Cartridge protection assembly

Abstract

The present application provides a cartridge protection assembly, wherein a frame of a cartridge is configured to limit a movable range of a photosensitive drum in a length direction of the photosensitive drum relative to the frame to a first range when a cover member is separated from the frame, the cover member has a held portion held by the frame when mounted on the frame, and a limiting portion configured to limit the movable range of the photosensitive drum relative to the frame to a second range smaller than the first range by contacting with a length direction end surface of the photosensitive drum when the photosensitive drum is moved in the length direction.

Description

Technical Field

[0001] This disclosure relates to a protective assembly for a housing of an image forming apparatus such as a photocopier or printer that employs an electrophotographic method. Background Technology

[0002] As an image forming apparatus, a known configuration employs a so-called processing cartridge configuration. In the drum unit of the processing cartridge, a photosensitive drum is rotatably supported, and part of the surface of the photosensitive drum protrudes from an opening in the cartridge frame. Therefore, there is a possibility that a user may come into contact with the surface of the photosensitive drum. If the user does come into contact with the surface of the photosensitive drum, there is a possibility that oils or other substances from the user's hands may adhere to the surface of the photosensitive drum, causing image defects. To prevent the user from contacting the surface of the photosensitive drum, sometimes a cover member (drum cover member) covers the surface of the photosensitive drum. The drum cover member serves both a dustproof function and a function to prevent user contact.

[0003] Furthermore, during maintenance such as blocking, the housing installed on the main unit may sometimes be temporarily removed and stored outside the main unit. In such cases, the possibility of the user reinstalling the drum housing component arises. In this situation, as mentioned above, by covering the surface of the photosensitive drum with the drum housing component, dust prevention and prevention of user contact can be achieved.

[0004] Before the box is delivered to the user, it is transported by bundling it with a material such as corrugated cardboard or cushioning material. The photosensitive drum or charged component, which serves as the processing mechanism, is rotatably supported by a bearing or support component connected to the box frame. The photosensitive drum or charged component has a side clearance in the longitudinal direction between itself and the associated component to ensure stable rotation during the printing process and prevent interference between components. The side clearance is set to account for thermal shrinkage due to environmental changes, in a way that corresponds to dimensional deviations of the components or use in various environments. Therefore, during transport, the charged component moves on the photosensitive drum by an amount corresponding to this side clearance, which may result in sliding friction. Depending on the situation, there is a possibility of image defects such as horizontal lines caused by triboelectric charging on the photosensitive drum. In addition, in cases with a large side clearance, there is a possibility of component breakage due to impact caused by component movement.

[0005] In view of the aforementioned possibilities, Japanese Patent Application Publication No. 2004-077820 discloses a locking member for restricting the longitudinal movement of a brush unit configured to move along the longitudinal direction of the photosensitive element while abutting against it within the cartridge. The locking member is detachable from a brush support member of the cartridge detached from the image forming apparatus body, and by restricting the movement of the brush support member during installation, it prevents the brush unit from moving along the longitudinal direction. Summary of the Invention

[0006] The purpose of this invention is to provide a technique for limiting the longitudinal movement of the photosensitive drum during transport or storage of the processing cartridge.

[0007] To achieve the above objectives, the box protection assembly of the present invention has:

[0008] A housing comprising a photosensitive drum and a frame, the frame rotatably supporting the photosensitive drum and covering the photosensitive drum with a portion of its peripheral surface exposed; and

[0009] A cover member that is detachable from the frame in a manner that covers at least a portion of the aforementioned portion of the photosensitive drum.

[0010] in,

[0011] The frame is configured to limit the movable range of the photosensitive drum relative to the frame in the longitudinal direction to a first range when the cover member detaches from the frame.

[0012] The above-mentioned cover component has:

[0013] The held part, which is held by the aforementioned frame; and

[0014] The limiting part is configured to limit the movable range of the photosensitive drum relative to the frame to a second range smaller than the first range when the photosensitive drum moves in the length direction by contacting the photosensitive drum.

[0015] According to the present invention, the longitudinal movement of the photosensitive drum can be restricted during the transport or storage of the processing cartridge.

[0016] Further features of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0017] Figure 1A and Figure 1B This is a cross-sectional view of the box protection assembly involved in Example 1.

[0018] Figure 2 This is a cross-sectional view of an image forming apparatus.

[0019] Figure 3 This is a cross-sectional view of the processing box.

[0020] Figure 4 This is a cross-sectional view of an image forming apparatus.

[0021] Figure 5 This is a cross-sectional view of an image forming apparatus.

[0022] Figure 6 This is a cross-sectional view of an image forming apparatus.

[0023] Figure 7 This is an exploded 3D view of the drum unit.

[0024] Figure 8 This is an exploded stereoscopic view of the developing unit.

[0025] Figure 9 This is a 3D view of the assembly of the processing box.

[0026] Figure 10 This is a 3D view of the processing box.

[0027] Figure 11 It is a perspective view of the drive side assembly, including the separation and contact mechanism on the drive side.

[0028] Figure 12 This is a side view of the assembled processing box of the limiting components, viewed from the drive side.

[0029] Figure 13 It is an assembly perspective view of the non-drive side of the separation and contact mechanism, including the non-drive side.

[0030] Figure 14A This is a side view showing the separation and contact actions of the processing box.

[0031] Figure 14B This is a side view showing the separation and contact actions of the processing box.

[0032] Figure 14C This is a side view showing the separation and contact actions of the processing box.

[0033] Figure 15 This is a side view of the processing box.

[0034] Figure 16 This is an exploded perspective view of the box protection assembly involved in Example 1.

[0035] Figure 17 This is an exploded perspective view of the box protection assembly involved in Example 1.

[0036] Figure 18 This is an exploded perspective view of the box protection assembly involved in Example 1.

[0037] Figure 19 This is an exploded perspective view of the box protection assembly involved in Example 1.

[0038] Figure 20 This is a perspective view of the box protection assembly involved in Example 1.

[0039] Figure 21This is a side view of the box protection assembly involved in Example 1.

[0040] Figure 22 This is a front view of the box protection assembly involved in Example 1.

[0041] Figure 23 This is a cross-sectional view of the box protection assembly involved in Example 1.

[0042] Figure 24 This is a cross-sectional view of the box protection assembly involved in Example 1.

[0043] Figure 25 This is a cross-sectional view of the box protection assembly involved in Example 2.

[0044] Figure 26 This is a cross-sectional view of the box protection assembly involved in Example 3.

[0045] Figure 27 This is a cross-sectional view of the box protection assembly involved in Example 4.

[0046] Figure 28 This is a sectional view illustrating the structure of the limiting ribs. Detailed Implementation

[0047] The following embodiments illustratively illustrate implementations of this disclosure. The configurations disclosed in these embodiments, such as the function, material, shape, and relative arrangement of components, represent an example of a form associated with the scope of the claims and are not intended to limit the scope of the claims to the configurations disclosed in these embodiments. Furthermore, the problems to be solved by the configurations disclosed in the following embodiments, or the effects or functions obtained from the disclosed configurations, are not intended to limit the scope of the claims.

[0048] (Example 1)

[0049] Hereinafter, the electrophotographic image forming apparatus according to Embodiment 1 of this disclosure will be described using the accompanying drawings. Here, an electrophotographic image forming apparatus (hereinafter, an image forming apparatus) refers to an apparatus that forms an image on a recording material using an electrophotographic image forming method. Examples of image forming apparatuses include copiers, fax machines, printers (laser beam printers, LED printers, etc.), and their multifunction printers. Recording materials include sheet-like recording media such as recording paper and plastic sheets. Furthermore, the image forming apparatus according to this embodiment is a so-called "cassette" type image forming apparatus. A cassette is a unit that can be attached and detached from the image forming apparatus; it is a unit having a photoreceptor and a processing mechanism (e.g., a charging member, a developing member, a cleaning member, etc.) that acts on the photoreceptor. In the following embodiments, a laser beam printer capable of attaching and detaching four processing cassettes (boxes) is shown as an example of an image forming apparatus. However, the number of processing cassettes installed in the image forming apparatus is not limited to this. It can be appropriately set as needed.

[0050] (Simplified structure of an image forming apparatus)

[0051] Figure 2 This is a schematic cross-sectional view illustrating the configuration of the image forming apparatus M. Additionally, Figure 3 This is a schematic cross-sectional view showing the configuration of the processing cartridge 100. The image forming apparatus M is a four-color full-color laser printer using electrophotographic processing to form a color image on the recording medium S. The image forming apparatus M is a cartridge type, with the processing cartridge 100 detachably mounted on the image forming apparatus main body (apparatus main body) 170 to form a color image on the recording medium S.

[0052] Here, regarding the image forming apparatus M, the side with the front door 11 is designated as the front side (front), and the side opposite to the front side is designated as the back side (rear). Furthermore, when viewing the image forming apparatus M from the front, the right side is referred to as the driving side, and the left side as the non-driving side. Also, when viewing the image forming apparatus M from the front, the upper side is designated as the top, and the lower side as the bottom. Figure 2 This is a cross-sectional view of the image forming apparatus M viewed from the non-driving side. The front of the paper shows the non-driving side of the image forming apparatus M, the right side of the paper shows the front of the image forming apparatus M, and the back of the paper shows the driving side of the image forming apparatus M.

[0053] Furthermore, the drive side of the processing cartridge 100 refers to the side where the drum coupling member (photoreceptor coupling member), described later, is arranged about the axis of the photosensitive drum (the axial direction of the rotation axis of the photosensitive drum). Similarly, the drive side of the processing cartridge 100 refers to the side where the developing coupling member, described later, is arranged about the axis of the developing roller (developing member) (the axial direction of the rotation axis of the developing roller). Moreover, the axis of the photosensitive drum is parallel to the axis of the developing roller, and the length direction of the processing cartridge 100 (photosensitive drum, developing roller) is also parallel to them.

[0054] In the image forming apparatus main body 170, processing cartridges 1 to 4 (100Y, 100M, 100C, 100K) are arranged in a generally horizontal direction. Each of the first to fourth processing cartridges 100 (100Y, 100M, 100C, 100K) has the same electrophotographic processing mechanism, and the color of the developer (hereinafter referred to as toner) is different for each of them. In the first to fourth processing cartridges 100 (100Y, 100M, 100C, 100K), a drive rotational force is transmitted from the drive output unit of the apparatus main body 170 (details will be described later). In addition, a bias voltage (charge bias, development bias, etc.) (not shown) is supplied from the apparatus main body 170 to each of the first to fourth processing cartridges 100 (100Y, 100M, 100C, 100K).

[0055] like Figure 3 As shown, each of the first to fourth processing cartridges 100 (100Y, 100M, 100C, 100K) in this embodiment has a drum unit 108, which includes a photosensitive drum 104 and a charging mechanism that acts on the photosensitive drum 104 as a processing mechanism. Here, the drum unit 108 sometimes includes not only the charging mechanism but also a cleaning mechanism as a processing mechanism. In addition, each of the first to fourth processing cartridges 100 (100Y, 100M, 100C, 100K) has a developing unit 109, which includes a developing mechanism for developing the electrostatic latent image on the photosensitive drum 104.

[0056] In each of the first to fourth processing cartridges 100, a drum unit 108 and a developing unit 109 are coupled together, with the developing unit 109 being movably supported relative to the drum unit 108. A more detailed description of the configuration of the processing cartridges 100 will follow.

[0057] The first processing cartridge 100Y contains yellow (Y) toner within the developing frame 125, forming a yellow toner image on the surface of the photosensitive drum 104. The second processing cartridge 100M contains magenta (M) toner within the developing frame 125, forming a magenta toner image on the surface of the photosensitive drum 104. The third processing cartridge 100C contains cyan (C) toner within the developing frame 125, forming a cyan toner image on the surface of the photosensitive drum 104. The fourth processing cartridge 100K contains black (K) toner within the developing frame 125, forming a black toner image on the surface of the photosensitive drum 104.

[0058] Above the first to fourth processing boxes 100 (100Y, 100M, 100C, 100K), a laser scanning unit 14, serving as an exposure mechanism, is provided. This laser scanning unit 14 outputs a laser beam U in correspondence with the image information. Furthermore, the laser beam U scans and exposes the surface of the photosensitive drum 104 through the exposure window 110 of the processing box 100.

[0059] Below the first to fourth processing boxes 100 (100Y, 100M, 100C, 100K), an intermediate transfer unit 12 serving as a transfer component is provided. This intermediate transfer unit 12 includes a drive roller 12e, a guide roller 12c, and a tension roller 12b, and a flexible transfer belt 12a is mounted on it. The lower area of ​​the peripheral surface of the photosensitive drum 104 of each of the first to fourth processing boxes 100 (100Y, 100M, 100C, 100K) contacts the upper-facing area of ​​the outer peripheral surface of the annular transfer belt 12a. This contact portion constitutes a primary transfer portion. Inside the transfer belt 12a, a primary transfer roller 12d is provided facing the photosensitive drum 104. A secondary transfer roller 6 abuts against the guide roller 12c via the transfer belt 12a. The contact portion between the transfer belt 12a and the secondary transfer roller 6 constitutes a secondary transfer portion.

[0060] Below the intermediate transfer unit 12, there is a feeding unit 4. The feeding unit 4 has a paper tray 4a and a paper roller 4b for loading and accommodating the recording medium S. The transport path of the recording medium S is configured to run from the feeding unit 4 toward approximately upward on the rear side of the device within the device body 170.

[0061] Downstream of the secondary transfer section in the transport path of the recording medium S ( Figure 2 The upper left of the main body 170 of the device is provided with a fixing unit 7 and a paper discharge unit 8. The top of the main body 170 serves as a paper discharge tray 13. The recording medium S is heated and pressurized by the fixing mechanism provided in the fixing unit 7 to fix the toner image and discharge it to the paper discharge tray 13.

[0062] (Image formation action)

[0063] The operation for forming a full-color image is as follows. The photosensitive drums 104 of each of the first to fourth processing boxes 100 (100Y, 100M, 100C, 100K) are driven to rotate at a predetermined speed. Figure 3 (Arrow A direction). The transfer belt 12a also rotates clockwise during the rotation of the photosensitive drum 104. Figure 2 (In the direction of arrow C) it is driven to rotate at a speed corresponding to the speed of the photosensitive drum 104.

[0064] The laser scanning unit 14 is also driven. Synchronously with the driving of the laser scanning unit 14, in each processing cartridge 100, the charged roller 105 uniformly charges the surface of the photosensitive drum 104 to a predetermined polarity and potential. The laser scanning unit 14 scans and exposes the surface of each photosensitive drum 104 with laser light U according to the image signal of each color. As a result, an electrostatic latent image corresponding to the corresponding color image signal is formed on the surface of each photosensitive drum 104. The formed electrostatic latent image is developed by a developing roller 106 driven to rotate at a predetermined speed. Through this electrophotographic image forming processing 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 processing cartridge 100Y. This toner image is then transferred once onto the transfer belt 12a.

[0065] Similarly, on the photosensitive drum 104 of the second processing cartridge 100M, a magenta toner image corresponding to the magenta component of the full-color image is formed. This toner image is then overlaid on a yellow toner image already transferred to transfer belt 12a and transferred in one step. Similarly, on the photosensitive drum 104 of the third processing cartridge 100C, a cyan toner image corresponding to the cyan component of the full-color image is formed. This toner image is then overlaid on yellow and magenta toner images already transferred to transfer belt 12a and transferred in one step. Similarly, on the photosensitive drum 104 of the fourth processing cartridge 100K, a black toner image corresponding to the black component of the full-color image is formed. This toner image is then overlaid on yellow, magenta, and cyan toner images already transferred to transfer belt 12a and transferred in one step. In this way, a four-color unfixed toner image of yellow, magenta, cyan, and black is formed on the transfer belt 12a.

[0066] On the other hand, the recording media S is separated and fed one sheet at a predetermined control timing. The recording media S is introduced into the secondary transfer section, the contact point between the secondary transfer roller 6 and the transfer belt 12a, according to the predetermined control timing. Thus, as the recording media S is conveyed to the secondary transfer section, the four overlapping toner images on the transfer belt 12a are sequentially transferred onto the surface of the recording media S. Then, the recording media S is conveyed to the fixing device 7, where the toner images are fixed, and then discharged onto the paper discharge tray 13.

[0067] (No cleaner system)

[0068] The image forming apparatus M involved in this embodiment employs a so-called cleanerless system. This system recovers residual developer from the transfer process simultaneously with the developing mechanism. This residual developer remains on the image holder, such as the photosensitive drum 104 or the transfer belt 12a, after the toner image (developer image) has been transferred to the transfer belt 12a. Specifically, the system is configured such that the developer remaining on the photosensitive drum 104 after the toner image (developer image) has been transferred to the transfer belt 12a is moved via the developing roller 106 to a frame containing the developer for recovery. By employing this system, a cleaning member is not required to remove residual toner from the photosensitive drum 104 that has not been transferred.

[0069] The residual toner remaining on the photosensitive drum 104 after the transfer process is charged to a negative polarity by discharge at the gap before the contact point (charged clamping part) between the charged roller 105 and the photosensitive drum 104. The negatively charged residual toner passes through the charged clamping part without adhering to the charged roller 105 due to the potential difference between the surface potential of the photosensitive drum and the charged roller. The residual toner reaches the irradiation position of the laser beam U after passing through the charged clamping part. Since the residual toner does not obscure the laser beam U to a great extent, it does not affect the process of creating the electrostatic latent image on the photosensitive drum 104. For toner that has passed the laser-irradiated area, at the contact point (developing clamping part) between the developing roller 106 and the photosensitive drum 104, the toner in the non-exposed area (the photosensitive drum surface that has not received laser irradiation) is recovered by the developing roller 106 through electrostatic force and is returned to the developing chamber of the developing unit 109. The toner in the exposed area (the photosensitive drum surface that has received laser irradiation) is not recovered by electrostatic force and remains on the photosensitive drum 104 as is. However, some toner is sometimes also recovered by physical force generated by the difference in circumferential speed between the developing roller 106 and the photosensitive drum 104. Thus, the toner that remains on the photosensitive drum 104 without being transferred to the transfer belt 12a is largely recovered to the developing chamber of the developing unit 109. The recovered toner is mixed with the toner remaining in the developing chamber and used.

[0070] (About the components of the packaging box)

[0071] use Figures 4-6 A more detailed description is given of the tray (hereinafter referred to as tray) 171 that supports the processing box. Figure 4 This is a cross-sectional view of the image forming apparatus M with the tray 171 located inside the main body 170 of the apparatus when the front door 11 is open. Figure 5 This is a cross-sectional view of the image forming apparatus M with the front door 11 open, the tray 171 located outside the main body 170 of the device, and the processing box 100 stored inside the tray 171. Figure 6 This is a cross-sectional view of the image forming apparatus M with the front door 11 open, the tray 171 located outside the main body 170 of the device, and the processing box 100 removed from the tray 171.

[0072] like Figure 4 , Figure 5 As shown, the tray 171 can move relative to the device body 170 in the direction of arrow X1 (push-in direction) and arrow X2 (pull-out direction), which are substantially horizontal (the front-to-back direction of the device). That is, the tray 171 is configured to be able to be pulled out and pushed in relative to the device body 170, and with the device body 170 positioned on a horizontal plane, the tray 171 is configured to move in a substantially horizontal direction. Here, the tray 171 is positioned outside the device body 170 (…). Figure 5 The state in which the tray 171 is located inside the main body 170 and the photosensitive drum 104 is separated from the transfer belt 12a is also referred to as the outer position. Figure 4 The state of (the state of) is called the inner position.

[0073] Additionally, tray 171 has an outer position such as Figure 6 The mounting portion 171a of the processing cartridge 100 can be detachably installed as shown. Furthermore, with the processing cartridge 100 positioned in the mounting portion 171a, it moves inward toward the device body 170 along with the movement of the tray 171. At this time, it moves with a gap between the transfer belt 12a and the photosensitive drum 104. Therefore, the photosensitive drum 104 does not contact the transfer belt 12a, and the tray 171 allows the processing cartridge 100 to move inward toward the device body 170.

[0074] In this embodiment, the intermediate transfer unit 12 moves to the position where the image is formed (the position where the photosensitive drum 104 contacts the intermediate transfer belt 12a) by a linkage mechanism (not shown) in the direction of arrow Z1 (upward direction) after the front door 11 is closed. Conversely, by opening the front door 11, the intermediate transfer unit 12 descends in the direction of arrow Z2 (downward direction), separating the photosensitive drum 104 from the intermediate transfer belt 12a. Thus, the photosensitive drum 104 does not contact the transfer belt 12a, and the tray 171 allows the processing cartridge 100 to move inward toward the device body 170.

[0075] As described above, the tray 171 allows multiple processing boxes 100 to move together to a position where image formation can be performed inside the device body 170, and also allows them to be pulled together to the outside of the device body 170.

[0076] (Overall structure of the processing box)

[0077] use Figures 7-10 The structure of the processing box will be explained. Figure 7 This is an exploded perspective view of the drum unit 108, showing the components of the drum unit 108 in dissection. Figure 8 This is an exploded stereoscopic view of the developing unit 109. Figure 9 This is an assembled perspective view of the processing box 100, showing the components of the processing box 100 as seen from one end of the photosensitive drum 104's axial direction, i.e., the drive side. Figure 10 This is a perspective view of the processing box 100 as seen from the drive side.

[0078] In this embodiment, the first to fourth processing cartridges 100 (100Y, 100M, 100C, 100K) have the same electrophotographic processing mechanism, although the color of the toner contained, the amount of toner filled, or the control performed by the device body 170 may sometimes differ. However, although these four processing cartridges may sometimes differ in size, etc., their basic structure and functions are the same. Therefore, the following description will focus on one processing cartridge 100 as an example.

[0079] The processing cartridge 100 includes a photosensitive drum 104 (104Y, 104M, 104C, 104K) and a processing mechanism acting on the photosensitive drum 104. Here, the processing mechanism includes a charged roller 105, which is a charging mechanism (charging member) for charging the photosensitive drum 104, and a developing roller 106, which is a developing mechanism (developing member) for developing the latent image formed on the photosensitive drum 104. Furthermore, the processing cartridge 100 is divided into drum units 108 (108Y, 108M, 108C, 108K) and developing units 109 (109Y, 109M, 109C, 109K).

[0080] In the following description, the length direction Y of the drum unit 108 and the developing unit 109 refers to the direction that is approximately parallel to the rotation axis a of the photosensitive drum 104. Figure 9 ).

[0081] (The structure of a drum unit)

[0082] like Figure 7 , Figure 9As shown, the drum unit 108 comprises a photosensitive drum 104, a charged roller 105, and a drum frame 115. The charged roller 105 is rotatably supported by a drive-side charged roller bearing 120a and a non-drive-side charged roller bearing 120b, and is subjected to force relative to the photosensitive drum 104 by pressure springs 121a and 121b. The photosensitive drum 104 is rotatably supported by drive-side housing members 116 and non-drive-side housing members 117 located at both ends of the processing cartridge 100 along its length. The drive-side housing member 116, serving as a second end support, supports one end (the second end) of the photosensitive drum 104 along its length. The non-drive-side housing member 117, serving as a first end support, supports the other end (the first end) of the photosensitive drum 104 along its length.

[0083] like Figure 9 As shown, a coupling member 143 for transmitting driving force to the photosensitive drum 104 is provided at one end along its length. The coupling member 143 is coupled to a drum drive coupling 180 on the main body side of the device body 170, which serves as a drum drive output section. Figure 5 as well as Figure 6 When engaged, the driving force of the drive motor (not shown) of the main body 170 is transmitted to the photosensitive drum 104 in the direction of arrow A. Figure 3 The photosensitive drum 104 has a drum flange 142 at the other end in the longitudinal direction. The charged roller 105 is supported on the drum frame 115 in such a way that it can contact and rotate automatically relative to the photosensitive drum 104.

[0084] (Structure of the developing unit)

[0085] like Figure 3 , Figure 8 As shown, the developing unit 109 comprises a developing roller 106, a toner delivery roller 107, a developing blade 130, and a developing frame 125. The developing frame 125 is composed of a lower frame 125a and a cover member 125b. The lower frame 125a and the cover member 125b are joined together by ultrasonic welding or the like. The developing frame 125 has a toner storage section 129 for storing the toner supplied to the developing roller 106. In addition, the developing frame 125 rotatably supports the developing roller 106 and the toner delivery roller 107 via a drive-side bearing 126 and a non-drive-side bearing 127, and maintains the developing blade 130, which limits the thickness of the toner layer on the circumference of the developing roller 106.

[0086] The developing blade 130 is mounted to a support member 130a, which is a sheet of metal with a thickness of approximately 0.1 mm, via welding or other means. The developing blade 130 is mounted to the developing frame 125 at two locations along its length, one at one end and the other at the other, using fixing screws 130c. The developing roller 106 is composed of a metal core 106c and a rubber portion 106d.

[0087] The developing roller 106 is rotatably supported by drive-side bearings 126 and non-drive-side bearings 127 mounted at both ends of the developing frame 125 along its length. The non-drive-side bearings 127 are supported relative to the lower frame 125a of the developing frame 125 by screws 307 (see reference). Figure 13 ( ) Tightening. Additionally, at one end (drive side) along the length of the developing unit 109, a developing drive input gear 132 is provided for transmitting driving force to the developing unit 109. On the developing drive input gear 132, a developing drive coupling 185 from the main body side of the device body 170 is provided. Figure 5 as well as Figure 6 The driving force of the drive motor (not shown) of the main body 170 is input to the developing unit 109 through the developing input coupling unit 132a, which receives the drive.

[0088] The driving force input to the developing unit 109 is transmitted to the developing roller gear 131, enabling the developing roller 106 to move towards... Figure 3 Rotate in the direction of arrow D. At one end (drive side) along the length of the developing unit 109, a developing cover member 128 is provided to support and cover the developing drive input gear 132. The developing cover member 128, together with the drive-side bearing 126, is positioned relative to the lower frame 125a of the developing frame 125 by screws 308 (see reference). Figure 11 (Tighten.) Furthermore, the outer diameter of the developing roller 106 is set to be smaller than the outer diameter of the photosensitive drum 104. In this embodiment, the outer diameter of the photosensitive drum 104 is set in the range of Φ18 to Φ22, and the outer diameter of the developing roller 106 is set in the range of Φ8 to Φ14. By setting these outer diameters, efficient configuration can be achieved.

[0089] (Assembly of the drum unit and developing unit)

[0090] use Figure 9 The assembly of the drum unit 108 and the developing unit 109 will be described. The drum unit 108 and the developing unit 109 are combined by drive-side cover members 116 and non-drive-side cover members 117 provided at both ends of the processing cartridge 100 in the longitudinal direction.

[0091] The drive-side housing member 116, located at one end of the processing cartridge 100 along its length, has a developing unit support hole 116f for pivotally (movably) supporting the developing unit 109. Similarly, the non-drive-side housing member 117, located at the other end of the processing cartridge 100 along its length, has a developing unit support hole 117f for pivotally supporting the developing unit 109. Furthermore, the drive-side housing member 116 and the non-drive-side housing member 117 each have drum support holes 116b and 117b for rotatably supporting the photosensitive drum 104.

[0092] Here, at one end of the processing cartridge 100 along its length, the outer diameter 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 cover member 116. At the other end of the processing cartridge 100 along its length, the outer diameter 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 cover member 117. Furthermore, both ends of the photosensitive drum 104 along its length are fitted into the drum support hole 116b of the drive-side cover member 116 and the drum support hole 117b of the non-drive-side cover member 117, respectively. The drive-side cover member 116 and the non-drive-side cover member 117 are then fixed to the drum unit 108 by screws or adhesives (not shown).

[0093] That is, the developing unit 109 is pivotally supported relative to the drive-side housing member 116 and the non-drive-side housing member 117 by the developing unit support hole 116f and the developing unit support hole 117f. On the other hand, the drum unit 108 is fixed relative to the drive-side housing member 116 and the non-drive-side housing member 117. In other words, the developing unit 109 can rotate relative to the drum unit 108 (photosensitive drum 104) by rotating relative to the drive-side housing member 116 and the non-drive-side housing member 117. Thus, the processing cartridge 100 is configured such that the relative position of the developing unit 109 and the drum unit 108 can be varied by the pivoting of the developing unit 109 relative to the drive-side housing member 116 and the non-drive-side housing member 117. As a result, during image formation, the developing roller 106 can be positioned at the position that acts on the photosensitive drum 104.

[0094] Figure 10This diagram shows the state where the drum unit 108 and the developing unit 109 are assembled and integrated into the processing cartridge 100 through the above processes. Furthermore, the axis connecting the center of the developing unit support hole 116f of the drive-side cartridge cover member 116 and the center of the developing unit support hole 117f of the non-drive-side cartridge cover member 117 is called the swing axis (rotation axis, rotation center) K. Here, the cylindrical portion 128b of the developing cover member 128 at one end of the length direction of the processing cartridge 100 is coaxial with the developing input coupling portion 132a. That is, the developing unit 109 is configured such that the driving force is transmitted from the device body 170 along this swing axis K. Furthermore, the developing unit 109 is supported with free rotation relative to the processing cartridge 100 with respect to the swing axis K.

[0095] (Explanation of the separate contact mechanism)

[0096] use Figure 11 , Figure 12 , Figure 13 The configuration in which the photosensitive drum 104 of the drum unit 108 and the developing roller 106 of the developing unit 109 are separated and abutted in this embodiment will be described.

[0097] The processing box 100 has a separation abutment mechanism on the driving side and the non-driving side. Figure 11 An assembled perspective view of the processing box 100, including the separation abutment mechanism on the drive side, is shown in an exploded view. Figure 12 This is a side view of the assembled processing box 100, which is the limiting member 151R described later, viewed from the drive side. Figure 13 An exploded view of the assembly perspective of the processing box 100, including the non-drive side of the separation abutment mechanism, is shown. Furthermore, the drive side and non-drive side of the separation abutment mechanism each have substantially the same function. For the reference numerals of each component constituting the drive side of the separation abutment mechanism, an "R" is added to the numerals. For the reference numerals of each component constituting the non-drive side of the separation abutment mechanism, an "L" is added to the numerals that are the same as those on the drive side.

[0098] like Figure 11 , Figure 12As shown, the separation and abutment mechanism on the drive side includes a limiting member 151R, a moving member 152R, and a tension spring 153. In the developing chamber member 128, a support portion 128c supporting the limiting member 151R and a support portion 128k supporting the moving member 152R are provided. The limiting member 151R has a supported portion 151Ra that serves as a hole, and the support portion 128c engages with the supported portion 151Ra. The limiting member 151R can rotate relative to the support portion 128c by rotating the supported portion 151Ra relative to the support portion 128c, and can rotate relative to the developing chamber member 128 with the support portion 128c as the center. The moving member 152R has a supported portion 152Ra that serves as an elongated hole, and the support portion 128k engages with the supported portion 152Ra. The movable member 152R can rotate relative to the support 128k by the supported part 152Ra or move relative to the support 128k in the length direction of the elongated hole. It can rotate relative to the developing mask member 128 with the support 128k as the center and can move in the direction of the elongated hole.

[0099] The separating abutment mechanism includes a tension spring 153, which applies force to the limiting member 151R so that it moves towards the support portion 128c. Figure 12 The spring rotates in the direction of arrow B1 and applies force to the moving member 152R in the direction of arrow Z1. The tension spring 153 is a helical spring and is an elastic member. The tension spring 153 is assembled by engaging with the spring latch 151Rg provided on the limiting member 151R and the spring latch 152Rs provided on the moving member 152R. The tension spring 153 rotates in the direction of arrow Z1 by applying force to the spring latch 151Rg on the limiting member 151R. Figure 12 A force is applied in the direction of arrow F2, providing a force to rotate the limiting member 151R in the direction of arrow B1. Furthermore, the tension spring 153 provides a force to move the moving member 152R in the direction of arrow Z1 by applying a force to the spring catch portion 152Rs of the moving member 152R in the direction of arrow F1.

[0100] use Figure 13 The separation and contact mechanism on the non-drive side is described. For example... Figure 13As shown, the non-drive-side separation and abutment mechanism includes a limiting member 151L, a moving member 152L, and a tension spring 153. In the non-drive-side bearing 127, a support portion 127b supporting the limiting member 151L and a support portion 127e supporting the moving member 152L are provided. The limiting member 151L has a supported portion 151La that serves as a hole, and the support portion 127b engages with the supported portion 151La. The limiting member 151L can rotate relative to the support portion 127b about the support portion 127b by rotating relative to the support portion 127b. The moving member 152L has a supported portion 152La that serves as an elongated hole, and the support portion 127e engages with the supported portion 152La. The movable member 152L can rotate relative to the support 127e by the supported part 152La or move relative to the support 127e in the length direction of the elongated hole. It can rotate about the support 127e and move in the direction of the elongated hole.

[0101] The tension spring 153 engages with the spring latch 151Lg provided on the limiting member 151L and the spring latch 152Ls provided on the moving member 152L, and is assembled thereunder. Furthermore, 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, and is therefore omitted.

[0102] (Explanation of the separated and contacted states of the processing box)

[0103] use Figure 12 , Figures 14A to 14C , Figure 15 The separation and contact states of the processing box 100 are described. Figures 14A to 14C The image shows only the photosensitive drum 104, drum frame 115, drive side cover member 116, developing cover member 128, limiting member 151R, and moving member 152R. Figure 14A This shows the developing unit 109 separated from the photosensitive drum 104. Figure 14B The state of the moving member 152R when it moves in the Z2 direction is shown. Figure 14C The image shows the developing unit 109 in contact with the photosensitive drum 104. Figure 15 This is a side view of the drive side with the drive-side housing member 116, developer housing member 128, moving member 152R, and tension spring 153 removed. Furthermore, since the separation and contact mechanisms for the drive side and non-drive side have the same configuration, the drive side will be used for explanation.

[0104] First, the state in which the developing unit 109 is in the separated position will be described. In this state, the abutting portion 151Rc of the restricting member 151R contacts the abutted portion 116c of the drive-side housing member 116. Furthermore, the developing unit 109 is pushed toward the photosensitive drum 104 by the action of the developing pressure spring (not shown) provided on the non-drive side. At this time, the abutting portion 151Rc of the restricting member 151R is pushed toward the abutted portion 116c of the drive-side housing member 116. Therefore, the drive-side housing member 116 maintains the developing roller 106 separated from the photosensitive drum 104 by (across) the restricting member 151R, in a manner that resists the force of the developing pressure spring (not shown). That is, the drum unit 108 is positioned and the developing unit 109 is held in place by the restricting member 151R. At this time, the photosensitive drum 104 and the developing roller 106 are separated by a gap P1. Set this state to the separated position (first position) Figure 12 , Figure 14A (state).

[0105] From this state, the pushed-in portion 152Re of the moving member 152R is pushed in the Z2 direction. As a result, the protrusion 152Rh of the moving member 152R moves towards the protruding position protruding from the developing frame 125. Furthermore, if the second force-bearing portion 152Rn is pushed in the direction of arrow X2, the moving member 152R rotates about the support portion 128k in the direction of arrow BB. The limiting member pressing surface 152Rr of the moving member 152R, by pushing the limited portion 151Re of the moving member 151R, causes the limiting member 151R to... Figure 12 The developing unit 109 rotates in the direction of arrow B2. If the limiting member 151R rotates in the direction of arrow B2, the abutting part 151Rc moves away from the abutted part 116c of the drive-side housing member 116, and the developing unit 109 can rotate from the separation position in the direction of arrow V2 about the swing axis K. That is, when the developing unit 109 rotates from the separation position in the direction of V2, the developing roller 106 abuts against the photosensitive drum 104. Here, the state in which the developing roller 106 abuts against the photosensitive drum 104 is defined as the abutting position (second position). Figure 14C (state).

[0106] Next, the movement from the contact position to the separation position will be explained. If the developing unit 109, in the contact position, pushes the first force-bearing part 152Rk of the moving member 152R in the direction of arrow X1, the moving member 152R rotates in the direction of arrow BA (see reference). Figure 14C The bearing pressing surface 152Rq abuts against the pressed surface 126c of the drive-side bearing 126 (refer to...). Figure 15 Therefore, the developing unit 109 rotates about the swing axis K in the direction of arrow V1, moving towards the separation position. Figure 15(state).

[0107] Furthermore, regarding the separation and abutment mechanism of this embodiment, if the moving member 152R is not pushed in the direction of arrow Z2, the moving member 152R cannot move in the direction of arrow X2. This is because, as Figure 14A As shown, the rib 128g of the developing mask member 128 interferes with the surface 152Rg of the opposing moving member 152R. Therefore, unless the moving member 152R is pushed in the direction of arrow Z2 so that the surface 152Rg is no longer facing the rib 128g, the restricting member 151R cannot be moved to the contact position.

[0108] (Description of the drum cover components and the housing protective assembly)

[0109] use Figure 1A and Figure 1B , Figure 16 , Figure 17 , Figure 18 , Figure 19 , Figure 20 , Figure 21 , Figure 22 , Figure 23 , Figure 24 The drum cover member 501 and the housing protection assembly 100X involved in this embodiment will be described. The drum cover member 501 is used to be installed on the processing housing 100 that has been removed from the device body 170. For the processing housing 100 removed from the device body 170, a part of the processing mechanism contained in the processing housing 100, especially a part of the peripheral surface of the photosensitive drum 104, is exposed to the outside. In order to prevent the user's hand from touching the exposed part or to prevent foreign objects such as dust from adhering to the exposed part, the drum cover member 501 is installed. The drum cover member 501 is installed on the processing housing 100 in a manner that covers the exposed part. Needless to say, if the processing housing 100 is in the state of having the drum cover member 501 installed, it cannot be installed on the device body 170. When the processing housing 100 is installed on the device body 170, the drum cover member 501 is removed from the processing housing 100. This refers to the state (style) of the processing box 100 after it has been disassembled from the main body 170 and the drum cover component 501 has been installed, that is, the processing box 100 and the drum cover component 501 are integrated into a structure, which is called the box protection assembly 100X in this embodiment.

[0110] Figures 16-19 The diagram shows the case protection assembly 100X disassembled (the case 100 separated from the drum cover member 501) to illustrate the configuration of the mounting portion between the case 100 and the drum cover member 501. Figure 16 This is an exploded perspective view of the box protection assembly 100X viewed from the drive side and the processing box 100 side, that is, an exploded perspective view showing the processing box 100 separated from the drum cover member 501. Figure 17This is an exploded perspective view of the box protection assembly 100X viewed from the drive side and the drum cover member 501 side, that is, an exploded perspective view showing the state in which the processing box 100 is separated from the drum cover member 501. Figure 18 This is an exploded perspective view of the housing protection assembly 100X viewed from the non-driving side and the side of the processing housing 100, that is, an exploded perspective view showing the processing housing 100 separated from the drum cover member 501. Figure 19 This is an exploded perspective view of the box protection assembly 100X viewed from the non-driving side and the drum cover member 501 side, that is, an exploded perspective view showing the state in which the processing box 100 is separated from the drum cover member 501.

[0111] Figure 20 , Figure 21 , Figure 22 The image shows the completed installation of the drum cover component 501 onto the processing box 100. Figure 20 This is a 3D view of the 100X box protection assembly from the driver side. Figure 21 This is a side view of the drive side of the box protection assembly 100X. Figure 22 This is a front view of the box protection assembly 100X, which is orthogonal to the length direction (Y direction in the figure) of the processing box 100 and viewed from the drum unit 108 side.

[0112] Figure 1A yes Figure 21 The A-A section at the intersection of the axis center of the photosensitive drum 104 and the Z-direction in the figure (a cross-sectional view viewed from the side of the developing unit 109). Figure 1B From Figure 21 A-A section ( Figure 1A A cross-sectional view of the processing box 100 with the drum cover component 501 installed at the B-B section offset in the X1 direction of the figure. Figure 1A The diagram shows cross-sectional views of the gear side and non-gear side at section A-A, with the central portion omitted. Figure 1B A cross-sectional view of the non-gear side at section B-B is shown. That is, in Figure 1A and Figure 1B In the diagram, the non-drive side configuration of the processing box 100 and the drum shroud member 501 is shown in sections A-A and B-B, while the drive side configuration is shown in section A-A.

[0113] Figure 23 From Figure 22 The C-C section of the processing box 100 viewed from the non-driving side shows the state in which the drum cover component 501 is installed in the processing box 100. Figure 24This is a cross-sectional view illustrating the configuration of the engaging part (retained part) for forming the state (retained state) in which the drum cover member 501 and the processing box 100 are locked together. Figure 24 (A) is from Figure 21 A-A section ( Figure 1A ) shifted towards direction X1 in the diagram and from Figure 21 B-B section ( Figure 1B A cross-sectional view of the processing box 100 with the drum cover component 501 installed at the C-C section offset in the X2 direction of the figure. Figure 24 (B) is from Figure 21 A-A section ( Figure 1A A cross-sectional view of the processing box 100 with the drum cover component 501 installed at the D-D section offset in the X2 direction of the figure.

[0114] like Figures 16-19 As shown, the drum cover member 501 is mounted on the processing cartridge 100 along its length direction, covering a portion of the exposed area of ​​the photosensitive drum 104 within the processing cartridge 100. The drum cover member 501 has engaging portions 501E1 and 501E2 that engage with both ends of the frame in the length direction of the processing cartridge 100, respectively. Between these engaging portions 501E1 and 501E2 is a cover portion 501F that covers the exposed portion of the photosensitive drum 104. The drive-side engaging portion 501E2 (the second engaging portion) is configured to engage with one end (the second end) in the length direction, which is the drive-side end of the processing cartridge 100, and is provided with drive-side locking claws 501q and 501r. The non-drive-side engaging portion 501E1 (the first engaging portion) is configured to engage with the other end (the first end) in the length direction, which is the non-drive-side end of the processing cartridge 100, and is provided with non-drive-side locking claws 501s and 501t. The cover portion 501F is provided in a manner that extends in the length direction of the processing box 100 (photosensitive drum 104) between the drive-side engaging portion 501E2 and the non-drive-side engaging portion 501E1.

[0115] The drive-side locking claws 501q and 501r of the drive-side engaging portion 501E2 of the drum cover member 501 engage with the locking groove 116r of the drive-side cover member 116 (second end support portion). The drive-side cover member 116 is the portion that supports the drive-side end (second end) of the photosensitive drum 104 in the frame of the processing box 100. The locking groove 116r (second recess) has a shape that is recessed in the Y1 direction (second direction) along the length direction. The drive-side engaging portion 501E2 has an extension portion 501h2 (second extension portion) that extends in a direction intersecting the length direction so as to have a portion that overlaps with the locking groove 116r when viewed in the length direction. The drive-side locking claws 501q and 501r (second protrusions) are provided in such a way that they protrude from the extension portion 501h2 in the Y1 direction along the length direction. In this embodiment, the extension 501h2 is configured to extend in a direction orthogonal to the length direction, but it can also be configured to extend in a direction having an angle relative to the orthogonal direction, as long as the desired engagement state can be formed.

[0116] The non-drive side locking claws 501s and 501t of the non-drive side engaging portion 501E1 of the drum cover member 501 engage with the locking grooves 117s and 117t of the non-drive side cover member 117 (first end support portion). The non-drive side cover member 117 is the portion that supports the non-drive side end (first end) of the photosensitive drum 104 in the frame of the processing box 100. The locking grooves 117s and 117t (first recesses) have a shape that is recessed in the Y2 direction (first direction) along the length direction. The non-drive side engaging portion 501E1 has an extension portion 501h1 (first extension portion) that extends in a direction intersecting the length direction so as to have a portion that overlaps with the locking grooves 117s and 117t when viewed in the length direction. The non-drive side locking claws 501s and 501t (first protrusions) are provided in such a way that they protrude from the extension portion 501h1 in the Y2 direction along the length direction. In this embodiment, the extension 501h1 is configured to extend in a direction orthogonal to the length direction. However, as long as the desired engagement state can be formed, it can also be configured to extend in a direction having an angle relative to the orthogonal direction. Details of the locking grooves 117s and 117t will be described later.

[0117] Through the above-described interlocking mechanism, the drum cover component 501 can be detachably assembled with respect to the processing box 100. Figure 20 (State of the process). When the drum cover member 501 is assembled to the processing cartridge 100, the limiting rib 501K, described later, adjusts the photosensitive drum 104 in the processing cartridge 100 by inserting it into a predetermined gap between the frame of the processing cartridge 100 and the photosensitive drum 104. For example, the drum cover member 501 is assembled to the processing cartridge 100 after the photosensitive drum 104 is positioned such that it is offset relative to the frame of the processing cartridge 100 in the longitudinal direction.

[0118] like Figure 1A and Figure 1B As shown, the photosensitive drum 104 is a unit integrating three components by pressing the drum flange 142 and coupling member 143 into the openings at both ends of the drum cylinder 104a and reinforcing them. The drum unit 108 rotatably supports both ends of the photosensitive drum 104. That is, on the non-drive side, the shaft portion of the drum flange 142 is rotatably supported by the drum support hole 117b of the non-drive side housing member 117. In addition, 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 housing member 116.

[0119] First, the structure of the non-driving side of the box protection assembly 100X will be described in detail. For example, cross-section A-A ( Figure 1A As shown on the non-driving side, a gap s1 exists 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 restricted portion) 117a of the non-driving side housing member 117. That is, the non-driving side housing member 117 has a first opposing surface 117a, which is the first restricted surface, facing the first surface 142a of the drum flange 142 in the Y2 direction (first direction) along the longitudinal direction. Considering dimensional deviations of the associated components and usage in various environments (high to low temperatures), a gap s1 is provided within the processing housing 100 so that the components can move (rotate) smoothly without interfering with each other. In other words, to ensure stable rotation of the photosensitive drum 104 during image formation, the photosensitive drum 104 is configured to allow movement within a predetermined range in the longitudinal direction relative to the frame of the processing housing 100. In this embodiment, the length of the gap s1 in the longitudinal direction is set to 1.2 mm, which is the range of motion of the photosensitive drum 104 allowed when the drum cover member 501 is detached from the frame of the processing box 100. In other words, when the drum cover member 501 is detached from the frame of the processing box 100, the range of motion of the photosensitive drum 104 relative to the frame is limited to the range specified above as the first range.

[0120] Additionally, such as the B-B section ( Figure 1BAs shown, the drum cover member 501 has a locking claw 501t that engages with the locking groove 117t of the non-drive side cover member 117. To assemble the drum cover member 501 toward the processing box 100 (in the Z1 direction in the figure), the locking claw 501t is retracted in the direction of arrow N in the figure, extending beyond the lower side 117u of the locking groove, and locking with the locking groove 117t. Furthermore, when disassembling the locked drum cover member 501 in the direction away from the processing box 100 (in the Z2 direction in the figure), it will not disengage unless a force is applied to flex the locking claw 501t in the N direction. To allow the aforementioned displacement of the locking claw 501t, the drum cover member 501 is configured such that at least the components (extensions 501h1, etc.) supporting the locking claw 501t can elastically deform.

[0121] Additionally, such as section A-A ( Figure 1A As shown on the drive side, the drum cover member 501 has a locking claw 501q that engages with the locking groove 116r of the drive side cover member 116. To assemble the drum cover member 501 toward the processing box 100 (in the Z1 direction in the figure), the locking claw 501q is retracted in the direction of arrow G in the figure, extending beyond the lower side 116u of the locking groove, and locking with the locking groove 116r. Furthermore, when disassembling the locked drum cover member 501 in the direction away from the processing box 100 (in the Z2 direction in the figure), it will not disengage unless a force is applied to flex the locking claw 501q in the G direction. To allow the aforementioned displacement of the locking claw 501q, the drum cover member 501 is configured such that at least the components (extensions 501h2, etc.) supporting the locking claw 501q can elastically deform.

[0122] As described above, the locked drum cover member 501 is configured to be selectively detachable from the drive side and non-drive side relative to the processing box 100.

[0123] Furthermore, as shown in section B-B, facing the fifth restricted portion 117c of the non-drive side cover member 117, the drum cover member 501 has a fifth restricted portion 501c (the third protrusion). The fifth restricted portion 501c is a protrusion that protrudes from the cover portion 501F in a direction intersecting the length direction relative to the non-drive side engaging portion 501E1 of the drum cover member 501 in the Y2 direction. The fifth restricted portion 501c protrudes in such a way that it overlaps with the fifth restricted portion 117c when viewed in the length direction. After the drum cover member 501 is engaged, the fifth restricted portion 117c and the fifth restricted portion 501c are in a contacting (abutting) state in the length direction (Y1 direction) (gap T1 = 0). In this embodiment, the fifth limiting part 501c is configured to protrude in a direction orthogonal to the length direction, but it may also be configured to extend in a direction having an angle relative to the orthogonal direction, as long as the desired contact state can be formed with respect to the fifth limited part 117c.

[0124] As shown in the non-driving side of the A-A cross section, the drum cover member 501 has a limiting rib 501K (first protrusion). The limiting rib 501K is a protrusion that protrudes from the cover portion 501F in a direction intersecting the length direction relative to the non-driving side engaging portion 501E1 and the fifth limiting portion 501c of the drum cover member 501 in the Y2 direction. The limiting rib 501K protrudes in such a way that it overlaps with the second limited portion 142b of the drum flange 142, which is the first end of the photosensitive drum 104, when viewed in the length direction. The limiting rib 501K is provided facing each other with a gap relative to the second limited portion 142b in the length direction. The limiting rib 501K is a limiting portion configured such that when the photosensitive drum 104 moves in the length direction, it limits the movable range of the photosensitive drum 104 relative to the frame of the processing cartridge 100 to a predetermined range by contacting the length direction end face of the photosensitive drum 104. In this embodiment, the limiting rib 501K is configured to protrude in a direction orthogonal to the length direction, but it can also be configured to extend in a direction having an angle relative to the orthogonal direction, as long as the movement of the photosensitive drum 104 in the length direction can be limited within the desired range.

[0125] Figure 23 As mentioned above, Figure 22 The C-C section of the processing box 100 at the non-drive side section line C-C shows the state in which the drum cover member 501 is installed. The limiting rib 501K is as follows... Figure 23 As shown, a second limiting portion 501b is provided facing the second limiting portion 142b of the drum flange 142. When the photosensitive drum 104 is viewed in the longitudinal direction, the second limiting portion 142b overlaps with the second limiting portion 501b. Furthermore, as shown... Figure 1A As shown, in the longitudinal direction (Y direction in the figure) of the photosensitive drum 104, there is a gap u1 between the second restricted portion 142b and the second restricted portion 501b. The gap u1 is set to be smaller (narrower) than the gap s1 (u1 < s1).

[0126] Next, the configuration of the drive side of the box protection assembly 100X will be described in detail. For example... Figure 1A As shown in the driving side of the A-A section, the third surface (third restricted part) 143a of the coupling member 143 and the third facing surface (third restricted part) 116a of the driving side cover member 116 are in contact in the length direction (Y direction in the figure) (gap T2 = 0).

[0127] Here, the configuration of the charged roller 105 and the photosensitive drum 104 will be explained. For example... Figure 1A and Figure 1BAs shown, the drum frame 115 supports the non-drive side charged roller bearing 120b and the drive side charged roller bearing 120a, allowing them to move approximately in the Z direction. The non-drive side charged roller bearing 120b and the drive side charged roller bearing 120a rotatably support the core portions 105b and 105a at both ends of the charged roller 105. Between the drum frame 115 and the non-drive side charged roller bearing 120b and the drive side charged roller bearing 120a, pressure springs 121b and 121a are respectively provided, applying force to the charged roller 105 toward the photosensitive drum 104 with a predetermined pressure.

[0128] As described above, there is a gap s1 between the photosensitive drum 104 and the non-drive side cover member 117 and drive side cover member 116 disposed on both sides thereon. Therefore, in the state where the drum cover member 501 is not installed, during the transport of the processing cartridge 100 or during user processing, there is a possibility that the photosensitive drum 104 may move relative to the frame of the processing cartridge 100 in the length direction (Y direction in the figure) by the amount of gap s1. In addition, there is a possibility that it may repeatedly reciprocate in the length direction (Y direction in the figure).

[0129] As a result, the following possibilities can be listed: sliding friction occurs at the contact portion on the photosensitive drum 104 that abuts against the charged roller 105, generating charged memory based on the state of sliding friction, resulting in horizontal stripes in the printed image. This occurs when the processing cartridge 100 is not equipped with the drum cover component 501. Figure 10 The state shown.

[0130] The most distinctive feature of this embodiment is that the relative movement of the photosensitive drum 104 relative to the frame of the processing box 100 in the longitudinal direction is suppressed by the limiting rib 501K provided on the drum cover member 501. Figure 1A and Figure 1B As shown, when the drum cover member 501 is installed, when the photosensitive drum 104 moves in the longitudinal direction (Y1 direction in the figure), the second restricted portion 142b of the drum flange 142 abuts against the second restricted portion 501b of the restricting rib 501K of the drum cover member 501. A gap u1 is provided between the second restricted portion 142b and the second restricted portion 501b in the longitudinal direction. Therefore, it is possible that the photosensitive drum 104 moves only by the gap u1 in the longitudinal direction (Y1 direction in the figure). Alternatively, it is possible that the photosensitive drum 104 repeatedly reciprocates in the longitudinal direction (Y direction in the figure) with a movement amount equivalent to the gap u1. In this embodiment, the gap u1 is set to 0.4 mm.

[0131] That is, the size (interval) of the gap u1 between the photosensitive drum 104 and the drum housing member 501, which allows relative movement in the longitudinal direction, is set to be smaller (shorter) than the gap s1 between the photosensitive drum 104 and the drum unit 108, which allows relative movement in the longitudinal direction, when the drum housing member 501 is not installed (u1 < s1). In other words, by using the limiting rib 501K as a limiting part, the movable range of the photosensitive drum 104 relative to the frame of the processing cartridge 100 is limited to a second range u1 that is narrower than s1, which is the first range. This reduces the amount of longitudinal movement of the photosensitive drum 104 within the drum unit 108 (the frame of the processing cartridge 100). Consequently, the sliding friction distance of the contact portion on the photosensitive drum 104 that abuts against the charged roller 105 can be suppressed, and the generation of charged memory caused by the sliding friction of the contact portion between the photosensitive drum 104 and the charged roller 105 in the longitudinal direction can be suppressed. Furthermore, this provides the user with a better printed image.

[0132] Furthermore, the limiting rib 501K is integrally provided with the drum cover member 501. Therefore, the limiting rib 501K is also released simultaneously with the action of removing the drum cover member 501 from the processing box 100 when the user installs the processing box 100 into the device body 170. Thus, for example, compared to cases where the limiting rib is separate from the drum cover member and needs to be released separately from the drum cover member, the limiting release process becomes simpler, and there is no need to worry about the user forgetting to release the limiting rib 501K.

[0133] That is, according to this embodiment, the limiting configuration that restricts the longitudinal movement of the photosensitive drum 104 relative to the processing cartridge 100 detached from the device body 170 is integrally formed with the drum cover member 501 for covering the exposed portion of the photosensitive drum 104. Therefore, by simply installing the drum cover member 501 onto the processing cartridge 100, a state in which the exposed portion of the photosensitive drum 104 is covered and the longitudinal movement of the photosensitive drum 104 is restricted can be achieved. Furthermore, when the processing cartridge 100 is installed onto the device body 170, the drum cover member 501 needs to be removed. By simply removing the drum cover member 501, both the cover configuration and the limiting configuration are simultaneously released. In other words, with a simple and low-cost configuration, protection of the exposed portion of the photosensitive drum 104 during transport or storage of the processing cartridge 100 and suppression of sliding between the photosensitive drum 104 and components in contact with it can be achieved without causing user errors.

[0134] Furthermore, when the drum housing member 501 is mounted in the processing cartridge, the gap u1, which allows for relative displacement in the longitudinal direction between the drum housing member 501 and the photosensitive drum 104, is smaller than the gap s1 (u1 < s1). Therefore, due to dimensional deviations of the associated components, or due to changes in the operating environment (e.g., from high to low temperature), there is a possibility that contact or interference between the components would not occur if the gap s1 were present. However, the drum housing member 501 is mounted during non-printing (non-image forming operation), therefore, such contact or interference between the components does not directly affect the image forming accuracy. Therefore, it can be configured such that the aforementioned interference is absorbed by the deformation of the constituent components of the cartridge protection assembly 100X during the mounting of the drum housing member 501. Since the photosensitive drum 104 is in a non-rotating state, contact in the longitudinal direction of the associated components is permitted.

[0135] Based on the above configuration, when the drum cover member 501 is installed, the gap in the longitudinal direction of the photosensitive drum 104 can be reduced. When the drum cover member 501 is disassembled (during printing), a predetermined gap s1 can be maintained that does not affect the rotation of the photosensitive drum 104. As mentioned above, the gap s1 refers to the gap 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 restricted portion) 117a of the non-drive side cover member 117.

[0136] Here, as one of the cleaning mechanisms used in the processing box, a cleaning component (not shown) can be cited. The cleaning component removes waste toner from the surface of the photosensitive drum. For example, the cleaning component consists of a rubber scraper as an elastic member and a support member supporting the rubber scraper. The support member is fixed to the cleaning frame such that the rubber scraper abuts against the photosensitive drum in the opposite direction of its rotation. The removed waste toner accumulates in a waste toner chamber formed by the cleaning frame and the cleaning component.

[0137] The processing cartridge 100 in this embodiment does not use (does not have) a cleaning member, and the load on the brake of the photosensitive drum 104, which is rotatably supported on the frame, is smaller than that of a processing cartridge that uses a cleaning member. Therefore, it is configured such that the photosensitive drum 104 can move more easily in the longitudinal direction (Y direction in the figure) within the processing cartridge 100. Thus, according to the aforementioned configuration of the cartridge protection assembly 100X, it is important to reduce the amount of movement of the photosensitive drum 104 in the longitudinal direction (Y direction in the figure) within the processing cartridge 100.

[0138] (Example 2)

[0139] use Figure 25The box protection assembly 100X2 (processing box 100 and drum cover member 511) according to Embodiment 2 of the present invention will be described. Furthermore, in the following description of Embodiment 2, descriptions of configurations common to Embodiment 1 are omitted. Matters not specifically described herein in Embodiment 2 are common to Embodiment 1. Additionally, regarding a portion of the configuration of Embodiment 2, reference numerals with letters added to "501" in Embodiment 1 are used in Embodiment 2 to indicate configurations with letters added to "511".

[0140] Figure 25 (A) is in the Z direction of the diagram and Figure 21 The A-A section at the intersection of the axis center of the photosensitive drum 104. Figure 25 (B) is from Figure 21 A-A section ( Figure 25 A cross-sectional view of the processing box 100 with the drum cover component 511 installed at the B-B section offset in the X1 direction of the figure (A). Figure 25 (A) shows a cross-sectional view of the drive side (GearSide) and non-drive side (NonGear Side) at section A-A, with the central portion omitted. Figure 25 (B) shows a cross-sectional view of the non-gear side at section B-B. That is, in Figure 25 In the diagram, the non-driving side configuration of the processing box 100 and the drum cover member 511 is represented by sections A-A and B-B, while the driving side configuration is represented by section A-A.

[0141] The difference between Embodiment 2 and Embodiment 1 lies in the configuration of the limiting rib 511K. The limiting rib 511K is a protrusion that extends from the cover portion 501F in a direction intersecting the length direction, relative to the non-driving side engaging portion 501E1 of the drum cover member 511 and the fifth limiting portion 511c, inside the Y2 direction. The limiting rib 511K protrudes in such a way that it overlaps with the second limiting portion 142b of the drum flange 142, which is the first end of the photosensitive drum 104, when viewed in the length direction. The most characteristic configuration of Embodiment 2 is that the limiting rib 511K provided on the drum cover member 501 restricts the relative movement of the photosensitive drum 104 relative to the frame of the processing cartridge 100 in the length direction. That is, the limiting rib 501K of Embodiment 1 has a gap u1 between itself and the second limiting portion 501b, allowing for a certain degree of relative movement. In contrast, in Embodiment 2, the limiting rib 511K is configured to contact (aggress) the second limited portion 142b of the drum flange 142 of the photosensitive drum 104 without any gap. More specifically, it is configured such that, with the drum cover member 511 mounted on the processing box 10, the second limiting portion 511b of the limiting rib 511K of the drum cover member 511 contacts the second limited portion 142b of the drum flange 142 of the photosensitive drum 104 (T3 = 0). Except for the above configuration, the configuration of Embodiment 2 is the same as that of Embodiment 1.

[0142] Based on the above configuration, the cartridge protection assembly 100X2 (drum cover member 511) according to this embodiment can eliminate the possibility of the photosensitive drum 104 moving in the longitudinal direction (Y direction in the figure). Therefore, the sliding friction distance of the contact portion on the photosensitive drum 104 that abuts against the charged roller 105 can be suppressed, and the generation of charged memory caused by the sliding friction of the contact portion between the photosensitive drum 104 and the charged roller 105 in the longitudinal direction can be suppressed. Furthermore, it can provide the user with a good printed image.

[0143] (Example 3)

[0144] use Figure 26 The box protection assembly 100x3 (processing box 100 and drum cover member 521) according to Embodiment 3 of the present invention will be described. Furthermore, in the following description of Embodiment 3, descriptions of configurations common to Embodiments 1 and 2 are omitted. Matters not specifically described herein in Embodiment 3 are common to Embodiments 1 and 2. Additionally, regarding a portion of the configuration of Embodiment 3, reference numerals with letters added above "501" in Embodiment 1 are used in Embodiment 3 to indicate configurations with letters added above "521".

[0145] Figure 26 (A) is in the Z direction of the diagram and Figure 21 The A-A section at the intersection of the axis center of the photosensitive drum 104. Figure 26 (B) is from Figure 21 A-A section ( Figure 26 A cross-sectional view of the processing box 100 with the drum cover component 521 installed at the B-B section offset in the X1 direction of the figure (A). Figure 26 (A) shows a cross-sectional view of the drive side (GearSide) and non-drive side (NonGear Side) at section A-A, with the central portion omitted. Figure 26 (B) shows a cross-sectional view of the non-gear side at section B-B. That is, in Figure 26 In the diagram, the non-drive side configuration of the processing box 100 and the drum shroud member 521 is shown by sections A-A and B-B, and the drive side configuration is shown by section A-A.

[0146] The case protection assembly 100X3 in Embodiment 3 is similar to the case protection assembly 100X in Embodiment 1, and is provided with a gap s1 that allows relative movement of the photosensitive drum 104 in the longitudinal direction within the processing case 100. That is, as Figure 26 As shown on the non-drive side of (A), considering the dimensional deviations of the associated components and the use in various environments (high temperature to low temperature), a gap s1 is provided in the processing box 100 so that the components can move (rotate) smoothly without interference with each other.

[0147] The difference between Example 3 and Example 1 lies in the configuration of the drive side. Specifically, as follows: Figure 26 As shown on the driving side of (A), a gap s2 exists in the length 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 restricted portion) 116a of the driving side cover member 116. That is, the driving side cover member 116 has a third opposing surface 116a, which is the second restricted surface, facing the third surface 143a of the coupling member 143 in the Y1 direction (second direction) along the length direction. As a result, compared with Embodiment 1, the movable amount (prescribed range) (s1+s2) of the photosensitive drum 104 in the length direction (Y direction in the figure) when the drum cover member 521 is not installed is set to a larger extent. The configuration of Embodiment 3 is the same as that of Embodiments 1 and 2 except for the above configuration.

[0148] Similar to Example 1, in Example 3, as... Figure 26As shown on the non-driving side of (A), the gap u1 is also set to be smaller (narrower) than the gap s1 (u1 < s1). Therefore, the sum of the movable amounts of the photosensitive drum 104 in the longitudinal direction (Y direction in the figure) when the drum cover member 521 is installed becomes u1 + s2. On the other hand, the sum of the movable amounts of the photosensitive drum 104 in the longitudinal direction (Y direction in the figure) when the drum cover member 521 is not installed becomes s1 + s2. Therefore, the length (range) of the distance by which the photosensitive drum 104 is allowed to move relatively in the longitudinal direction within the processing cartridge 100 is shortened (narrowed) by installing the drum cover member 521 (u1 + s2 < s1 + s2).

[0149] Based on the above configuration, with the drum cover member 521 installed, the sliding friction distance of the contact portion on the photosensitive drum 104 that abuts against the charged roller 105 can be suppressed. This suppresses the generation of charged memory caused by sliding friction along the length of the contact portion between the photosensitive drum 104 and the charged roller 105. Consequently, it provides the user with a high-quality printed image.

[0150] (Example 4)

[0151] use Figure 27 The box protection assembly 100x4 (processing box 100 and drum cover member 521) according to Embodiment 4 of the present invention will be described below. Furthermore, in the following description of Embodiment 4, descriptions of configurations common to Embodiments 1, 2, and 3 will be omitted. Matters not specifically described herein in Embodiment 4 are common to Embodiments 1, 2, and 3. Additionally, regarding a portion of the configuration of Embodiment 4, the reference numeral "531" is used in Embodiment 4, whereas "501" in Embodiment 1 is replaced by a reference numeral "531".

[0152] Figure 27 (A) is in the Z direction of the diagram and Figure 21 The A-A section at the intersection of the axis center of the photosensitive drum 104. Figure 27 (B) is from Figure 21 A-A section ( Figure 27 A cross-sectional view of the processing box 100 with the drum cover component 531 installed at the B-B section offset in the X1 direction of the figure (A). Figure 27 (A) shows a cross-sectional view of the drive side (GearSide) and non-drive side (NonGear Side) at section A-A, with the central portion omitted. Figure 27 (B) shows a cross-sectional view of the non-gear side at section B-B. That is, in Figure 27 In the diagram, the non-drive side configuration of the processing box 100 and the drum shroud member 531 is shown by sections A-A and B-B, and the drive side configuration is shown by section A-A.

[0153] The difference between Example 4 and Example 1 lies in the configuration of the drive side. For example... Figure 27 As shown on the drive side of (A), a gap s2 is provided in the length direction (Y direction in the figure) between the third surface (third restricted part) 143a of the coupling member 143 and the third opposing surface (third restricted part) 116a of the drive-side cover member 116. Taking into account dimensional deviations of the associated components and usage under various environments (high temperature to low temperature), this gap is provided to allow the components inside the processing box 100 to move (rotate) smoothly without interference when the drum cover member 531 is removed. In Embodiment 4, in addition to the gap s1 described in Embodiment 1, a gap s2 is also provided as this gap.

[0154] like Figure 27 As shown on the drive side of (A) (A-A section), the drum cover member 531 has a limiting rib 531L (second protrusion). The limiting rib 531L is a protrusion that protrudes from the cover portion 501F in a direction intersecting the length direction relative to the drive side engaging portion 501E2 of the drum cover member 531 in the Y1 direction. The limiting rib 531L protrudes in such a way that it overlaps with the fourth limited portion 143b of the coupling member 143, which is the second end of the photosensitive drum 104, when viewed in the length direction. The limiting rib 531L is provided facing each other with a gap relative to the fourth limited portion 143b in the length direction. In this embodiment, the limiting rib 531L is configured to protrude in a direction orthogonal to the length direction, but it may also be configured to extend in a direction having an angle relative to the orthogonal direction, as long as the movement of the photosensitive drum 104 in the length direction can be limited within the desired range.

[0155] The limiting rib 531L and the fourth limited portion 143b of the coupling member 143 have a fourth limiting portion 531d facing each other. When the photosensitive drum 104 is viewed in the longitudinal direction, the fourth limited portion 143b and the fourth limiting portion 531d overlap. Furthermore, in the longitudinal direction (Y direction in the figure) of the photosensitive drum 104, there is a gap u2 between the fourth limited portion 143b and the fourth limiting portion 531d. The gap u2 is set to be smaller than the gap s2 (u2 < s2). Except for the above configuration, it is the same as the configuration in Embodiment 1.

[0156] Similar to Example 1, in Example 4, as... Figure 27As shown on the non-driving side of (A), the gap u1 is also set to be smaller (narrower) than the gap s1 (u1 < s1). Therefore, the sum of the movable amounts of the photosensitive drum 104 in the longitudinal direction (Y direction in the figure) when the drum cover member 531 is installed becomes u1 + u2. On the other hand, the sum of the movable amounts of the photosensitive drum 104 in the longitudinal direction (Y direction in the figure) when the drum cover member 531 is not installed becomes s1 + s2. Therefore, the length (range) of the distance by which the photosensitive drum 104 is allowed to move relatively in the longitudinal direction within the processing cartridge 100 is shortened (narrowed) by installing the drum cover member 531 (u1 + u2 < s1 + s2).

[0157] Based on the above configuration, with the drum cover member 531 installed, the sliding friction distance of the contact portion on the photosensitive drum 104 that abuts against the charged roller 105 can be suppressed. This suppresses the occurrence of charged memory caused by sliding friction along the length of the contact portion between the photosensitive drum 104 and the charged roller 105. Consequently, it provides the user with a high-quality printed image.

[0158] (Example 5)

[0159] use Figure 28 The box protection assembly according to Embodiment 5 of the present invention will be described. Furthermore, in the following description of Embodiment 5, descriptions of configurations common to Embodiments 1, 2, 3, and 4 are omitted. Matters not specifically described herein in Embodiment 5 are common to Embodiments 1, 2, 3, and 4. Additionally, regarding a portion of the configuration of Embodiment 5, the reference numeral "541" is used in Embodiment 5, whereas "501" in Embodiment 1 is replaced by a reference numeral "541".

[0160] Figure 28 (A) is Figure 25 Detailed enlarged view 1 (DT1) of the periphery of the limiting rib 511K in (Example 2), Figure 28 (B) is a detailed enlargement of the periphery of the limiting rib 541K, which is a different form from the limiting rib 511K. Figure 2 (DT2). When assembling the drum cover component 511 (541) into the processing box 100, it is necessary to assemble each component in the desired longitudinal positional relationship.

[0161] In particular, when the drum cover member 511 (541) is assembled toward the processing box 100 in the mounting direction E, contact or interference may occur between the drum cover member 511 (541) and the processing box 100, which are configured to be close to each other. Due to such contact or interference, there is a possibility that the installation of the drum cover member 511 (541) may be obstructed. In Embodiment 5, at the locations where such contact or interference may occur, a shape is provided to avoid obstruction of the installation of the drum cover member 511 (541). That is, during the installation of the drum cover member 511 (541), a chamfer shape 142d (511d) or a rounded corner shape (R shape) 142R (541R) is provided at the corners of the opposing ends between the second restricted portion 142b and the second restricted portion 511b (541b). Thus, the second restricted part 142b and the second restricted part 511b (541b) are configured to contact and slide in a manner that guides each other. This avoids the second restricted part 142b and the second restricted part 511b (541b) from interfering with each other and getting stuck, thereby preventing the installation of the drum cover member 511 (541) from being obstructed.

[0162] Furthermore, the end face (side face) of the limiting rib 511K (541K) facing the second restricted part 142b in the length direction (Y2 direction) is also provided as a tapered shape 511e (541e). The tapered shape 511e (541e) is an inclined surface shape that is inclined at an angle θ relative to the direction orthogonal to the length direction, such that the closer to the end face of the limiting rib 511K (541K) the more it is inclined to the direction opposite to the direction facing the second restricted part 142b (Y2 direction) (Y1 direction).

[0163] Therefore, when assembling the drum cover member 511 (541) into the processing box 100, each component can be easily assembled in the desired longitudinal positional relationship. In addition, the configuration shown in this embodiment is not only for the second restricted part 142b and the second restricted part 511b (541b), but the same effect can be obtained even when applied to other restricted parts and restricted parts.

[0164] In addition, in this embodiment, for those targeting Figure 25 The limiting rib 511K in (Example 2) has been described using the characteristic configuration of this embodiment described above, but it can also be applied to other embodiments. That is, in Figure 1A and Figure 1B (Example 1) Figure 26 (Example 3) Figure 27 In (Example 4), the DT1 portion also has a gap u1, but the aforementioned problem occurs when the drum cover component is assembled with the mounting direction E facing the processing box 100. Therefore, it is possible to apply [something] to each limiting rib. Figure 28 The interference avoidance shape is shown.

[0165] (Example 6)

[0166] Embodiment 6 of the present invention will be described. Embodiment 6 is an example illustrating the materials used for the drum cover members 501, 511, 521, 531, and 541 of each of Embodiments 1 to 5. Furthermore, in the following description of Embodiment 6, descriptions of configurations common to Embodiments 1 to 5 are omitted. Matters not specifically described herein in Embodiment 6 are common to Embodiments 1 to 5.

[0167] As described in Examples 1-5, when the drum cover member is installed in the processing box 100, since there is no printing, even if the associated components come into contact with each other, they can be rectified by deformation of the constituent components. To make the rectification obtained through deformation more reliable, in this embodiment, the drum cover member is made of a material with a lower Young's modulus than the material constituting the frame of the drum unit 108. Therefore, the deformation caused by contact can be reliably absorbed by the deformation of the drum cover member. The frame constituting the drum unit 108 corresponds to the drum frame 115, the drive-side cover member 116, and the non-drive-side cover member 117. In this embodiment, a polystyrene-based resin material is used for the frame of the drum unit 108, and a polypropylene-based resin material is used for the drum cover member. However, these specific materials are merely examples. That is, a combination of materials that produces the desired difference in deformability can also be used, even if the combination is different from the above-described materials.

[0168] Although the invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the claims is set forth for the broadest interpretation to cover all variations and equivalent structures and functions.

Claims

1. A case protection assembly used in the main body of an image forming apparatus, the case protection assembly comprising: A housing comprising a photosensitive drum and a frame, the frame rotatably supporting the photosensitive drum and covering the photosensitive drum with a portion of its peripheral surface exposed; and A cover member, which is detachably mounted to the frame such that it covers at least a portion of the aforementioned portion of the peripheral surface of the photosensitive drum. in, The frame is configured such that, when the photosensitive drum moves in the longitudinal direction while the cover member is detached from the frame, the movable range of the photosensitive drum relative to the frame in the longitudinal direction is limited to a first range by contacting the photosensitive drum. The frame has a first end support portion that supports a first end of the photosensitive drum in the length direction and a second end support portion that supports a second end of the photosensitive drum on the side opposite to the first end in the length direction. The above-mentioned cover component has: The retained part is held by the aforementioned frame; A cover portion extending in the aforementioned length direction and facing the aforementioned portion of the peripheral surface of the photosensitive drum exposed from the aforementioned frame in a direction intersecting the aforementioned length direction; and The limiting part is configured such that, when the photosensitive drum moves in the longitudinal direction while the cover member is mounted on the frame, it contacts the photosensitive drum and limits the movable range of the photosensitive drum relative to the frame to a second range smaller than the first range. The aforementioned retained part has: The first engaging portion engages with the frame to prevent the cover member from disengaging from the frame in a direction intersecting the length direction; and The second engaging portion engages with the frame to prevent the cover member from disengaging from the frame in the direction intersecting the length direction. The aforementioned cover extends along the aforementioned length direction between the aforementioned first engaging portion and the aforementioned second engaging portion. With the cover member installed on the frame, the limiting portion, which is located between the first engaging portion and the second engaging portion in the length direction, protrudes from the cover portion in a direction intersecting the length direction into the gap between the first end and the first end support portion of the photosensitive drum in the length direction. When the photosensitive drum moves along the length direction, the limiting portion contacts the first end of the photosensitive drum, thereby limiting the movable range to the second range. The box is configured such that, with the cover member detached from the frame, the box is mounted on the device body; and with the cover member mounted on the frame, the box cannot be mounted on the device body. When viewed along the aforementioned length direction, the distal end of the aforementioned limiting portion is located between the rotation axis of the aforementioned cover and the aforementioned photosensitive drum in the direction in which the limiting portion protrudes from the aforementioned cover.

2. The box protection assembly as claimed in claim 1, wherein, The aforementioned limiting portion is a protrusion that protrudes in a direction intersecting the aforementioned length direction in such a way that it overlaps with the aforementioned photosensitive drum when viewed in the aforementioned length direction.

3. The box protection assembly as described in claim 1, wherein, The first end support portion has a first limiting surface facing the first end in a first direction along the length direction. The second end support portion has a second limiting surface facing the second end in a second direction opposite to the first direction. The first range mentioned above is the sum of the distance between the first end and the first limiting surface in the length direction and the distance between the second end and the second limiting surface in the length direction. The sum of the distance between the first end and the limiting portion in the aforementioned length direction and the distance between the second end and the second limiting surface in the aforementioned length direction is less than the sum of the distance between the first end and the first limiting surface in the aforementioned length direction and the distance between the second end and the second limiting surface in the aforementioned length direction.

4. The box protection assembly as described in claim 3, wherein, The first end support portion has a first recess on its outer end face in the length direction. The second end support portion has a second recess on its outer end face in the length direction, which is recessed in the second direction. The first engaging part described above has: The first extension extends from the side of the cover member where the cover portion is provided in a direction intersecting the length direction, in such a way that it has a portion that overlaps with the first recess when viewed in the length direction. as well as The first protrusion protrudes from the first extension in the first direction and engages with the first recess. The second engaging part described above has: A second extension, which extends from the side of the cover member where the cover portion is provided, in a direction intersecting the length direction, such that it overlaps with the second recess when viewed in the aforementioned length direction; and The second protrusion protrudes from the second extension in the second direction and engages with the second recess.

5. The box protection assembly as described in claim 3 or 4, wherein, The aforementioned limiting portion serves as the first protrusion, and the cover member also has a second protrusion in the gap between the second end and the second end support portion. The second protrusion protrudes in a direction intersecting the length direction, such that it overlaps with the second end portion when viewed in the length direction, and faces the second end portion in the second direction. The sum of the distance between the first protrusion and the first end in the aforementioned length direction and the distance between the second protrusion and the second end in the aforementioned length direction is shorter than the aforementioned first range.

6. The box protection assembly as described in claim 3 or 4, wherein, The aforementioned cover member also has a third protrusion in the gap between the first end and the first end support. The third protrusion protrudes in a direction intersecting the length direction in such a way that it overlaps with the first end when viewed in the length direction, and abuts against the first end support in the second direction opposite to the first direction.

7. The box protection assembly as described in any one of claims 2 to 4, wherein, The corner of the far end of the aforementioned limiting part on the side facing the end of the aforementioned photosensitive drum has a chamfered shape or a rounded shape.

Images