Process cartridge

Abstract

To prevent a link member from falling from a cartridge frame body when a drum shutter unit for protecting a photoreceptor drum is provided in a process cartridge.SOLUTION: A photosensitive drum, a frame body, a shutter member that moves between a protection position and an exposure position with respect to the photosensitive drum, a link member that is rotatable with respect to the frame body and is connected to the shutter member to move the shutter member, and a torsion coil spring that is supported by the frame body, is in contact with the link member, and biases the shutter member to the protection position, wherein the torsion coil spring and the link member are in contact with each other to form a first restriction portion that restricts movement of the link member in an axial direction, and the frame body and the torsion coil spring are in contact with each other to form a second restriction portion that restricts movement of the torsion coil spring in the axial direction. A process cartridge is used.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] The present invention relates to a process cartridge. [Background technology]

[0002] Conventionally, in image forming apparatuses using an electrophotographic image forming method, maintenance of various process means is generally required. In order to facilitate the maintenance of these various process means, a process cartridge has been put into practical use, in which an electrophotographic photosensitive member (photosensitive drum), charging means, developing means, cleaning means, etc. are assembled together in a frame to form a cartridge that is detachably mountable to the main body of the image forming apparatus.

[0003] In the process cartridge described above, scratches or dents on the photosensitive drum can cause image degradation. Therefore, it is necessary to protect the photosensitive drum from scratches and dents even when the process cartridge is removed from the image forming apparatus. One proposed configuration for protecting the photosensitive drum is a drum shutter unit that exposes the photosensitive drum to the outside of the cartridge frame when the process cartridge is installed in the image forming apparatus main body, and has a shutter member that protects the photosensitive drum when the process cartridge is removed from the image forming apparatus main body. Patent Document 1 discloses a configuration in which the shutter member is supported by a link member and a molded arm member to protect the photosensitive drum.

[0004] Patent document 2 also discloses a configuration in which, in order to prevent the link member from falling off during the attachment and detachment of the process cartridge to the image forming device, a groove is provided at the point where the link member of the cartridge frame engages, and the link member is machined to have a protrusion shape that can pass through this groove. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-75619 [Patent Document 2] Japanese Patent Application Publication No. 9-26739 Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, there has been a demand for miniaturization of image forming apparatuses and process cartridges due to demands for resource and space conservation. However, in order to prevent the link member that supports the shutter member from coming off, it has been necessary to process the link member or the cartridge frame, or to provide a separate member to prevent it from coming off.

[0007] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to prevent a link member from falling off from a cartridge frame when a drum shutter unit for protecting a photosensitive drum is provided in a process cartridge. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention employs the following configuration. A process cartridge detachably mountable to an image forming apparatus body, A photosensitive drum; A cartridge frame; a shutter member that is movable between a protection position that protects the surface of the photosensitive drum and an exposure position that exposes the surface of the photosensitive drum; a link member rotatably supported on the cartridge frame and connected to the shutter member, the link member moving the shutter member between the protection position and the exposure position; a torsion coil spring supported on the cartridge frame, the torsion coil spring contacting the link member to urge the shutter member to the protection position, and rotating when subjected to a load to move the shutter member to the exposure position; In a process cartridge having the torsion coil spring and the link member come into contact with each other to form a first regulating portion, and the movement of the link member in the direction of the rotation axis of the photosensitive drum is regulated by the first regulating portion; The cartridge frame and the torsion coil spring come into contact with each other to form a second restricting portion, and the second restricting portion restricts movement of the torsion coil spring in the direction of the rotation axis. The process cartridge is characterized by: [Effects of the Invention]

[0009] According to the present invention, when a drum shutter unit for protecting a photosensitive drum is provided in a process cartridge, it is possible to prevent the link member from falling off from the cartridge frame. [Brief explanation of the drawings]

[0010] [Figure 1A] FIG. 1 is a side view of a process cartridge according to an embodiment; [Figure 1B] FIG. 1 is an enlarged side view of a process cartridge according to an embodiment of the present invention; [Figure 2] Cross-sectional view of the image forming apparatus main body and the process cartridge [Figure 3] Cross-sectional view of a process cartridge [Figure 4A] FIG. 1 is a perspective view illustrating a configuration of a process cartridge. [Figure 4B] FIG. 10 is a perspective view illustrating the configuration of the process cartridge in a different direction. [Figure 5A] FIG. 1 is a perspective view of a process cartridge before it is inserted into an apparatus main body; [Figure 5B] FIG. 10 is a perspective view of the process cartridge before insertion into the main assembly of the apparatus in a different direction. [Figure 6] Perspective view of the drum shutter unit [Figure 7] Side view of the process cartridge [Figure 8A] A cross-sectional view of the main part of the configuration of the embodiment. [Figure 8B] FIG. 1 is a cross-sectional view of a key portion of the configuration of an embodiment taken from another cross section. [Figure 9] FIG. 1 is a diagram showing the configuration of a control block of an image forming apparatus. [Figure 10] Diagram explaining torsion coil springs [Figure 11] FIG. 1 is a diagram illustrating the configuration of the drive side of a process cartridge. [Figure 12] FIG. 10 is a diagram illustrating the drive side retainer of the process cartridge. [Figure 13] FIG. 10 is a perspective view illustrating an operation when the process cartridge is inserted. [Figure 14] FIG. 10 is a top view illustrating the operation when the process cartridge is inserted. 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 FIG. 2 is a cross-sectional view showing a schematic configuration of a laser beam printer 100, which is an example of an electrophotographic image forming apparatus (image forming apparatus).

[0013] <Overview of laser beam printer> 2, the laser beam printer 100 is made up of an apparatus main body A and a process cartridge B. The process cartridge B is installed in the apparatus main body A so as to be detachable.

[0014] The apparatus main body A is provided with a sheet storage section 101, a sheet feeding section 102, a sheet transport section 103, a transfer roller 104, a fixing section 105, a sheet discharge section 106, a laser scanner 110, a power supply 160, a drive source 170, etc. The process cartridge B is provided with a photosensitive drum 11, a charging roller 12, a developing roller 21, etc. Each of these will be described in detail below.

[0015] The apparatus main body A also has an opening / closing door 107 for closing an opening G provided for installing and removing a process cartridge B. Details will be described later. Note that although only a single process cartridge B is shown here, a configuration in which multiple process cartridges B corresponding to multiple colors are provided may also be used. In this case, an intermediate transfer system may be used in which an image is formed for each color on an intermediate transfer belt, and a full-color image is transferred from the intermediate transfer belt to a sheet S. Alternatively, a drum cartridge system in which the photosensitive drum 11 and its corresponding operating unit are integrated into a cartridge may also be used. Alternatively, a developer cartridge system in which the developing roller 21, toner storage unit, etc. are integrated into a cartridge may also be used.

[0016] <Image formation process> Next, a series of operations of the image forming apparatus in this embodiment will be described. Here, Fig. 9 is a diagram illustrating the configuration of the control block of the laser beam printer 100. The control unit 150 is an information processing device equipped with calculation resources such as a CPU 151 and memory 152. Each step of the image forming operation is executed by the control unit 150 controlling the components of the laser beam printer 100.

[0017] The power supply 160 is a high-voltage power supply, and is controlled by the control unit 150 to apply a voltage to the charging roller 12 and the like. The power supply 160 does not have to be a single power supply device. A power supply device may be provided for each of one or more components. The drive source 170 is a drive device such as a motor, and is controlled by the control unit 150 to perform various drive operations such as driving the photosensitive drum 11 to rotate. The drive source 170 does not have to be a single drive device. A drive device may be provided for each of one or more components.

[0018] The image forming operation is started by a print start signal transmitted together with image data from the external device 250. Note that the image forming operation may also be started by a user instruction using an operation panel provided on the apparatus main body A.

[0019] Based on a print start signal, the sheet feeding unit 102 feeds the sheet S stored in the sheet storage unit 101. The sheet transport unit 103 transports the sheet S along the dashed line C. When the sheet S has been transported to a predetermined position, the image formation process is started based on an image formation start signal sent by the control unit 150. When the image formation process is started, the photosensitive drum 11, which is driven to rotate around its axis by the drive source 170, is uniformly charged to a predetermined potential by the charging roller 12. The photosensitive drum 11 is supported so as to be rotatable about an axis K (FIG. 2).

[0020] The control unit 150 exposes the surface of the charged photosensitive drum 11 based on image data using the laser scanner 110. This removes the charge from the exposed area, forming an electrostatic latent image. The supply roller 22 supplies the toner in the process cartridge B to the developing roller 21. The developing roller 21 transfers the carried toner to the photosensitive drum 11 by rotation. As a result, the electrostatic latent image is developed and a toner image is formed on the photosensitive drum 11.

[0021] When the sheet S conveyed by the sheet conveying unit 103 passes through the nip portion between the transfer roller 104 and the photosensitive drum 11, the control unit 150 controls the power supply 160 to apply voltage to the transfer roller 104. As a result, the toner image on the photosensitive drum 11 is transferred to the sheet S as an unfixed image. Thereafter, the sheet S with the transferred toner image is conveyed to the fixing unit 105. The fixing unit 105 applies heat and pressure to the unfixed image to fix it to the surface of the sheet S. The sheet S with the fixed toner image is discharged by the sheet discharge unit 106 to the discharge tray 108 and stacked thereon.

[0022] <Process cartridge configuration> The process cartridge B will be described with reference to Figures 3, 4A, and 4B. Figure 3 is a cross-sectional view of the process cartridge B. Figure 4A is a perspective view of the drive side of the process cartridge B, which has a drive unit. Figure 4B is a perspective view of the non-drive side of the process cartridge B, which does not have a drive unit.

[0023] As shown in FIG. 3, the process cartridge B is composed of a drum unit 10 having a photosensitive drum 11 and a developing unit 20 having a developing roller 21.

[0024] The drum unit 10 has a photosensitive drum 11, a charging roller 12, a charging roller cleaner 14, a cleaning blade 17, a waste toner storage compartment 18, and a drum unit frame 19. The photosensitive drum 11 is a photosensitive member that functions as an image carrier. The charging roller 12 is disposed so as to contact the outer circumferential surface of the photosensitive drum 11, and charges the photosensitive drum 11 by application of voltage from a power supply 160 in the apparatus main body A. The charging roller cleaner 14 is a cleaning member that cleans the charging roller 12. The cleaning blade 17 is an elastic member that is disposed so as to contact the outer circumferential surface of the photosensitive drum 11, and cleans the surface of the photosensitive drum 11. The toner (waste toner) removed from the photosensitive drum 11 by the cleaning blade 17 is stored in the waste toner storage compartment 18.

[0025] The developing unit 20 includes a developing roller 21, a supply roller 22, a developing blade 23, a developing chamber 25 in which the developing roller 21 and the supply roller 22 are disposed, a developer storage chamber 26 that supplies toner to the developing chamber 25, and a developing unit frame 29 that forms the developing chamber 25 and the developer storage chamber 26. The developing roller 21 develops the electrostatic latent image formed on the photosensitive drum 11. The supply roller 22 supplies toner from the developing chamber 25 to the developing roller 21. The developing blade 23 contacts the circumferential surface of the developing roller 21 to regulate the thickness of the toner layer adhering to the circumferential surface of the developing roller 21 and at the same time, imparts a frictional charge to the toner. In this configuration, the drum unit frame 19 and the developing unit frame 29 may be collectively considered to be a cartridge frame, which is the frame of the process cartridge B.

[0026] Next, a detailed description will be given of the structure in which the developing unit 20 is supported by the drum unit 10. As shown in Figures 4A and 4B, the developing unit 20 has a drive-side bearing member 54 and a non-drive-side bearing member 55 at the axial ends of the developing roller 21 (see Figure 3), and is coupled to the drum unit 10 so as to be rotatable about a swing axis 8 defined by a straight line including support shafts 8a and 8b. A drive-side pressure spring 52 and a non-drive-side pressure spring 53 are arranged in the process cartridge B, and one ends of the drive-side pressure spring 52 and the non-drive-side pressure spring 53 are attached to the developing unit 20 and the other ends are attached to the drum unit 10.

[0027] As shown in Fig. 4A, a cylindrical portion 54a provided on the driving side bearing member 54 is supported in a cylindrical hole portion 58a provided in a side cover 58 of the drum unit 10. , which is defined by a common axis between the cylindrical hole portion 58a of the side cover 58 and the cylindrical portion 54a of the drive-side bearing member 54. In addition, a development coupling 56 as a development drive input member for receiving drive from the apparatus main body A is provided at the rotation center of the cylindrical portion 54a of the drive-side bearing member 54.

[0028] 4B, on the non-drive side, pin 57 is inserted so as to straddle hole 19a of drum unit frame 19 and a cylindrical hole (not shown) in non-drive-side bearing member 55. Support shaft 8b is defined by the common axis of pin 57 and the cylindrical hole in non-drive-side bearing member 55. Support shafts 8a and 8b are arranged approximately coaxially, and as described above, swing axis 8 is defined by a straight line including support shafts 8a and 8b.

[0029] As a result, the developing unit 20 is supported rotatably around the swing axis 8 relative to the drum unit 10. The developing unit 20 is also urged toward the drum unit 10 by the driving-side pressure spring 52 and the non-driving-side pressure spring 53, which are elastic members, and the developing roller 21 comes into contact with the photosensitive drum 11.

[0030] Figures 11(a) and 11(b) are diagrams further illustrating the configuration of the drive side of the process cartridge B, showing the state with the side cover removed. Figure 11(b) is an enlarged view of area Y in Figure 11(a). On the drive side, only the link member 202 biased by the torsion coil spring 204 is engaged with the engagement hole of the drive-side bearing member 54. The other configuration is the same as that of the non-drive side.

[0031] <How to install and remove the process cartridge> Next, a method for installing and removing the process cartridge B in the apparatus main body A will be described with reference to Figures 5A and 5B. Figures 5A and 5B are perspective views from different directions, showing how the door 107 of the apparatus main body A is opened and the process cartridge B is inserted.

[0032] 5A and 5B, the space inside the apparatus main body A serves as the mounting portion for the process cartridge B, and is configured to have an opening 425 and an opening / closing door 107 on the top side of the apparatus main body A. The opening / closing door 107 is provided so as to be rotatable in the direction of arrow R around a rotation axis 107a relative to the apparatus main body A. Furthermore, inside the opening of the apparatus main body A, a drive-side guide member 114 and a non-drive-side guide member 115 are provided along the mounting direction D of the process cartridge B.

[0033] The process cartridge B is provided, on both sides in the longitudinal direction, with a drive-side support boss 91, a non-drive-side support boss 92, a drive-side positioning boss 94, and a non-drive-side positioning boss 95. As described above, the process cartridge B is also provided with a handle portion 59 which allows the user to grip the process cartridge B.

[0034] When the user mounts the process cartridge B into the apparatus main body A, he or she grips the handle portion 59 of the process cartridge B and inserts the process cartridge B in the mounting direction D. During the insertion process, the drive-side support boss 91 of the process cartridge B rides on the upper side of the drive-side guide member 114, and the drive-side positioning boss 94 slips under the drive-side guide member 114. Similarly, on the non-drive side of the process cartridge B, the non-drive-side support boss 92 rides on the upper side of the non-drive-side guide member 115, and the non-drive-side positioning boss 95 slips under the non-drive-side guide member 115. In other words, the drive-side guide member 114 and the non-drive-side guide member 115 are sandwiched between the drive-side support boss 91, the non-drive-side support boss 92 and the drive-side positioning boss 94, the non-drive-side positioning boss 95.

[0035] In this way, the process cartridge B is guided by the driving side guide member 114 and the non-driving side guide member The laser beam printer 100 is inserted while its posture is regulated by 115, and it comes to a complete insertion state when it hits a predetermined position. When the opening and closing door 107 is closed in this state, the laser beam printer 100 is ready to form an image.

[0036] When removing the process cartridge B, the above procedure is reversed.

[0037] [Explanation of Drum Shutter Unit 200] The configuration of the drum shutter unit 200 will be described using Figures 1A, 1B, 6, and 7. In the following description, the side on which the development coupling 56 is provided in the axial direction of the photosensitive drum 11 will be referred to as the drive side, and the opposite side will be referred to as the non-drive side.

[0038] FIG. 1A is a side view of a portion of the non-drive side of the process cartridge B when the drum shutter unit 200 is in a position to protect the photosensitive drum 11 (when not installed in the main body). FIG. 1B is an enlarged view of area Q shown in FIG. 1A. FIG. 6 is a perspective view of the drum shutter unit 200 (excluding the torsion coil spring 204). FIG. 7 is a side view of the process cartridge B when the drum shutter unit 200 is in the protection position.

[0039] The drum shutter unit 200 is composed of a drum shutter member 201 (hereinafter also simply referred to as "shutter member 201"), a link member 202, an arm member 203, and a torsion coil spring 204. The link member 202 is rotatably fitted to the non-drive-side link member support portion 55a of the non-drive-side bearing member 55 of the developing unit 20 and the drive-side link member support portion (not shown) of the drive-side bearing member (not shown), and is provided with a connected portion 202a extending in the axial direction of the photosensitive drum 11.

[0040] Here, the drive-side link member support portion (not shown) of the drive-side bearing member (not shown) and the non-drive-side link member support portion 55a of the non-drive-side bearing member 55 are located at the same position when viewed from the axial direction of the photosensitive drum 11. Therefore, the link member 202 is rotatable around the rotation axis E (see FIG. 6). The shutter member 201 extends in the axial direction of the photosensitive drum 11 and is provided with a connecting portion 201a at one end in a direction perpendicular to the axial direction of the photosensitive drum 11 (the upstream side in a first direction R1 described later). In addition, an arm member connecting portion 201b is provided at the non-drive-side end of the shutter member 201. The arm member connecting portion 201b is provided on the other end side of the connecting portion 201a in the direction perpendicular to the axial direction of the photosensitive drum 11 (the downstream side in a first direction R1 described later).

[0041] A connecting portion 201a of the shutter member 201 is rotatably connected to a connected portion 202a of the link member 202. That is, the shutter member 201 is rotatably connected to the link member 202. The arm member 203 is provided with a shutter member connecting portion 203a at one end and a cartridge frame connecting portion 203b at the other end. The cartridge frame connecting portion 203b is rotatably supported by the arm member support portion 55b of the non-drive-side bearing member 55. The shutter member connecting portion 203a is rotatably supported by the arm member connecting portion 201b of the shutter member 201.

[0042] The arm member connecting portion 201b is provided downstream in the first direction R1 from the connecting portion 201a, and the arm member support portion 55b is provided at a position closer to the photosensitive drum 11 than the non-drive side link member support portion 55a. Therefore, the arm member 203 is provided at a position closer to the photosensitive drum 11 than the link member 202. The arm member 203 has the role of determining the attitude of the shutter member 201 which is rotatably connected to the link member 202. The shutter member 201 can move between a protection position which covers the photosensitive drum 11 and an exposure position which exposes the photosensitive drum 11 in accordance with the rotational movement of the link member 202 and the arm member 203. The direction in which the shutter member 201 moves from the exposure position to the protection position is the first direction R1. be.

[0043] Before the process cartridge B is inserted, the shutter member 201 is closed to protect the photosensitive drum 11. As the insertion progresses, a part of the link member 202 abuts against the main assembly A of the apparatus, causing the link member 202 and the arm member 203 to rotate in the R1 direction in FIG. 7, and the torsion coil spring 204 to be compressed and deformed. The rotated link member 202 then abuts against an abutment portion 410 of the main assembly guide of the main assembly A of the apparatus. FIG. 13(a) shows the abutment portion 410a against which the non-drive side link member 202 abuts. As shown in FIG. 14(a), the non-drive side link member 202 rides up on the abutment portion 410a, and the torsion coil spring 204 is compressed by the force transmitted through the pressed link member 202. Similarly, on the drive side, the link member 202 rides up on the abutment portion 410b shown in FIG. 13(b), as shown in FIG. 14(b).

[0044] As a result of this operation, the shutter member 201 opens and moves to the exposure position, exposing the photosensitive drum 11. On the other hand, when the process cartridge B is removed, the pressure on the torsion coil spring 204 is released as the cartridge is removed, causing the torsion coil spring 204 to expand and return to its natural state. As a result, the shutter member 201, biased by the torsion coil spring 204, closes and moves to the protection position.

[0045] The torsion coil spring 204 is provided between the non-drive side bearing member 55 and the link member 202, and urges the link member 202 in the first direction R1, thereby urging the shutter member 201 to the protection position. Therefore, while the process cartridge B is not installed in the apparatus main body A, the shutter member 201 is maintained in the protection position. Note that by providing both the arm member 203 and the torsion coil spring 204 on the non-drive side, the shutter member 201 can be operated stably.

[0046] Next, torsion coil spring 204 will be described with reference to Figures 1B, 8A, 8B, and 10(a) to (d). Figure 8A is a cross-sectional view taken along line aa in Figure 7, showing the vicinity of the end on the non-drive side. Figure 8B is a cross-sectional view taken along line bb in Figure 7, showing the vicinity of the end on the non-drive side. Figures 10(a) to (d) are diagrams for explaining the structure and deformation of torsion coil spring 204.

[0047] Figures 10(a) and 10(b) are perspective views of the torsion coil spring 204 in a normal extended state (a natural state with no load applied) viewed from different directions. Figure 10(c) is a side view showing the torsion coil spring 204 in an extended state, which corresponds to the state in which the shutter member 201 is closed. Figure 10(d) is a side view showing the torsion coil spring 204 in a compressed and deformed state, which corresponds to the state in which the shutter member 201 is open.

[0048] Of both ends of the coil wire that constitutes the coil portion 204b of the torsion coil spring 204, one end protrudes from the coil portion 204b as a link member gripping portion 204a, and the other end protrudes from the coil portion 204b as a fixed end 204c. When the torsion coil spring 204 is actually arranged in the cartridge frame L, with the side closer to the cartridge frame L being the inside and the side farther from the cartridge frame L being the outside, the link member gripping portion 204a (first restricting portion 50A, described later) is arranged on the outside and the fixed end 204c (second restricting portion 50B, described later) is arranged on the inside.

[0049] Figure 12 shows the structure for preventing the link member 202 from coming off on the drive side of the process cartridge B. Figure 12 shows the process cartridge B shown in Figure 11(a) as viewed from the direction of arrow U. On the drive side, the link member 202 is sandwiched between the drive side bearing member 54 and the side cover 58, thereby preventing it from coming off.

[0050] [First Regulatory Department] Torsion coil spring 204 biases link member 202 and is provided with link member gripping portion 204a. Link member gripping portion 204a is bent into an L-shape and engages with gripped portion 202c of link member 202 so as to intersect with the axial direction of link member gripping portion 202c. The shape of the gripping portion of link member gripping portion 204a is not limited to an L-shape, as long as it can grip gripped portion 202c. For example, it may be bent at an angle greater than or less than a right angle, or may have a curved shape. Engagement between gripped portion 202c of link member 202 and link member gripping portion 204a of torsion coil spring 204 biases link member 202 in the first direction R. In addition to the biasing force, the torsion coil spring 204 also serves to restrict movement of the link member 202 in the direction of arrow F (see FIGS. 6, 8A, and 8B), which is parallel to the rotation axis of the photosensitive drum.

[0051] The link member gripping portion 204a of the torsion coil spring 204 and the gripped portion 202c of the link member 202 come into contact with each other to form a first restricting portion 50A (FIG. 1B) that restricts outward axial movement of the link member 202. Note that "outside" in the axial direction refers to the side farther from the cartridge frame L, and "inside" refers to the side closer to the cartridge frame L.

[0052] [Second Regulatory Department] As described above, the coil body portion (coil portion 204b) of the torsion coil spring 204 is provided between the non-drive-side bearing member 55 and the link member 202 in the direction of arrow F. A rib 55c is provided on the non-drive-side link member support portion 55a of the non-drive-side bearing member 55. The rib 55c abuts against the coil portion 204b of the torsion recoil spring 204, thereby restricting movement of the torsion coil spring 204 in the direction of arrow F and preventing the torsion coil spring 204 from falling off the cartridge frame. The rib 55c of the non-drive-side link member support portion 55a and the coil portion 204b of the torsion coil spring 204 come into contact with each other to form a second restriction portion 50B (FIG. 1B) that restricts outward movement of the torsion coil spring 204 in the axial direction.

[0053] [Third Regulatory Department] Furthermore, the torsion coil spring 204 is provided with a fixed end 204c, and the non-drive-side bearing member 55 is provided with an engaged portion 55d that contacts the fixed end 204c. The non-drive-side bearing member 55 is also provided with a fixed end restricting portion 55e. The fixed end restricting portion 55e contacts the fixed end 204c of the torsion coil spring 204, thereby restricting movement of the torsion coil spring 204 in the direction of arrow F and preventing the torsion coil spring 204 from falling off the cartridge frame. The fixed end 204c of the torsion coil spring 204 and the engaged portion 55d of the non-drive-side bearing member 55 come into contact with each other to form a third restricting portion 50C that restricts outward movement of the torsion coil spring 204 in the axial direction (FIG. 1B).

[0054] In addition, as a configuration for restricting the movement of the torsion coil spring 204 itself in the direction of arrow F and preventing it from falling off, it is necessary to provide at least either the second restricting portion 50B or the third restricting portion 50C, and it is more preferable to provide both.

[0055] Next, the positional relationship of the first restricting portion 50A to the third restricting portion 50C that come into contact with the torsion coil spring 204 will be described in more detail with reference to FIGS. 8A and 8B.

[0056] The contact position between the link member gripping portion 204a of the torsion coil spring 204 and the gripped portion 202c of the link member 202 is called the first restricting portion. The contact position between the coil portion 204b of the torsion coil spring 204 and the rib is called the second restricting portion. The contact position between the fixed end portion 204c of the torsion coil spring 204 and the fixed end restricting portion 55e of the non-drive side bearing member 55 is called the third restricting portion. It is called the regulatory department.

[0057] At this time, in this embodiment, when the first regulating portion and the second regulating portion that contacts the cartridge frame body (the second regulating portion at this time includes the second regulating portion and the third regulating portion described above) are present, the movement of the link member 202 and the torsion coil spring 204 in the direction of arrow F is regulated, and the effect of preventing the link member 202 and the torsion coil spring 204 from coming off the cartridge frame body can be obtained.

[0058] Furthermore, when the first restricting portion, the second restricting portion, and the third restricting portion are all present, the same effect can be obtained.

[0059] At this time, the positional relationship of the respective engaging portions when viewed in the direction of arrow F is such that, from the upstream side, the third restricting portion, the second restricting portion, and the first restricting portion are in this order.

[0060] As described above, according to this configuration, the link member gripping portion 204a provided on the torsion coil spring 204 can prevent the link member 202 from falling off the process cartridge B.

[0061] In addition, the drum shutter unit 200 can prevent the link member 202 and the torsion coil spring 204 from coming off without the need for separate members or processing on the link member 202, which leads to cost reduction.

[0062] In addition, this leads to space saving around the rotation axis of the link member 202 and to a reduction in the size of the process cartridge B.

[0063] This embodiment can also be applied to a process cartridge having a developing cartridge and to an apparatus main body to which the process cartridge is detachably attached, and the same effects can be obtained.

[0064] As described above, according to the configuration of the present application, the link member 202 can be prevented from coming off by the link member gripping portion 204a of the torsion coil spring 204. This makes it possible to avoid a configuration in which the link member 202 is prevented from coming off by being sandwiched between molded parts, which contributes to the miniaturization of the process cartridge B. As a result, when the process cartridge B is provided with the drum shutter unit 200 that protects the photosensitive drum 11, it is possible to save space and prevent the link member 202 from coming off from the cartridge frame.

[0065] [Configuration 1] A process cartridge detachably mountable to an image forming apparatus body, A photosensitive drum; A cartridge frame; a shutter member that is movable between a protection position that protects the surface of the photosensitive drum and an exposure position that exposes the surface of the photosensitive drum; a link member rotatably supported on the cartridge frame and connected to the shutter member, the link member moving the shutter member between the protection position and the exposure position; a torsion coil spring supported on the cartridge frame, the torsion coil spring contacting the link member to urge the shutter member to the protection position, and rotating when subjected to a load to move the shutter member to the exposure position; In a process cartridge having The torsion coil spring and the link member come into contact with each other to form a first restricting portion, and a restricting portion restricting movement of the link member in the direction of the rotation axis of the photosensitive drum; The cartridge frame and the torsion coil spring come into contact with each other to form a second restricting portion, and the second restricting portion restricts movement of the torsion coil spring in the direction of the rotation axis. A process cartridge characterized by: [Configuration 2] The torsion coil spring has a link member gripping portion that grips the link member at the first restricting portion. 2. The process cartridge according to claim 1, [Configuration 3] In the first restricting portion, the link member gripping portion of the torsion coil spring comes into contact with a gripped portion of the link member to restrict outward movement of the link member in the direction of the rotation axis. 3. The process cartridge according to configuration 2. [Configuration 4] In the first restricting portion, the link member gripping portion protrudes from the coil body of the torsion coil spring and has a gripping portion bent to engage with the gripped portion of the link member, and the gripping portion intersects with the gripped portion. 3. The process cartridge according to configuration 2. [Configuration 5] When the side closer to the cartridge frame is defined as the inside and the side farther from the cartridge frame is defined as the outside in the direction of the rotation axis, the coil body is provided inside the gripped portion, and at least a part of the gripped portion is provided outside the gripped portion. 5. The process cartridge according to configuration 4. [Configuration 6] The process cartridge according to any one of configurations 1 to 5, characterized in that, in the direction of the rotation axis, the side closer to the cartridge frame is the inside and the side farther from it is the outside, the first regulating portion is arranged on the outside and the second regulating portion is arranged on the inside. [Configuration 7] In the second restricting portion, the cartridge frame has a rib that comes into contact with the coil body of the torsion coil spring. 7. The process cartridge according to any one of Configurations 1 to 6. [Configuration 8] In the second restricting portion, the rib is located outward of the coil body in the direction of the rotation axis, and the rib and the coil body come into contact with each other to restrict movement of the torsion coil spring. 8. The process cartridge according to Configuration 7. [Configuration 9] When the side closer to the cartridge frame body in the direction of the rotation axis is defined as the inside and the side farther from the cartridge frame body is defined as the outside, the rib is provided outside the coil body. 9. The process cartridge according to configuration 8. [Configuration 10] The cartridge frame and the torsion coil spring come into contact with each other to form a third restricting portion, and the third restricting portion restricts movement of the torsion coil spring in the direction of the rotation axis. 10. The process cartridge according to any one of Configurations 1 to 9. [Configuration 11] In the third restricting portion, the torsion coil spring has a fixed end protruding from a coil body, and when the side closer to the cartridge frame is defined as the inside and the side farther from the cartridge frame is defined as the outside in the direction of the rotation axis, the cartridge frame contacts the fixed end from outside the fixed end. It has a fixed end restriction part that comes into contact with the 11. The process cartridge according to claim 10. [Explanation of symbols]

[0066] 11: photosensitive drum, 50A: first regulating portion, 50B: second regulating portion, 55: non-drive side bearing member, 201: shutter member, 202: link member, 204: torsion coil spring, A: apparatus main body, B: process cartridge, L: cartridge frame

Claims

1. A process cartridge detachably mountable to an image forming apparatus body, A photosensitive drum; A cartridge frame; a shutter member that is movable between a protection position that protects the surface of the photosensitive drum and an exposure position that exposes the surface of the photosensitive drum; a link member rotatably supported on the cartridge frame and connected to the shutter member, the link member moving the shutter member between the protection position and the exposure position; a torsion coil spring supported on the cartridge frame, the torsion coil spring contacting the link member to urge the shutter member to the protection position, and rotating when subjected to a load to move the shutter member to the exposure position; In a process cartridge having the torsion coil spring and the link member come into contact with each other to form a first regulating portion, and the movement of the link member in the direction of the rotation axis of the photosensitive drum is regulated by the first regulating portion; The cartridge frame and the torsion coil spring come into contact with each other to form a second restricting portion, and the second restricting portion restricts movement of the torsion coil spring in the direction of the rotation axis. A process cartridge characterized by:

2. The torsion coil spring has a link member gripping portion that grips the link member at the first restricting portion.

2. The process cartridge according to claim 1, wherein the ink is a resin.

3. In the first restricting portion, the link member gripping portion of the torsion coil spring comes into contact with a gripped portion of the link member to restrict outward movement of the link member in the direction of the rotation axis.

3. The process cartridge according to claim 2, wherein the ink is a resin.

4. In the first restricting portion, the link member gripping portion protrudes from the coil body of the torsion coil spring and has a gripping portion bent to engage with the gripped portion of the link member, and the gripping portion intersects with the gripped portion.

3. The process cartridge according to claim 2, wherein the ink is a resin.

5. When the side closer to the cartridge frame is defined as the inside and the side farther from the cartridge frame is defined as the outside in the direction of the rotation axis, the coil body is provided inside the gripped portion, and at least a part of the gripped portion is provided outside the gripped portion.

5. The process cartridge according to claim 4.

6. A process cartridge according to any one of claims 1 to 5, characterized in that, in the direction of the rotation axis, when the side closer to the cartridge frame is the inside and the side farther from it is the outside, the first regulating portion is arranged on the outside and the second regulating portion is arranged on the inside.

7. In the second restricting portion, the cartridge frame has a rib that comes into contact with the coil body of the torsion coil spring.

6. The process cartridge according to claim 1, wherein the ink-receiving element is a resin.

8. In the second restricting portion, the rib is positioned so as to be spaced apart from the coil body in the direction of the rotation axis. The rib and the coil body are in contact with each other to restrict the movement of the torsion coil spring.

8. The process cartridge according to claim 7, wherein the ink is a resin.

9. When the side closer to the cartridge frame body in the direction of the rotation axis is defined as the inside and the side farther from the cartridge frame body is defined as the outside, the rib is provided outside the coil body.

9. The process cartridge according to claim 8, wherein the ink is a resin.

10. The cartridge frame and the torsion coil spring come into contact with each other to form a third restricting portion, and the third restricting portion restricts movement of the torsion coil spring in the direction of the rotation axis.

6. The process cartridge according to claim 1, wherein the ink-receiving element is a resin.

11. In the third restricting portion, the torsion coil spring has a fixed end protruding from a coil body, and when the side closer to the cartridge frame is defined as the inside and the side farther from the cartridge frame is defined as the outside in the direction of the rotation axis, the cartridge frame has a fixed end restricting portion that contacts the fixed end from outside the fixed end.

11. The process cartridge according to claim 10.

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