Cartridge protection assembly

Abstract

To provide a technology capable of regulating longitudinal movements of a photoconductor drum during transportation or storage of a process cartridge.SOLUTION: In a cartridge protection assembly 100X, a frame body of a cartridge 100 is configured to regulate a movable range to a frame body of a photoconductor drum 104 in a longitudinal direction of the photoconductor drum 104 to a first range in the case that the cover member 501 is removed from the frame body. The cover member 501 has: a held part held by the frame body when worn on the frame body; and a regulation part 501K configured to regulate the movable range to the frame body of the photoconductor drum 104 to a second range narrower than the first range by contacting a longitudinal end surface of the photoconductor drum 104 when the photoconductor drum 104 moves in the longitudinal direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a protection assembly for a cartridge provided in an image forming apparatus such as a copying machine or a printer that employs an electrophotographic method.

Background Art

[0002] As a device configuration of an image forming apparatus, a device configuration employing a so-called process cartridge method is known. In the drum unit of the process cartridge, a photosensitive drum is rotatably supported, and a part of the surface of the photosensitive drum is exposed from an opening of the cartridge frame. Therefore, there is a possibility that the user may touch the surface of the photosensitive drum. When the user touches the surface of the photosensitive drum, fingerprints or the like may adhere to the surface of the photosensitive drum, and there is a risk of image defects. In order to prevent the user from touching the surface of the photosensitive drum, the surface of the photosensitive drum may be covered with a cover member (drum cover member). The drum cover member has a role of preventing dust and user contact.

[0003] Also, when performing maintenance such as jam processing, the cartridge once installed in the main body may be removed and temporarily stored outside the main body. In that case, there is a possibility that the user may reattach the drum cover member. Also in this case, similar to the above, by covering the surface of the photosensitive drum with the drum cover member, dust prevention and user contact can be prevented.

[0004] Before the cartridge reaches the user, the cartridge is packaged and transported by packaging materials and cushioning materials formed of cardboard or the like. The photosensitive drum and charging member, which are process means, are rotatably supported via bearing members and support members coupled to the cartridge frame. The photosensitive drum and charging member have play in the longitudinal gap with related components to prevent interference between components so that rotation during printing can be performed stably. The play is set to an amount considering the thermal shrinkage of environmental variations so as to cope with dimensional variations of components and use in various environments. Therefore, during transportation, the charging member may move and rub on the photosensitive drum by the amount of the play. In some cases, triboelectrification may occur on the photosensitive drum, and image defects such as horizontal streaks may occur. Also, when the play is large, there is a possibility that the components may be damaged by the impact caused by the movement of the components.

[0005] In view of such possibilities, Patent Document 1 proposes a locking member for restricting the longitudinal movement of a brush unit configured to move in the longitudinal direction of a photoreceptor while contacting the photoreceptor in a cartridge. The locking member is detachably configured on a brush support member of a cartridge removed from the main body of the image forming apparatus, and is configured not to move the brush unit in the longitudinal direction by restricting the movement of the brush support member when mounted.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] An object of the present invention is to provide a technique capable of restricting the longitudinal movement of a photosensitive drum during transportation and storage of a process cartridge.

Means for Solving the Problems

[0008] To achieve the above object, the cartridge protection assembly in the present invention is a cartridge including a photosensitive drum and a frame that rotatably supports the photosensitive drum and covers the photosensitive drum such that a part of the circumferential surface of the photosensitive drum is exposed, and a cover member detachably attached to the frame so as to cover at least a part of the part of the photosensitive drum, and is a cartridge protection assembly having wherein the frame is configured to restrict a movable range of the photosensitive drum with respect to the frame in the longitudinal direction of the photosensitive drum to a first range when the cover is detached from the frame, and the cover member has a held portion held by the frame, and a restricting portion configured to restrict a movable range of the photosensitive drum with respect to the frame to a second range narrower than the first range by contacting a longitudinal end surface of the photosensitive drum when the photosensitive drum moves in the longitudinal direction, and is characterized by having the above.

Advantages of the Invention

[0009] According to the present invention, the longitudinal movement of the photosensitive drum can be restricted during transportation or storage of the process cartridge.

Brief Description of the Drawings

[0010]

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Mode for Carrying Out the Invention

[0011] In the following examples, the embodiments in the present disclosure will be exemplarily described. However, the configurations disclosed in the following examples, for example, the functions, materials, shapes, and relative arrangements of components, are examples of forms related to the scope of the claims, and are not intended to limit the scope of the claims to the configurations disclosed in these examples. Also, the problems solved by the configurations disclosed in the following examples or the actions or effects obtained from the disclosed configurations are not intended to limit the scope of the claims.

[0012] (Example 1) Hereinafter, an electrophotographic image forming apparatus according to Example 1 of the present disclosure will be described with reference to the drawings. Here, an electrophotographic image forming apparatus (hereinafter, the image forming apparatus) is an apparatus that forms an image on a recording material using the electrophotographic image forming method. Examples of the image forming apparatus include a copying machine, a facsimile apparatus, a printer (laser beam printer, LED printer, etc.), and a multifunction machine (multifunction printer) of these. Examples of the recording material include sheet-like recording media such as recording paper and plastic sheets. Also, the image forming apparatus according to the present embodiment is an image forming apparatus that employs a so-called cartridge system. A cartridge is a unit that can be attached to and detached from the image forming apparatus, and is a unit having a photoreceptor and process means (for example, a charging member, a developing member, a cleaning member, etc.) that act on the photoreceptor. In the following examples, a laser beam printer to which four process cartridges (cartridges) can be attached and detached is exemplified as the image forming apparatus. Note that the number of process cartridges attached to the image forming apparatus is not limited to this, and may be appropriately set as needed.

[0013] (Schematic Configuration of the Image Forming Apparatus) FIG. 2 is a cross-sectional view schematically showing the configuration of the image forming apparatus M. Further, FIG. 3 is a cross-sectional view schematically showing the configuration of the process cartridge 100. This image forming apparatus M is a four-color full-color laser printer using 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 the process cartridge 100 is detachably mounted on the image forming apparatus main body (apparatus main body) 170 to form a color image on the recording medium S.

[0014] Here, with respect to the image forming apparatus M, the side provided with the front door 11 is defined as the front (front surface), and the surface opposite to the front is defined as the back (rear surface). Also, when the image forming apparatus M is viewed 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. Further, when the image forming apparatus M is viewed from the front, the upper side is defined as the upper surface, and the lower side is defined as the lower surface. FIG. 2 is a cross-sectional view of the image forming apparatus M viewed from the non-drive side, with the front side of the image forming apparatus M being the front side of the paper, the non-drive side of the image forming apparatus M being the front side of the paper, and the drive side of the image forming apparatus M being the back side of the paper.

[0015] Also, the drive side of the process cartridge 100 is the side on which a drum coupling member (photosensitive member coupling member) described later is arranged with respect to the axial direction of the photosensitive drum (axial direction of the rotation axis of the photosensitive drum). Also, the drive side of the process cartridge 100 is the side on which a developing coupling member described later is arranged with respect to the axial direction of the developing roller (axial direction of the rotation axis of the developing roller). Note that the axial direction of the photosensitive drum and the axial direction of the developing roller are parallel, and the longitudinal direction of the process cartridge 100 (photosensitive drum, developing roller) is also parallel to these.

[0016] The first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) are arranged in a substantially horizontal direction in the image forming apparatus main body 170. Each of the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) has the same It has an electrophotographic process mechanism, and the colors of the developers (hereinafter referred to as toners) are different from each other. The first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) are rotationally driven by a driving output section (details will be described later) of the apparatus main body 170. Further, a bias voltage (charging bias, developing bias, etc.) is supplied from the apparatus main body 170 to each of the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) (not shown).

[0017] As shown in FIG. 3, each of the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) of the present embodiment has a drum unit 108 including a photosensitive drum 104 and a charging unit as a process unit acting on the photosensitive drum 104. Here, the drum unit 108 may have not only a charging unit but also a cleaning unit as a process unit. Further, each of the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) has a developing unit 109 including a developing unit that develops an electrostatic latent image on the photosensitive drum 104.

[0018] In each of the first to fourth process cartridges 100, the drum unit 108 and the developing unit 109 are coupled to each other, and the developing unit 109 is movably supported with respect to the drum unit 108. A more specific configuration of the process cartridge 100 will be described later.

[0019] The first process cartridge 100Y contains yellow (Y) toner in the developing frame 125 and forms a yellow toner image on the surface of the photosensitive drum 104. The second process cartridge 100M contains magenta (M) toner in the developing frame 125 and forms a magenta toner image on the surface of the photosensitive drum 104. The third process cartridge 100C contains cyan (C) toner in the developing frame 125 and forms a cyan toner image on the surface of the photosensitive drum 104. The fourth process cartridge 100K contains black (K) toner in the developing frame 125 and forms a black toner image on the surface of the photosensitive drum 104.

[0020] Above the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K), a laser scanner unit 14 is provided as exposure means. This laser scanner unit 14 outputs laser light U corresponding to the image information. Then, the laser light U passes through the exposure window 110 of the process cartridge 100 and scans and exposes the surface of the photosensitive drum 104.

[0021] Below the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K), an intermediate transfer unit 12 is provided as a transfer member. This intermediate transfer unit 12 has a driving roller 12e, a turn roller 12c, and a tension roller 12b, and a flexible transfer belt 12a is stretched over them. The photosensitive drums 104 of the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) have a lower region on their circumferential surfaces in contact with a region of the outer peripheral surface of the annular transfer belt 12a that faces upward. The contact portion is the primary transfer portion. Inside the transfer belt 12a, a primary transfer roller 12d is provided facing the photosensitive drum 104. The secondary transfer roller 6 is brought into contact with the turn roller 12c via the transfer belt 12a. The contact portion between the transfer belt 12a and the secondary transfer roller 6 is the secondary transfer portion.

[0022] Below the intermediate transfer unit 12, a paper feed unit 4 is provided. This paper feed unit 4 has a paper feed tray 4a for loading and accommodating the recording medium S, and a paper feed roller 4b. The conveyance path of the recording medium S is configured to go substantially upward from the paper feed unit 4 on the back side of the apparatus body 170 within the apparatus body 170.

[0023] On the downstream side of the secondary transfer unit in the conveyance path of the recording medium S (the upper left within the apparatus body 170 in FIG. 2), a fixing device 7 and a paper discharge device 8 are provided. The upper surface of the apparatus body 170 serves as a paper discharge tray 13. The recording medium S is heated and pressed by the fixing means provided in the fixing device 7 to fix the toner image, and is discharged to the paper discharge tray 13.

[0024] (Image forming operation) The operation for forming a full-color image is as follows. The photosensitive drums 104 of the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) are rotationally driven at a predetermined speed (in the direction of arrow A in FIG. 3). The transfer belt 12a is also rotationally driven in the forward direction (in the direction of arrow C in FIG. 2) at a speed corresponding to the speed of the photosensitive drum 104 in accordance with the rotation of the photosensitive drum 104.

[0025] The laser scanner unit 14 is also driven. In synchronization with the driving of the laser scanner unit 14, in each process cartridge 100, the charging roller 105 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 according to the image signals of each color. Thereby, an electrostatic latent image corresponding to the image signal of the corresponding color is formed on the surface of each photosensitive drum 104. The formed electrostatic latent image is developed by a developing roller 106 that is rotationally driven at a predetermined speed. By such an electrophotographic image forming process operation, 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. Then, the toner image is primarily transferred onto the transfer belt 12a.

[0026] Similarly, on the photosensitive drum 104 of the second process cartridge 100M, a magenta toner image corresponding to the magenta component of the full-color image is formed. Then, the toner image is superimposed on the yellow toner image already transferred onto the transfer belt 12a and is primarily transferred. Similarly, on the photosensitive drum 104 of the third process cartridge 100C, a cyan toner image corresponding to the cyan component of the full-color image is formed. Then, the toner image is superimposed on the yellow and magenta toner images already transferred onto the transfer belt 12a and is primarily transferred. Similarly, on the photosensitive drum 104 of the fourth process cartridge 100K, a black toner image corresponding to the black component of the full-color image is formed. Then, the toner image is superimposed on the yellow, magenta, and cyan toner images already transferred onto the transfer belt 12a and is primarily transferred. In this way, an unfixed toner image of four-color full-color, namely yellow, magenta, cyan, and black, is formed on the transfer belt 12a.

[0027] On the other hand, the recording media S are separated and fed one by one at a predetermined control timing. The recording media S are introduced into the secondary transfer section, which is the contact section between the secondary transfer roller 6 and the transfer belt 12a, at a predetermined control timing. As a result, in the process of transporting the recording media S to the secondary transfer section, the four-color superimposed toner image on the transfer belt 12a is sequentially batch-transferred onto the surface of the recording media S. Then, the recording media S are transported to the fixing device 7 to fix the toner image on the recording media S, and then further discharged to the paper discharge tray 13.

[0028] (Cleanerless System) The image forming apparatus M according to this embodiment employs a so-called cleanerless system that recovers the transfer residual developer remaining on the image carrier such as the photosensitive drum 104 and the transfer belt 12a by the developing means simultaneously with the development after the transfer by the transfer means. That is, after the transfer of the toner image (developer image) to the transfer belt 12a, the developer remaining on the photosensitive drum 104 is moved and recovered via the developing roller 106 to the frame body that houses the developer. By adopting such a system, it is possible to configure not to provide a cleaning member for removing the transfer residual toner remaining on the photosensitive drum 104 without being transferred. The transfer residual toner remaining on the photosensitive drum 104 after the transfer process is charged negatively in the same manner as the photosensitive drum 104 by the discharge in the gap portion in front of the contact portion (charging nip) between the charging roller 105 and the photosensitive drum 104. The transfer residual toner charged negatively does not adhere to the charging roller 105 and passes through due to the potential difference between the surface potential of the photosensitive drum and the potential of the charging roller at the charging nip. The transfer residual toner that has passed through the charging nip reaches the irradiation position of the laser beam U. Since the transfer residual toner is not so much as to shield the laser beam U, it does not affect the process of forming the electrostatic latent image on the photosensitive drum 104. The toner that has passed through the laser irradiation position is, at the contact portion (developing nip) between the developing roller 106 and the photosensitive drum 104, the toner on the non-exposed portion (the surface of the photosensitive drum not irradiated with the laser) is recovered by the electrostatic force to the developing roller 106 and is recovered into the developing chamber etc. of the developing unit 109. The toner on the exposed portion (the surface of the photosensitive drum irradiated with the laser) remains on the photosensitive drum 104 without being electrostatically recovered. However, a part of the toner may be recovered by the physical force due to the peripheral speed difference between the developing roller 106 and the photosensitive drum 104. Thus, the toner remaining on the photosensitive drum 104 without being transferred to the transfer belt 12a is generally recovered into the developing chamber etc. of the developing unit 109. The recovered toner is mixed with the toner remaining in the developing chamber etc. and used.

[0029] The transfer residual toner remaining on the photosensitive drum 104 after the transfer process is charged negatively in the same manner as the photosensitive drum 104 by the discharge in the gap portion in front of the contact portion (charging nip) between the charging roller 105 and the photosensitive drum 104. The transfer residual toner charged negatively does not adhere to the charging roller 105 and passes through due to the potential difference between the surface potential of the photosensitive drum and the potential of the charging roller at the charging nip. The transfer residual toner that has passed through the charging nip reaches the irradiation position of the laser beam U. Since the transfer residual toner is not so much as to shield the laser beam U, it does not affect the process of forming the electrostatic latent image on the photosensitive drum 104. The toner that has passed through the laser irradiation position is, at the contact portion (developing nip) between the developing roller 106 and the photosensitive drum 104, the toner on the non-exposed portion (the surface of the photosensitive drum not irradiated with the laser) is recovered by the electrostatic force to the developing roller 106 and is recovered into the developing chamber etc. of the developing unit 109. The toner on the exposed portion (the surface of the photosensitive drum irradiated with the laser) remains on the photosensitive drum 104 without being electrostatically recovered. However, a part of the toner may be recovered by the physical force due to the peripheral speed difference between the developing roller 106 and the photosensitive drum 104. Thus, the toner remaining on the photosensitive drum 104 without being transferred to the transfer belt 12a is generally recovered into the developing chamber etc. of the developing unit 109. The recovered toner is mixed with the toner remaining in the developing chamber etc. and used.

[0030] (Schematic of the process cartridge attachment / detachment configuration) Using FIGS. 4 to 6, the cartridge tray 171 (hereinafter referred to as the tray) that supports the process cartridge will be described in more detail. FIG. 4 is a cross-sectional view of the image forming apparatus M in which the tray 171 is located inside the apparatus main body 170 with the front door 11 open. FIG. 5 is a cross-sectional view of the image forming apparatus M in which the tray 171 is located outside the apparatus main body 170 with the front door 11 open and the process cartridge 100 is housed inside the tray 171. FIG. 6 is a cross-sectional view of the image forming apparatus M in which the tray 171 is located outside the apparatus main body 170 with the front door 11 open and the process cartridge 100 is removed from the tray 171.

[0031] As shown in FIGS. 4 and 5, the tray 171 is movable relative to the apparatus main body 170 in the direction of arrow X1 (push-in direction) and arrow X2 (pull-out direction), which are substantially horizontal directions (the front-rear direction of the apparatus). That is, the tray 171 is provided so as to be pullable and pushable relative to the apparatus main body 170, and in a state where the apparatus main body 170 is installed on a horizontal plane, the tray 171 is configured to be movable in a substantially horizontal direction. Here, the state where the tray 171 is located outside the apparatus main body 170 (the state of FIG. 5) is referred to as the outer position. Also, the state where the tray 171 is located inside the apparatus main body 170 with the front door 11 open and the photosensitive drum 104 and the transfer belt 12a are separated (the state of FIG. 4) is referred to as the inner position.

[0032] Further, the tray 171 has a mounting portion 171a at the outer position where the process cartridge 100 can be removably mounted as shown in FIG. 6. And the process cartridge 100 moves inside the apparatus main body 170 as the tray 171 moves while being disposed in the mounting portion 171a. At this time, it moves with a gap between the transfer belt 12a and the photosensitive drum 104. For this reason, the tray 171 can move the process cartridge 100 inside the apparatus main body 170 without the photosensitive drum 104 contacting the transfer belt 12a.

[0033] In this embodiment, the intermediate transfer unit 12 is lifted in the direction of arrow Z1 (upward) by a link mechanism (not shown) when the front door 11 is closed, and moves to the position during image formation (the position where the photosensitive drum 104 and the intermediate transfer belt 12a are in contact). Also, when the front door 11 is opened, the intermediate transfer unit 12 descends in the direction of arrow Z2 (downward), and the photosensitive drum 104 and the intermediate transfer belt 12a are separated. Therefore, without the photosensitive drum 104 contacting the transfer belt 12a, the tray 171 can move the process cartridge 100 inside the apparatus main body 170. As described above, the tray 171 can move a plurality of process cartridges 100 together to a position where image formation is possible inside the apparatus main body 170, and can also pull them out together to the outside of the apparatus main body 170.

[0034] As described above, the tray 171 can move a plurality of process cartridges 100 together to a position where image formation is possible inside the apparatus main body 170, and can also pull them out together to the outside of the apparatus main body 170.

[0035] (Overall Configuration of Process Cartridge) The configuration of the process cartridge will be described with reference to FIGS. 7 to 10. FIG. 7 is an exploded perspective view of the drum unit 108 showing the constituent members of the drum unit 108 disassembled. FIG. 8 is an exploded perspective view of the developing unit 109. FIG. 9 is an assembled perspective view of the process cartridge 100 showing the constituent members of the process cartridge 100 when viewed from the driving side, which is one end side in the axial direction of the photosensitive drum 104. FIG. 10 is a perspective view of the process cartridge 100 viewed from the driving side.

[0036] In this embodiment, the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) have the same electrophotographic process mechanism, and there may be differences in the color of the toner contained, the filling amount of the toner, and the control by the apparatus main body 170. However, although these four process cartridges may have differences in dimensions and the like, their basic structures and functions are the same. Therefore, hereinafter, one process cartridge 100 will be described as a representative.

[0037] The process cartridge 100 includes a photosensitive drum 104 (104Y, 104M, 104C, 104K) and process means that act on the photosensitive drum 104. Here, as the process means, there are a charging roller 105 as a charging means (charging member) for charging the photosensitive drum 104, a developing roller 106 as a developing means (developing member) for developing the latent image formed on the photosensitive drum 104, and the like. And the process cartridge 100 is divided into a drum unit 108 (108Y, 108M, 108C, 108K) and a developing unit 109 (109Y, 109M, 109C, 109K).

[0038] In the following description, the longitudinal direction Y of the drum unit 108 and the developing unit 109 is a direction substantially parallel to the rotation axis a of the photosensitive drum 104 (FIG. 9).

[0039] (Configuration of Drum Unit) As shown in FIGS. 7 and 9, the drum unit 108 is composed of a photosensitive drum 104, a charging roller 105, and a drum frame 115. The charging roller 105 is rotatably supported by a drive-side charging roller bearing 120a and a non-drive-side charging roller bearing 120b and is biased against the photosensitive drum 104 by compression springs 121a , 121b. The photosensitive drum 104 is rotatably supported by a drive-side cartridge cover member 116 and a non-drive-side cartridge cover member 117 provided at both longitudinal ends of the process cartridge 100. The drive-side cartridge cover member 116 as the second end support portion supports one end (the second end) of both longitudinal ends of the photosensitive drum 104. The non-drive-side cartridge cover member 117 as the first end support portion supports the other end (the first end) of both longitudinal ends of the photosensitive drum 104.

[0040] As shown in FIG. 9, a coupling member 143 for transmitting a driving force to the photosensitive drum 104 is provided on one end side in the longitudinal direction of the photosensitive drum 104. The coupling member 143 engages with a main body side drum driving coupling 180 (FIGS. 5 and 6) as a drum driving output portion of the apparatus main body 170, and the driving force of a driving motor (not shown) of the apparatus main body 170 is transmitted to the photosensitive drum 104 and rotated in the direction of arrow A (FIG. 3). Further, the photosensitive drum 104 has a drum flange 142 on the other end side in the longitudinal direction. The charging roller 105 is supported by the drum frame body 115 so as to be in contact with the photosensitive drum 104 and capable of being driven to rotate. The drum flange 142 is provided on the other end side in the longitudinal direction. The charging roller 105 is supported by the drum frame body 115 so as to be in contact with the photosensitive drum 104 and capable of being driven to rotate.

[0041] (Configuration of Developing Unit) As shown in FIGS. 3 and 8, the developing unit 109 includes a developing roller 106, a toner conveying roller 107, a developing blade 130, a developing frame body 125, and the like. The developing frame body 125 is composed of a lower frame body 125a and a lid member 125b. The lower frame body 125a and the lid member 125b are joined by ultrasonic welding or the like. The developing frame body 125 has a toner storage portion 129 for storing toner to be supplied to the developing roller 106. Further, the developing frame body 125 rotatably supports the developing roller 106 and the toner conveying roller 107 via a driving side bearing 126 and a non-driving side bearing 127, and holds a developing blade 130 for regulating the layer thickness of the toner on the circumferential surface of the developing roller 106.

[0042] The developing blade 130 is formed by welding an elastic member 130b, which is a sheet-like metal having a thickness of about 0.1 mm, to a support member 130a, which is a metal material having an L-shaped cross section. The developing blade 130 is attached to the developing frame body 125 with fixing screws 130c at two positions on one end side and the other end side in the longitudinal direction. The developing roller 106 is composed of a core metal 106c made of a metal material and a rubber portion 106d.

[0043] The developing roller 106 is rotatably supported by a driving-side bearing 126 and a non-driving-side bearing 127 attached to both longitudinal ends of the developing frame 125. The non-driving-side bearing 127 is fastened to the lower frame 125a of the developing frame 125 by screws 307 (see FIG. 13). Further, a developing drive input gear 132 for transmitting a driving force to the developing unit 109 is provided at one longitudinal end side (driving side) of the developing unit 109. The developing drive input gear 132 is provided with a developing input coupling portion 132a that receives drive from the main body side developing drive coupling 185 (FIGS. 5 and 6) of the apparatus main body 170, and the driving force of a drive motor (not shown) of the apparatus main body 170 is input to the developing unit 109.

[0044] The driving force input to the developing unit 109 is transmitted to the developing roller gear 131, enabling the developing roller 106 to rotate in the direction of arrow D in FIG. 3. A developing cover member 128 that supports and covers the developing drive input gear 132 is provided at one longitudinal end side (driving side) of the developing unit 109. The developing cover member 128 is fastened to the lower frame 125a of the developing frame 125 by screws 308 (see FIG. 11) together with the driving-side bearing 126. Incidentally, the outer diameter of the developing roller 106 is set to be smaller than the outer diameter of the photosensitive drum 104. The outer diameter of the photosensitive drum 104 in this embodiment 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. By setting the outer diameter in this way, an efficient arrangement becomes possible.

[0045] (Assembly of the Drum Unit and the Developing Unit) The assembly of the drum unit 108 and the developing unit 109 will be described with reference to FIG. 9. The drum unit 108 and the developing unit 109 are coupled by a driving-side cartridge cover member 116 and a non-driving-side cartridge cover member 117 provided at both longitudinal ends of the process cartridge 100.

[0046] On the drive - side cartridge cover member 116 provided at one longitudinal end of the process cartridge 100, a developing unit support hole 116f for swingably (movable) supporting the developing unit 109 is provided. Similarly, on the non - drive - side cartridge cover member 117 provided at the other longitudinal end of the process cartridge 100, a developing unit support hole 117f for swingably supporting the developing unit 109 is provided. Further, on the drive - side cartridge cover member 116 and the non - drive - side cartridge cover member 117, drum support holes 116b and 117b for rotatably supporting the photosensitive drum 104 are respectively provided. The drum support holes 116b and 117b for rotatably supporting the photosensitive drum 104 are respectively provided.

[0047] Here, at one longitudinal end of the process cartridge 100, the outer diameter portion of the cylindrical portion 128b of the developing cover member 128 of the developing unit 109 is fitted into the developing unit support hole 116f of the drive - side cartridge cover member 116. At the other longitudinal end of the process cartridge 100, the outer diameter portion of the cylindrical portion (not shown) of the non - drive - side bearing 127 of the developing unit 109 is fitted into the developing unit support hole 117f of the non - drive - side cartridge cover member 117. Further, both longitudinal ends of the photosensitive drum 104 are respectively fitted into the drum support hole 116b of the drive - side cartridge cover member 116 and the drum support hole 117b of the non - drive - side cartridge cover member 117. Then, the drive - side cartridge cover member 116 and the non - drive - side cartridge cover member 117 are fixed to the drum unit 108 by screws, adhesives, etc. (not shown).

[0048] That is, the developing unit 109 is swingably supported by the driving-side cartridge cover member 116 and the non-driving-side cartridge cover member 117 by the developing unit support holes 116f and 117f. On the other hand, the drum unit 108 is fixed to the driving-side cartridge cover member 116 and the non-driving-side cartridge cover member 117. That is, the developing unit 109 can rotate with respect to the drum unit 108 (photosensitive drum 104) by rotating with respect to the driving-side cartridge cover member 116 and the non-driving-side cartridge cover member 117. In this way, in the process cartridge 100, the relative position between the developing unit 109 and the drum unit 108 is configured to be variable by the swing of the developing unit 109 with respect to the driving-side cartridge cover member 116 and the non-driving-side cartridge cover member 117. Thereby, at the time of image formation, the developing roller 106 can be positioned at a position where it acts on the photosensitive drum 104.

[0049] FIG. 10 shows a state in which the drum unit 108 and the developing unit 109 are assembled by the above steps and integrated as the process cartridge 100. The axis connecting the center of the developing unit support hole 116f of the driving-side cartridge cover member 116 and the center of the developing unit support hole 117f of the non-driving-side cartridge cover member 117 is referred to as a swing axis (rotation axis, rotation center) K. Here, the cylindrical portion 128b of the developing cover member 128 on one end side in the longitudinal direction of the process cartridge 100 is coaxial with the developing input coupling section 132a. That is, the developing unit 109 is configured to receive a driving force from the apparatus main body 170 at the swing axis K. Also, the developing unit 109 is rotatably supported with respect to the process cartridge 100 about the swing axis K.

[0050] (Description of the separation contact mechanism) Using FIGS. 11, 12, and 13, a configuration in which the photosensitive drum 104 of the drum unit 108 and the developing roller 106 of the developing unit 109 in this embodiment are separated and brought into contact will be described.

[0051] The process cartridge 100 has a separation contact mechanism on the drive side and the non-drive side. FIG. 11 shows an assembled perspective view showing the disassembled configuration of the drive side of the process cartridge 100 including the separation contact mechanism on the drive side. FIG. 12 is a side view of the process cartridge 100 after the assembly of the regulating member 151R described later, viewed from the drive side. FIG. 13 shows an assembled perspective view showing the disassembled configuration of the non-drive side of the process cartridge 100 including the separation contact mechanism on the non-drive side. Note that the separation contact mechanism has substantially the same function on the drive side and the non-drive side. An R is added to the numerals in the reference numerals of the respective members constituting the separation contact mechanism on the drive side. An L is added to the same numerals as those on the drive side for the reference numerals of the respective members constituting the separation contact mechanism on the non-drive side.

[0052] As shown in FIGS. 11 and 12, the separation contact mechanism on the drive side includes a regulating member 151R, a moving member 152R, and a tension spring 153. The developing cover member 128 is provided with a support portion 128c for supporting the regulating member 151R and a support portion 128k for supporting the moving member 152 R. The regulating member 151R has a supported portion 151Ra that is a hole, and the support portion 128c fits into the supported portion 151Ra. The regulating member 151R is rotatable relative to the developing cover member 128 about the support portion 128c by the rotation of the supported portion 151Ra with respect to the support portion 128c. The moving member 152R has a supported portion 152Ra that is an oblong hole, and the support portion 128k fits into the supported portion 152Ra. The moving member 152R is rotatable relative to the developing cover member 128 about the support portion 128k and movable in the longitudinal direction of the oblong hole by the rotation of the supported portion 152Ra with respect to the support portion 128k or the relative movement of the supported portion 152Ra with respect to the support portion 128k in the longitudinal direction of the oblong hole.

[0053] The separation and contact mechanism includes a tension spring 153 that biases the regulating member 151R to rotate about the support portion 128c in the direction of arrow B1 in FIG. 12 and biases the moving member 152R in the direction of arrow Z1. The tension spring 153 is a coil spring and an elastic member. The tension spring 153 engages with and is assembled to a spring hanging portion 151Rg provided on the regulating member 151R and a spring hanging portion 152Rs provided on the moving member 152R. The tension spring 153 applies a force in the direction of arrow F2 in FIG. 12 to the spring hanging portion 151Rg of the regulating member 151R, thereby applying a biasing force for rotating the regulating member 151R in the direction of arrow B1. Further, the tension spring 153 applies a force in the direction of arrow F1 to the spring hanging portion 152Rs of the moving member 152R, thereby applying a biasing force for moving the moving member 152R in the direction of arrow Z1.

[0054] The separation and contact mechanism on the non-driving side will be described with reference to FIG. 13. As shown in FIG. 13, the separation and contact mechanism on the non-driving side includes a regulating member 151L, a moving member 152L, and a tension spring 153. The non-driving side bearing 127 is provided with a support portion 127b for supporting the regulating member 151L and a support portion 127e for supporting the moving member 152 L. The regulating member 151L has a supported portion 151La which is a hole, and the support portion 127b fits into the supported portion 151La. The regulating member 151L is rotatable relative to the non-driving side bearing 127 about the support portion 127b as the supported portion 151La rotates relative to the support portion 127b. The moving member 152L has a supported portion 152La which is an oblong hole, and the support portion 127e fits into the supported portion 152La. The moving member 152L is rotatable relative to the non-driving side bearing 127 about the support portion 127e and movable in the direction of the oblong hole by the supported portion 152La rotating relative to the support portion 127e or moving relative to the support portion 127e in the longitudinal direction of the oblong hole.

[0055] The tension spring 153 is engaged with and assembled to a spring mounting portion 151Lg provided on the regulating member 151L and a spring mounting portion 152Ls provided on the moving member 152L. Note that the function of the tension spring 153 on the non-driving side is the same as that of the tension spring 153 on the driving side, so it is omitted.

[0056] (Explanation of the separated state and the contacting state of the process cartridge) With reference to FIGS. 12, 14A to 14C, and 15, the separated state and the contacting state of the process cartridge 100 will be described. In FIGS. 14A to 14C, only the photosensitive drum 104, the drum frame 115, the driving-side cartridge cover member 116, the developing cover member 128, the regulating member 151R, and the moving member 152R are shown. FIG. 14A shows a state where the developing unit 109 is separated from the photosensitive drum 104. FIG. 14B shows a state when the moving member 152R moves in the Z2 direction. FIG. 14C shows a state where the developing unit 109 is in contact with the photosensitive drum 104. FIG. 15 is a side view of the driving side excluding the driving-side cartridge cover member 116, the developing cover member 128, the moving member 152R, and the tension spring 153. Note that since the separation and contact mechanism on the driving side and the non-driving side has the same configuration, the driving side will be used for the explanation.

[0057] First, the state where the developing unit 109 is located at the separated position will be described. In this state At this time, the contact portion 151Rc of the regulating member 151R comes into contact with the portion 116c to be contacted of the driving-side cartridge cover member 116. Further, due to the action of a developing pressure spring (not shown) provided on the non-driving side, the developing unit 109 is pressed toward the photosensitive drum 104. At this time, the contact portion 151Rc of the regulating member 151R is in a state of being pressed toward the portion 116c to be contacted of the driving-side cartridge cover member 116. Therefore, the driving-side cartridge cover member 116 positions (clamps) the developing cover member 128 via the regulating member 151R so that the developing roller 106 is maintained in a state of being separated from the photosensitive drum 104 against the biasing force of the developing pressure spring (not shown). That is, the drum unit 108 positions and holds the developing unit 109 via the regulating member 151R. At this time, the photosensitive drum 104 and the developing roller 106 are in a state separated by a gap P1. This state is defined as a separated position (first position) (the state shown in FIGS. 12 and 14A).

[0058] From this state, the portion 152Re to be pushed in of the moving member 152R is pushed in in the Z2 direction. As a result, the protruding portion 152Rh of the moving member 152R moves to a protruding position protruding from the developing frame 125. Then, when the second force receiving portion 152Rn is pressed in the direction of arrow X2, the moving member 152R rotates in the direction of arrow BB about the support portion 128k. The regulating member pressing surface 152Rr of the moving member 152R presses the portion 151Re to be regulated of the moving member 151R, thereby rotating the regulating member 151R in the direction of arrow B2 in FIG. 12. When the regulating member 151R rotates in the direction of arrow B2, contact portion 151Rc separates from the portion 116c to be contacted of the driving-side cartridge cover member 116 and the developing unit 109 becomes rotatable in the direction of arrow V2 about the swing axis K from the separated position. That is, the developing unit 109 rotates in the V2 direction from the separated position, and the developing roller 106 comes into contact with the photosensitive drum 104. Here, the state where the developing roller 106 and the photosensitive drum 104 are in contact is defined as a contact position (second position) (the state shown in FIG. 14C).

[0059] Next, the operation of moving from the contact position to the separated position will be described. When the first force receiving portion 152Rk of the moving member 152R is pressed in the direction of arrow X1 in the state where the developing unit 109 is at the contact position, the moving member 152R rotates in the direction of arrow BA (see FIG. 14C), and the bearing pressing surface 152Rq comes into contact with the pressed surface 126c of the drive side bearing 126 of (see FIG. 15). As a result, the developing unit 109 rotates in the direction of arrow V1 about the swing axis K and moves to the separated position (the state shown in FIG. 15).

[0060] Note that in the separation contact mechanism of the present embodiment, the moving member 152R cannot move in the direction of arrow X2 unless the moving member 152R is pushed in the direction of arrow Z2. This is because, as shown in FIG. 14A, the surface 152Rg of the moving member 152R facing the rib 128g of the developing cover member 128 interferes. Therefore, the moving member 152R cannot move the regulating member 151R to the contact position unless it is pushed in the direction of arrow Z2 until the surface 152Rg no longer faces the rib 128g.

[0061] (Description of the Drum Cover Member and the Cartridge Protection Assembly) With reference to FIGS. 1, 16, 17, 18, 19, 20, 21, 22, 23, and 24, the drum cover member 501 and the cartridge protection assembly 100X according to this embodiment will be described. The drum cover member 501 is used by being attached to the process cartridge 100 removed from the apparatus main body 170. When the process cartridge 100 is removed from the apparatus main body 170, a part of the process means included in the process cartridge 100, particularly, a part of the circumferential surface of the photosensitive drum 104 is exposed to the outside. In order to prevent a user from touching this exposed portion or foreign matter such as dust from adhering thereto, the drum cover member 501 is attached. The drum cover member 501 is attached to the process cartridge 100 so as to cover the above-exposed portion. Needless to say, the process cartridge 100 cannot be mounted on the apparatus main body 170 while the drum cover member 501 is attached. When the process cartridge 100 is mounted on the apparatus main body 170 the drum cover member 501 is removed from the process cartridge 100. Thus, in this embodiment, the process cartridge 100 in a state (aspect) in which it is removed from the apparatus main body 170 and the drum cover member 501 is attached, that is, a structure in which the process cartridge 100 and the drum cover member 501 are integrated is referred to as the cartridge protection assembly 100X.

[0062] Figs. 16 to 19 show the structure of the mounting portion between the process cartridge 100 and the drum cover member 501, showing the state in which the cartridge protection assembly 100X is disassembled (the state in which the process cartridge 100 and the drum cover member 501 are separated). Fig. 16 is an exploded perspective view of the cartridge protection assembly 100X as viewed from the drive side and the process cartridge 100 side, that is, an exploded perspective view showing the state in which the process cartridge 100 and the drum cover member 501 are separated. Fig. 17 is an exploded perspective view of the cartridge protection assembly 100X as viewed from the drive side and the drum cover member 501 side, that is, an exploded perspective view showing the state in which the process cartridge 100 and the drum cover member 501 are separated. Fig. 18 is an exploded perspective view of the cartridge protection assembly 100X as viewed from the non-drive side and the process cartridge 100 side, that is, an exploded perspective view showing the state in which the process cartridge 100 and the drum cover member 501 are separated. Fig. 19 is an exploded perspective view of the cartridge protection assembly 100X as viewed from the non-drive side and the drum cover member 501 side, that is, an exploded perspective view showing the state in which the process cartridge 100 and the drum cover member 501 are separated.

[0063] Figs. 20, 21, and 22 show the state in which the drum cover member 501 is completely mounted on the process cartridge 100. Fig. 20 is a perspective view of the cartridge protection assembly 100X as viewed from the drive side. Fig. 21 is a side view of the drive side of the cartridge protection assembly 100X. Fig. 22 is a front view of the cartridge protection assembly 100X as viewed from the drum unit 108 side and orthogonal to the longitudinal direction (Y direction in the figure) of the process cartridge 100.

[0064] FIG. 1(A) is a cross-sectional view taken along the cutting line A-A that intersects the axis center of the photosensitive drum 104 in FIG. 21 in the Z direction in the drawing (a cross-sectional view seen from the developing unit 109 side). FIG. 1(B) is a cross-sectional view of the process cartridge 100 in a state where the drum cover member 501 is attached at the B-B cross-section shifted in the X1 direction in the drawing from the A-A cross-section of FIG. 21 (FIG. 1(A)). FIG. 1(A) shows cross-sectional views of the drive side (Gear Side) and the non-drive side (Non Gear Side) at the A-A cross-section, with the central part omitted. FIG. 1(B) shows a cross-sectional view of the non-drive side (Non Gear Side) at the B-B cross-section. That is, in FIG. 1, the arrangement relationship of the process cartridge 100 and the drum cover member 501 on the non-drive side is shown by the A-A cross-section and the B-B cross-section, and the arrangement relationship on the drive side is shown by the A-A cross-section.

[0065] FIG. 23 is a C-C cross-section of the process cartridge 100 taken along the cutting line C-C seen from the non-drive side in FIG. 22, with the drum cover member 501 attached to the process cartridge 100. FIG. 24 is a cross-sectional view for explaining the configuration of the engaging portion (held portion) for locking (holding) the drum cover member 501 to the process cartridge 100. FIG. 24(A) is a cross-sectional view of the process cartridge 100 in a state where the drum cover member 501 is attached at the C-C cross-section shifted in the X1 direction in the drawing from the A-A cross-section of FIG. 21 (FIG. 1(A)) and shifted in the X2 direction in the drawing from the B-B cross-section of FIG. 21 (FIG. 1(B)). FIG. 24(B) is a cross-sectional view of the process cartridge 100 in a state where the drum cover member 501 is attached at the D-D cross-section shifted in the X2 direction in the drawing from the A-A cross-section of FIG. 21 (FIG. 1(A)).

[0066] As shown in FIGS. 16 to 19, the drum cover member 501 covers the region where a part of the photosensitive drum 104 is exposed in the process cartridge It is attached to the process cartridge 100 along the longitudinal direction of 100. The drum cover member 501 has engaging portions 501E1 and 501E2 that respectively engage with both end portions of the frame body in the longitudinal direction of the process cartridge 100, and has a cover portion 501F that covers the exposed portion of the photosensitive drum 104 between the engaging portions 501E1 and 501E2. The drive-side engaging portion 501E2 (the second engaging portion) is configured to engage with one end portion (the second end portion) in the longitudinal direction, which is the drive-side end portion of the process cartridge 100, and drive-side locking claws 501q and 501r are provided. The non-drive-side engaging portion 501E1 (the first engaging portion) is configured to engage with the other end portion (the first end portion) in the longitudinal direction, which is the non-drive-side end portion of the process cartridge 100, and non-drive-side locking claws 501s and 501t are provided. The cover portion 501F is provided so as to extend in the longitudinal direction of the process cartridge 100 (photosensitive drum 104) between the drive-side engaging portion 501E2 and the non-drive-side engaging portion 501E1.

[0067] For the drum cover member 501, the drive-side locking claws 501q and 501r of the drive-side engaging portion 501E2 engage with the locking groove 116r of the drive-side cartridge cover member 116 (the second end portion support portion). The drive-side cartridge cover member 116 is a portion that supports the drive-side end portion (the second end portion) of the photosensitive drum 104 in the frame body of the process cartridge 100. The locking groove 116r (the second recess) has a shape that is recessed in the Y1 direction (the second direction) along the longitudinal direction. The drive-side engaging portion 501E2 has an extending portion 501h2 (the second extending portion) that extends in a direction intersecting the longitudinal direction so as to have a portion overlapping the locking groove 116r when viewed in the longitudinal direction. The drive-side locking claws 501q and 501r (the second protrusions) are provided so as to protrude in the Y1 direction along the longitudinal direction from the extending portion 501h2. In this embodiment, the extending portion 501h2 is configured to extend in a direction orthogonal to the longitudinal direction, but as long as a desired engagement state can be formed, it may be configured to extend in a direction having an angle with respect to the orthogonal direction.

[0068] The drum cover member 501 has the non-driving side locking claws 501s and 501t of the non-driving side engaging portion 501E1 engaged with the locking grooves 117s and 117t of the non-driving side cartridge cover member 117 (the first end support portion), respectively. The non-driving side cartridge cover member 117 is a portion that supports the non-driving side end portion (the first end portion) of the photosensitive drum 104 in the frame of the process cartridge 100. The locking grooves 117s and 117t (the first recesses) have a shape recessed in the Y2 direction (the first direction) along the longitudinal direction. The non-driving side engaging portion 501E1 has an extending portion 501h1 (the first extending portion) extending in a direction intersecting the longitudinal direction so as to have a portion overlapping the locking grooves 117s and 117t when viewed in the longitudinal direction. The non-driving side locking claws 501s and 501t (the first protrusions) are provided so as to protrude in the Y2 direction along the longitudinal direction from the extending portion 501h1. In this embodiment, the extending portion 501h1 is configured to extend in a direction orthogonal to the longitudinal direction, but may be configured to extend in a direction having an angle with respect to the orthogonal direction as long as a desired engagement state can be formed. Details of the locking grooves 117s and 117t will be described later.

[0069] With the above engagement configuration, the drum cover member 501 is detachably assembled to the process cartridge 100 (the state in FIG. 20). When assembling the drum cover member 501 to the process cartridge 100, the photosensitive drum 104 in the process cartridge 100 is adjusted so that the regulating rib 501K described later is inserted into a predetermined gap between the frame of the process cartridge 100 and the photosensitive drum 104. For example, after the photosensitive drum 104 is offset to one side in the longitudinal direction with respect to the frame of the process cartridge 100, the drum cover member 501 is assembled to the process cartridge 100.

[0070] As shown in FIG. 1, the photosensitive drum 104 is a unit in which a drum flange 142 and a coupling member 143 are press-fitted and caulked into the openings at both ends of the drum cylinder 104a, and the three parts are integrated. The drum unit 108 rotatably supports both ends of the photosensitive drum 104. That is, on the non-driving side, the shaft portion of the drum flange 142 is non-driving It is rotatably supported by the drum support hole 117b of the side cartridge cover member 117. On the drive side, the shaft portion of the coupling member 143 is rotatably supported by the drum support hole 116b of the drive-side cartridge cover member 116.

[0071] First, the non-drive side configuration of the cartridge protection assembly 100X will be described in detail. As shown on the non-drive side of the A-A cross-section (FIG. 1(A)), there is a gap s1 in the longitudinal direction (Y direction in the figure) between the first surface (first restricted portion) 142a of the drum flange 142 and the first opposing surface (first restricting portion) 117a of the non-drive side cartridge cover member 117. That is, the non-drive side cartridge cover member 117 has a first opposing surface 117a as a first restricting surface that faces the first surface 142a of the drum flange 142 in the Y2 direction (first direction) along the longitudinal direction. Considering the dimensional variations of the related parts and the use in various environments (from high temperature to low temperature), a gap s1 is provided so that the parts can operate (rotate) smoothly without interfering with each other within the process cartridge 100. That is, to ensure the stable rotation of the photosensitive drum 104 during the image forming operation, the photosensitive drum 104 is configured to be allowed to move within a predetermined range in the longitudinal direction with respect to the frame of the process cartridge 100. In this embodiment, the length of the gap s1 in the longitudinal direction is set to 1.2 mm as a predetermined range, which is the movable range of the photosensitive drum 104 allowed when the drum cover member 501 is detached from the frame of the process cartridge 100. In other words, when the drum cover member 501 is detached from the frame of the process cartridge 100, the movable range of the photosensitive drum 104 with respect to the frame is restricted to the above-mentioned predetermined range as the first range.

[0072] Also, as shown in the B-B cross-section (FIG. 1(B)), the drum cover member 501 has a locking claw 501t that engages with the locking groove 117t of the non-driving side cartridge cover member 117. To assemble the drum cover member 501 toward the process cartridge 100 (in the Z1 direction in the figure), the locking claw 501t is retracted in the direction of arrow N in the figure, locking groove and is made to straddle the lower side 117u and engage with the locking groove 117t. Also, to remove the drum cover member 501 after locking in the direction away from the process cartridge 100 (Z2 direction in the figure), it cannot be removed unless a force is applied to bend the locking claw 501t in the N direction. The drum cover member 501 is configured such that at least the locking claw 501t and the component (such as the extending portion 501h1) that supports the locking claw 501t can be elastically deformed to enable the above displacement of the locking claw 501t.

[0073] Also, as shown on the driving side of the A-A cross-section (FIG. 1(A)), the drum cover member 501 has a locking claw 501q that engages with the locking groove 116r of the driving side cartridge cover member 116. To assemble the drum cover member 501 toward the process cartridge 100 (in the Z1 direction in the figure), the locking claw 501q is retracted in the direction of arrow G in the figure, locking groove and is made to straddle the lower side 116u and engage with the locking groove 116r. Also, to remove the drum cover member 501 after locking in the direction away from the process cartridge 100 (Z2 direction in the figure), it cannot be removed unless a force is applied to bend the locking claw 501q in the G direction. The drum cover member 501 is configured such that at least the locking claw 501q and the component (such as the extending portion 501h2) that supports the locking claw 501q can be elastically deformed to enable the above displacement of the locking claw 501q.

[0074] As described above, the drum cover member 501 after locking is configured to be selectively removable from the process cartridge 100, either from the driving side or the non-driving side.

[0075] Further, as shown in the B-B cross section, the drum cover member 501 has a fifth regulating portion 501c (third protruding portion) facing the fifth regulated portion 117c of the non-driving side cartridge cover member 117. The fifth regulating portion 501c is a protruding portion that protrudes from the cover portion 501F in a direction intersecting the longitudinal direction on the inner side in the Y2 direction with respect to the non-driving side engaging portion 50 1E1. The fifth regulating portion 501c protrudes so as to have a portion overlapping the fifth regulated portion 117c when viewed in the longitudinal direction. After the drum cover member 501 is locked, the fifth regulated portion 117c and the fifth regulating portion 501c are in a state of being in contact (butting) in the longitudinal direction (Y1 direction) (gap T1 = 0). In the present embodiment, the fifth regulating portion 501c is configured to protrude in a direction orthogonal to the longitudinal direction, but as long as a desired contact state can be formed with respect to the fifth regulated portion 117c, it may be configured to extend in a direction having an angle with respect to the orthogonal direction.

[0076] As shown on the non-driving side of the A-A cross section, the drum cover member 501 has a regulating rib 501K (first protruding portion). The regulating rib 501K is a protruding portion that protrudes from the cover portion 501F in a direction intersecting the longitudinal direction on the inner side in the Y2 direction with respect to the non-driving side engaging portion 501E1 and the fifth regulating portion 501c of the drum cover member 501. The regulating rib 501K protrudes so as to have a portion overlapping the second regulated portion 142b of the drum flange 142 which is the first end portion of the photosensitive drum 104 when viewed in the longitudinal direction. The regulating rib 501K is provided so as to face the second regulated portion 142b with a gap in the longitudinal direction. The regulating rib 501K is a regulating portion configured to regulate the movable range of the photosensitive drum 104 with respect to the frame of the process cartridge 100 to a predetermined range by contacting the longitudinal end surface of the photosensitive drum 104 when the photosensitive drum 104 moves in the longitudinal direction. In the present embodiment, the regulating rib 501K is configured to protrude in a direction orthogonal to the longitudinal direction, but as long as the movement of the photosensitive drum 104 in the longitudinal direction can be regulated to a desired range, it may be configured to extend in a direction having an angle with respect to the orthogonal direction.

[0077] FIG. 23 is a cross-sectional view taken along the cutting line C-C on the non-driving side in FIG. 22 of the process cartridge 100 as described above, in a state where the drum cover member 501 is attached. As shown in FIG. 23, the regulating rib 501K has a second regulating portion 501b facing the second regulated portion 142b of the drum flange 142. When viewed in the longitudinal direction of the photosensitive drum 104, the second regulated portion 142b and the second regulating portion 501b overlap. And as shown in FIG. 1(A), in the longitudinal direction (Y direction in the figure) of the photosensitive drum 104, there is a gap u1 between the second regulated portion 142b and the second regulating portion 501b. The gap u1 is set to be smaller (narrower) than the gap s1 (u1 < s1).

[0078] Next, the configuration on the driving side of the cartridge protection assembly 100X will be described in detail. As shown on the driving side of the A-A cross-section of FIG. 1, the third surface (third regulated portion) 143a of the coupling member 143 and the third opposing surface (third regulating portion) 116a of the driving-side cartridge cover member 116 are in contact with each other in the longitudinal direction (Y direction in the figure) (gap T2 = 0).

[0079] Here, the configurations of the charging roller 105 and the photosensitive drum 104 will be described. As shown in FIG. 1, the drum frame 115 supports the non-driving-side charging roller bearing 120b and the driving-side charging roller bearing 120a so as to be movable in the substantially Z direction in the figure. non-driving side The charging roller bearing 120b and the driving-side charging roller bearing 120a rotatably support both end mandrel portions 105b, 105a of the charging roller 105. Between the drum frame 115, the non-driving-side charging roller bearing 120b, and the driving-side charging roller bearing 120a, pressure springs 121b, 121a are respectively provided, and the charging roller 105 is biased toward the photosensitive drum 104 with a predetermined pressure.

[0080] As described above, there is a gap s1 between the photosensitive drum 104 and the non-driving side cartridge cover member 117 and the driving side cartridge cover member 116 disposed on both sides thereof. Therefore, in a state where the drum cover member 501 is not attached, during the transportation of the process cartridge 100 or during the user's handling, the photosensitive drum 104 may move in the longitudinal direction (Y direction in the figure) by the amount of the gap s1 with respect to the frame of the process cartridge 100. There is also a possibility of repeating reciprocating movement in the longitudinal direction (Y direction in the figure).

[0081] As a result, rubbing may occur at the contact portion between the charging roller 105 on the photosensitive drum 104, and depending on the rubbing state, a charging memory may occur, which may appear as horizontal streaks in the image during printing. When the cover member 501 is not attached to the process cartridge 100 drum the state is the state shown in FIG. 10.

[0082] As the most characteristic configuration of the present embodiment, the regulating rib 501K provided on the drum cover member 501 is configured to suppress the relative movement of the photosensitive drum 104 in the longitudinal direction with respect to the frame of the process cartridge 100. As shown in FIG. 1, when the drum cover member 501 is attached, when the photosensitive drum 104 moves in the longitudinal direction (Y1 direction in the figure) of the photosensitive drum 104, the second regulated portion 142b of the drum flange 142 contacts the second regulating portion 501b of the regulating rib 501K of the drum cover member 501. A gap u1 is provided in the longitudinal direction between the second regulated portion 142b and the second regulating portion 501b. Therefore, the photosensitive drum 104 may move in the longitudinal direction (Y1 direction in the figure) only by the amount of the gap u1. Further, the photosensitive drum 104 may repeat reciprocating movement with a movement amount of the gap u1 in the longitudinal direction (Y direction in the figure). In the present embodiment, the gap u1 is set to 0.4 mm.

[0083] That is, the size (interval) of the gap u1 that allows relative movement in the longitudinal direction between the photosensitive drum 104 and the drum cover member 501 is set to be smaller (shorter) than the gap s1 that allows relative movement in the longitudinal direction between the photosensitive drum 104 and the drum unit 108 when the drum cover member 501 is not attached (u1 < s1). That is, the regulation rib 501K as a regulating part restricts the movable range of the photosensitive drum 104 with respect to the frame of the process cartridge 100 to the second range u1 that is narrower than the first range s1. As a result, it becomes possible to reduce the amount of movement in the longitudinal direction within the drum unit 108 (process cartridge 100 frame) of the photosensitive drum 104. Therefore, it becomes possible to suppress the rubbing distance of the contact portion with the charging roller 105 on the photosensitive drum 104, and it is possible to suppress the generation of charge memory due to longitudinal rubbing of the contact portion between the photosensitive drum 104 and the charging roller 105. As a result, it is possible to provide a user with a good printed image.

[0084] Further, the regulation rib 501K is integrally provided on the drum cover member 501. Therefore, when the user attaches the process cartridge 100 to the apparatus main body 170, the regulation rib 501K is also released simultaneously with the operation of removing the drum cover member 501 from the process cartridge 100. Thus, for example, compared to the case where the regulation rib is separate from the drum cover member and the release of the regulation rib is required separately from the removal of the drum cover member, the process of releasing the regulation becomes simpler, and there is no need to worry about the user forgetting to perform the release operation of the regulation rib 501K.

[0085] That is, according to the present embodiment, for the process cartridge 100 removed from the apparatus main body 170, a restricting configuration for restricting the longitudinal movement of the photosensitive drum 104 is integrally configured with a drum cover member 501 for covering the exposed portion of the photosensitive drum 104. Therefore, only by the step of attaching the drum cover member 501 to the process cartridge 100, the exposed portion of the photosensitive drum 104 can be covered and the photosensitive drum 104 can be in a state where its longitudinal movement is restricted. Further, when the process cartridge 100 is attached to the apparatus main body 170, it is necessary to remove the drum cover member 501, and by only the step of removing the drum cover member 501, both the above-described cover configuration and restricting configuration are simultaneously released. That is, protection of the exposed portion of the photosensitive drum 104 during transportation or storage of the process cartridge 100 and suppression of sliding between the photosensitive drum 104 and members in contact therewith can be realized with a simple and low-cost configuration without causing mistakes to the user. can be achieved.

[0086] Also, a clearance u1 allowing relative displacement in the longitudinal direction between the drum cover member 501 and the photosensitive drum 104 in a state where the drum cover member 501 is attached to the process cartridge is smaller than the clearance s1 (u1 < s1). Therefore, depending on dimensional variations of related components or due to the influence of environmental changes (for example, from high temperature to low temperature) during use, there may occur contact or interference between components that would not occur with the clearance s1. However, since the drum cover member 501 is attached during non-printing (non-image forming operation), such contact or interference between components does not directly affect the image forming accuracy. Therefore, while the drum cover member 501 is attached, the configuration may be such that deformation of the components of the cartridge protection assembly 100X absorbs the above-described interference amount. Since the photosensitive drum 104 is in a non-rotating state, longitudinal contact between related components is allowed.

[0087] As described above, when the drum cover member 501 is attached, the longitudinally movable gap of the photosensitive drum 104 can be reduced. When the drum cover member 501 is removed (during printing), a predetermined gap s1 that does not affect the rotation of the photosensitive drum 104 can be provided. As described above, the gap s1 is the gap in the longitudinal direction (Y direction in the figure) between the first surface (first regulated portion) 142a of the drum flange 142 and the first opposing surface (first regulating portion) 117a of the non-driving side cartridge cover member 117.

[0088] Here, as one of the cleaning means used in the process cartridge, a cleaning member (not shown) can be mentioned. The cleaning member has the role of removing waste toner from the surface of the photosensitive drum. The cleaning member is composed of, for example, a rubber blade that is an elastic member and a support member that supports the rubber blade. The support member is fixed to the cleaning frame so that the rubber blade contacts the photosensitive drum in the counter direction with respect to the rotation direction of the photosensitive drum. The removed waste toner is stored in a waste toner chamber formed by the cleaning frame and the cleaning member.

[0089] The process cartridge 100 according to the present embodiment does not use (is not provided with) a cleaning member, and the load that serves as a brake for the photosensitive drum 104 rotatably supported by the frame is smaller than that of a process cartridge using a cleaning member. As a result, the photosensitive drum 104 is configured to be more easily movable in the longitudinal direction (Y direction in the figure) within the process cartridge 100. Therefore, with the configuration of the cartridge protection assembly 100X described above, it may be important to reduce the amount of movement of the photosensitive drum 104 in the longitudinal direction (Y direction in the figure) within the process cartridge 100.

[0090] (Example 2) With reference to FIG. 25, the cartridge protection assembly 100X2 (process cartridge 100 and drum cover member 511) according to Example 2 of the present invention will be described. In the following description of Example 2, descriptions of configurations common to Example 1 will be omitted. Matters not particularly described herein in Example 2 are the same as those in Example 1. Note that for a part of the configuration of Example 2, a reference numeral obtained by adding an alphabet to "501" in Example 1 is denoted by a reference numeral obtained by adding an alphabet to "511" in Example 2.

[0091] FIG. 25(A) is a cross-sectional view taken along the cutting line intersecting the axial center of the photosensitive drum 104 in FIG. 21 in the Z direction in the drawing. FIG. 25(B) is a cross-sectional view of the process cartridge 100 with the drum cover member 511 attached in a B-B cross-section shifted in the X1 direction in the drawing from the A-A cross-section (FIG. 25(A)) of FIG. 21. FIG. 25(A) shows a cross-sectional view of the drive side (Gear Side) and the non-drive side (Non Gear Side) in the A-A cross-section, with the central part omitted. FIG. 25(B) shows a cross-sectional view of the non-drive side (Non Gear Side) in the B-B cross-section. That is, in FIG. 25, the arrangement relationship between the process cartridge 100 and the drum cover member 511 on the non-drive side is shown in the A-A cross-section and the B-B cross-section, and the arrangement relationship on the drive side is shown in the A-A cross-section.

[0092] The difference between Example 2 and Example 1 lies in the configuration of the regulating rib 511K. The regulating rib 511K is a protruding portion that protrudes from the cover portion 501F in a direction intersecting the longitudinal direction inside the non-driven side engaging portion 501E1 and the fifth regulating portion 511c of the drum cover member 511 in the Y2 direction. The regulating rib 511K protrudes so as to have a portion overlapping with the second regulated portion 142b of the drum flange 142, which is the first end portion of the photosensitive drum 104, when viewed in the longitudinal direction. As the most characteristic configuration of Example 2, the regulating rib 511K provided on the drum cover member 501 is configured to regulate the relative movement of the photosensitive drum 104 in the longitudinal direction with respect to the frame of the process cartridge 100. That is, the regulating rib 501K of Example 1 had a gap u1 between it and the second regulating portion 501b and allowed a certain degree of relative movement. In contrast, the regulating rib 511K of Example 2 is configured to contact (abut against) the second regulated portion 142b of the drum flange 142 of the photosensitive drum 104 without a gap. More specifically, in a state where the drum cover member 511 is attached to the process cartridge 10, the second regulating portion 511b of the regulating rib 511 of the drum cover member 511 K is configured to contact the second regulated portion 142 of the drum flange 142 of the photosensitive drum 104 (T3 = 0). The configuration of Example 2 other than the above is the same as that of Example 1. b

[0093] From the above, according to the cartridge protection assembly 100X2 (drum cover member 511) according to this example, the possibility of the photosensitive drum 104 moving in the longitudinal direction (Y direction in the figure) can be eliminated. Thereby, it is possible to suppress the rubbing distance of the contact portion with the charging roller 105 on the photosensitive drum 104, and it is possible to suppress the generation of a charging memory due to the longitudinal rubbing of the contact portion between the photosensitive drum 104 and the charging roller 105. As a result, it is possible to provide a user with a good printed image.

[0094] (Example 3) With reference to FIG. 26, the cartridge protection assembly 100X3 (process cartridge 100 and drum cover member 521) according to Example 3 of the present invention will be described. In the following description of Example 3, descriptions of configurations common to Examples 1 and 2 will be omitted. Matters not particularly described in Example 3 here are common to Examples 1 and 2. Note that for a part of the configuration of Example 3, the reference numerals obtained by adding an alphabet to "501" in Example 1 are denoted by reference numerals obtained by adding an alphabet to "521" in Example 3.

[0095] FIG. 26(A) is a cross-sectional view taken along the cutting line A-A at the axial center of the photosensitive drum 104 in FIG. 21 that intersects the Z direction in the drawing. FIG. 26(B) is a cross-sectional view of the process cartridge 100 with the drum cover member 521 attached in a B-B cross-section shifted in the X1 direction in the drawing from the A-A cross-section (FIG. 26(A)) of FIG. 21. FIG. 26(A) shows cross-sectional views of the drive side (Gear Side) and the non-drive side (Non Gear Side) in the A-A cross-section, with the central part omitted. FIG. 26(B) shows a cross-sectional view of the non-drive side (Non Gear Side) in the B-B cross-section. That is, in FIG. 26, the arrangement relationship between the process cartridge 100 and the drum cover member 521 on the non-drive side is shown in the A-A cross-section and the B-B cross-section, and the arrangement relationship on the drive side is shown in the A-A cross-section.

[0096] The cartridge protection assembly 100X3 according to Example 3 is provided with a gap s1 that allows relative movement in the longitudinal direction of the photosensitive drum 104 in the process cartridge 100, similar to the cartridge protection assembly 100X according to Example 1. That is, as shown on the non-drive side of FIG. 26(A), considering the dimensional variations of the related parts and also considering use in various environments (from high temperature to low temperature ), a gap s1 is provided to allow the parts in the process cartridge 100 to move (rotate) smoothly without interference between the parts.

[0097] The difference between Example 3 and Example 1 lies in the configuration on the driving side. Specifically, as shown on the driving side of Fig. 26(A), there is a gap s2 in the longitudinal direction (Y direction in the figure) between the third surface (third restricted portion) 143a of the coupling member 143 and the third opposing surface (third restricting portion) 116a of the driving-side cartridge cover member 116. That is, the driving-side cartridge cover member 116 has a third opposing surface 116a as a second restricting surface that opposes the third surface 143a of the coupling member 143 in the Y1 direction (second direction) along the longitudinal direction. Therefore, compared with Example 1, the movable amount (predetermined range) of the photosensitive drum 104 in the longitudinal direction (Y direction in the figure) when the drum cover member 521 is not attached is set larger (s1 + s2). The configuration of Example 3 other than the above is the same as that of Examples 1 and 2.

[0098] Similar to Example 1, in Example 3 as well, as shown on the non-driving side of Fig. 26(A), the gap u1 is set smaller (narrower) than the gap s1 (u1 < s1). Therefore, the total movable amount of the photosensitive drum 104 in the longitudinal direction (Y direction in the figure) when the drum cover member 521 is attached is u1 + s2. On the other hand, the total movable amount of the photosensitive drum 104 in the longitudinal direction (Y direction in the figure) when the drum cover member 521 is not attached is s1 + s2. Therefore, the length (range) of the distance that the photosensitive drum 104 is allowed to relatively move in the longitudinal direction in the process cartridge 100 becomes shorter (narrower) when the drum cover member 521 is attached (u1 + s2 < s1 + s2).

[0099] From the above, in the state where the drum cover member 521 is attached, it becomes possible to suppress the rubbing distance of the contact portion between the charging roller 105 on the photosensitive drum 104. Therefore, it is possible to suppress the generation of a charging memory due to the longitudinal rubbing of the contact portion between the photosensitive drum 104 and the charging roller 105. As a result, it is possible to provide a user with a good printed image.

[0100] (Example 4) With reference to FIG. 27, the cartridge protection assembly 100X4 (process cartridge 100 and drum cover member 531) according to Example 4 of the present invention will be described. In the following description of Example 4, descriptions of configurations common to Examples 1, 2, and 3 will be omitted. Matters not particularly described in Example 4 are common to Examples 1, 2, and 3. Note that, for a part of the configuration of Example 4, codes obtained by adding an alphabet to "531" in Example 4 are used instead of codes obtained by adding an alphabet to "501" in Example 1.

[0101] FIG. 27(A) is a cross-sectional view taken along the cutting line AA that intersects the axis center of the photosensitive drum 104 in FIG. 21 in the Z direction in the drawing. FIG. 27(B) is a cross-sectional view of the process cartridge 100 in a state where the drum cover member 531 is attached at the BB cross-section shifted in the X1 direction in the drawing from the AA cross-section (FIG. 27(A)) of FIG. 21. FIG. 27(A) shows cross-sectional views of the drive side (Gear Side) and the non-drive side (Non Gear Side) at the AA cross-section, with the central part omitted. FIG. 27(B) shows a cross-sectional view of the non-drive side (Non Gear Side) at the BB cross-section. That is, in FIG. 27, the arrangement relationship between the process cartridge 100 and the drum cover member 531 on the non-drive side is shown by the AA cross-section and the BB cross-section, and the arrangement relationship on the drive side is shown by the AA cross-section.

[0102] The difference between Example 4 and Example 1 lies in the configuration of the drive side. As shown on the drive side of FIG. 27(A), a gap s2 is provided in the longitudinal direction (Y direction in the drawing) between the third surface (third restricted portion) 143a of the coupling member 143 and the third opposing surface (third restricting portion) 116a of the drive-side cartridge cover member 116. Considering the dimensional variations of the related parts and the use in various environments (from high temperature to low temperature), a gap is provided so that the parts can operate (rotate) smoothly without interference within the process cartridge 100 in a state where the drum cover member 531 is removed. As such a gap, in Example 4, in addition to the gap s1 described in Example 1, a gap s2 is provided.

[0103] As shown on the drive side of FIG. 27(A) (section A-A), the drum cover member 531 has a regulating rib 531L (second protruding portion). The regulating rib 531L is a protruding portion that protrudes from the cover portion 501F in a direction intersecting the longitudinal direction on the inner side in the Y1 direction with respect to the drive side engaging portion 501E2 of the drum cover member 531. The regulating rib 531L protrudes so as to have a portion overlapping with the fourth regulated portion 143b of the coupling member 143 which is the second end portion of the photosensitive drum 104 when viewed in the longitudinal direction. The regulating rib 531L is provided so as to face the fourth regulated portion 143b with a gap in the longitudinal direction. In the present embodiment, the regulating rib 531L is configured to protrude in a direction orthogonal to the longitudinal direction, but as long as the movement of the photosensitive drum 104 in the longitudinal direction can be regulated within a desired range, it may be configured to extend in a direction having an angle with respect to the orthogonal direction.

[0104] The regulating rib 531L has a fourth regulating portion 531d facing the fourth regulated portion 143b of the coupling member 143. When the photosensitive drum 104 is viewed in the longitudinal direction, the fourth regulated portion 143b and the fourth regulating portion 531d overlap. And in the longitudinal direction (Y direction in the figure) of the photosensitive drum 104, there is a gap u2 between the fourth regulated portion 143b and the fourth regulating portion 531d. The gap u2 is set to be smaller than the gap s2 (u2 < s2). The configuration is the same as that of the first embodiment except for the above.

[0105] Similar to the first embodiment, also in the fourth embodiment, as shown on the non-drive side of FIG. 27(A), the gap u1 is set to be smaller (narrower) than the gap s1 (u1 < s1). Therefore, the total amount of movement of the photosensitive drum 104 in the longitudinal direction (Y direction in the figure) when the drum cover member 531 is mounted is u1 + u2. On the other hand, the total amount of movement of the photosensitive drum 104 in the longitudinal direction (Y direction in the figure) when the drum cover member 531 is not mounted is s1 + s2. Therefore, the length (range) of the distance that the photosensitive drum 104 is allowed to relatively move in the longitudinal direction in the process cartridge 100 becomes shorter (narrower) when the drum cover member 531 is mounted (u1 + u2 < s1 + s2).

[0106] As described above, when the drum cover member 531 is attached, it is possible to suppress the rubbing distance at the contact portion with the charging roller 105 on the photosensitive drum 104. Therefore, it is possible to suppress the generation of charge memory due to longitudinal rubbing at the contact portion between the photosensitive drum 104 and the charging roller 105. As a result, it is possible to provide a user with a good printed image.

[0107] (Example 5) The cartridge protection assembly according to Example 5 of the present invention will be described with reference to FIG. 28. In the following description of Example 5, descriptions of configurations common to Examples 1, 2, 3, and 4 will be omitted. Matters not particularly described herein in Example 5 are common to Examples 1, 2, 3, and 4. Note that, for a part of the configuration of Example 5, the reference numeral obtained by adding an alphabet to "501" of Example 1 is denoted by the reference numeral obtained by adding an alphabet to "541" in Example 5.

[0108] FIG. 28(A) is a detailed enlarged view 1 (DT1) of the periphery of the regulation rib 511K in FIG. 25 (Example 2), and FIG. 28(B) is a detailed enlarged view 2 (DT2) of the periphery of the regulation rib 541K which is a different form from the regulation rib 511K. When assembling the drum cover member 511 (541) to the process cartridge 100, each component needs to be assembled in a desired longitudinal positional relationship.

[0109] In particular, when assembling the drum cover member 511 (541) toward the process cartridge 100 in the mounting direction E, contact or interference may occur between the members that are arranged in proximity to each other between the drum cover member 511 (541) and the process cartridge 100. Such contact or interference may inhibit the mounting of the drum cover member 511 (541). In Example 5, a shape is provided at the site where such contact or interference may occur to avoid inhibiting the mounting of the drum cover member 511 (541). That is, when mounting the drum cover member 511 (541), chamfered shapes 142d (511d) or R shapes 142R (541R) are provided at the corners of the respective tip portions facing each other between the second regulated portion 142b and the second regulating portion 511b (541b). As a result, the second regulated portion 142b and the second regulating portion 511b (541b) are configured to contact and slide so as to attract each other. Therefore, it is avoided that the second regulated portion 142b and the second regulating portion 511b (541b) interfere with each other and get caught, and thus, it is avoided that the mounting of the drum cover member 511 (541) is inhibited.

[0110] Further, the end face (side face) of the regulating rib 511K (541K) facing the second regulated portion 142b in the longitudinal direction (Y2 direction) may be a tapered shape 511e (541e). The tapered shape 511e (541e) is an inclined surface shape inclined by an angle θ with respect to the direction orthogonal to the longitudinal direction so as to go in the direction opposite to the facing direction (Y2 direction) with the second regulated portion 142b as it goes toward the tip side of the regulating rib 511K (541K).

[0111] Thereby, when assembling the drum cover member 511 (541) to the process cartridge 100, each component can be easily assembled in the desired longitudinal positional relationship. Further, the configuration shown in this embodiment can obtain the same effect when applied not only to the second regulated portion 142b and the second regulating portion 511b (541b) but also to other regulated portions and regulating portions.

[0112] In addition, in this embodiment, although the case where the characteristic configuration of this embodiment is applied to the regulation rib 511K in FIG. 25 (Embodiment 2) has been described, it may be similarly applied to other embodiments. That is, also in FIG. 1 (Embodiment 1), FIG. 26 (Embodiment 3), and FIG. 27 (Embodiment 4), although there is a gap u1 in the DT1 part in the figure, the above-described problems may occur when assembling the drum cover member in the mounting direction E toward the process cartridge 100. Therefore, the interference avoidance shape shown in FIG. 28 may be applied to each regulation rib.

[0113] (Embodiment 6) Embodiment 6 of the present invention will be described. Embodiment 6 is an embodiment showing an example of the material used for each of the drum cover members 501, 511, 521, 531, and 541 in Embodiments 1 to 5. In the following description of Embodiment 6, descriptions of configurations common to Embodiments 1 to 5 will be omitted. Matters not particularly described here in Embodiment 6 are common to Embodiments 1 to 5.

[0114] As described in Embodiments 1 to 5, in the state where the drum cover member is attached to the process cartridge 100, since it is non-printing, even if the related parts come into contact with each other, it is assumed that the deformation of the configured parts can cope with it. In order to make the response by this deformation more reliable, in this embodiment, the drum cover member is made of a material that is more easily deformed than the material of the frame body constituting the drum unit 108, that is, a material having a low Young's modulus. Thereby, the deformation due to the above-described contact can be more reliably absorbed by the deformation of the drum cover member. The frame body constituting the drum unit 108 corresponds to the drum frame body 115, the drive-side cartridge cover member 116, and the non-drive-side cartridge cover member 117. In this embodiment, a polystyrene-based resin material is used for the frame body constituting the drum unit 108, and a polypropylene-based resin material is used for the drum cover member. Note that these specific materials are merely examples. That is, any combination of materials that produces a desired difference in ease of deformation may be used, as long as it is different from the above materials. It may be.

Description of Signs

[0115] 100…Process cartridge, 104…Photosensitive drum, 115…Drum frame, 116…Drive-side cartridge cover member, 116a…Third opposing surface, 116r…Locking groove, 117…Non-drive-side cartridge cover member, 117a…First opposing surface, 117c…Fifth regulated portion, 117s, 117t…Locking grooves, 142…Drum flange, 142a…First surface, 142b…Second regulated portion, 143…Coupling member, 143a…Third surface, 143b…Fourth regulated portion, 170…Image forming apparatus main body, 501, 511, 521, 531, 541…Drum cover members, 501K, 511K, 521K, 531K, 541K, 531L…Regulating ribs, 501b, 511b, 521b, 531b, 541b…Second regulating portions, 501c, 511c, 521c, 531c…Fifth regulating portions, 531d…Fourth regulating portion, 501q, 501r…Drive-side locking claws, 501s, 501t…Non-drive-side locking claws, s1, s2, u1, u2…Clearances.

Claims

1. A cartridge comprising a photosensitive drum and a frame that rotatably supports the photosensitive drum and covers the photosensitive drum such that a part of the circumferential surface of the photosensitive drum is exposed. A cover member that is detachable from the frame so as to cover at least a part of the part of the photosensitive drum. A cartridge protection assembly having the same. The frame is configured to regulate a movable range of the photosensitive drum with respect to the frame in the longitudinal direction of the photosensitive drum to a first range when the cover member is detached from the frame. The cover member A held portion held by the frame, A regulating portion configured to regulate a movable range of the photosensitive drum with respect to the frame to a second range narrower than the first range by contacting a longitudinal end surface of the photosensitive drum when the photosensitive drum moves in the longitudinal direction. A cartridge protection assembly, characterized by having the same.

2. The cartridge protection assembly according to claim 1, wherein the regulating portion is a protruding portion that protrudes in a direction intersecting the longitudinal direction so as to have a portion overlapping the photosensitive drum when viewed in the longitudinal direction. Cartridge protection assembly.

3. The frame A first end support portion that supports a first end of both ends of the photosensitive drum in the longitudinal direction, A second end support portion that supports a second end opposite to the first end of both ends, Having the same, The cartridge protection assembly according to claim 2, wherein the protruding portion is inserted into a gap between the first end and the first end support portion and faces the first end in a first direction along the longitudinal direction.

4. The first end support portion has a first regulating surface that faces the first end in the first direction. The second end support portion has a second restricting surface facing the second end in a second direction opposite to the first direction, The first range is the sum of the distance of the gap between the first end and the first restricting surface and the distance of the gap between the second end and the second restricting surface in the longitudinal direction, The cartridge protection assembly according to claim 3, characterized in that the sum of the distance of the gap between the first end and the protruding portion and the distance of the gap between the second end and the second restricting surface in the longitudinal direction is smaller than the sum of the distance of the gap between the first end and the first restricting surface and the distance of the gap between the second end and the second restricting surface.

5. The held portion has a first engaging portion that abuts against the frame body in the first direction and engages in a direction intersecting the longitudinal direction, has a second engaging portion that abuts against the frame body in the second direction and engages in a direction intersecting the longitudinal direction, and a cover portion that extends along the longitudinal direction between the first engaging portion and the second engaging portion and faces a part of the photosensitive drum exposed from the frame body, and the protruding portion protrudes from the cover portion into the gap between the first end and the first end support portion in a direction intersecting the longitudinal direction. The cartridge protection assembly according to claim 4, characterized in that.

6. The first end support portion has a first recess recessed in the first direction on an outer end surface in the longitudinal direction, The second end support portion has a second recess recessed in the second direction on an outer end surface in the longitudinal direction, The first engaging portion has a first extending portion that extends in a direction intersecting the longitudinal direction from the side where the cover portion is provided in the cover member so as to overlap a portion overlapping the first recess when viewed in the longitudinal direction, A first convex portion that protrudes from the first extending portion in the first direction and engages with the first concave portion; and has The second engaging portion has a second extending portion that extends in a direction intersecting the longitudinal direction from the side of the cover member where the cover portion is provided so as to have a portion overlapping the second concave portion when viewed in the longitudinal direction; a second convex portion that protrudes from the second extending portion in the second direction and engages with the second concave portion; The cartridge protection assembly according to claim 5, characterized by having the above.

7. The cover member has the protruding portion as a first protruding portion, and has a second protruding portion that protrudes in a direction intersecting the longitudinal direction so as to have a portion overlapping the second end portion when viewed in the longitudinal direction in a gap between the second end portion and the second end portion support portion, and further has a second protruding portion that faces the second end portion in a second direction opposite to the first direction with respect to the second end portion; The cartridge protection assembly according to any one of claims 3 to 6, characterized in that the sum of the distance of the gap between the first protruding portion and the first end portion and the distance of the gap between the second protruding portion and the second end portion in the longitudinal direction is shorter than the first range.

8. The cover member has a third protruding portion that protrudes in a direction intersecting the longitudinal direction so as to have a portion overlapping the first end portion when viewed in the longitudinal direction in a gap between the first end portion and the first end portion support portion, and further has a third protruding portion that abuts against the first end portion support portion in a second direction opposite to the first direction; the cartridge protection assembly according to any one of claims 3 to 7, characterized by having the above.

9. The cartridge protection assembly according to any one of claims 2 to 8, characterized in that a corner portion of a tip end portion on a side facing the end portion of the photosensitive drum has a chamfered shape or an R shape.

Images