spiral-shaped inclined surface 143d) serving as a guide described in the first embodiment are formed as smooth inclined surfaces, and the brake engaging members (204, 208) are guided along the surfaces (see FIG. 56, etc.). However, even if the inclined portion has a different shape, the drum coupling 143 can still function. An example of such a shape is shown in a perspective view in FIG. 54.

[0457] 54(a) is a re-presentation of the shape described in Example 1. A gentle spiral inclined surface 143d is formed from an inclination start portion 143f toward the braking force receiving portion 143c.

[0458] On the other hand, the shapes in Figures 54(b) and 73(a) show modified examples. The height changes in a stepped manner between the inclination start portion 147f and the brake force receiving portion 147c. In other words, the top surface (inclined portion) is a stepped portion 147d, and the inclination is formed by multiple steps. In this way, the inclined portion (top surface) may not be a spiral slope, but may be a spiral staircase-like portion that slopes downward in the direction in which the second brake engaging member 208 advances, forming the inclination.

[0459] The stepped step portion 147d has the same function as the spiral inclined surface 143d in Fig. 54(a) described above by moving the second brake engaging member 208 along the stepped step portion 147d in the direction of arrow C in Fig. 73(a). While the inclined surface 143d is an inclined portion made up of a continuously inclined surface, the stepped portion 147d can be considered to be an inclined portion that is inclined in stages by a plurality of planes.

[0460] If it is difficult to form the spiral inclined surface 143d on the coupling 143 due to limitations on the configuration of the mold for manufacturing the coupling 143, a step portion 147d can be used instead of the inclined surface 143d.

[0461] In this case, it is preferable to configure the step portion 147d, which is the top surface, so that when the second brake engaging member 208 comes into contact with the step portion 147d, the second brake engaging member 208 is guided smoothly without getting caught on the step portion 147d. For example, it is possible to sufficiently narrow the width of each flat surface of the step portion 147d. Also, in FIG. 73(a), the top surface (inclined portion, guide) is configured in a stepped shape by combining multiple flat surfaces, but the same function can be achieved by configuring the top surface (inclined portion, guide) by combining multiple curved surfaces. Like the inclined surface 143d, the step portion 147d is a guide (inclined portion) that uses its own inclination to guide the brake engaging member (204, 208) toward the brake force receiving portion.

[0462] 54(c) and 73(b), the top surface may be divided into an inclined surface (upstream top surface, downstream top surface) 148d1 and an inclined surface (downstream top surface, downstream guide, downstream top surface) 148d2, with a space 148g between them. Even in this case, the top surfaces (148d1, 148d2) can fulfill their guide function as long as they are shaped so that they do not get caught when the second brake engaging member 208 comes into contact with them. This type of coupling can be used when there are limitations on the configuration of the mold for molding the coupling.

[0463] Furthermore, Figures 54(d) and 73(c) show modified examples in which the shapes of each part of the coupling 143 are configured with ribs. Even if the top surface (inclined surface 149d) is configured with the surfaces of multiple ribs 149p and the top surface is divided into multiple parts, the same function can be achieved. In other words, as shown in Figure 73(c), the guide forming portion 149n that forms the upstream top surface (upstream guide, upstream inclined portion) 149d2 is a protrusion (rib) that protrudes in the radial direction.

[0464] This can be used when the characteristics of the material used require the construction of ribs without creating thick sections.

[0465] 54(a) to 54(d), each top surface (143d, 147f, 148d1, 148d2, 149d) guides the brake engaging members (204, 208) toward the brake force receiving portion 143c, regardless of its shape. In other words, each top surface is a guide (inclined portion) for guiding the brake engaging members (204, 208) toward the brake force receiving portion 143c, regardless of its shape. At least a portion of such a top surface (guide) is formed by the guide forming portion 143n.

[0466] As with the top surface, the shape of the push-back surface (push-back portion) 143k shown in FIG. 52 can also be various. For example, the push-back portion (push-back surface) 143k of this modified example is a smoothly continuous spiral slope, but the push-back portion may be sloped by multiple surfaces or steps. For example, like the push-back portion 143k of Example 1 shown in FIG. 48(b) and FIG. 56(d), the push-back portion 143k may be two surfaces with different slopes. Furthermore, while the push-back surface 143k is an upslope, it may have localized downslope portions.

[0467] The drum coupling 143 may have either the eaves 143g or the push-back surface (push-back portion) 143k, or may have both. As described above, the drum coupling 143 of the first embodiment shown in Figures 48(b), 55(b), and 56(d) has both the eaves 143g and the push-back portion 143k. Normally, the drum coupling 143 can block the brake engagement members (204, 208) from improperly entering or approaching by the eaves 143g, but in the unlikely event that the blocking is not possible, the push-back surface 143k pushes back the brake engagement members (204, 208) and moves them away from the coupling 143.

[0468] The drum coupling 143 has a protrusion shape (push-back portion forming portion, second guide forming portion) 143m that forms the push-back surface 143k (see FIGS. 79(b) and 79(c)).

[0469] The engaging portion 143i, the guide forming portion 143n, the protruding shape 143m, and the eaves 143g (see FIG. 79) may be referred to as the first, second, third, fourth shape portion, etc. in no particular order.

[0470] Next, modified examples of the braking force receiving portion (second side surface) will be shown using Figure 54(e) and Figure 73(d).

[0471] The braking force receiving portion 143c described in the first embodiment shown in Figure 54(a), Figure 1(a), Figures 55 to 57, and the other modified examples shown in Figure 52 and Figures 54(b) to (d) has a shape that protrudes downstream in the direction of rotation. This is because the braking force receiving portion 143c has a shape that protrudes downstream in the direction of rotation, which increases the stability of engagement when it engages with the brake engaging members (204, 208).

[0472] In other words, this shape generates a force that attracts the brake force receiving portion 143c and the brake engagement members (204, 208) when they engage with each other. The brake force receiving portion 143c protrudes downstream in the rotation direction. Therefore, when the brake force engagement members (204, 208) come into contact with the brake force receiving portion 143c, a force is generated that pulls the brake force engagement members (204, 208) inward in the axial direction toward the drum coupling 143 and the photosensitive drum 104. This stabilizes the engagement state between the brake force receiving portion 143c and the brake force engagement members (204, 208), making it difficult for the engagement to come off.

[0473] As described above, the brake engaging members (204, 208) are configured to be movable in the axial direction relative to the drum drive coupling 180 (see Figures 67 and 68). However, if the brake engaging members (204, 208) move in the axial direction while the drive transmission unit 203 is driving the drum coupling 143, there is a possibility that the state of engagement with the brake force receiving portion 143c may be released or become unstable. Therefore, it is preferable that the brake force receiving portion 143c has a shape that stabilizes the state of engagement with the brake engaging members (204, 208) and that suppresses axial movement of the brake engaging members (204, 208) when the drum up ring 143 is driven.

[0474] However, when the braking force that needs to be applied to the braking force receiving portion is small or when the friction coefficient of the braking force receiving portion is high, the engagement between the braking force receiving portion and the brake engaging member (204, 208) is inherently stable. Therefore, it is possible to eliminate any protruding portion from the braking force receiving portion. Such a braking force receiving portion 144t is shown in Figures 54(e) and 73(d). In the modified drum coupling 143 shown in Figures 54(e) and 73(d), the braking force receiving portion 144c does not protrude downstream in the rotation direction (arrow A).

[0475] On the other hand, it is also possible to consider devising measures to further stabilize the state of engagement with the brake engagement members (204, 208) for the brake force receiving portion 144c having such a shape.

[0476] In order to stabilize the engagement between the brake force receiving portion 144c and the brake engaging member, it is possible to attach an elastic member (elastic portion) 144t such as rubber to the brake force receiving portion 144c, or to integrally mold the elastic portion with the brake force receiving portion 144c. By increasing the coefficient of friction of the brake force receiving portion 144t or by having the brake engaging member (204, 208) bite into the elastic portion of the brake force receiving portion 144t, the engagement with the brake engaging member (204, 208) becomes less likely to be released, and the engagement can be stabilized.

[0477] One possible method for increasing the frictional force of the braking force receiving portion 144c is to use an adhesive member (adhesive member) instead of the elastic member 144t. For example, if double-sided tape (adhesive member) is applied to the surface of the braking force receiving portion 144c, the adhesiveness of the tape increases the frictional force between the braking force receiving portion 144c and the brake engaging members (204, 208), making it more difficult for them to disengage. Another possible method for increasing the coefficient of friction of the braking force receiving portion 144c is to treat the surface of the braking force receiving portion 144c without using the elastic member 144t.

[0478] It is desirable that the helical inclined surface 143d (see FIG. 67) for guiding the brake engagement members (204, 208) have a small coefficient of friction in order to achieve smooth guiding. Therefore, even if a material with a high coefficient of friction is selected for the brake force receiving portion 144c or surface treatment is applied, it is desirable to avoid using such a material or surface treatment for the helical inclined surface 143d rather than applying such a treatment to the entire coupling. In other words, it is desirable to make the coefficient of friction of the brake force receiving portion 144c higher than that of the helical inclined surface 143d.

[0479] It should be noted that an elastic portion 144t may be provided on the braking force receiving portion 143c of the drum coupling 143 as shown in Figures 54(a) to (d).

[0480] Next, the preferred positional and dimensional relationships of the drum coupling 143 will be described with reference to Figure 101. Figure 101 is a front view of the drum coupling 143 of the first embodiment. θ (theta)11 is the dimension from the driving force receiving portion 143b to the braking force receiving portion 143c of the engaging portion 143i, expressed as an angle with the axis of the drum coupling 143 as the origin. In other words, it is the angle of the region of the downstream inclined portion 143d1.

[0481] Regarding the upper limit of θ11, it is desirable that θ11 be 90° or less, and more preferably 80° or less. θ11 corresponds to the gap that occurs between the drum drive coupling 180 and the brake engaging members (204, 208) when the drum coupling engages with the drive transmission unit 203 (see FIG. 64). In order to reliably sandwich the driving force receiving portion 143b and the braking force receiving portion 143c between the brake engaging members (204, 208) of the device main body and the drum drive coupling 180, it is desirable that θ11 be 90° or less, and more preferably 80° or less.

[0482] On the other hand, regarding the lower limit of θ11, if the strength of the engaging portion 143i, which forms the driving force receiving portion 143b or the braking force receiving portion 143c, is increased by using metal for the engaging portion 143i, θ11 can be reduced. As will be described in detail later, in a modified drum coupling shown in FIG. 74, the drum coupling 143 is made of metal, thereby making the thickness of the engaging portion 145i corresponding to the engaging portion 143i smaller than in this embodiment. Considering this configuration, the preferable condition for the lower limit of θ11 (FIG. 101) is that θ11 is 1° or more, more preferably 2° or more, and even more preferably 8° or more. In this embodiment, θ11 is set to be 30° or more, and θ11 is set to approximately 35°.

[0483] This is because it is desirable to ensure that the angle θ11, which corresponds to the thickness of the engaging portion 143i, is large to a certain extent in order to increase the strength of the driving force receiving portion 143b and the braking force receiving portion 143c so that they can stably receive forces.

[0484] When θ11 is converted into length, it becomes the thickness of the engaging portion 143i, that is, the distance measured along the rotation direction from the driving force receiving portion 143b to the braking force receiving portion 143c. The desirable range for this distance is 0.3 mm or more, and more preferably 1 mm or more.

[0485] 101, θ12 indicates the angle of the area occupied by the upstream slope (upstream guide, upstream inclined portion) 143d2. Regarding the lower limit of θ12, it is desirable that the value of θ12 be equal to or greater than half the value of θ11, and more desirably, the value of θ12 be equal to or greater than the value of θ11. This is because the upstream inclined portion 143d2 needs to have a length in the rotational direction sufficient to guide the brake engagement member (204, 208) to the brake force receiving portion 143c by means of the upstream inclined portion 143d2.

[0486] The smaller θ11 is and the larger the inclination angle of the upstream slope 143d2 is, the smaller the lower limit of θ12 can be made.

[0487] Thus, the lower limit of θ12 depends on the value of θ11 and the angle of the upstream slope 143d2, but if expressed numerically, θ12 is 1° or more, more preferably 2° or more, even more preferably 8° or more, and even more preferably 30° or more. In this embodiment, θ12 is set to 60° or more.

[0488] The upper limit of θ12 can be relatively large and can exceed 360°. However, θ12 is preferably 360° or less, more preferably 270° or less, and in this embodiment, θ12 is 180° or less. Specifically, θ12 is set to approximately 67°.

[0489] A configuration in which θ12 is larger than that of this embodiment will be described later with reference to FIGS.

[0490] θ13 is the angle obtained by adding θ11 and θ12, and corresponds to the angle occupied by the entire spiral slope 143d. If θ13 were to be expressed numerically, θ13 is preferably 2° or more, and more preferably 8° or more. θ13 is preferably 360° or less, and even more preferably 270° or less. In this embodiment, θ13 is set to 180° or less. Specifically, θ13 is set to approximately 102°.

[0491] Another modified example of the coupling 143 will be described with reference to FIG.

[0492] FIG. 74 shows a perspective view and a front view of a modified coupling from two viewing directions.

[0493] The coupling 143 of this modification has an engaging portion 145i having a driving force receiving portion 145b and a braking force receiving portion 145b, and a guide forming portion 145n having a spiral inclined surface 145d. The engaging portion 145i and the guide forming portion 145n correspond to the engaging portion 143i and the guide forming portion 143n of the coupling 143 shown in Example 1 (see FIG. 79), but have partially different shapes.

[0494] The coupling 143 of this modified example has a canopy 143g that comes into contact with the second brake engaging member 208 (not shown), and the spiral inclined surface 145d is formed by a curved surface. This curved surface is approximately arc-shaped and is disposed so as to connect the inclination start point 143f to the braking force receiving portion 145c. In this modified example, the braking force receiving portion 145c does not have a shape that protrudes downstream in the rotational direction, and therefore an elastic member (elastic portion) 145t may be attached to the braking force receiving portion 145c as in Figure 54(e).

[0495] The spiral slope 145d in this modification (FIG. 74) is a top surface that corresponds to the upstream slope 143d2 in the first embodiment (FIG. 57).

[0496] On the other hand, in this modification (FIG. 74), the top surface (upper portion) 145e (FIG. 74(b)) of the engagement portion 145i corresponds to the downstream side inclined surface 143d1 of the first embodiment (FIG. 57), but unlike the downstream side inclined surface 143d1, it is not inclined.

[0497] That is, the top surface 145e located downstream is connected to the top surface (spiral inclined surface 145d) located upstream, but the inclination angles of the two surfaces at the boundary are different. Top surface 145e and spiral inclined surface 145d are not smoothly connected.

[0498] Furthermore, because the distance between the driving force receiving portion 145b and the braking force receiving portion 145c is short, the length of the top surface 145e measured along the rotation direction is smaller (shorter) than the length of the downstream slope 143d1 in Figure 57. As described above, the top surface 145e is not inclined. In this modified example, the top surface 145e can also be considered not to be used as a guide.

[0499] However, even with this configuration, the spiral inclined surface 145d, which serves as a guide (inclined portion), can guide the brake engaging members (204, 208) toward the brake force receiving portion 145c.

[0500] A flat surface 145h is adjacent to the upstream side of the spiral slope 145d, and the spiral slope 145d and the flat surface 145h are connected to each other. The flat surface 145h may be inclined in the same direction as the spiral slope 145d to form a part of the spiral slope 145d. The drum coupling of this modified example may also have the eaves 143g or the push-back surface 143k described in the first embodiment or another modified example of the first embodiment (see FIGS. 1, 52, etc.).

[0501] Furthermore, with regard to the shape of the drum coupling, the shape of the shaft portion 143j shown in FIG. 1 can also be selected for design reasons. For example, FIG. 75 shows the shape of a modified drum coupling. In the example of FIG. 75, the diameter of the shaft portion 146j is the same as the diameter of the photosensitive drum 104. The shaft portion 146j is rotatably supported by the drive-side cartridge cover member 116 (see FIG. 15). Positioning in the direction of arrow MB1 can be achieved, for example, using the shaft portion end surface 146s. In this way, the shape of the shaft portion 146j can also be selected appropriately depending on the relationship with peripheral parts and the manufacturing method.

[0502] Another modified example of the drum coupling 143 is shown in Figures 76(b) and (c) and Figures 78(a), (b), (c), and (d). These show a drum coupling in which the two coupling portions 143s and 143r have different shapes. Figures 76(b) and (c) are developments of the coupling 143, and Figure 76(c) also shows the drum drive coupling 180 and brake engagement member 208 on the device main body side in addition to the development. Figures 78(a) and (b) are perspective views of the drum coupling 143. Figures 78(c) and (d) show the engagement state of the brake engagement members (204, 208) and the drum drive coupling 180 with respect to the drum coupling 143.

[0503] In the coupling 143 shown in these figures, the engaging portion 143i of one coupling part 143s does not have the braking force receiving portion 143c, but only has the driving force receiving portion 143b. In other words, the side surface 143y provided on the engaging portion 143i of the coupling part 143s does not engage with the brake engaging member (204, 208). In contrast, the engaging portion 143i of the other coupling part 143r has only the braking force receiving portion 143c, but does not have the driving force receiving portion 143b. The side surface 143x of the engaging portion 143i of the coupling part 143r does not engage with the drum drive coupling 180.

[0504] Figure 76(d) shows another example of an asymmetrical coupling 143. The coupling portion 143s is an example that does not have any side surface that corresponds to the driving force receiving portion 143c.

[0505] The modified examples of the coupling 143 shown in Figures 76(b) and (c) and Figures 78(a), (b), (c), and (d) receive the driving force at only one point and the braking force at only one point. Therefore, in order for the drum coupling to stably receive the driving force and the braking force, it is advisable to increase the accuracy of the fit between the circular hole portion 143a and the positioning boss 180i of the drum drive coupling 180 (see Figure 51). In other words, it is advisable to reduce the gap between them and increase the positioning accuracy of the drum coupling 143 relative to the drive transmission unit 203, thereby ensuring stable and reliable engagement between the drive transmission unit 203 and the drum coupling 143.

[0506] Another modified example of a drum coupling having one driving force receiving portion and one braking force receiving portion is shown in Figure 77. The drum coupling 143 shown in Figure 77 has only one upstream inclined surface 143d2, one downstream inclined surface 143d1, one eaves 143g, one driving force receiving portion 143b, one braking force receiving portion 143c, and one pushing surface 143k. Figure 77(a) is a perspective view of the drum coupling, and Figure 77(b) is a front view.

[0507] In addition, in a modified example of the drum coupling 143 as shown in Figure 77, any part of the inclined surface 143d, the eaves 143g, the driving force receiving portion 143b, the braking force receiving portion 143c, and the pushing surface 143k may be arranged at a position that is 180° symmetrical (axially symmetrical).

[0508] For example, as shown in FIG. 96, the eaves 143g of the drum coupling 143 shown in FIG. 77 may be moved to a region S143g symmetrical at 180 degrees, or the pushing surface 143k may be moved to a symmetric region S143k.

[0509] This is because the drum drive coupling 180 and the brake engaging members (204, 208) both have shapes that are symmetrical by 180 degrees.

[0510] Therefore, no matter which of the two 180-degree symmetrical positions a single spiral inclined surface 143d is located at, that inclined surface 143d can act on the entire brake engagement member (204, 208). Similarly, the pushing surface 143k may be located at which of the two 180-degree symmetrical positions. The same applies to not only the eaves 143g and the pushing surface 143k, but also the brake force receiving portion 143c.

[0511] Moreover, the drum drive coupling 180 can engage with the driving force receiving portion 143b no matter which of the two positions symmetrically arranged at 180 degrees is the driving force receiving portion 143b.

[0512] The drum drive coupling 180 has two drive transmission surfaces 180d, which move together (see Figure 45(a)). The brake engagement members (204, 208) each have two coupling engagement portions 204b, 208b, which all move together (see Figure 45(b)).

[0513] Another example of a modified drum coupling 143 having an asymmetrical shape is as follows: That is, one coupling portion 143s may have an engaging portion 143i but not a guide forming portion 143n, and the other coupling portion 143r may have a guide forming portion 143n but not an engaging portion 143i.

[0514] An example of such a configuration is shown in Figures 97(a) and (b), where Figure 97(a) is a perspective view of a modified drum coupling, and Figure 97(b) is a front view.

[0515] The modified drum coupling shown in these figures has one guide forming portion 343n and one engaging portion 343i. The guide forming portion 343n forms a spiral inclined surface (guide, top surface, inclined portion) 343d2. The engaging portion 343i forms a driving force receiving portion 343b and a spiral inclined surface (guide, top surface, inclined portion) 343d1. The guide forming portion 343n and the engaging portion 343i are located on opposite sides of each other with respect to the axis L. Furthermore, in this modified example, the braking force receiving portion 343b is not located on the engaging portion 343i but is located at the downstream end of the guide forming portion 343n in the rotational direction. In other words, the engaging portion 343i engages with the driving force applying member (drum drive coupling) 180 but does not engage with the braking force applying member (brake engaging members 204, 208).

[0516] 99(a), (b), and (c) show, in this order, the engagement process between the drum coupling of this modified example and the brake engagement members (204, 208). For the sake of explanation, the drum drive coupling 180 of the drive transmission unit 203 is not shown.

[0517] As shown in Figure 99(a), when the second brake engaging member 208 comes into contact with the inclined surface 343d2 of the guide forming portion 343n, the second brake engaging member 208 begins to move downstream in the rotational direction and closer to the photosensitive drum 104 in the axial direction.

[0518] As shown in Figure 99(b), when the second brake engaging member 208 reaches near the end of the upstream slope 343d2, the first brake engaging member 204 comes into contact with the slope 343d1, which is the top surface of the engaging portion 343i. Thereafter, the brake engaging members (204, 208) continue to rotate, and as shown in Figure 99(c), the tip of the first brake engaging member 204 enters the space downstream of the engaging portion 343i. The first brake engaging member 204 reaches a position where it can engage with the brake force receiving portion 343c (see Figure 97(b)).

[0519] As described above, in the drum coupling of this modified example shown in Figures 97 and 99, any part can be moved to a position symmetrical by 180 degrees. For example, as shown in Figure 98(a), the engaging portion 343i and the driving force receiving portion 343b can be moved to positions S343i and S343b, respectively, which are symmetrical by 180 degrees. If the engaging portion 343i is moved to S343i, the shape will be similar to that of the modified drum coupling shown in Figure 77. In other words, if a part of the drum coupling shown in Figure 77 is moved to a position symmetrical by 180 degrees, the shape will be similar to that of the drum coupling of this modified example shown in Figure 97.

[0520] 98(a), in this modification, when the engaging portion 343i is virtually positioned at a 180-degree symmetrical position S343i, the inclined surface 343d2 is adjacent to the virtually positioned engaging portion S343i. The upstream portion 343d2a of the inclined surface 343d2 extends from upstream to downstream in the rotational direction toward the virtually positioned engaging portion S343i and the virtually positioned driving force receiving portion S343b.

[0521] The angles θ41, θ42, θ51, and θ52 relating to the dimensions of each part in this modified example are shown in FIG. 98(b).

[0522] θ41 is the angle of the area where the engaging portion 343i is arranged. θ42 is the angle of the area occupied by the spiral inclined surface 343d2 of the guide forming portion 343n. θ51 is the angle indicating the area from S343b, which is virtually positioned 180° symmetrically with the driving force receiving portion 343b, to the braking force receiving portion 343c. θ52 is the angle of the area occupied by a portion 343d2a of the spiral inclined surface 343d2 that is located upstream in the rotational direction from the virtually positioned position S343b of the driving force receiving portion.

[0523] In order to ensure the strength of the driving force receiving portion 343b, θ41 is preferably 1° or greater, more preferably 2° or greater, and even more preferably 8° or greater.

[0524] θ51 corresponds to the angle of the gap between the brake engaging members (204, 208) and the drum drive coupling 180. Therefore, as described above, it is desirable that the angle be 80° or less.

[0525] Furthermore, since θ51 is larger than θ41, θ51 is preferably 1° or more, more preferably 2° or more, and even more preferably 8° or more. Furthermore, θ41 is preferably 80° or less.

[0526] θ52 is an angle corresponding to θ12 in Fig. 101, and the preferred range of θ52 is the same as that of θ12. Also, θ42 is an angle corresponding to θ13 in Fig. 101, and the preferred range of θ42 is the same as that of θ13.

[0527] Another modified example of an asymmetric drum coupling is shown in Figures 100(a) and (b). In this modification, the upstream slope 143d2 (see Figure 58, etc.) of the first embodiment is divided into two portions. That is, the upstream slope 143d2 is divided into an upstream portion 143d2a and a downstream portion 143d2b. The engagement portion 143i is adjacent to the downstream portion 143d2b of the upstream slope 143d2.

[0528] The dimensional relationship in this modified example is shown in Figure 100(b). Angle θ21 is the angle of engagement portion 143i and corresponds to angle θ11 in Figure 101. The preferred angle for θ21 is the same as angle θ11. θ22b is the angle occupied by downstream portion 143d2b of upstream slope 143d2, and θ22b is the angle occupied by upstream portion 143d2a of upstream slope 143d2.

[0529] The region obtained by virtually moving downstream portion 143d2b of upstream slope 143d2 to a position 180° symmetrical to it is defined as S143d2b. The angle between virtual region S143d2b and upstream portion 143d2a is θ32. θ32 corresponds to angle θ12 in FIG. 101, and therefore the preferred angle range for θ32 is the same as the preferred angle range for θ12.

[0530] The suitable angle ranges for θ22a and θ22b are also similar to that for θ12.

[0531] Furthermore, another modified example of the drum coupling will be described. The spiral inclined surface 143d and the upstream inclined surface 143d2 serving as the guide and the upstream guide can be modified to be longer than those of the drum coupling of the first embodiment (FIG. 1, etc.). Such an example is shown in FIGS. 102 and 103. In the drum coupling shown in these figures, the spiral inclined surface 443d2 corresponding to the upstream inclined surface 143d2 is arranged over 360°. In other words, the spiral inclined surface 443d2 is arranged for more than one revolution.

[0532] An engagement portion 443i, which corresponds to engagement portion 143i of the first embodiment, is disposed separately from inclined surface 443d2. Engagement portion 443i has a braking force receiving portion 443c1 and a driving force receiving portion 443b. A braking force receiving portion 443c2 is also disposed near the end of spiral inclined surface 443d2. Braking force receiving portion 443c1 and braking force receiving portion 443c2 are disposed at positions symmetrical by 180°.

[0533] 103(a), (b), and (c) show, in chronological order, the engagement process between the drum coupling of this modified example and the brake engagement member. Note that the drum drive coupling 180 is not shown for ease of explanation.

[0534] As shown in FIG. 103, the brake engagement members (204, 208) are guided by the spiral inclined surface 443d2 and rotate one or more revolutions. In this way, it is possible to make the length of the spiral inclined surface 443d2, which serves as a guide and an inclined portion, larger than 360°. However, if the spiral inclined surface 443d2 is long, the time required for the brake engagement members (204, 208) to pass through the spiral inclined surface 443d2 may become longer, or the speed at which the brake engagement members (204, 208) move along the spiral inclined surface 443d2 may become slower. To address this, when engaging the drive transmission unit 203 with the coupling 143, it may be necessary to take measures such as slowing down the rotational speed of the drive transmission 203 to ensure sufficient time for the brake engagement members (204, 208) to pass through the spiral inclined surface 443d2.

[0535] In order to smoothly engage the drive transmission unit 203 with the drum coupling 143 while rotating the drive transmission unit 203 at high speed, it is desirable to shorten the time it takes for the brake engagement members (204, 208) to pass over the spiral inclined surface 443d2. From this perspective, it is more preferable to set the length of the spiral inclined surface (inclined portion, guide) 443d2 to 360° or less, and even more preferable to set it to 270° or less.

[0536] As described above, it is also possible to use a modified example in which the drum coupling 143 of the first embodiment is changed to an asymmetrical shape.

[0537] However, a configuration in which the coupling 143 has two driving force receiving portions 143b and two braking force receiving portions 143c at positions 180° apart, like the drum coupling 143 of embodiment 1 shown in Figures 1 and 58, is more preferable because it stabilizes the engagement state of the drive transmission unit 203 with the coupling 143 and the transmission state of the driving force. The coupling 143 can receive the driving force at two symmetrically arranged points, and similarly, the braking force can be received at two symmetrically arranged points. Therefore, it is easier to maintain the balance of the forces applied to the coupling 143.

[0538] In the drum coupling 143 of the first embodiment (see FIG. 1), the respective configuration parts of the coupling (engagement parts, guide forming parts, eaves, etc.) have a specific arrangement relationship. However, it is also possible to change the arrangement relationship by configuring any part of the coupling 143 to be movable.

[0539] As an example, Figures 104 to 106 show a configuration in which the engaging portion 243i is movable relative to other portions of the drum coupling 143, specifically, a configuration in which the engaging portion 243i is movable forward and backward in the radial direction. As shown in Figure 105, the drum coupling 143 has two openings 243p formed therein, and the engaging portion 243i is opened so as to be partially exposed from the inside of the drum coupling 143 through these openings 243p.

[0540] 105(a), the two engaging portions 243i are supported by guides 199a of a support member 199 arranged inside the drum coupling. Furthermore, the engaging portions 243i are configured to be movable radially along the guides 199a, but are biased radially inward by tension springs 200.

[0541] Therefore, when the cartridge is not in use, the two engaging portions 243i are retracted inside the drum coupling as shown in Figures 104(a) and (c). On the other hand, when an attempt is made to mount the cartridge in the image forming apparatus main body, the positioning boss 180i enters the interior of the drum coupling and comes into contact with the engaging portions 243i as shown in Figure 106(a). Furthermore, when the positioning boss 180i enters the interior of the drum coupling 143, the engaging portions 243i are pushed outward in the radial direction by the positioning boss 180i. As a result, a part of the engaging portion 243i advances toward the outside of the drum coupling 143 as shown in Figures 104(b) and (d).

[0542] In this state, both sides of the engaging portion 243i, that is, the driving force receiving portion 243b and the braking force receiving portion 243c, are exposed and can receive the driving force and the braking force from the main body of the image forming apparatus, respectively.

[0543] In this way, the positional relationship and shape of the coupling 143 are not constant and may fluctuate or change. For example, it may be possible to protect the drum coupling portion, which is vulnerable to external shock, by retracting it when the cartridge is not in use.

[0544] When a portion of the coupling 143 is movable, the state of the coupling 143 when it is actually used, that is, when the cartridge and drum unit are mounted in the image forming apparatus main body and the coupling 143 engages with the drive transmission unit 203, may be considered to be the reference state. In this reference state, the shape of the coupling 143 and the relative positions of the various parts may be configured to satisfy the desired conditions described above.

[0545] Furthermore, Figures 107 and 108 show another modified example of the drum coupling 143, in which a portion of the drum coupling 143 is deformed and moved. In the previously described modified example (see Figure 105), the engaging portion 243i is configured to move in the radial direction, but in this modified example, the engaging portion 643i is configured to move in the axial direction. Figure 107(a) shows a state in which the engaging portion 643i is retracted inside the drum coupling, and Figure 107(b) shows a state in which the engaging portion 643i is advanced toward the outside of the drum coupling, away from the photosensitive drum. Figure 107(c) is an exploded perspective view of the drum unit in this modified example.

[0546] Figures 108(a) and (b) show cross-sectional views of the drum unit. Figure 108(a) shows the state before the drum unit is installed in the apparatus main body, and (b) shows the state after it has been installed.

[0547] When the drum unit is attached to the apparatus main body, the positioning boss 180i provided on the drive transmission unit comes into contact with the acting member 698 of the drum coupling. Then, as shown in FIG. 108(b), the acting member 698 moves inward in the axial direction (to the right in the figure). As the acting member 698 moves, the interlocking member 698 is pushed radially outward inside the drum coupling. As the interlocking member 698 moves radially outward, the engaging portion 643i is pressed radially outward by the interlocking member 698. As a result, the engaging portion 643i changes from a state in which it is retracted inside the drum unit (FIGS. 107(a) and 108(a)) to a state in which a portion of it is exposed to the outside (FIGS. 107(b) and 108(b)).

[0548] When a part of the drum coupling is provided to be movable in this manner, the direction of movement may be either the radial direction or the axial direction, or the part of the drum coupling may move in both the radial direction and the axial direction, or may move in the rotational direction.

[0549] Next, another modified example of the drum coupling will be described with reference to Figures 109 and 110. As with the two modified examples described above, the drum coupling 1043 of this modified example also has a configuration in which a part of it deforms and moves.

[0550] Figure 109(a) is an exploded perspective view of the drum unit of this modified example. (b) shows the state in which the engaging portion 1043i of the drum coupling is extended toward the outside of the drum unit, and (c) shows the state in which the engaging portion 1043i is partially retracted toward the inside.

[0551] In this modified example, before the drum unit is attached to the device body, the engaging portion 1043i is in a protruding (advanced) state as shown in Figure 109(b). On the other hand, after the drum unit is attached to the device body, the engaging portion 1043i changes to a retracted state as shown in Figure 109(c).

[0552] Figures 110(a) and (b) show cross-sectional views of the drum unit. (a) shows the state before the drum unit is completely installed in the device main body, and (b) shows the state after installation is complete.

[0553] 109(a), an engaging member 1043 is arranged axially movably inside the drum coupling 143. The engaging member 1043 is urged (pressed) outward in the axial direction by a compression coil spring 1020 arranged inside the drum coupling 143, and an engaging portion 1043i that is a part of the engaging member 1043 is exposed to the outside of the drum coupling 143.

[0554] The engaging member 1043 has an acting portion 1043p on its rotation axis. When the drum unit is attached to the apparatus main body as shown in Figure 110(b), the acting portion 1043p is pressed by the positioning boss 180i, causing the engaging member 1043 and the engaging portion 1043i to retreat inward in the axial direction.

[0555] In the three modified examples described above, an acting portion that can be acted upon from outside the cartridge is disposed inside the coupling 143, and this acting portion is actuated by the positioning boss 180i to change the shape of the coupling 143. However, it is also possible to dispose an acting portion for changing the shape of the coupling 143 in a location other than inside the coupling 143.

[0556] As explained above, various shapes and configurations of the coupling can be selected depending on design reasons regarding the arrangement, production reasons taking into account the molds used to produce the coupling, and purposes such as protection of the coupling.

[0557] In addition, in all three of the above-described modified drum couplings, the engaging portion having the driving force receiving portion and the braking force receiving portion is movable relative to the other portions. However, the spiral slope, the eaves, and other portions may be movable relative to the other portions.

[0558] Furthermore, while the cartridge 100 described above includes a photosensitive drum and a developing roller, the configuration of the cartridge 100 is not limited to this. For example, the cartridge 100 may be configured to include a photosensitive drum but not a developing roller. One example of such a configuration is a cartridge 100 that includes only a drum holding unit 108 (see FIG. 19).

[0559] In the first embodiment and its various modifications, the drum coupling 143 is disposed near one end (the end on the driving side) of the photosensitive drum 104 and is press-fitted into a cavity formed by the photosensitive drum 104. As a result, driving force can be transmitted from the drum coupling 143 to the end of the photosensitive drum 104. However, the method of connecting the drum coupling 143 and the photosensitive drum 104 is not limited to press-fitting. In the above-described examples, the drum coupling 143 and the photosensitive drum 104 are integrated to form the drum unit 103, but the drum coupling 143 and the photosensitive drum 104 may be separate and not form a drum unit.

[0560] In other words, as long as the drum coupling 143 is operatively connected to the photosensitive drum 104, i.e., connected in a manner that allows drive transmission, other connection methods may be used, and the coupling 143 and the photosensitive drum 104 do not have to constitute the same unit.

[0561] For example, one or more relay members may be interposed between the coupling 143 and the photosensitive drum 104. In this case, the drum coupling 143 can be considered to be indirectly connected to the drive side end of the photosensitive drum 104 via the relay members. The drum coupling 143 operates the photosensitive drum 104 via the relay members by rotating itself.

[0562] For example, it is conceivable to attach a gear to the end of the photosensitive drum 104, and form a gear on the outer circumferential surface of the drum coupling 143. In this way, the driving force can be transmitted from the drum coupling 143 to the photosensitive drum 104 by directly meshing the gear of the coupling 143 with the gear of the photosensitive drum 104, or by further interposing another idler gear between the two gears.

[0563] In addition to using a gear as a relay member, a method of connecting a drive transmission belt between the drum coupling 143 and the photosensitive drum 104 to serve as a relay member is also conceivable.

[0564] It is also possible to connect the drive side end of the photosensitive drum 104 and the drum coupling 143 using an Oldham coupling as a relay member. In this case, the drum unit 103 can be considered as a unit having the photosensitive drum 104, the Oldham coupling (relay member), and the drum coupling 143.

[0565] In this way, the photosensitive drum 104 and the drum coupling 143 may be connected directly or indirectly. Furthermore, the photosensitive drum 104 and the drum coupling 143 may be integrated into a unit to form the drum unit 103, or the photosensitive drum 104 and the drum coupling 143 may be arranged separately in the cartridge and not integrated into a single unit.

[0566] However, if the coupling 143 and the photosensitive drum 104 form a drum unit 103 that can rotate integrally, or if the coupling 143 is directly connected to the end of the photosensitive drum 104, the drive (rotation) of the coupling 143 can be more accurately transmitted to the photosensitive drum 104, which is more preferable.

[0567] In this embodiment, the axes of the drum coupling 143 and the photosensitive drum 104 are aligned. That is, the drum coupling 143 and the photosensitive drum 104 are aligned along the same rotation axis L (see FIG. 1). However, when the drum coupling 143 and the photosensitive drum 104 are indirectly connected, the positions of their axes may differ.

[0568] In any case, the cartridge can be driven stably by engaging the coupling 143 with the drive transmission unit 203 provided in the main body of the apparatus.

[0569] An example in which the configuration of the cartridge etc. is changed will be f...

Claims

1. A cartridge detachably mountable to a main body of an image forming apparatus, the cartridge comprising a driving force applying member and a braking force applying member, A photosensitive drum; a coupling operatively connected to the photoreceptor drum so as to be capable of transmitting a driving force toward the photoreceptor drum; and The coupling is The main body and a movable member movable relative to a main body of the coupling; and the movable member has an engaging portion, and is configured to move relative to the main body of the coupling to cause the engaging portion to enter between the driving force applying member and the braking force applying member, The cartridge is configured so that the movable member receives the driving force from the driving force applying member and also receives a braking force from the braking force applying member for applying a load to the rotation of the coupling.

2. 2. The cartridge according to claim 1, wherein the movable member is configured to move the braking force applying member relative to the driving force receiving member, thereby causing the engaging portion to enter between the driving force applying member and the braking force applying member.

3. 3. A cartridge according to claim 1, wherein the movable member is configured to move the braking force application member downstream in the rotation direction of the driving force receiving member relative to the driving force receiving member.

4. 4. The cartridge according to claim 1, wherein the engaging portion includes an acting portion configured to come into contact with the braking force applying member to move the braking force applying member relative to the driving force receiving member.

5. 5. A cartridge according to claim 1, wherein the engaging portion includes a driving force receiving portion configured to receive the driving force from the driving force applying member.

6. 6. The cartridge according to claim 1, wherein the engaging portion includes a braking force receiving portion configured to receive the braking force from the braking force applying member.

7. The movable member is configured to be movable between an initial position and an operating position, 7. A cartridge according to claim 1, further comprising an elastic member that biases the movable member toward the initial position.

8. 8. A cartridge according to claim 1, wherein the engaging portion of the movable member is movable in a circumferential direction of the coupling relative to a main body of the coupling.

9. 8. A cartridge according to claim 1, wherein the engaging portion of the movable member is movable in a radial direction of the coupling relative to a main body of the coupling.

10. The coupling further includes an operating portion, 10. A cartridge according to claim 1, wherein the engaging portion is configured to move in response to movement of the operating portion.

11. 11. A cartridge according to claim 10, wherein the engaging portion moves in response to the operation portion moving in the axial direction of the coupling.

12. the coupling is disposed on a first side of the cartridge in an axial direction of the photosensitive drum, The cartridge according to claim 10 or 11, wherein the engaging portion is configured to move away from the axis of the coupling in response to movement of the operating portion toward a second side of the cartridge opposite the first side.

13. 13. A cartridge according to claim 10, wherein when the operating portion is in an initial position, the operating portion is positioned farther away from the axis of the coupling than the engaging portion.

14. the coupling is disposed on a first side of the cartridge in an axial direction of the photosensitive drum, The cartridge according to claim 10 or 11, wherein the engaging portion is configured to move downstream in a rotational direction of the coupling in response to movement of the operating portion toward a second side of the cartridge opposite to the first side.

15. 15. A cartridge according to claim 10, wherein the operating portion is disposed on an axis of the coupling or in the vicinity of the axis.

16. 16. A cartridge according to claim 1, wherein the movable member has two of the engaging portions, and the two engaging portions are located on opposite sides of the axis of the coupling.

17. 16. A cartridge according to claim 1, wherein the coupling has two of the movable members, the two movable members being located on opposite sides of the axis of the coupling.

18. A cartridge detachably mountable to a main body of an image forming apparatus, the cartridge comprising: a driving force applying member; and a braking force applying member configured to apply a load to rotation of the driving force applying member and movable relative to the driving force applying member, A photosensitive drum; a coupling operatively connected to the photoreceptor drum so as to be capable of transmitting a driving force toward the photoreceptor drum; and The coupling has an engaging portion configured to engage with the braking force applying member, and is configured to receive the driving force from the driving force applying member via the braking force applying member.

19. 19. The cartridge according to claim 18, wherein the engagement portion comprises a recess configured to engage with a tip of the braking force applying member.

20. 20. The cartridge according to claim 19, wherein the recessed portion is open on an upstream side in the rotation direction of the coupling.

21. The coupling is The first wall and a second wall disposed radially inward of the first wall; and a groove formed by the first wall and the second wall; and 21. A cartridge according to claim 19 or 20, wherein the second wall comprises the recess.

22. the coupling is disposed on a first side of the cartridge in an axial direction of the photosensitive drum, the first wall is configured to contact the braking force applying member, 22. The cartridge according to claim 21, wherein the first wall is configured such that the distance from the first wall to the axis of the coupling increases as the distance from the first wall to the axis of the coupling increases in the axial direction of the photosensitive drum from a second side of the cartridge opposite the first side.

23. the coupling is disposed on a first side of the cartridge in an axial direction of the photosensitive drum, the coupling has an inclined portion configured to come into contact with the braking force applying member, At least a portion of the inclined portion is disposed downstream of the recessed portion in the rotational direction of the coupling, 23. A cartridge according to any one of claims 18 to 22, wherein the inclined portion is inclined so as to move away from a second side of the cartridge opposite the first side in the axial direction of the photosensitive drum as it moves downstream in the rotation direction.

24. In the cartridge, A photosensitive drum; a casing including a first end and a second end opposite to the first end in an axial direction of the photosensitive drum, the casing rotatably supporting the photosensitive drum; a coupling operatively connected to the photoreceptor drum for transmitting a driving force toward the photoreceptor drum, the coupling being located near a first end of the casing; and The coupling is The main body and a movable part that is movable between a first position and a second position relative to the main body of the coupling, the movable part being configured to be located closer to the second end of the casing in the axial direction of the photosensitive drum when located at the second position than when located at the first position; a protrusion configured to move in a circumferential direction of the coupling relative to a main body of the coupling in response to movement of the movable portion from the first position to the second position; A cartridge having

25. The cartridge according to claim 24, wherein the coupling has two of the protrusions, the two protrusions being arranged on opposite sides of the axis of the coupling, and the two protrusions being configured to move in response to movement of the movable part.

26. 26. A cartridge according to claim 24 or 25, wherein the movable part is arranged on or in the vicinity of the axis of the coupling.

27. 27. A cartridge according to any one of claims 24 to 26, wherein the projection projects away from the axis of the coupling.

28. 28. A cartridge according to any one of claims 24 to 27, wherein the protrusion is configured to move through an angle of 20° or more around the axis of the coupling.

29. 29. A cartridge according to any one of claims 24 to 28, wherein the projection is configured to move an angle of 180° or less around the axis of the coupling.

30. The coupling includes a visor portion that protrudes in a radial direction of the coupling, 30. A cartridge according to any one of claims 24 to 29, wherein the eaves portion is positioned farther from the second end of the casing than the projection in the axial direction of the coupling.

31. 31. The cartridge according to claim 30, wherein there is a phase in the circumferential direction of the coupling where neither the visor portion nor the protrusion is disposed.

32. The coupling is a first movable member including the movable portion; a second movable member having the protrusion and interlocking with the first movable member; 32. A cartridge according to any one of claims 24 to 31, comprising:

33. 33. A cartridge according to claim 32, wherein at least a portion of the first movable member is disposed within the body of the coupling when the movable portion is in the second position.

34. 34. A cartridge according to claim 32 or 33, wherein the coupling comprises a cam including the first movable member and the second movable member.

35. 35. A cartridge according to any one of claims 24 to 34, wherein the protrusion is configured to receive the driving force from outside the cartridge.

36. 36. A cartridge according to any one of claims 24 to 35, wherein the protrusion is configured to move downstream in the rotational direction of the coupling in response to the movable portion moving from the first position to the second position.

37. In the cartridge, A photosensitive drum; a casing including a first end and a second end opposite to the first end in an axial direction of the photosensitive drum, the casing rotatably supporting the photosensitive drum; a coupling operatively connected to the photoreceptor drum for transmitting a driving force toward the photoreceptor drum, the coupling being located near a first end of the casing; and The coupling is The main body and a movable part that is movable between a first position and a second position relative to a main body of the coupling, the movable part being configured to be closer to the second end of the casing in the axial direction of the coupling when positioned at the second position than when positioned at the first position; a protrusion configured to move relative to a main body of the coupling in a direction away from an axis of the coupling in response to movement of the movable part from the first position to the second position; A cartridge having

38. When the movable portion is in the first position, the movable portion is positioned farther away from the axis of the coupling than the protrusion, 38. A cartridge according to claim 37, wherein when the movable portion is in the first position, the movable portion is located closer to the second end of the casing in the axial direction of the photosensitive drum than the protrusion.

39. 39. A cartridge according to claim 37 or 38, further comprising an elastic member that biases the movable portion towards the first position.

40. 40. A cartridge according to any one of claims 37 to 39, wherein the protrusion is configured to receive the driving force from outside the cartridge.

41. 41. A cartridge according to any one of claims 37 to 40, wherein when the movable part is in the second position, the projection projects outward in the radial direction of the coupling.

42. 42. A cartridge according to any one of claims 37 to 41, wherein the movable portion projects away from the second end of the casing when in the first position.

43. the coupling body has an end surface facing away from the second end of the casing; 43. A cartridge according to any one of claims 37 to 42, wherein when the movable part is in the first position, at least a part of the movable part protrudes from an end face of the main body.

44. the coupling has two of the movable parts and two of the protrusions, The two movable parts are disposed on opposite sides of the axis of the coupling, 44. A cartridge according to any one of claims 37 to 43, wherein the two protrusions are arranged on opposite sides of the axis of the coupling.

45. the coupling has a movable member provided with the movable portion and the protrusion, 45. A cartridge according to any one of claims 37 to 44, wherein the movable member is rotatable relative to the main body of the coupling.

46. A cartridge according to claim 45, wherein when the movable portion is in the first position, the movable portion is positioned farther away from the second casing in the axial direction of the photosensitive drum than the rotation axis of the movable member.

47. 47. A cartridge according to claim 45 or 46, wherein at least a part of the movable portion is located upstream of the protrusion in a rotation direction when the coupling rotates by receiving the driving force.

48. 48. A cartridge according to any one of claims 45 to 47, wherein the body of the coupling has an opening on the axis of the coupling.

49. In the cartridge, A photosensitive drum; a casing including a first end and a second end opposite to the first end in an axial direction of the photosensitive drum, the casing rotatably supporting the photosensitive drum; a coupling operatively connected to the photoreceptor drum so as to be capable of transmitting a driving force toward the photoreceptor drum; and The coupling is The first wall and a second wall provided radially inward of the coupling relative to the first wall; and a groove formed by the first wall and the second wall; a recessed portion provided in the second wall; an inclined portion located near the recessed portion, at least a portion of which is located farther from the axis of the coupling than the recessed portion in the radial direction; Equipped with one side of the recessed portion is open in a circumferential direction of the coupling, and at least a part of the inclined portion is disposed on the other side of the recessed portion in the circumferential direction, The inclined portion is inclined so as to move away from the second end of the casing in the axial direction of the photosensitive drum as it moves away from the recessed portion in the circumferential direction.

50. The inclined portion is a first inclined portion, the second wall has a second inclined portion that forms the recessed portion; 50. The cartridge according to claim 49, wherein the second inclined portion is inclined so as to approach the second end of the casing in the axial direction of the coupling as it moves downstream in the rotational direction of the coupling.

51. 51. A cartridge according to claim 49 or 50, wherein the second inclined portion is inclined so as to move away from the second end of the casing in the axial direction of the coupling as it moves away from the axis of the coupling.

52. 52. A cartridge as described in any one of claims 49 to 51, characterized in that the distance between the first wall and the axis of the coupling in the radial direction becomes shorter as it approaches the second end of the casing in the axial direction of the photosensitive drum.

53. 53. A cartridge according to any one of claims 49 to 52, wherein the groove has an arcuate shape.

54. 54. A cartridge according to any one of claims 49 to 53, wherein at least a portion of the recessed portion and at least a portion of the inclined portion are disposed within the groove portion.

55. A cartridge as described in any one of claims 49 to 54, wherein the upstream side of the recessed portion is open in the rotational direction of the coupling that rotates in response to the driving force, and the inclined portion is inclined so as to move away from the second end of the casing as it moves downstream in the rotational direction.

56. the coupling includes a clutch; The clutch is a rotating member including the first wall, the second wall, the groove portion, and the inclined portion; a transmission member configured to transmit a driving force from the rotating member to the photosensitive drum; Equipped with 56. A cartridge according to any one of claims 49 to 55, wherein the rotating member is rotatable relative to the transmission member.

57. 57. A cartridge according to claim 56, wherein the rotating member is movable relative to the transmission member in the axial direction of the coupling.

58. 58. A cartridge according to any one of claims 49 to 57, wherein the recessed portion is configured to receive the driving force from outside the cartridge.

59. In the cartridge, A photosensitive drum; a casing including a first end and a second end opposite to the first end in an axial direction of the photosensitive drum, the casing rotatably supporting the photosensitive drum; a coupling operatively connected to the photoreceptor drum for transmitting a driving force toward the photoreceptor drum, the coupling being located near a first end of the casing; and The coupling is a base portion extending in the axial direction of the coupling; a first projection having a cylindrical shape that projects outward in the radial direction of the coupling from the base portion; a second projection having a cylindrical shape that projects outward in the radial direction of the coupling from the base portion; Equipped with In a radial direction of the coupling, a distance from an axis of the coupling to an outermost edge of the first projection is shorter than a distance from the axis of the coupling to an outermost edge of the second projection, When viewed along the axial direction of the coupling, a direction in which the first projection extends from the base portion is different from a direction in which the second projection extends from the base portion, A cartridge in which the first protrusion is positioned farther from the second end of the casing than the second protrusion in the axial direction of the coupling.

60. The coupling is a visor portion that protrudes from the base portion to the outside in the radial direction of the coupling, the eave portion is disposed farther away from the second end of the casing than the second projection in the axial direction of the coupling, The eaves portion is provided upstream of the first protrusion in the rotation direction of the coupling, 60. The cartridge of claim 59 adjacent the first protrusion.

61. An image forming apparatus a main body of the image forming apparatus; A cartridge according to any one of claims 1 to 60; An image forming apparatus having the same.

62. A drum unit used in a cartridge detachably attached to a main body of an image forming apparatus, the drum unit including a driving force applying member and a braking force applying member, A photosensitive drum; a coupling operatively connected to the photoreceptor drum so as to be capable of transmitting a driving force toward the photoreceptor drum; and The coupling is The main body and a movable member movable relative to a main body of the coupling; and the movable member has an engaging portion, and is configured to move relative to the main body of the coupling to cause the engaging portion to enter between the driving force applying member and the braking force applying member, The movable member is configured to receive the driving force from the driving force applying member and to receive a braking force from the braking force applying member for applying a load to the rotation of the coupling.

63. 63. The drum unit according to claim 62, wherein the movable member is configured to move the braking force applying member relative to the driving force receiving member, thereby causing the engagement portion to enter between the driving force applying member and the braking force applying member.

64. 64. The drum unit according to claim 62 or 63, wherein the movable member is configured to move the braking force applying member downstream in the rotation direction of the driving force receiving member relative to the driving force receiving member.

65. 65. The drum unit according to any one of claims 62 to 64, wherein the engagement portion includes an action portion configured to come into contact with the braking force application member to move the braking force application member relative to the driving force receiving member.

66. 66. The drum unit according to any one of claims 62 to 65, wherein the engagement portion includes a driving force receiving portion configured to receive the driving force from the driving force applying member.

67. 67. The drum unit according to any one of claims 62 to 66, wherein the engagement portion comprises a braking force receiving portion configured to receive the braking force from the braking force applying member.

68. The movable member is configured to be movable between an initial position and an operating position, 68. A drum unit according to any one of claims 62 to 67, further comprising an elastic member that biases the movable member toward the initial position.

69. 69. The drum unit according to any one of claims 62 to 68, wherein the engaging portion of the movable member is movable in the circumferential direction of the coupling relative to the main body of the coupling.

70. 70. The drum unit according to any one of claims 62 to 69, wherein the engaging portion of the movable member is movable in a radial direction of the coupling relative to a main body of the coupling.

71. The coupling further includes an operating portion, 71. The drum unit according to claim 62, wherein the engaging portion is configured to move in response to movement of the operating portion.

72. 72. The drum unit according to claim 71, wherein the engaging portion is configured to move in response to the operation portion moving in the axial direction of the coupling.

73. the coupling is disposed on a first side of the drum unit in an axial direction of the photosensitive drum, A drum unit as described in claim 71 or 72, wherein the engagement portion is configured to move away from the axis of the coupling in response to movement of the operating portion toward a second side of the drum unit opposite the first side.

74. 74. The drum unit according to any one of claims 71 to 73, wherein when the first movable part is in an initial position, the operating part is positioned farther away from the axis of the coupling than the engaging part.

75. the coupling is disposed on a first side of the cartridge in an axial direction of the photosensitive drum, 73. The drum unit according to claim 71 or 72, wherein the engagement portion is configured to move downstream in the rotation direction of the coupling in response to movement of the operating portion toward a second side of the cartridge opposite to the first side.

76. 76. The drum unit according to any one of claims 71, 72 and 75, wherein the operating portion is disposed on an axis of the coupling or in the vicinity of the axis.

77. 77. The drum unit according to any one of claims 62 to 76, wherein the movable member has two of the engaging portions, and the two engaging portions are located on opposite sides of the axis of the coupling.

78. 78. The drum unit according to any one of claims 62 to 77, wherein the coupling has two movable members, the two movable members being positioned on opposite sides of the axis of the coupling.

79. A drum unit used in a cartridge detachable from a main body of an image forming apparatus, the drum unit comprising: a driving force applying member; and a braking force applying member configured to apply a load to rotation of the driving force applying member and movable relative to the driving force applying member, A photosensitive drum; a coupling operatively connected to the photoreceptor drum so as to be capable of transmitting a driving force toward the photoreceptor drum; and The coupling has an engagement portion configured to engage with the braking force applying member, and is configured to receive the driving force from the driving force applying member via the braking force applying member.

80. 80. The drum unit according to claim 79, wherein the engaging portion comprises a recess configured to engage with a tip of the braking force applying member.

81. 81. The drum unit according to claim 80, wherein the recessed portion is open on an upstream side in the rotation direction of the coupling.

82. The coupling is The first wall and a second wall disposed radially inward of the first wall; and a groove formed by the first wall and the second wall; and 82. A drum unit according to claim 80 or 81, wherein the second wall has the recessed portion.

83. the coupling is disposed on a first side of the drum unit in an axial direction of the photosensitive drum, the first wall is configured to contact the braking force applying member, 83. A cartridge according to claim 82, wherein the distance from the first wall to the axis of the coupling increases with increasing distance in the axial direction from a second side of the drum unit opposite the first side.

84. the coupling is disposed on a first side of the drum unit in an axial direction of the photosensitive drum, the coupling has an inclined portion configured to come into contact with the braking force applying member, At least a portion of the inclined portion is disposed downstream of the recessed portion in the rotational direction of the coupling, 84. A drum unit according to any one of claims 79 to 83, wherein the inclined portion is inclined so as to move away from a second side of the drum unit opposite to the first side as it moves downstream in the rotation direction.

85. In a drum unit used in a cartridge, a photoreceptor drum having a first end and a second end opposite the first end; a coupling operatively connected to the photoreceptor drum to transmit a driving force toward the photoreceptor drum, the coupling being located near a first end of the photoreceptor drum; and The coupling is The main body and a movable part that is movable between a first position and a second position relative to the main body of the coupling, the movable part being configured to be located closer to a second end of the photosensitive drum in the axial direction of the photosensitive drum when located at the second position than when located at the first position; a protrusion configured to move in a circumferential direction of the coupling relative to a main body of the coupling in response to movement of the movable portion from the first position to the second position; A drum unit having

86. A drum unit as described in claim 85, wherein the coupling has two of the protrusions, the two protrusions being arranged on opposite sides of the axis of the coupling, and the two protrusions being configured to move in response to movement of the movable part.

87. 87. A drum unit according to claim 85 or 86, wherein the movable portion is disposed on or in the vicinity of the axis of the coupling.

88. 88. A drum unit according to any one of claims 85 to 87, wherein the projection projects away from the axis of the coupling.

89. 89. The drum unit according to any one of claims 85 to 88, wherein the protrusion is configured to move by 20 degrees or more around the axis of the coupling.

90. 90. The drum unit according to any one of claims 85 to 89, wherein the projection is configured to move about an axis of the coupling through an angle of 180 degrees or less.

91. The coupling includes a visor portion that protrudes in a radial direction of the coupling, 91. The drum unit according to claim 85, wherein the eaves portion is positioned farther from the second end of the photosensitive drum than the protrusion is in the axial direction of the coupling.

92. 92. The drum unit according to claim 91, wherein there is a phase in the circumferential direction of the coupling where neither the visor portion nor the protrusion is disposed.

93. The coupling is a first movable member including the movable portion; a second movable member having the protrusion and interlocking with the first movable member; 93. A drum unit according to any one of claims 85 to 92, comprising:

94. 94. The drum unit according to claim 93, wherein when the movable portion is located at the second position, at least a portion of the first movable member is disposed inside the main body of the coupling.

95. 95. A drum unit according to claim 93 or 94, wherein the coupling comprises a cam including the first movable member and the second movable member.

96. 96. The drum unit according to any one of claims 85 to 95, wherein the protrusion is configured to receive the driving force from outside the drum unit.

97. A drum unit as described in any one of claims 85 to 96, wherein the protrusion is configured to move downstream in the rotation direction of the coupling in response to the movable part moving from the first position to the second position.

98. In a drum unit used in a cartridge, a photoreceptor drum having a first end and a second end opposite the first end; a coupling operatively connected to the photoreceptor drum to transmit a driving force toward the photoreceptor drum, the coupling being located near a first end of the photoreceptor drum; and The coupling is The main body and a movable part that is movable between a first position and a second position relative to a main body of the coupling, the movable part being configured to be closer to a second end of the photosensitive drum in the axial direction of the coupling when positioned at the second position than when positioned at the first position; a protrusion configured to move relative to a main body of the coupling in a direction away from an axis of the coupling in response to movement of the movable part from the first position to the second position; A drum unit having

99. When the movable portion is in the first position, the movable portion is positioned farther away from the axis of the coupling than the protrusion, A drum unit as described in claim 98, wherein when the movable portion is in the first position, the movable portion is located closer to the second end of the photosensitive drum in the axial direction of the photosensitive drum than the protrusion.

100. 100. A drum unit according to claim 98 or 99, further comprising an elastic member that biases the movable portion toward the first position.

101. 101. The drum unit according to any one of claims 98 to 100, wherein the protrusion is configured to receive the driving force from outside the drum unit.

102. 102. A drum unit according to any one of claims 98 to 101, wherein when the movable part is in the second position, the protrusion protrudes outward in a radial direction of the coupling.

103. 103. The drum unit according to any one of claims 98 to 102, wherein the movable portion protrudes in a direction away from the second end of the photosensitive drum when in the first position.

104. the coupling body has an end surface facing the opposite side to the second end of the photosensitive drum; 104. A drum unit according to any one of claims 98 to 103, wherein at least a part of the movable part protrudes from an end surface of the main body when the movable part is in the first position.

105. the coupling has two of the movable parts and two of the protrusions, The two movable parts are disposed on opposite sides of the axis of the coupling, 105. A drum unit according to any one of claims 98 to 104, wherein the two protrusions are arranged on opposite sides of the axis of the coupling.

106. the coupling has a movable member provided with the movable portion and the protrusion, 106. A drum unit according to any one of claims 98 to 105, wherein the movable member is rotatable relative to the main body of the coupling.

107. A drum unit as described in claim 106, wherein when the movable part is in the first position, the movable part is positioned farther away from the second casing in the axial direction of the photosensitive drum than the rotation axis of the movable member.

108. 108. The drum unit according to claim 106 or 107, wherein at least a part of the movable portion is located upstream of the protrusion in a rotation direction when the coupling receives the driving force and rotates.

109. 109. A drum unit according to any one of claims 98 to 108, wherein the main body of the coupling has an opening on the axis of the coupling.

110. In a drum unit used in a cartridge, a photoreceptor drum having a first end and a second end opposite the first end; a coupling operatively connected to the photoreceptor drum so as to be capable of transmitting a driving force toward the photoreceptor drum; and The coupling is The first wall and a second wall provided radially inward of the coupling relative to the first wall; and a groove formed by the first wall and the second wall; a recessed portion provided in the second wall; an inclined portion located near the recessed portion, at least a portion of which is located farther from the axis of the coupling than the recessed portion in the radial direction; Equipped with one side of the recessed portion is open in a circumferential direction of the coupling, and at least a part of the inclined portion is disposed on the other side of the recessed portion in the circumferential direction, The inclined portion is inclined so as to move away from the second end of the photosensitive drum in the axial direction of the photosensitive drum as it moves away from the recessed portion in the circumferential direction.

111. The inclined portion is a first inclined portion, the second wall has a second inclined portion that forms the recessed portion; 111. A drum unit according to claim 110, wherein the second inclined portion is inclined so as to approach the second end of the photosensitive drum in the axial direction of the coupling as it moves downstream in the rotational direction of the coupling.

112. 112. A drum unit according to claim 110 or 111, wherein the second inclined portion is inclined so as to move away from the second end of the photosensitive drum in the axial direction of the coupling as it moves away from the axis of the coupling.

113. 113. A drum unit according to any one of claims 110 to 112, characterized in that the distance between the first wall and the axis of the coupling in the radial direction becomes shorter as it approaches the second end of the photosensitive drum.

114. 114. The drum unit according to any one of claims 110 to 113, wherein the groove has an arcuate shape.

115. 115. The drum unit according to claim 110, wherein at least a part of the inclined portion and at least a part of the recessed portion are disposed inside the groove portion.

116. A drum unit described in any one of claims 110 to 115, wherein the upstream side of the recessed portion is open in the rotational direction of the coupling that rotates in response to the driving force, and the inclined portion is inclined so as to move away from the second end of the casing as it moves downstream in the rotational direction.

117. the coupling includes a clutch; The clutch is a rotating member including the first wall, the second wall, the groove portion, and the inclined portion; a transmission member configured to transmit a driving force from the rotating member to the photosensitive drum; Equipped with 117. A drum unit according to any one of claims 110 to 116, wherein the rotating member is rotatable relative to the transmission member.

118. 118. A drum unit according to any one of claims 110 to 117, wherein the rotating member is movable relative to the transmission member in the axial direction of the coupling.

119. 119. The drum unit according to any one of claims 110 to 118, wherein the recessed portion is configured to receive the driving force from outside the drum unit.

120. In a drum unit used in a cartridge, a photoreceptor drum having a first end and a second end opposite the first end; a coupling operatively connected to the photoreceptor drum to transmit a driving force toward the photoreceptor drum, the coupling being located near a first end of the photoreceptor drum; and The coupling is a base portion extending in the axial direction of the coupling; a first projection having a cylindrical shape that projects outward in the radial direction of the coupling from the base portion; a second projection having a cylindrical shape that projects outward in the radial direction of the coupling from the base portion; Equipped with In a radial direction of the coupling, a distance from an axis of the coupling to an outermost edge of the first projection is shorter than a distance from the axis of the coupling to an outermost edge of the second projection, When viewed along the axial direction of the coupling, a direction in which the first projection extends from the base portion is different from a direction in which the second projection extends from the base portion, The drum unit is configured such that the first protrusion is disposed farther from the second end of the photosensitive drum than the second protrusion in the axial direction of the coupling.

121. The coupling is a visor portion that protrudes from the base portion to the outside in the radial direction of the coupling, the eaves portion is disposed farther away from the second end of the photosensitive drum than the second protrusion is in the axial direction of the coupling, The eaves portion is provided upstream of the first protrusion in the rotation direction of the coupling, 121. The drum unit of claim 120 adjacent to the first protrusion.

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