Cartridge Unit

Abstract

To provide a technique that can improve workability of attachment and detachment of a cover member to and from a cartridge.SOLUTION: A cartridge protective assembly is to protect a cartridge B removably attached to an image forming apparatus body, and the cartridge protective assembly comprises: the cartridge B that includes a rotating body 62, and frame bodies 71, 73 rotatably supporting the rotating body 62, the frame bodies 71, 73 formed with an opening 71a for exposing part of an outer peripheral surface of the rotating body 62 and having a part to be engaged; and a cover member 1001 that has an engaging part to be engaged with the part to be engaged, covers at least part of the opening 71a, and is removably attached to the frame bodies 71, 73. The cover member 1001 has a light transmissivity of 40% or more in a portion including at least the engaging part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a protection assembly for a cartridge that is detachable from an electrophotographic image forming apparatus. [Background technology]

[0002] In image forming apparatuses that form images on recording media using an electrophotographic image forming method, a process cartridge type device configuration is known. That is, in order to facilitate toner supply and maintenance, a process cartridge in which a photosensitive member, charging means, developing means, cleaning means, etc. are integrated into a frame and made into a cartridge that can be detachably attached to the main body of the image forming apparatus has been put into practical use.

[0003] The cleaning frame of the process cartridge rotatably supports a photosensitive member, with a portion of the surface of the photosensitive member exposed through an opening in the frame. This creates the risk of the user coming into contact with the surface of the photosensitive member. If the user comes into contact with the surface of the photosensitive member, hand oils and the like may adhere to the surface of the photosensitive member, potentially causing image degradation. To prevent the user from coming into contact with the surface of the photosensitive member, the surface of the photosensitive member may be covered with a cover member. The cover member serves to protect against dust and prevent contact by the user.

[0004] Furthermore, when performing maintenance such as clearing a jam, a cartridge that has been installed in the main body may be removed and temporarily stored outside the main body. In this case, there is a possibility that the user will have to reattach the cover member. In this case, as described above, covering the surface of the photoreceptor with a cover member can prevent dust and user contact. In order to further reduce the risk of the user accidentally touching the surface of the photoreceptor, Patent Document 1 proposes a cover member and a sheet member attached to the cover member. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-207731 Summary of the Invention [Problem to be solved by the invention]

[0006] The cover member described in Patent Document 1 can be reattached to the cartridge after being removed once.

[0007] An object of the present invention is to provide a technique that can improve the workability of attaching and detaching a cover member to and from a cartridge. [Means for solving the problem]

[0008] In order to achieve the above object, the cartridge of the present invention unit teeth, Image forming device Equipment Removable cartridge for the main unit and the cartridge To protect a cover member that needs to be removed from the cartridge when the cartridge is mounted in the apparatus main body. cartridge unit And, The cartridge includes a photosensitive drum and The aforementioned Photosensitive drum It is a frame that supports the The above Photosensitive drum A part of the outer surface of Outside the cartridge Expose And also Engaged part was established A frame body and picture, The cover member is an engaging portion that engages with the engaged portion and , a cover portion that covers the part of the outer peripheral surface of the photosensitive drum, the cover member Of At least the engagement portion The cover is transparent or semi-transparent. It is characterized by: [Effects of the Invention]

[0009] According to the present invention, the workability of attaching and detaching the cover member to and from the cartridge can be improved. [Brief explanation of the drawings]

[0010] [Figure 1]FIG. 1 is a perspective view of a cartridge protection assembly according to a first embodiment of the present invention; [Figure 2] 1 is a cross-sectional view of an image forming apparatus according to a first embodiment of the present invention. [Figure 3] 1 is a cross-sectional view of a cartridge according to a first embodiment of the present invention; [Figure 4] FIG. 1 is an exploded perspective view of a cartridge according to a first embodiment of the present invention; [Figure 5] FIG. 1 is an exploded perspective view of a cartridge according to a first embodiment of the present invention; [Figure 6] 1 is a cross-sectional view of an image forming apparatus according to a first embodiment of the present invention. [Figure 7] 1 is a cross-sectional view of an image forming apparatus according to a first embodiment of the present invention. [Figure 8] 1 is a perspective view and a partial perspective view of an image forming apparatus according to a first embodiment of the present invention; [Figure 9] 1 is a perspective view of a cartridge and a cover member according to a first embodiment of the present invention; [Figure 10] FIG. 1 is a front view of a cartridge according to a first embodiment of the present invention; [Figure 11] 1 is a side view of a cartridge according to a first embodiment of the present invention; [Figure 12] 1A and 1B are a side view and a partial cross-sectional view of a cartridge according to a first embodiment of the present invention; [Figure 13] Transmittance measurement method [Figure 14] Relationship between color, thickness and light transmittance of cover material [Figure 15] FIG. 10 is a front view of a cartridge according to a second embodiment of the present invention. [Figure 16] FIG. 10 is a partial cross-sectional view of a cartridge according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] The following describes in detail exemplary embodiments of the present invention with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of the components described in the embodiments may be changed as appropriate depending on the configuration of the device to which the invention is applied and various conditions. In other words, the scope of the present invention is not limited to the following embodiments.

[0012] Example 1 An electrophotographic image forming apparatus forms an image on a recording medium using an electrophotographic image forming method. Examples of electrophotographic image forming apparatuses include electrophotographic copiers, electrophotographic printers (LED printers, laser beam printers, etc.), facsimile machines, and word processors. A process cartridge is a cartridge that integrates an electrophotographic photosensitive member and a process means that acts on the electrophotographic photosensitive member, and is removably mounted in the main body of an electrophotographic image forming apparatus. For example, a cartridge that integrates an electrophotographic photosensitive member and at least one of the process means, namely, a developing means, a charging means, and a cleaning means, may be used. Alternatively, the electrophotographic photosensitive member and the developing means may be separately packaged in cartridges, with the former being referred to as a photosensitive unit (or cleaning unit) and the latter being referred to as a developing unit. In the following description, the direction of the rotational axis of the electrophotographic photosensitive drum is defined as the longitudinal direction. In the longitudinal direction, the side on which the electrophotographic photosensitive drum receives a driving force from the main body of the image forming apparatus is defined as the driving side, and the opposite side is defined as the non-driving side.

[0013] The overall configuration and image forming process will be described with reference to Figures 2 and 3. Figure 2 is a cross-sectional view of an apparatus main body (electrophotographic image forming apparatus main body, image forming apparatus main body) A of an electrophotographic image forming apparatus according to one embodiment of the present invention and a process cartridge (hereinafter referred to as cartridge) B. Figure 3 is a cross-sectional view of cartridge B. Here, apparatus main body A refers to the portion of the electrophotographic image forming apparatus excluding cartridge B.

[0014] <Overall configuration of electrophotographic image forming apparatus> The electrophotographic image forming apparatus (image forming apparatus) shown in Figure 2 is a laser beam printer that uses electrophotographic technology and in which a cartridge B is detachably mounted in an apparatus main body A. When the cartridge B is mounted in the apparatus main body A, an exposure device 3 (laser scanner unit) is disposed for forming a latent image on an electrophotographic photosensitive drum 62 serving as an image carrier of the cartridge B. Also disposed below the cartridge B is a sheet tray 4 that stores a recording medium (hereinafter referred to as sheet material PA) on which an image is to be formed. The electrophotographic photosensitive drum 62 is a photosensitive member (electrophotographic photosensitive member) used for forming an electrophotographic image.

[0015] Furthermore, in the apparatus main body A, a pickup roller 5a, a pair of feeding rollers 5b, a transfer guide 6, a transfer roller 7, a conveyance guide 8, a fixing device 9, a pair of discharge rollers 10, a discharge tray 11, etc. are arranged in this order along the conveyance direction D of the sheet material PA. The fixing device 9 is composed of a heating roller 9a and a pressure roller 9b.

[0016] <Image formation process> Next, an outline of the image formation process will be described. Based on a print start signal, the electrophotographic photosensitive drum (hereinafter referred to as the photosensitive drum 62, or simply the photosensitive body 62 or the drum 62) is rotated in the direction of arrow R at a predetermined peripheral speed (process speed).

[0017] A charging roller (charging member) 66 to which a bias voltage is applied comes into contact with the outer peripheral surface of the drum 62 and uniformly charges the outer peripheral surface of the drum 62 (see FIG. 3). The exposure device 3 outputs a laser beam L corresponding to image information. The laser beam L passes through a laser aperture 71h provided in the cleaning frame 71 of the cartridge B and scans and exposes the outer peripheral surface of the drum 62. As a result, an electrostatic latent image corresponding to the image information is formed on the outer peripheral surface of the drum 62.

[0018] On the other hand, as shown in FIG. 3, in the developing unit 20 as a developing device, the toner T in the toner chamber 29 is stirred and transported by the rotation of the transport member (stirring member) 43, and is sent out to the toner supply chamber .

[0019] The toner T is carried on the surface of the developing roller 32 by the magnetic force of the magnet roller 34 (fixed magnet). The developing roller 32 is a developer carrier that carries developer (toner T) on its surface in order to develop the latent image formed on the drum 62. The toner T is frictionally charged by the developing blade 42, and the layer thickness on the circumferential surface of the developing roller 32 as a developer carrier is regulated.

[0020] The toner T is supplied to the drum 62 in accordance with the electrostatic latent image, and develops the latent image. This makes the latent image visible as a toner image. The drum 62 is an image carrier that carries on its surface the latent image and an image formed with toner (toner image, developer image). As shown in FIG. 2, a sheet material PA stored in the lower part of the apparatus main body A is fed from the sheet tray 4 by a pickup roller 5a and a pair of feed rollers 5b in synchronization with the output timing of the laser light L. The sheet material PA is then transported via a transfer guide 6 to a transfer position between the drum 62 and a transfer roller 7. At this transfer position, the toner image is sequentially transferred from the drum 62 to the sheet material PA.

[0021] The sheet material PA onto which the toner image has been transferred is separated from the drum 62 and transported along a transport guide 8 to a fixing device 9. The sheet material PA then passes through a nip between a heating roller 9a and a pressure roller 9b that constitute the fixing device 9. A pressure and heat fixing process is carried out at this nip, and the toner image is fixed to the sheet material PA. The sheet material PA, which has undergone the toner image fixing process, is transported to a pair of discharge rollers 10 and discharged onto a discharge tray 11.

[0022] 3, after transfer, the drum 62 has residual toner removed from its outer peripheral surface by a cleaning member 77, and is then used again in the image forming process. The toner removed from the drum 62 is stored in a waste toner chamber 71b of the cleaning unit 60. The cleaning unit 60 is a photosensitive drum unit having the photosensitive drum 62.

[0023] In the above, the charging roller 66, the developing roller 32, the transfer roller 7, and the cleaning member 77 are process means that act on the drum 62.

[0024] <Overall cartridge configuration> Next, the overall configuration of cartridge B will be described with reference to Figures 3, 4, and 5. Figure 3 is a cross-sectional view of cartridge B, and Figures 4 and 5 are exploded perspective views illustrating the configuration of cartridge B. Note that in this embodiment, the screws used to join the various parts will not be described.

[0025] The cartridge B has a cleaning unit (photosensitive member holding unit, drum holding unit, image carrier holding unit, first unit) 60 and a developing unit (developer carrier holding unit, second unit) 20.

[0026] As shown in Fig. 3, cleaning unit 60 as a first unit has a drum 62 as a first rotating body, a charging roller 66, a cleaning member 77, and a cleaning frame 71 as a first frame that supports these. On the drive side of drum 62, a drive-side drum flange 63 provided on the drive side is rotatably supported by a hole 73a of a drum bearing 73 (see Fig. 4). In a broad sense, drum bearing 73 and cleaning frame 71 can be collectively referred to as the cleaning frame.

[0027] 5, on the non-drive side, a hole (not shown) in the non-drive side drum flange is rotatably supported by a drum shaft 78 press-fitted into a hole 71c provided in the cleaning frame 71. Each drum flange is a bearing-supported part that is rotatably supported by a bearing part.

[0028] 3, in the cleaning unit 60, the charging roller 66 and the cleaning member 77 are each disposed in contact with the outer circumferential surface of the drum 62. The cleaning member 77 has a rubber blade 77a, which is a blade-shaped elastic member made of rubber as an elastic material, and a support member 77b that supports the rubber blade. The rubber blade 77a abuts against the drum 62 in a counter direction to the rotation direction R of the drum 62. In other words, the rubber blade 77a abuts against the drum 62 so that its tip faces upstream in the rotation direction R of the drum 62.

[0029] The waste toner removed from the surface of the drum 62 by the cleaning member 77 is collected in a waste toner chamber 71b formed by the cleaning frame 71 and the cleaning member 77. As shown in FIG. 3, a catch sheet 65 for preventing the waste toner from leaking from the cleaning frame 71 is provided on the edge of the cleaning frame 71 so as to come into contact with the drum 62.

[0030] The charging roller 66 is rotatably attached to the cleaning unit 60 via charging roller bearings 67 at both ends in the longitudinal direction of the cleaning frame 71. The longitudinal direction of the cleaning frame 71 (the longitudinal direction of the cartridge B) is approximately parallel to the direction in which the rotation axis of the drum 62 extends (axial direction). Therefore, hereinafter, when simply referring to the longitudinal direction or axial direction without any particular mention, this refers to the axial direction of the drum 62. The charge roller 66 is pressed against the drum 62 by a charging roller bearing 67 being pressed against the drum 62 by a biasing member 68. The charge roller 66 is rotated by the rotation of the drum 62.

[0031] 3, the developing unit 20 as the second unit has a developing roller 32 as a second rotating body, a developing container 23 as a second frame body that supports the developing roller 32, a developing blade 42, etc. The developing roller 32 is rotatably attached to the developing container 23 by bearing members 26 (FIG. 4) and 27 (FIG. 5) provided at both ends.

[0032] A magnet roller 34 is provided within the developing roller 32. A developing blade 42 is disposed in the developing unit 20 to regulate the toner layer on the developing roller 32. As shown in Figures 4 and 5, spacing members 38 are attached to both ends of the developing roller 32, and the developing roller 32 is held with a small gap between it and the drum 62 by the spacing members 38 coming into contact with the drum 62.

[0033] 3, a blowout prevention sheet 33 for preventing toner from leaking from the developing unit 20 is provided on the edge of the developing container 23 so as to abut against the developing roller 32. Furthermore, a transport member 43 is provided in the toner chamber 29 formed by the developing container 23 and the bottom member 22. The transport member 43 agitates the toner contained in the toner chamber 29 and transports the toner to the toner supply chamber 28.

[0034] As shown in FIGS. 4 and 5, the cartridge B is formed by combining the cleaning unit 60 and the developing unit 20. When combining the developing unit 20 and the cleaning unit 60, first, the center of the first developer support boss 26a of the bearing member 26 is aligned with the first hanging hole 71i on the drive side of the cleaning frame 71, and the center of the second developer support boss 27a of the bearing member 27 is aligned with the second hanging hole 71j on the non-drive side. Specifically, by moving the developing unit 20 in the direction of arrow G, the first developer support boss 26a and the second developer support boss 27a fit into the first hanging hole 71i and the second hanging hole 71j, respectively. This allows the developing unit 20 to be movably connected to the cleaning unit 60. More specifically, the developing unit 20 is rotatably connected to the cleaning unit 60. That is, the developing roller 32 is connected so as to be capable of approaching and retracting from the drum 62. The drum bearing 73 is then attached to the cleaning unit 60, completing the cartridge B.

[0035] In this embodiment, the non-drive-side urging member 46L (FIG. 5) and the drive-side urging member 46R (FIG. 4) are formed of compression springs. The urging forces of these springs allow the drive-side urging member 46L and the non-drive-side urging member 46R to urge the developing unit 20 toward the cleaning unit 60, thereby reliably pressing the developing roller 32 toward the drum 62. Furthermore, the developer container 23 is equipped with spacing members 38 attached to both ends of the developing roller 32. That is, the drum 62 and the developing roller 32 come into contact with each other at a predetermined contact pressure via the spacing members 38, so that the developing roller 32 is held at a predetermined distance from the drum 62, and their relative positions are determined.

[0036] <Cartridge installation> Next, the installation of cartridge B will be specifically described with reference to Figures 6(a), 6(b), 7(a), and 7(b). Figure 6(a) is a cross-sectional view of the drive-side guide portion of image forming apparatus A to explain the installation of cartridge B, and Figure 6(b) is a cross-sectional view of the non-drive-side guide portion of image forming apparatus A to explain the installation of cartridge B. Figure 7(a) is a cross-sectional view of the drive-side of image forming apparatus A to explain the positioning of cartridge B. Figure 7(b) is a cross-sectional view of the non-drive-side of image forming apparatus A to explain the positioning of cartridge B.

[0037] The installation of the cartridge B will now be described. As shown in FIGS. 6(a) and 6(b), the first drive The side plate 15 has upper guide rails 15g and 15h as guides, and the non-drive side plate 16 has upper guide rails 16d and 16e. The drum bearing 73 provided on the drive side of the cartridge B has a rotation-stopped portion 73c. ​​The cartridge B is mounted in a direction (arrow C) that is substantially perpendicular to the axis of the drum 62 (FIG. 3).

[0038] Furthermore, the cleaning frame 71 has, on the non-drive side in the longitudinal direction, a positioned portion 71d as a first positioning portion and a rotation-stopped portion 71f as a second positioning portion. When the cartridge B is mounted through the cartridge insertion opening 17 of the main body A of the apparatus, the rotation-stopped portion 73c of the cartridge B on the drive side is guided by the guide rail 15h of the main body A of the apparatus. On the non-drive side of the cartridge B, the positioned portion 71d and the rotation-stopped portion 71f of the cartridge B are guided by the guide rail 16d and guide rail 16e of the main body A of the apparatus. In this way, the cartridge B is mounted in the main body A of the apparatus.

[0039] Next, the state of closing the door 13 will be described. As shown in Figures 6(a), 6(b), 7(a), and 7(b), the first drive side plate 15 has an upper positioning portion 15a, a lower positioning portion 15b, and a rotation stop portion 15c for positioning, and the non-drive side plate 16 has a positioning portion 16a and an upper rotation stop portion 16c. The drum bearing 73 has an upper positioned portion (first positioned portion, first protrusion, first protrusion) 73d and a lower positioned portion (second positioned portion, second protrusion, second protrusion) 73f.

[0040] Furthermore, the cartridge pressing members 1 and 2 are rotatably attached to both axial ends of the opening / closing door 13. The cartridge pressing springs 19 and 21 are attached to both longitudinal ends of a front plate provided in the image forming apparatus A. The drum bearing 73 has a pressed portion 73e as a biasing force receiving portion, and the cleaning frame 71 has a pressed portion 71o on the non-drive side (see FIG. 3). By closing the opening / closing door 13, the pressed portions 73e and 71o of the cartridge B are pressed by the cartridge pressing members 1 and 2 biased by the cartridge pressing springs 19 and 21 of the apparatus main body A (see FIG. 7).

[0041] As a result, on the drive side, the positioned upper portion 73d, the positioned lower portion 73f, and the rotation stop portion 73c of the cartridge B are fixed to the positioning upper portion 15a, the positioning lower portion 15b, and the rotation stop portion 15c of the main assembly A of the apparatus, respectively. As a result, the cartridge B and the drum 62 are positioned on the drive side. Also, on the non-drive side, the positioned portion 71d and the rotation stop portion 71f of the cartridge B are fixed to the positioning portion 16a and the rotation stop portion 16c of the main assembly A of the apparatus, respectively. As a result, the cartridge B and the drum 62 are positioned on the non-drive side.

[0042] The above has been described as an example of a configuration for determining the position of cartridge B relative to the apparatus main body A, but this is not intended to limit the means for positioning. A configuration may be used in which the positioning portions are fixed by directly acting on the positioned portion 73d and the rotation-stopped portion 73f on the drive side of cartridge B and the positioned portion 71d and the rotation-stopped portion 71f on the non-drive side.

[0043] Next, the configuration in which cartridge B receives a driving force from the apparatus main assembly A will be described with reference to Figures 8(a), 8(b), 8(c), and 8(d). Figure 8(a) is a diagram showing the configuration of the drive unit of the apparatus main assembly A, and Figure 8(b) is a diagram showing the configuration of the drive unit of cartridge B. Figure 8(c) is a diagram showing the state before the drive units of the apparatus main assembly A and cartridge B are engaged. Figure 8(d) is a diagram showing the state when the power of the apparatus main assembly A is turned on and the drive units of the apparatus main assembly A and cartridge B are engaged.

[0044] As shown in FIG. 8(a), the main body A of the apparatus is supplied with a driving force from a driving source (not shown) of the main body A of the apparatus. 8(b), cartridge B is provided with a drive transmission member 81 that receives the drive force and transmits it to cartridge B. Also, as shown in FIG. 8(b), cartridge B is provided with a drive-receiving portion 63b on the drive-side drum flange 63 to engage with the drive transmission member 81 and receive the drive force. Here, when the opening / closing door 13 is closed and the apparatus main body A is turned on, the drive transmission member 81 moves in the direction of arrow E in FIG. 8(c). Then, as shown in FIG. 8(d), the drive transmission portion 81b of the drive transmission member 81 engages with the drive-receiving portion 63b of the drive-side drum flange 63, and the drum 62 rotates via the drive-side drum flange 63.

[0045] Furthermore, a gear shape 81g is provided on the outer periphery of the drive transmission member 81. Furthermore, a developing roller gear 90 is coupled to the end of the developing roller 32 of the cartridge B. When the drive-receiving portion 63b of the driving-side drum flange 63 is engaged as shown in FIG. 8(d), the gear shape 81g provided on the drive transmission member 81 and the developing roller gear 90 are also arranged to mesh with each other. That is, the drive transmission member 81 rotates the drum 62 via the driving-side drum flange, and simultaneously rotates the developing roller 32 via the developing roller gear 90.

[0046] <Cover material> The characteristic cover member of this embodiment will be described in detail using Figures 1 and 9. Figures 1 and 9 show the cartridge B and cover member 1001 of this embodiment. Figure 1 shows the state in which the cover member 1001 is assembled to the cartridge B, and Figure 9 shows the state before the cover member 1001 is assembled to the cartridge B. The configuration in which the cover member 1001 is assembled to the cartridge B in the state removed from the apparatus main body A as shown in Figure 1 is referred to as a cartridge protection assembly for protecting the cartridge B.

[0047] As described above with respect to the overall cartridge configuration, the lower right in the figure indicates the non-drive side having the bearing 27, and the upper left in the figure indicates the drive side having the drum bearing 73. The photosensitive element 62 is rotatably supported in the cleaning frame 71 of cartridge B, and a portion of the surface of the photosensitive element 62 is exposed through the opening 71a of the frame 71 (see FIG. 3). Therefore, for example, there is a possibility that the user's hand may come into contact with the surface of the photosensitive element 62. If the user's hand comes into contact with the surface of the photosensitive element 62, oils from the user's hands may adhere to the surface of the photosensitive element 62, which may cause image defects.

[0048] To prevent the user's hands or the like from coming into contact with the surface of the photoreceptor 62, the photoreceptor 62 is shipped in a protective assembly state with the surface covered by a cover member 1001 at the time of purchase (see FIG. 1). The cover member 1001 serves to prevent dust and to prevent the user from coming into contact with the photoreceptor 62. It also serves to protect the photoreceptor 62 from hitting anything.

[0049] Furthermore, when performing maintenance such as clearing a jam, cartridge B that has been installed in the apparatus main body A may be removed and temporarily stored outside the apparatus main body A. In this case, it is conceivable that the user will reattach the cover member 1001 to cartridge B (see FIG. 9). In this case, as in the case described above, covering the surface of the photosensitive member 62 with the cover member 1001 can prevent dust and user contact.

[0050] The cover member 1001 has a shape that follows the longitudinal direction of the cartridge B (axial direction of the photosensitive member 62), and has recessed portions 1020, 1030 at both ends thereof that are shaped to fit the outer diameter shape of the ends of the cartridge B. The first recessed portion 1020 provided at one end of the cover member 1001 has a shape that fits the shape of the non-drive side end of the cleaning frame 71, which is one end of the cartridge B. The first recessed portion 1020 includes a first wall portion 1021 that faces the non-drive side end of the cleaning frame 71 in the longitudinal direction, and a second wall portion 1022 that faces the non-drive side end in a direction perpendicular to the longitudinal direction, and is configured to cover part of the outer shape of the non-drive side end. Similarly, the second wall portion 1021 provided at the other end of the cover member 1001 The second recessed portion 1030 has a shape that matches the shape of the drive side end of the cleaning frame 71, which is the other end of the cartridge B. The second recessed portion 1030 includes a first wall portion 1031 that faces the drive side end of the cleaning frame 71 in the longitudinal direction, and a second wall portion 1032 that faces the drive side end in a direction perpendicular to the longitudinal direction, and is configured to cover part of the outer shape of the drive side end.

[0051] The following describes the positioning of the cover member 1001 to the cartridge B and the procedure for attaching the cover member 1001 to the cartridge B. The positioning configuration will be described in more detail with reference to Figures 10, 11, and 12. Figure 10 is a front view of the cartridge B according to the first embodiment of the present invention, Figure 11 is a side view of the cartridge B according to the first embodiment of the present invention, and Figure 12 is a side view and partial cross-sectional view of the cartridge B according to the first embodiment of the present invention. Figure 10 is a front view of the cartridge B with the cover member 1001 attached, with the right side of the figure indicating the non-drive side and the left side of the figure indicating the drive side.

[0052] The assembly of the cover member 1001 to the cartridge B on the non-drive side will be described using Figure 11. Figure 11 is a side view of the cartridge B as seen from the non-drive side, along the arrow F in Figure 10. Figure 11(a) shows the state before the cover member 1001 is assembled, and Figure 11(b) shows the state after the cover member 1001 is assembled.

[0053] The cartridge B has a cylindrical positioned portion 71d provided on the frame 71, which protrudes in the longitudinal direction of the cartridge B. The cylindrical positioned portion 71d has an engaged portion 71k and a locked portion 71m formed on the cylindrical surface of the positioned portion 71d. The non-drive side positioning portion 1002 of the cover member 1001 has a cylindrical engaging portion 1002a, a locking arm 1002b, and a triangular claw-shaped locking portion 1002c at the tip of the locking arm 1002b.

[0054] 11(a), the cover member (non-drive side) 1002 is attached to the cartridge B by gripping the cleaning unit 60 and the developing unit 20 and separating them to open a gap S. Then, the cover member 1001 is assembled in the direction of arrow K so that the spacing spacer portion 1002d is inserted into the gap S (sandwiching the spacing spacer portion 1002d between the cleaning unit 60 and the developing unit 20 in the gap S).

[0055] At the same time, the cover member (non-drive side) 1002 is assembled to the frame 71 so that the engaged portion 71k fits into the engaging portion 1002a. The cover member (non-drive side) 1002 is provided with guide portions 1002e and 1002f, which enable the user to easily assemble the cover member 1001 to the cartridge B.

[0056] During assembly, locking arm 1002b bends in the direction of arrow M due to elastic deformation, and locking portion 1002c climbs over locked portion 71m. Engaging portion 1002a abuts against engaged portion 71k, completing assembly of cover member (non-drive side) 1002. Locking portion 1002c, which has climbed over, abuts against locked portion 71m, thereby functioning as a snap fit portion that prevents cover member 1001 from coming off in the direction opposite to arrow K.

[0057] When the cover member (non-drive side) 1002 is assembled to the cartridge B, the engaging portion 1002a of the cover member (non-drive side) 1002 is provided inside the first recessed portion 1020 and is arranged to be hidden by the cover member (non-drive side) 1002. That is, when viewed in the longitudinal direction of the cartridge B, the engaging portion 1002a is located in a position hidden by the first wall portion 1021, and a part of the tip of the cylindrical positioned portion 71d and the engaged portion 71k are also arranged to be hidden by the first wall portion 1021. Also, when viewed from the opposite side to the engaged portion 71k in a direction perpendicular to the longitudinal direction, the engaging portion 1002a is hidden by the second wall portion 1022. It's a hiding place.

[0058] The locking portion 1002c also has a convex shape that protrudes in a direction perpendicular to the longitudinal direction of the cartridge B from the tip of the locking arm 1002b, which extends in a direction perpendicular to the longitudinal direction of the cartridge B, and when viewed in the perpendicular direction, it is hidden by the locking arm 1002b depending on the viewing angle. In other words, when viewed in the perpendicular direction, it has an angle such that the locked state between the locking portion 1002c and the locked portion 71m is hidden by the locking arm 1002b.

[0059] An engaged portion 71k is provided on a part of the outer periphery of the cylindrical positioned portion 71d, and a locked portion 71m is provided on the back side of the engaged portion 71k as a part of the outer periphery. That is, the cover member (non-drive side) 1002 is configured to have a wide range of angles at which the engaged state with the engaged portion 71k and the locked state with the locked portion 71m are hidden by the cover member (non-drive side) 1002 when viewed in a direction perpendicular to the longitudinal direction.

[0060] Furthermore, the spacing spacer portion 1002d is also angled such that the contact portion with the cleaning unit 60 is hidden by the first wall portion 1021 when viewed in the longitudinal direction, and is hidden by the second wall portion 1022 when viewed in a direction perpendicular to the longitudinal direction.

[0061] Figure 12 is a side view of the cartridge B as seen from the drive side, taken along the arrow G in Figure 10. Figure 12(a) shows the state before the cover member 1001 is attached, and Figure 12(b) shows the state after the cover member 1001 is attached. Also shown are partial cross-sectional views HH and JJ, which are cut along a horizontal plane that intersects the central axis of the photosensitive member 62.

[0062] The cartridge B has a drum bearing 73 serving as a frame body, which has a cylindrical (convexly curved) upper positioned portion 73d and lower positioned portion 73f, as well as a concave locked portion 73g. The drive-side positioning portion 1003 of the cover member 1001 has a cylindrical upper engaging portion 1003a and lower engaging portion 1003b, and a triangular claw-shaped locking portion 1003d at the tip of a locking arm 1003c (HH cross section).

[0063] 12(a), the cover member (driving side) 1003 is attached to the cartridge B by gripping the cleaning unit 60 and the developing unit 20 and separating them to open a gap S. Then, the cover member 1001 is assembled in the direction of arrow L so that the spacing spacer portion 1003e is inserted into the gap S (the spacing spacer portion 1003e is sandwiched between the cleaning unit 60 and the developing unit 20 in the gap S).

[0064] At the same time, the cover member (driving side) 1002 is assembled to the drum bearing 73 so that the upper positioned portion 73d and the lower positioned portion 73f fit into the upper engaging portion 1003a and the lower engaging portion 1003b.

[0065] During assembly, the locking arm 1003c bends in the direction of arrow N due to elastic deformation, and the locking portion 1003d climbs over the locked portion 73g. The upper engaging portion 1003a and the upper engaging portion 1003b abut against the upper positioning portion 73d and the lower positioned portion 73f, respectively, completing the assembly of the cover member (drive side) 1003. The climbing over locking portion 1003d abuts against the locked portion 73g, thereby functioning as a snap fit portion that prevents the cover member 1001 from coming off in the direction opposite to the arrow L. The direction of elastic deformation of the locking portion 1003d is different from the direction of elastic deformation of the non-drive side locking portion 1002c.

[0066] When the cover member (driving side) 1003 is assembled to the cartridge B, the engaging portions 1003a and 1003b of the cover member (driving side) 1003 are engaged with the first recessed portion 1030. and are arranged to be hidden by the cover member (driving side) 1003. That is, the engaging portions 1003a and 1003b are located in positions hidden by the first wall portion 1031 when viewed in the longitudinal direction of the cartridge B, and the positioned portions 73d and 73f are also arranged to be hidden by the first wall portion 1031. The engaging portions 1003a and 1003b are also located in positions hidden by the second wall portion 1032 when viewed from the opposite side to the positioned portions 73d and 73f in a direction perpendicular to the longitudinal direction.

[0067] The locking portion 1003d also has a convex shape that protrudes in the longitudinal direction from the tip of the locking arm 1003c that extends in a direction perpendicular to the longitudinal direction of the cartridge B, and is arranged so as to be hidden by the locking arm 1003c when viewed in the longitudinal direction. The locking portion 1003d is also hidden by other components of the cover member (driving side) 1003, depending on the angle at which it is viewed, even in the direction perpendicular to the longitudinal direction. That is, the locking portion 1003d is angled so that its engagement with the locked portion 73g, which has a concave shape recessed in the longitudinal direction, is hidden by the locking arm 1002b and other components of the cover member (driving side) 1003.

[0068] Furthermore, the spacing spacer portion 1003e is also angled such that the contact portion with the cleaning unit 60 is hidden by the first wall portion 1031 when viewed in the longitudinal direction, and is hidden by the second wall portion 1032 when viewed in a direction perpendicular to the longitudinal direction.

[0069] In this embodiment, a protruding cylindrical positioned portion 71d is used on the non-drive side to form a snap-fit ​​portion in the cross-sectional direction. Since there is no protruding portion on the drive side, a recessed engaged portion 73g is provided to form a snap-fit ​​portion that elastically deforms in the longitudinal direction. As described above, in relation to other functional shapes, a snap-fit ​​configuration in which elastic deformation occurs in different directions on the non-drive side and the drive side, i.e., on one side and the other side in the longitudinal direction, is possible. Note that the locations of the positioning portions described above are not limited to both ends in the longitudinal direction along the rotational axis of the photoreceptor 62 (outside the longitudinal direction of the opening), as described above. For example, instead of providing them at both ends, a positioning configuration in which multiple positions are provided along the long edge of the opening extending in the longitudinal direction may be adopted. Alternatively, additional positions may be provided at locations other than both ends.

[0070] Furthermore, a separating spacer portion 1002d is inserted into the gap S on the non-drive side, and a separating spacer portion 1003e is inserted into the gap S on the drive side, and they are sandwiched between the cleaning unit 60 and the developing unit 20. This generates and maintains a gap between the photosensitive member 62 held in the cleaning unit 60 and the developing roller 32 held in the developing unit 20, and prevents the photosensitive member 62 and the developing roller 32 from coming into contact with each other due to an impact during transportation.

[0071] In this embodiment, the cover member 1001 is made of a transparent or semi-transparent material. As a result, as shown in FIG. 9, when assembling the cover member 1001 to the cartridge B, the cover member 1001 can be assembled while visually checking the photosensitive element 62, which should not be touched by the user. As a result, the risk of the user accidentally touching the surface of the photosensitive element 62 can be reduced. Note that, although the entire cover member 1001 is made of a transparent or semi-transparent material in this embodiment, it may be configured so that only necessary portions have transparent or semi-transparent portions.

[0072] In addition, the area around the positioning portion for engaging the cover member 1001 with the cartridge B is made transparent or semi-transparent. This improves the visibility of the shape for engaging the cover member 1001 with the cartridge B, and further reduces the risk that the user will accidentally touch the surface of the photosensitive member 62 while assembling the cover member 1001 with the cartridge B.

[0073] In particular, the non-drive side positioning portion for engaging the cover member 1001 with the cartridge B The cover member 1001 and its surroundings, including the drive-side positioning portion 1002 and the drive-side positioning portion 1003, are made transparent or translucent. This is because, if the cover member 1001 is somewhat soft, it may be necessary to provide positioning portions at both longitudinal ends to make it easier to remove the cover member 1001 from the ends. This allows the user to recognize the engaging portion of the cover member 1001 with the cartridge B, improving the visibility of the shape for engagement and further reducing the risk of the user accidentally touching the surface of the photosensitive member 62.

[0074] <Transparency> 13 is a diagram showing a system for measuring the light transmittance. The light transmittance was measured for each portion of the cover member 1001 as follows.

[0075] As shown in Fig. 13, a 6 mm diameter window 1104h, which serves as the light source entrance, was placed above the box structure to prevent light from leaking from the inside, and the measurement unit 1101a of an illuminance meter 1101 ("HIOKI 3423 LUX HiTESTER" manufactured by Hioki E.E. Corporation) was placed below the light source entrance. Furthermore, a sample fixing unit 1102 was installed midway between the light source entrance and the measurement unit.

[0076] The sample fixing section 1102 is composed of a fixing plate 1103 on which the sample 1001a is placed and a cover plate 1104 that covers the sample 1001a and also serves as the light source incident section. The fixing plate 1103 has a recess 1103a facing the center of the measurement section 1101a as a blank for placing the sample 1001a. Both the fixing plate 1103 and the cover plate 1104 have 6 mm diameter windows 1103h and 1104h, respectively, through which light from the light source passes, facing the center of the measurement section 1101a. Using this evaluation device, the light transmittance of the sample 1101a was evaluated.

[0077] In detail, the measurement method was as follows: light from light source 1105 was passed through 6 mm diameter windows 1103h and 1104h of fixing plate 1103 and cover plate 1104 (without a sample), and the light from the light source was adjusted so that the reading on illuminometer 1101 was 2000 lux. Then, sample 1001a was placed on blank 1103a of fixing plate 1103 and covered with cover plate 1104, so that sample 1001a was interposed in the path of light from light source 1105. The value (U) of illuminometer 1101 at this time was read. This operation was performed three times for each part, and the average value was taken as the light transmittance. The light transmittance T (%) was calculated using the following formula: Light transmittance T(%)=U / 2000×100

[0078] Table 1 in Figure 14 shows the relationship between the thickness of the cover member and light transmittance. The light transmittance of each part of a prior art cover member made of PS (polystyrene) and orange in color and a cover member of this embodiment made of PP (polypropylene) and natural in color was measured using the procedure described above. In addition to the light transmittance results, a determination was also made as to whether the engagement portion was visible.

[0079] As a result, it was found that if the light transmittance of the periphery of the cover member 1001, including the non-drive-side positioning portion 1002 and the drive-side positioning portion 1003 for engaging with the cartridge B, is 40% or more, the engaging portions are visible, making it easy to aim and assemble. Therefore, by making the periphery of the positioning portion for engaging the cover member 1001 with the cartridge B transparent or semi-transparent, the visibility of the shape for engaging the cover member 1001 with the cartridge B is improved. This further reduces the risk that the user will accidentally touch the surface of the photosensitive element 62 while assembling the cover member 1001 with the cartridge B.

[0080] It should be noted that the terms "transparent" and "semi-transparent" in this specification do not necessarily need to be clearly defined. For example, a relatively high value of the light transmittance close to 100% can be defined as "transparent," and a light transmittance that is away from 100% but is still at 40% or more can be defined as "semi-transparent." In other words, the user can easily attach and detach the cover member 1001 to and from the cartridge unit. In the industry, the term "transparent or translucent" refers to a material that is transparent (translucent) enough to allow the position of the engagement portion and the photosensitive member 62 to be seen through the cover member 1001. In this embodiment, PP (polypropylene) is used as the material for the cover member as described above, but PS (polystyrene) may also be used as long as it provides similar visibility.

[0081] Example 2 Fig. 15 is a front view of a cartridge B according to a second embodiment of the present invention. Fig. 16 is a partial cross-sectional view of the cartridge B according to the second embodiment of the present invention, showing a partial portion of the E-E cross section of Fig. 15.

[0082] The cover member 1201 has a character-shaped portion 1201b on which characters indicating handling precautions are displayed on the outer surface 1201a that covers the photoconductor 62. This character-shaped portion 1201b has the function of, for example, warning the user not to touch the photoconductor 62 and informing them of the upper side of how to remove the cover member 1201. Because the character-shaped portion 1201b is arranged so as to cover the photoconductor 62, it can be emphasized as a warning to the target photoconductor 62. One possible method for arranging the character-shaped portion 1201b is to carve the characters into a mold and then engrave the characters 1201b by molding. Other means that allow for the arrangement of characters or illustrations may also be used.

[0083] Furthermore, it is desirable to reduce the amount of material used to reduce the cost of the cover member 1201. To achieve this, as shown in FIG. 16, we consider reducing the thickness t of the cover member 1201. If the thickness is too thin, the resin may not circulate completely, resulting in a short circuit, and therefore a balance must be taken into account with moldability. Specifically, it is necessary to ensure that the resin flowing into the mold through the gate (portion 1201g of the cover member 1201 corresponding to the gate) reaches every corner of the cavity of the mold. To achieve this, we consider a method in which thickness t1 of portion 1201c of cover member 1201 corresponding to the central flow path of the mold (central flow path portion) is made thicker than thickness t2 of portion 1201d of cover member 1201 corresponding to the other flow paths of the mold (other flow path portions). This allows sufficient fluidity to be maintained while reducing the amount of resin used.

[0084] In this case, a thickness difference (t2-t1) occurs between the adjacent central flow path portion 1201c and the other flow path portion 1201d, but by smoothly connecting them at the seam 1201e, the difference in thickness can be made less noticeable. That is, the change in thickness at the seam 1201e connecting the portions of the cover member 1201 with different thicknesses is configured to gradually change, at least in the area overlapping with the character-shaped portion 1201b. As a result, the difference in thickness at the seam 1201e is made less noticeable against the outline of the character 1201b drawn on the surface of the transparent or translucent cover member 1201, thereby maintaining the visibility of the character-shaped portion 1201b. Furthermore, by coloring the engraving, the visibility of the character-shaped portion 1201b can be further improved.

[0085] <Developing roller cover member> In this embodiment, the cover member for the photosensitive member has been described as a rotating member of the cartridge, but a similar configuration can also be applied to a cover member for the developing roller, and similar effects can be obtained. For example, the present invention is particularly applicable to cases where a developing unit including a developing roller is separated from a photosensitive member unit including a photosensitive member and is configured as a cartridge, and the developing cartridge is configured to be detachable from the main body of the device on its own. In other words, the visibility of the shape for engaging the cover member with the developing cartridge is improved, further reducing the risk of the user accidentally touching the surface of the developing roller while assembling the cover member to the developing cartridge. [Explanation of symbols]

[0086] B... cartridge, 62... photosensitive drum, 71... cleaning frame, 71a... opening, 73... drum bearing, 1001... cover member

Claims

[Claim 1] A cartridge unit including a cartridge detachably mountable to a main body of an image forming apparatus, and a cover member for protecting the cartridge, the cover member being required to be removed from the cartridge when the cartridge is mounted to the main body of the image forming apparatus, the cartridge includes a photosensitive drum and a frame that rotatably supports the photosensitive drum, the frame having an engaging portion and exposing a part of an outer circumferential surface of the photosensitive drum to the outside of the cartridge, the cover member is integrally formed with an engaging portion that engages with the engaged portion and a cover portion that covers the part of the outer circumferential surface of the photosensitive drum, The cartridge unit is characterized in that at least the engaging portion and the cover portion of the cover member are made transparent or translucent.

Images