Processing box

Abstract

Provided is a process cartridge capable of pressing a developing cartridge toward a photosensitive drum at a position close to the photosensitive drum by a pressing member. The process cartridge (5) is provided with a drum cartridge (6) and a developing cartridge (7) that can be attached to and detached from the drum cartridge (6). The drum cartridge (6) includes a photosensitive drum (61) and a pressing member (150A) that presses the developing cartridge (7) toward the photosensitive drum (61) in a state where the developing cartridge (7) is attached to the drum cartridge (6). The developing cartridge (7) includes a developing roller (71), a supply roller (72) having a supply roller shaft (72A), and a developing frame (75). The developing frame (75) has a side wall (210A) and a pressing wall (220A) protruding from the side wall (210A) and surrounding one end of the supply roller shaft (72A). In a state in which the developing cartridge (7) is attached to the drum cartridge (6), the pressing wall (220A) is pressed by the pressing member (150A).

Description

Technical Field

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

[0002] Conventionally, a process cartridge having a drum cartridge and a developer cartridge that can be attached and detached from the drum cartridge is known (Patent Document 1). The drum cartridge has a photosensitive drum, a pressing member, and a drum frame that supports the photosensitive drum and the pressing member. The pressing member presses the developer cartridge toward the photosensitive drum when the developer cartridge is mounted on the drum cartridge. The developer cartridge has a developer roller and a developer frame that supports the developer roller. In this technology, when the developer cartridge is mounted on the drum cartridge, a wall of the developer frame at an end portion away from the photosensitive drum is pressed by the pressing member.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2014-016480

[0006] Technical problem to be solved by the invention

[0007] However, when the pressing member receives a reaction force from the pressing member's pressing force from the developing cartridge and the drum frame is deformed, a loss of pressing force occurs. In a structure where the pressing member presses the end of the developing frame away from the photosensitive drum, the loss of pressing force caused by the deformation of the drum frame becomes large. Summary of the invention

[0008] Therefore, it is desirable to be able to press the developing cartridge toward the photosensitive drum at a position close to the photosensitive drum by a pressing member.

[0009] Technical means for solving technical problems

[0010] The process cartridge includes a drum cartridge and a developing cartridge that is attachable to and detachable from the drum cartridge.

[0011] The drum cartridge includes a photosensitive drum and a pressing member.

[0012] The photosensitive drum is rotatable about a drum axis extending in a first direction.

[0013] In a state where the developing cartridge is mounted on the drum cartridge, the pressing member presses the developing cartridge toward the photosensitive drum.

[0014] The developing cartridge includes a developing roller, a supply roller, and a developing frame.

[0015] The developing roller is rotatable about a developing roller axis extending in a first direction.

[0016] The supply roller is rotatable about a supply roller axis extending in a first direction. The supply roller has a supply roller shaft extending in the first direction.

[0017] The developing frame has side walls and a pressing wall.

[0018] The side wall is located at one end portion of the developing frame in the first direction.

[0019] The pressing wall protrudes from the side wall in the first direction. The pressing wall surrounds one end portion of the supply roller shaft in the first direction.

[0020] In a state where the developing cartridge is mounted on the drum cartridge, the pressing wall is pressed by the pressing member.

[0021] By pressing the pressing wall surrounding the one end portion of the supply roller shaft in the first direction with the pressing member, the developing cartridge can be pressed toward the photosensitive drum at a position close to the photosensitive drum by the pressing member.

[0022] The pressing wall may include a first wall, a second wall, and a third wall.

[0023] The second wall is opposite to the first wall in a second direction orthogonal to the first direction.

[0024] The third wall connects one end of the first wall and one end of the second wall.

[0025] One end portion of the supply roller shaft in the first direction is located between the first wall and the second wall.

[0026] In a state where the developing cartridge is mounted on the drum cartridge, the third wall is pressed by the pressing member.

[0027] The dimension of the third wall in the first direction may be larger than the dimension of the first wall in the first direction, and larger than the dimension of the second wall in the first direction.

[0028] By making the dimension of the third wall pressed by the pressing member in the first direction larger, the developing cartridge can be stably pressed toward the photosensitive drum when the third wall is pressed by the pressing member.

[0029] The developing frame may be capable of storing toner, and the developing cartridge may further include a seal.

[0030] The seal is located between the supply roller shaft and the pressing wall.

[0031] By providing a seal between the supply roller shaft and the pressing wall, it is possible to suppress leakage of toner from between the supply roller shaft and the pressing wall. The pressing wall surrounding the supply roller shaft can be used as a portion for holding the seal.

[0032] The pressing wall may have ribs.

[0033] In a state where the developing cartridge is mounted on the drum cartridge, the rib protrudes toward the pressing member. The rib is pressed by the pressing member.

[0034] Since the pressing wall has the rib, the pressing wall that receives the pressing force from the pressing member can be reinforced.

[0035] Alternatively, the rib may have an arc shape when viewed from the first direction.

[0036] The rib has an arc shape, so that when the developer box is installed and removed from the drum box, the rib is less likely to be hooked on the pressing member.

[0037] Alternatively, a plurality of ribs may be arranged in parallel along the first direction.

[0038] By arranging a plurality of ribs in the first direction, the developer cartridge can be stably pressed toward the photosensitive drum when the ribs are pressed by the pressing member. The pressing wall can be further reinforced by the plurality of ribs.

[0039] Alternatively, when the developing cartridge is mounted on the drum cartridge, the pressing wall may be located on a virtual straight line passing through the drum axis and the developing roller axis when viewed from the first direction.

[0040] Since the pressing wall is located on the imaginary straight line passing through the drum axis and the developing roller axis, when the pressing member presses the pressing wall, the developing roller can be pressed toward the drum axis of the photosensitive drum.

[0041] The process cartridge may include a supply roller bearing in which the supply roller shaft is fitted, and the third wall and the supply roller bearing may be arranged in a direction orthogonal to both the first direction and the second direction.

[0042] The third wall and the supply roller bearing are arranged in a direction orthogonal to both the first direction and the second direction, so that the developing cartridge can be made compact in the first direction. Thus, the drum cartridge and the process cartridge can be made compact in the first direction.

[0043] The pressing wall and the supply roller may be arranged along the first direction.

[0044] The process cartridge may further include a supply roller gear, and the pressing wall may be located between the supply roller gear and the side wall.

[0045] The supply roller gear is located at one end of the supply roller shaft in the first direction and can rotate around the supply roller axis together with the supply roller.

[0046] Alternatively, when the developing cartridge is mounted on the drum cartridge, the supply roller shaft may be located on a virtual straight line passing through the drum axis and the developing roller axis when viewed from the first direction.

[0047] Effects of the Invention

[0048] The developing cartridge can be pressed toward the photosensitive drum at a position close to the photosensitive drum by the pressing member. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is a diagram showing an image forming apparatus using a process cartridge.

[0050] Figure 2 This is a diagram showing the image forming apparatus in a state where the process cartridge is removed.

[0051] Figure 3 (a) is a perspective view showing a process cartridge, and (b) is a perspective view showing a drum cartridge and a developer cartridge.

[0052] Figure 4 It is a perspective view showing a lock lever and a pressing member of the drum cartridge.

[0053] Figure 5 It is a cross-sectional view showing a first pressing member and a first pressing wall of the process cartridge.

[0054] Figure 6 It is a three-dimensional view showing a first pressing wall and a second pressing wall of a developing box.

[0055] Figure 7 It is a sectional view showing a state where the developing cartridge is lifted from the drum cartridge.

[0056] Figure 8 It is a perspective view showing one end portion of the developing cartridge in an exploded manner.

[0057] Fig. 9 It is a cross-sectional perspective view showing one end portion of the process cartridge.

[0058] Fig.10 It is a cross-sectional view showing one end portion and the other end portion of the process cartridge.

[0059] Explanation of symbols

[0060] 5. Processing Box

[0061] 6-Drum Box

[0062] 7Developer Box

[0063] 61 Photosensitive drum

[0064] 61X drum axis

[0065] 71Developing roller

[0066] 71X developing roller axis

[0067] 72 Supply roller

[0068] 72A Supply roller shaft

[0069] 72X supply roller axis

[0070] 75 Development Frame

[0071] 150A first pressing member (pressing member)

[0072] 210A first side wall (side wall)

[0073] 220A: first pressing wall (pressing wall). DETAILED DESCRIPTION

[0074] Next, an embodiment will be described.

[0075] like Figure 1 As shown, the image forming apparatus 1 includes a housing 2 , a sheet feeding unit 3 , an exposure device 4 , a process cartridge 5 , and a fixing device 8 .

[0076] The sheet feeding section 3 is located at the lower part of the housing 2. The sheet feeding section 3 includes a sheet tray 31, a pressing plate 32, and a sheet feeding mechanism 33. The sheet tray 31 stores sheets S such as paper. The pressing plate 32 lifts the sheets S in the sheet tray 31 upward. The sheet feeding mechanism 33 feeds the sheets S lifted by the pressing plate 32 toward the processing box 5.

[0077] The exposure device 4 is located above the sheet tray 31. The exposure device 4 includes a light source, a deflector, a lens, a reflector, etc. As shown by the imaginary line, the exposure device 4 emits a light beam to expose the surface of the photosensitive drum 61.

[0078] The process cartridge 5 is located above the sheet feeding mechanism 33. The process cartridge 5 includes a drum cartridge 6 and a developing cartridge 7.

[0079] The drum cartridge 6 includes a photosensitive drum 61, a charger 62, a transfer roller 63, and a drum frame 65. The photosensitive drum 61 is rotatable about a drum axis 61X extending in a first direction. In the present embodiment, the first direction corresponds to the left-right direction of the image forming apparatus 1.

[0080] The charger 62 charges the surface of the photosensitive drum 61 . The transfer roller 63 is rotatable about a transfer roller axis 63X extending in the first direction. The drum frame 65 holds the photosensitive drum 61 , the charger 62 , and the transfer roller 63 .

[0081] The developing cartridge 7 includes a developing roller 71 , a supply roller 72 , a layer thickness regulating blade 73 , an agitator 74 , and a developing frame 75 .

[0082] The developing roller 71 is rotatable about a developing roller axis 71X extending in the first direction. The supply roller 72 is rotatable about a supply roller axis 72X extending in the first direction. The layer thickness regulating blade 73 regulates the thickness of the toner layer on the developing roller 71 to a constant thickness.

[0083] The developing frame 75 holds the developing roller 71, the supply roller 72, the layer thickness regulating blade 73, and the agitator 74. The developing frame 75 can store toner. Specifically, the developing frame 75 has a toner storage portion 76 that can store toner.

[0084] The agitator 74 is rotatable about an agitator axis 74X extending in the first direction. The agitator 74 agitates the toner in the toner storage section 76 by rotating. The supply roller 72 supplies the toner stored in the toner storage section 76 to the developing roller 71 .

[0085] The fixing device 8 is located above the process cartridge 5. The fixing device 8 includes a heating roller 81 and a pressure roller 82. The heating roller 81 heats the sheet S. The pressure roller 82 sandwiches the sheet S with the heating roller 81.

[0086] The image forming apparatus 1 charges the surface of the photosensitive drum 61 by the charger 62. Next, the image forming apparatus 1 exposes the charged surface of the photosensitive drum 61 by the light beam emitted from the exposure device 4. Thus, an electrostatic latent image based on image data is formed on the photosensitive drum 61. Next, the image forming apparatus 1 supplies toner from the developing roller 71 to the photosensitive drum 61. Thus, a toner image is formed on the photosensitive drum 61.

[0087] Subsequently, the image forming apparatus 1 conveys the sheet S supplied from the sheet supply unit 3 between the photosensitive drum 61 and the transfer roller 63. Thus, the toner image formed on the photosensitive drum 61 is transferred to the sheet S. Subsequently, the image forming apparatus 1 conveys the sheet S to which the toner image is transferred between the heating roller 81 and the pressure roller 82. Thus, the toner image transferred to the sheet S is fixed on the sheet S.

[0088] The image forming apparatus 1 discharges the sheet S on which the toner image is fixed to the discharge tray 2A by the discharge roller 9 .

[0089] The housing 2 includes a housing body 21 and a cover 22. The housing body 21 has an opening 21A. The cover 22 opens and closes the opening 21A. Figure 1 The closed position shown is Figure 2 The cover 22 is movable relative to the housing body 21 between the open position shown. Specifically, the cover 22 can rotate relative to the housing body 21 between the closed position and the open position. The closed position is a position where the opening 21A is closed. The open position is a position where the opening 21A is opened.

[0090] like Figure 2 As shown, the process cartridge 5 is attachable to and detachable from the casing 2. Specifically, the process cartridge 5 is attachable to and detachable from the casing main body 21 through the opening 21A in a state where the cover 22 is located at the open position.

[0091] like Figure 3As shown in (a) and (b) of the drawings, the developing cartridge 7 is attachable to and detachable from the drum cartridge 6 . Figure 3 (a) shows a process cartridge 5 in which a developing cartridge 7 is mounted on a drum cartridge 6 . Figure 3 (b) shows a state where the developing cartridge 7 is removed from the drum cartridge 6 .

[0092] In the following referenced drawings, the arrows in the first direction, the second direction, and the third direction indicate one direction, and the arrows without arrows indicate the other direction. The second direction is a direction perpendicular to the first direction. The third direction is a direction perpendicular to both the first direction and the second direction.

[0093] like Figure 4 As shown, the drum cartridge 6 further includes a lock lever 140, and a first pressing member 150A and a second pressing member 150B as pressing members. The drum frame 65 includes a first drum end portion 65A and a second drum end portion 65B.

[0094] The first drum end 65A is an end of the drum frame 65 in the third direction that is close to the photosensitive drum 61. In other words, the first drum end 65A is an end of the drum frame 65 in the other direction. The second drum end 65B is an end of the drum frame 65 in the third direction that is far from the photosensitive drum 61. In other words, the second drum end 65B is an end of the drum frame 65 in the third direction.

[0095] The lock lever 140 locks the developer cartridge 7 to the drum cartridge 6 when the developer cartridge 7 is mounted on the drum cartridge 6. The lock lever 140 is located at the other end in the first direction of the drum frame 65. The lock lever 140 is located closer to the second drum end 65B than the photosensitive drum 61 in the third direction.

[0096] The first pressing member 150A and the second pressing member 150B press the developing cartridge 7 toward the photosensitive drum 61 in a state where the developing cartridge 7 is mounted on the drum cartridge 6 . Thus, the first pressing member 150A and the second pressing member 150B press the developing roller 71 against the photosensitive drum 61 .

[0097] The first pressing member 150A is located at one end in the first direction of the drum frame 65. The second pressing member 150B is located at the other end in the first direction of the drum frame 65. The first pressing member 150A and the second pressing member 150B are located closer to the photosensitive drum 61 than the lock lever 140 in the third direction. The first pressing member 150A and the second pressing member 150B have configurations that are symmetrical to each other in the first direction.

[0098] like Figure 5 As shown, the first pressing member 150A includes a pressing member body 151 and a spring 152. Similarly, the second pressing member 150B (see Fig.10 ) has a pressing component body 151 and a spring 152.

[0099] The pressing member main body 151 contacts the developing cartridge 7 when the developing cartridge 7 is mounted on the drum cartridge 6. The pressing member main body 151 is held by the drum frame 65. The pressing member main body 151 is linearly movable relative to the drum frame 65 in the third direction.

[0100] The spring 152 is located between the pressing member main body 151 and the second drum end 65B of the drum frame 65. The spring 152 urges the pressing member main body 151 toward the other direction of the third direction. As an example, the spring 152 is a compression coil spring.

[0101] like Figure 5 and Figure 6 As shown, the developing frame 75 has a first pressing wall 220A and a second pressing wall 220B as pressing walls. In addition, the developing frame 75 has a first developing end portion 75A and a second developing end portion 75B.

[0102] The first developing end portion 75A is an end portion of the developing frame 75 close to the photosensitive drum 61 in the third direction when the developing cartridge 7 is mounted on the drum cartridge 6. In other words, the first developing end portion 75A is the other end portion of the developing frame 75 in the third direction.

[0103] The second developing end portion 75B is an end portion of the developing frame 75 that is away from the photosensitive drum 61 in the third direction when the developing cartridge 7 is mounted on the drum cartridge 6. In other words, the second developing end portion 75B is one end portion of the developing frame 75 in the third direction.

[0104] The first pressing wall 220A is pressed by the first pressing member 150A in a state where the developing cartridge 7 is mounted on the drum cartridge 6. The first pressing wall 220A is located at one end of the developing frame 75 in the first direction.

[0105] The second pressing wall 220B is pressed by the second pressing member 150B (see Fig.10 The second pressing wall 220B is located at the other end of the developing frame 75 in the first direction.

[0106] like Figure 5 As shown in FIG. 1 , when the developer cartridge 7 is mounted on the drum cartridge 6, the first pressing wall 220A is aligned with the photosensitive drum 61 and the developing roller 71 as viewed from the first direction. Specifically, when the developer cartridge 7 is mounted on the drum cartridge 6, the first pressing wall 220A is located on an imaginary straight line L passing through the drum axis 61X and the developing axis 71X as viewed from the first direction. The same is true for the second pressing wall 220B.

[0107] The developing roller 71 includes a developing roller shaft 71A and a developing roller body 71B. The developing roller shaft 71A extends in a first direction. As an example, the developing roller shaft 71A is made of metal. The developing roller body 71B covers the outer peripheral surface of the developing roller shaft 71A. As an example, the developing roller body 71B is made of rubber.

[0108] The supply roller 72 includes a supply roller shaft 72A and a supply roller body 72B. The supply roller shaft 72A extends in the first direction. As an example, the supply roller shaft 72A is made of metal. The supply roller body 72B covers the outer peripheral surface of the supply roller shaft 72A. As an example, the supply roller body 72B is made of sponge.

[0109] When the developer cartridge 7 is mounted on the drum cartridge 6, the supply roller 72 is aligned with the photosensitive drum 61 and the developer roller 71 in a straight line as viewed from the first direction. Specifically, when the developer cartridge 7 is mounted on the drum cartridge 6, the supply roller shaft 72A is located on the imaginary straight line L as viewed from the first direction.

[0110] The locking rod 140 can be connected to the drum frame 65. Figure 5 The locked position shown is the same as Figure 7 Specifically, the lock lever 140 is able to swing between the lock position and the lock release position relative to the drum frame 65.

[0111] The lock lever 140 has a shaft portion 141 , a lock portion 142 , a lift portion 143 , and an operation portion 144 .

[0112] The shaft portion 141 is rotatable with respect to a rod axis 140X extending in the first direction. The shaft portion 141 is rotatably supported by the drum frame 65 .

[0113] The locking portion 142 is Figure 5 The locking lever 140 shown is in the locked position, locking the developing cartridge 7 to the drum frame 65. The locking portion 142 extends from the shaft portion 141 toward one side in the second direction when the locking lever 140 is in the locked position. The locking portion 142 has a recess 142A into which the protrusion 77 of the developing cartridge 7 enters.

[0114] The operation portion 144 is operated by the user when the lock lever 140 is moved from the lock position to the unlock position. When the lock lever 140 is at the lock position, the operation portion 144 extends from the lock portion 142 toward one side in the second direction and one side in the third direction.

[0115] The lifting portion 143 contacts the developing cartridge 7 when the lock lever 140 moves from the locked position to the unlocked position, and lifts the developing cartridge 7. The lifting portion 143 extends from the shaft portion 141 toward the other side in the second direction when the lock lever 140 is located at the locked position.

[0116] The lock lever 140 is located at the lock position in a state where the developer cartridge 7 is mounted on the drum cartridge 6. At this time, the protrusion 77 of the developer cartridge 7 enters the recess 142A of the lock portion 142. Thus, the developer cartridge 7 is locked relative to the drum cartridge 6.

[0117] When the locking lever 140 is moved from the locking position to Figure 7 When the lock release position shown is moved, the recessed portion 142A of the locking portion 142 is disengaged from the protrusion 77 of the developer cartridge 7, and the lifting portion 143 lifts the developer cartridge 7. As a result, the lock of the developer cartridge 7 relative to the drum cartridge 6 is released, and mainly the second developing end portion 75B of the developer cartridge 7 is separated from the drum frame 65. As a result, the developer cartridge 7 is separated from the drum cartridge 6.

[0118] like Figure 8 As shown, the developing cartridge 7 further includes a first seal 230A and a first bearing 240A as seals. The developing frame 75 includes a first side wall 210A as a side wall.

[0119] The first side wall 210A is located at one end portion in the first direction of the developing frame 75. In the present embodiment, the first side wall 210A is orthogonal to the first direction.

[0120] The first pressing wall 220A protrudes from the first side wall 210A toward one side in the first direction. The first pressing wall 220A surrounds one end portion of the supply roller shaft 72A in the first direction. Specifically, the first pressing wall 220A includes a first wall 221 , a second wall 222 , and a third wall 223 .

[0121] The first wall 221 and the second wall 222 extend in the third direction. The second wall 222 is opposite to the first wall 221 in the second direction. One end of the supply roller shaft 72A in the first direction is located between the first wall 221 and the second wall 222. The first wall 221 is located on one side of the supply roller shaft 72A in the second direction. The second wall 222 is located on the other side of the supply roller shaft 72A in the second direction.

[0122] The third wall 223 extends along the second direction. The third wall 223 connects one end of the first wall 221 and one end of the second wall 222. Specifically, the third wall 223 connects one end of the first wall 221 in the third direction and one end of the second wall 222 in the third direction.

[0123] The third wall 223 protrudes in the first direction compared to the first wall 221 and the second wall 222. Specifically, the dimension of the third wall 223 in the first direction is larger than the dimension of the first wall 221 in the first direction, and larger than the dimension of the second wall 222 in the first direction. In the present embodiment, the dimension of the first wall 221 in the first direction is the same as the dimension of the second wall 222 in the first direction. The third wall 223 is directly opposite to the supply roller shaft 72A.

[0124] The first pressing wall 220A further has a rib 224. When the developing cartridge 7 is mounted on the drum cartridge 6, the rib 224 faces the first pressing member 150A (see Figure 5 Specifically, the rib 224 protrudes from the third wall 223 toward one side in the third direction.

[0125] A plurality of ribs 224 are arranged along the first direction. In this embodiment, two ribs 224 are arranged along the first direction. The rib 224 has an arc shape when viewed from the first direction. Specifically, one surface of the rib 224 in the third direction has an arc shape when viewed from the first direction.

[0126] like Fig. 9 As shown, the third wall 223 of the first pressing wall 220A is pressed by the first pressing member 150A when the developing cartridge 7 is mounted on the drum cartridge 6. Specifically, when the developing cartridge 7 is mounted on the drum cartridge 6, the rib 224 protruding from the third wall 223 of the first pressing wall 220A is pressed by the first pressing member 150A.

[0127] The first seal 230A restricts toner from leaking from between the supply roller shaft 72A and the first pressing wall 220A. The first seal 230A is located between the supply roller shaft 72A and the first pressing wall 220A. The first pressing wall 220A holds the first seal 230A. Specifically, the first pressing wall 220A is located between the first wall 221 (see Figure 5 ) and the second wall 222 to maintain a first seal 230A.

[0128] Before the developing roller 71 is mounted on the developing frame 75, the first seal 230A is mounted on the developing frame 75 together with the supply roller 72. Specifically, the supply roller shaft 72A is inserted into the through hole 231 (see Figure 8 ), the first seal 230A is mounted on the developing frame 75 together with the supply roller 72. The first seal 230A is mounted on the inner side of the first pressing wall 220A from the first developing end portion 75A of the developing frame 75 toward one side in the third direction.

[0129] Back to Figure 8The first bearing 240A rotatably supports the developing roller 71 and the supply roller 72. The first bearing 240A includes a first developing bearing 241A and a first supply bearing 242A serving as a supply roller bearing.

[0130] The first developing bearing 241A rotatably supports the developing roller 71. One end portion of the developing roller shaft 71A in the first direction is fitted into the first developing bearing 241A.

[0131] The first supply bearing 242A rotatably supports the supply roller 72. One end portion of the supply roller shaft 72A in the first direction is fitted into the first supply bearing 242A. In the present embodiment, the first developing bearing 241A and the first supply bearing 242A are formed integrally.

[0132] like Fig.10 As shown, the third wall 223 of the first pressing wall 220A and the first supply bearing 242A are arranged in the third direction. The third wall 223 of the first pressing wall 220A is located on one side of the first supply bearing 242A in the third direction.

[0133] The developing cartridge 7 further includes a supply roller gear 72G. The supply roller gear 72G can rotate together with the supply roller 72 around the supply roller axis 72X. The supply roller gear 72G is located at one end of the supply roller shaft 72A in the first direction. The supply roller gear 72G is fixed to the supply roller shaft 72A. The supply roller 72 rotates by inputting a driving force to the supply roller gear 72G.

[0134] The first pressing wall 220A is located between the supply roller gear 72G and the first side wall 210A of the developing frame 75. The first pressing wall 220A is located on one side of the first side wall 210A in the first direction. The first pressing wall 220A is located on the other side of the supply roller gear 72G in the first direction.

[0135] The first pressing wall 220A and the supply roller 72 are arranged in the first direction. The first pressing wall 220A is located on one side of the supply roller 72 in the first direction. Specifically, the first pressing wall 220A and the supply roller body 72B are arranged in the first direction. The first pressing wall 220A is located on one side of the supply roller body 72B in the first direction.

[0136] The developing cartridge 7 further includes a second seal 230B and a second bearing 240B. The developing frame 75 includes a second side wall 210B.

[0137] The second side wall 210B is located at the other end portion in the first direction of the developing frame 75. In the present embodiment, the second side wall 210B is orthogonal to the first direction. The second side wall 210B is opposite to the first side wall 210A in the first direction.

[0138] The second pressing wall 220B protrudes from the second side wall 210B toward the other side of the first direction. The second pressing wall 220B surrounds the other end of the supply roller shaft 72A in the first direction. The second pressing wall 220B has a structure symmetrical to the first pressing wall 220A in the first direction. Specifically, the second pressing wall 220B has a first wall 221, a second wall 222, a third wall 223, and a rib 224 (partial illustration omitted) in the same manner as the first pressing wall 220A.

[0139] The other end of the supply roller shaft 72A in the first direction is located between the first wall 221 and the second wall 222 of the second pressing wall 220B. The rib 224 of the second pressing wall 220B projects toward the second pressing member 150B when the developing cartridge 7 is mounted on the drum cartridge 6.

[0140] When the developer cartridge 7 is mounted on the drum cartridge 6 , the third wall 223 of the second pressing wall 220B is pressed by the second pressing member 150B. Specifically, when the developer cartridge 7 is mounted on the drum cartridge 6 , the rib 224 of the second pressing wall 220B is pressed by the second pressing member 150B.

[0141] The second seal 230B restricts toner leakage from between the supply roller shaft 72A and the second pressing wall 220B. The second seal 230B is located between the supply roller shaft 72A and the second pressing wall 220B. The second pressing wall 220B holds the second seal 230B. The second seal 230B is attached to the developing frame 75 in the same manner as the first seal 230A.

[0142] The second bearing 240B has a second developing bearing 241B and a second supply bearing 242B.

[0143] The second developing bearing 241B rotatably supports the developing roller 71. The other end portion of the developing roller shaft 71A in the first direction is fitted into the second developing bearing 241B.

[0144] The second supply bearing 242B rotatably supports the supply roller 72. The other end portion of the supply roller shaft 72A in the first direction is fitted into the second supply bearing 242B. In the present embodiment, the second developing bearing 241B and the second supply bearing 242B are formed integrally.

[0145] The third wall 223 of the second pressing wall 220B and the second supply bearing 242B are arranged in the third direction. The third wall 223 of the second pressing wall 220B is located on one side of the second supply bearing 242B in the third direction.

[0146] The second pressing wall 220B and the supply roller 72 are arranged in the first direction. The second pressing wall 220B is located on the other side of the supply roller 72 in the first direction. Specifically, the second pressing wall 220B and the supply roller body 72B are arranged in the first direction. The second pressing wall 220B is located on the other side of the supply roller body 72B in the first direction.

[0147] Next, the effects of the embodiment will be described.

[0148] The pressing walls 220A and 220B surrounding the end portions of the supply roller shaft 72A in the first direction are pressed by the pressing members 150A and 150B, so that the developing cartridge 7 can be pressed toward the photosensitive drum 61 at a position close to the photosensitive drum 61 by the pressing members 150A and 150B.

[0149] By shortening the distance from the pressing walls 220A and 220B to the photosensitive drum 61, it is possible to suppress deformation of the drum frame 65 due to the reaction force of the pressing force of the pressing members 150A and 150B received from the developer cartridge 7. Thus, it is possible to reduce the loss of the pressing force caused by the deformation of the drum frame 65. By reducing the loss of the pressing force, it is possible to press the developer cartridge 7 toward the photosensitive drum 61 with a small pressing force. In other words, even if the acting force of the spring 152 of the pressing members 150A and 150B is small, it is possible to press the developer cartridge 7 toward the photosensitive drum 61 with a sufficient pressing force.

[0150] In the process cartridge 5, the pressing walls 220A and 220B pressed by the pressing members 150A and 150B of the developer cartridge 7 are not located at the second developing end portion 75B of the developer frame 75, but at the side surface in the first direction of the developer frame 75. Thus, the toner storage portion 76 of the developer frame 75 can be enlarged toward one side in the second direction and / or one side in the third direction. Thus, the toner storage volume of the developer cartridge 7 can be increased.

[0151] By making the dimension of the third wall 223 pressed by the pressing members 150A and 150B in the first direction larger, the developing cartridge 7 can be stably pressed toward the photosensitive drum 61 when the third wall 223 is pressed by the pressing members 150A and 150B.

[0152] By providing the seals 230A and 230B between the supply roller shaft 72A and the pressing walls 220A and 220B, it is possible to suppress leakage of toner from between the supply roller shaft 72A and the pressing walls 220A and 220B. The pressing walls 220A and 220B surrounding the supply roller shaft 72A can be used as a portion for holding the seals 230A and 230B.

[0153] Since the pressing walls 220A and 220B have the ribs 224 , the pressing walls 220A and 220B that receive the pressing force from the pressing members 150A and 150B can be reinforced.

[0154] Since the rib 224 has an arc shape, the rib 224 is not easily caught on the pressing members 150A and 150B when the developer cartridge 7 is attached to and detached from the drum cartridge 6. Thus, the developer cartridge 7 can be easily attached to and detached from the drum cartridge 6.

[0155] Since the plurality of ribs 224 are arranged in the first direction, when the pressing members 150A and 150B press the ribs 224, the developing cartridge 7 can be stably pressed toward the photosensitive drum 61. The plurality of ribs 224 can further reinforce the pressing walls 220A and 220B.

[0156] By positioning the pressing walls 220A and 220B on the imaginary straight line L passing through the drum axis 61X and the developing roller axis 71X, the developing roller 71 can be pressed toward the drum axis 61X of the photosensitive drum 61 when the pressing members 150A and 150B press the pressing walls 220A and 220B.

[0157] The third wall 223 and the supply bearings 242A and 242B are arranged in the third direction, so that the developing cartridge 7 can be made compact in the first direction compared with the case where the third wall and the supply bearings are offset in the first direction.

[0158] As mentioned above, although embodiment was demonstrated, the process cartridge can be deformed suitably and implemented as shown below.

[0159] In the above-described embodiment, the rib 224 has an arc shape, but the rib may also have a trapezoidal shape or a rectangular shape, for example.

[0160] In the above-mentioned embodiment, the first pressing wall 220A has two ribs 224, but for example, the first pressing wall may also have three or more ribs. In addition, the first pressing wall may have only one rib. In addition, the first pressing wall may have no ribs. The same is true for the second pressing wall.

[0161] In the above-mentioned embodiment, the dimension of the third wall 223 in the first direction is larger than the dimension of the first wall 221 and the second wall 222 in the first direction, but for example, the dimension of the third wall in the first direction may be the same as the dimension of at least one of the first wall and the second wall in the first direction. In other words, the dimension of at least one of the first wall and the second wall in the first direction may be the same as the dimension of the third wall in the first direction. In addition, the dimensions of the first wall and the second wall in the first direction may be different.

[0162] In the above embodiment, the third wall 223 of the first pressing wall 220A is located between the supply roller gear 72G and the first side wall 210A so as to overlap the supply roller gear 72G when viewed from the first direction. However, for example, the third wall may be located at a position not overlapping the supply roller gear when viewed from the first direction.

[0163] In the above embodiment, the first pressing wall 220A is arranged along the first direction with the supply wheel 72 so as to overlap with the supply roller 72 when viewed from the first direction, but the first pressing wall may be located at a position not overlapping with the supply roller when viewed from the first direction. The same applies to the second pressing wall.

[0164] In the above embodiment, the first pressing wall 220A and the first supply bearing 242A are arranged in the third direction, but for example, the first pressing wall may be located at a position different from the first supply bearing in the first direction. The same applies to the second pressing wall and the second supply bearing.

[0165] In the above-described embodiment, the pressing walls 220A and 220B are located on the imaginary straight line L, but, for example, the pressing walls may not be located on the imaginary straight line. Similarly, the supply roller shaft may not be located on the imaginary straight line.

[0166] In the above-mentioned embodiment, the developer cartridge 7 has a toner storage portion 76 capable of storing toner, but for example, the developer cartridge may also have a structure without a toner storage portion. The developer cartridge without a toner storage portion may also have a structure capable of storing toner and the toner box may be detachable. Furthermore, the process cartridge may also have a structure including a drum cartridge, a developer cartridge, and a toner box.

[0167] The respective elements described in the above-mentioned embodiment and modified examples can be implemented in any combination.

Claims

1. A process cartridge comprising a drum cartridge and a developer cartridge that can be attached to and detached from the drum cartridge, characterized in that: The drum box has: a photosensitive drum rotatable about a drum axis extending in a first direction; and a pressing member that presses the developing cartridge toward the photosensitive drum when the developing cartridge is mounted on the drum cartridge; The developing box comprises: a developing roller rotatable about a developing roller axis extending along the first direction; a supply roller rotatable about a supply roller axis extending in the first direction and having a supply roller shaft extending in the first direction; as well as a developing frame having a side wall and a pressing wall, The side wall is located at one end of the developing frame in the first direction. The pressing wall protrudes from the side wall in the first direction and surrounds one end of the supply roller shaft in the first direction. In a state where the developing cartridge is mounted on the drum cartridge, the pressing wall is pressed by the pressing member.

2. The process cartridge according to claim 1, wherein: The pressing wall has: First wall; a second wall, the second wall being opposite to the first wall in a second direction orthogonal to the first direction; as well as a third wall connecting one end of the first wall and one end of the second wall, One end portion of the supply roller shaft in the first direction is located between the first wall and the second wall. In a state where the developing cartridge is mounted on the drum cartridge, the third wall is pressed by the pressing member.

3. The process cartridge according to claim 2, wherein: A dimension of the third wall in the first direction is larger than a dimension of the first wall in the first direction, and larger than a dimension of the second wall in the first direction.

4. The process cartridge according to claim 1, wherein: The developing frame can accommodate toner, The developing cartridge further includes a seal member located between the supply roller shaft and the pressing wall.

5. The process cartridge according to claim 1, wherein: The pressing wall has a rib that projects toward the pressing member and is pressed by the pressing member in a state in which the developing cartridge is mounted on the drum cartridge.

6. The process cartridge according to claim 5, wherein: When viewed from the first direction, the rib has an arc shape.

7. The process cartridge according to claim 5 or 6, wherein: A plurality of the ribs are arranged along the first direction.

8. The process cartridge according to claim 1, wherein: When the developing cartridge is mounted on the drum cartridge, the pressing wall is located on a virtual straight line passing through the drum axis and the developing roller axis as viewed from the first direction.

9. The process cartridge according to claim 2 or 3, characterized in that: A supply roller bearing is provided, into which the supply roller shaft is embedded, The third wall and the supply roller bearing are arranged in a direction orthogonal to both the first direction and the second direction.

10. The process cartridge according to claim 1, wherein: The pressing wall and the supply roller are arranged along the first direction.

11. The process cartridge according to claim 1, wherein: A supply roller gear is further provided, the supply roller gear being located at one end of the supply roller shaft in the first direction and being rotatable around the supply roller axis together with the supply roller, The pressing wall is located between the supply roller gear and the side wall.

12. The process cartridge according to claim 1, wherein: In a state where the developing cartridge is mounted on the drum cartridge, the supply roller shaft is located on an imaginary straight line passing through the drum axis and the developing roller axis when viewed from the first direction.

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