Developing cartridge

Abstract

To provide a structure in which insulation of a developing roller shaft is easily maintained and an arm of a collar is easily bent even when a developing cartridge is miniaturized.SOLUTION: A non-conductive first collar 50 covers one end of the developing roller shaft 32. Therefore, even when the developing cartridge is downsized, insulation between the one end portion of the developing roller shaft 32 and other components can be easily maintained. Further, the first pawl 522 engages not with the developing roller shaft 32 but with the electrode 40 positioned outside the developing roller shaft 32. With this configuration, the length of the first arm 521 can be ensured while reducing the length of the developing roller shaft 32 in the first direction. Therefore, it is possible to make the first arm 521 easy to bend.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a developer cartridge. [Background technology]

[0002] Electrophotographic image forming apparatuses such as laser printers and LED printers are known. A developer cartridge is used in the image forming apparatus. The developer cartridge has a developer roller for supplying developer. A conventional developer cartridge is described in, for example, Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-125361 Summary of the Invention [Problem to be solved by the invention]

[0004] The developing roller has a developing roller shaft. The developing roller shaft is conductive. An end of the developing roller shaft is exposed at an end of the developing cartridge. When the image forming apparatus and the developing cartridge are made smaller, the distance between the end of the developing roller shaft and other components in the image forming apparatus becomes shorter. This makes it difficult to maintain insulation between the developing roller shaft and other components.

[0005] In some cases, a collar is attached to the end of the developing roller shaft. The developing roller shaft has a groove. The collar has a claw. The claw of the collar engages with the groove of the developing roller shaft. This attaches the collar to the developing roller shaft. However, when the developing cartridge is made smaller, the length of the arm connecting the collar and the claw becomes shorter. This makes it difficult for the arm to bend.

[0006] An object of the present disclosure is to provide a structure that makes it easy to maintain insulation of the developing roller shaft and allows the collar arm to bend easily even when the developing cartridge is made smaller. [Means for solving the problem]

[0007] The first disclosure of the present application is a developer cartridge comprising: a housing capable of containing developer; a developer roller having a developer roller shaft extending in a first direction; an electrode located at one end of the housing in the first direction, the electrode being electrically connected to the developer roller shaft and made of conductive resin; and a first collar covering one end of the developer roller shaft in the first direction, the first collar being made of non-conductive resin, wherein the first collar has a first arm extending in the first direction and a first claw engageable with the electrode, the first claw protruding from the first arm in a direction away from the developer roller shaft, and the first claw being movable between a first position engageable with the electrode and a second position away from the electrode.

[0008] A second disclosure of the present application is the developing cartridge of the first disclosure, characterized in that the developing roller shaft is made of metal.

[0009] A third disclosure of the present application is the developing cartridge according to the first or second disclosure, characterized in that the first claw protrudes in a direction away from the developing roller shaft in the radial direction of the developing roller.

[0010] A fourth disclosure of the present application is a developing cartridge according to any one of the first to third disclosures, characterized in that the first claw is inserted between the housing and the electrode in the first direction.

[0011] The fifth disclosure of the present application is a developing cartridge according to any one of the first to fourth disclosures, characterized in that the developing roller is positioned at one end of the housing in a second direction intersecting the first direction, and the first claw protrudes in a direction away from the one end of the housing in the second direction.

[0012] The sixth disclosure of the present application is a developing cartridge according to the fifth disclosure, characterized in that the first collar has an end wall portion covering the end surface of the one end of the developing roller shaft, and a peripheral wall portion covering the outer circumferential surface of the one end of the developing roller shaft, the peripheral wall portion having a notch, and the first arm and the first claw are located on the opposite side of the developing roller shaft from the notch in the second direction.

[0013] A seventh disclosure of the present application is the developing cartridge of the sixth disclosure, wherein the first arm extends in the first direction from an edge of the end wall portion toward the housing.

[0014] The eighth disclosure of the present application is a developing cartridge according to any one of the fifth to seventh disclosures, characterized in that the electrode has a first tapered surface that faces the first arm in the second direction, and the first tapered surface approaches the first arm in the second direction as it approaches the first claw in the first direction.

[0015] The ninth disclosure of the present application is a developing cartridge according to any one of the fifth to eighth disclosures, further comprising: a second collar covering the other end of the developing roller shaft in the first direction, the second collar being made of a non-conductive resin; and a gear cover located at the other end of the housing in the first direction, the gear cover being located between the housing and the second collar in the first direction, wherein the gear cover has a second arm extending in the first direction and a second claw protruding from the second arm in a direction away from the developing roller shaft, and the second collar has a claw receiving portion inserted between the housing and the second claw.

[0016] A tenth disclosure of the present application is the developing cartridge of the ninth disclosure, wherein the second claw protrudes in a direction away from the one end of the housing in the second direction.

[0017] An eleventh disclosure of the present application is the developing cartridge according to the ninth or tenth disclosure, characterized in that the second arm extends in a direction away from the housing in the first direction.

[0018] The 12th disclosure of the present application is a developing cartridge according to any one of the 9th to 11th disclosures, characterized in that the second collar has a through hole that penetrates in the first direction and in which the claw receiving portion is located, and the second arm and the second claw are inserted into the through hole.

[0019] The 13th disclosure of the present application is a developing cartridge according to the 12th disclosure, characterized in that the second claw has a second tapered surface that faces the inner surface of the through hole of the second collar in the second direction, and that approaches the inner surface in the second direction as it approaches the claw receiving portion in the first direction. [Effects of the Invention]

[0020] According to the first to thirteenth disclosures of the present application, a non-conductive first collar covers one end of the developing roller shaft. Therefore, even if the developer cartridge is made smaller, it is easy to maintain insulation between the one end of the developing roller shaft and other components. Furthermore, the first claw engages with an electrode located outside the developing roller shaft, rather than the developing roller shaft itself. This ensures the length of the first arm while minimizing the length of the developing roller shaft in the first direction. Therefore, the first arm can be easily bent.

[0021] Furthermore, according to the sixth disclosure of the present application, the positions of the first arm and the first claw can be closer to the developing roller shaft than when there is no notch, which allows the first collar to be made more compact.

[0022] Furthermore, according to the eighth disclosure of the present application, by inserting a jig between the first tapered surface and the first arm, the first arm can be bent, and the engagement of the first claw with the electrode can be easily released.

[0023] Furthermore, according to the thirteenth disclosure of the present application, by inserting a jig between the inner surface of the second collar and the second tapered surface, the second arm can be bent, thereby easily releasing the engagement of the second claw with the claw receiving portion. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. [Figure 2] FIG. 2 is a view of the developing cartridge as seen from the first outer surface side. [Figure 3] FIG. 2 is a view of the developing cartridge as seen from the second outer surface side. [Figure 4] FIG. 2 is a cross-sectional view of the developing cartridge. [Figure 5] FIG. 2 is a perspective view of the vicinity of a first collar. [Figure 6] FIG. 2 is a cross-sectional view of the vicinity of a first collar. [Figure 7] FIG. 10 is a cross-sectional view of the vicinity of the first collar with the jig inserted therein. [Figure 8] FIG. 2 is a perspective view of the vicinity of a second collar. [Figure 9] FIG. 10 is a cross-sectional view of the vicinity of a second collar. [Figure 10] FIG. 10 is a cross-sectional view of the vicinity of the second collar with the jig inserted therein. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0026] In the following description, the direction in which the developing roller shaft 32 extends is referred to as the "first direction." Furthermore, the direction in which one end of the casing 10 where the developing roller 30 is located is aligned with the other end of the casing 10 is referred to as the "second direction." The first direction and the second direction intersect (preferably perpendicular to) each other.

[0027] <1. Structure of the developing cartridge> FIG. 1 is a perspective view of the developer cartridge 1. FIG. 2 is a view of the developer cartridge 1 viewed from the side of a first outer surface 11, which will be described later. FIG. 3 is a view of the developer cartridge 1 viewed from the side of a second outer surface 12, which will be described later. FIG. 4 is a cross-sectional view of the developer cartridge 1. Note that FIG. 4 shows a cross section perpendicular to the first direction.

[0028] The developer cartridge 1 is used in an electrophotographic image forming apparatus. The image forming apparatus is, for example, a laser printer or an LED printer. The developer cartridge 1 can be attached to a drum cartridge having a photosensitive drum. The developer cartridge 1 is attached to the drum cartridge and then attached to the image forming apparatus.

[0029] An image forming apparatus can be fitted with, for example, four developer cartridges 1. The four developer cartridges 1 contain developers (e.g., toner) of different colors (e.g., cyan, magenta, yellow, and black). The image forming apparatus forms an image on printing paper using the developers supplied from the developer cartridges 1. However, the number of developer cartridges 1 that can be fitted to the image forming apparatus may be one to three, or may be five or more.

[0030] As shown in FIGS. 1 to 4, the developing cartridge 1 includes a casing 10, an agitator 20, a developing roller 30, an electrode 40, a first collar 50, a gear portion 60, and a second collar .

[0031] The casing 10 is a housing capable of containing a developer. The casing 10 has a first outer surface 11 and a second outer surface 12. The first outer surface 11 is located at one end of the casing 10 in the first direction. The second outer surface 12 is located at the other end of the casing 10 in the first direction. The first outer surface 11 and the second outer surface 12 are spaced apart from each other in the first direction.

[0032] The casing 10 has a storage chamber 13. The storage chamber 13 is located inside the casing 10. The developer is stored in the storage chamber 13. The casing 10 also has an opening 14. The opening 14 is located at one end of the casing 10 in the second direction. The external space of the casing 10 and the storage chamber 13 communicate with each other via the opening 14. The casing 10 may have a handle on the outer surface of the other end in the second direction.

[0033] The agitator 20 has an agitator shaft 21 and a film 22. The agitator shaft 21 extends along a first direction. The film 22 extends from the agitator shaft 21 toward the inner surface of the casing 10. That is, the film 22 extends radially outward from the agitator shaft 21. A portion of the agitator shaft 21 and the film 22 are located within the accommodation chamber 13 of the casing 10.

[0034] The end of the agitator shaft 21 in the first direction is fixed to an agitator gear included in the gear unit 60. When the agitator gear rotates, the agitator shaft 21 and the film 22 rotate about an agitator axis extending in the first direction. The rotation of the film 22 then agitates the developer in the containing chamber 13.

[0035] The developing roller 30 is a roller that can rotate about a developing roller shaft that extends in the first direction. The developing roller 30 is located in the opening 14 of the casing 10. In other words, the developing roller 30 is located at one end of the casing 10 in the second direction.

[0036] The developing roller 30 has a developing roller main body 31 and a developing roller shaft 32. The developing roller main body 31 is a cylindrical member extending in a first direction. The developing roller main body 31 is made of, for example, elastic rubber. The developing roller shaft 32 is a cylindrical member that penetrates the developing roller main body 31 and extends in the first direction. The developing roller main body 31 is fixed to the developing roller shaft 32. The developing roller shaft 32 is conductive. The developing roller shaft 32 is made of metal or conductive resin.

[0037] The developing roller shaft 32 does not have to penetrate the developing roller main body 31 in the first direction. For example, the developing roller shaft 32 may extend in the first direction from both ends of the developing roller main body 31 in the first direction.

[0038] The electrode 40 is located on the first outer surface 11 of the casing 10. Specifically, the electrode 40 is fixed to the first outer surface 11 of the casing 10. The electrode 40 is conductive. Specifically, the electrode 40 is made of a conductive resin.

[0039] The electrode 40 has a bearing hole 41 (see FIG. 6). The bearing hole 41 penetrates the electrode 40 in the first direction. One end of the developing roller shaft 32 in the first direction is inserted into the bearing hole 41. This allows the developing roller shaft 32 to be rotatably supported relative to the electrode 40. Furthermore, one end of the developing roller shaft 32 in the first direction comes into contact with the electrode 40. This allows the electrode 40 to be electrically connected to the developing roller shaft 32.

[0040] When the drum cartridge with the developer cartridge 1 attached thereto is installed in an image forming apparatus, the image forming apparatus supplies a bias voltage to the developer roller shaft 32 via the electrode 40. Then, the developer is carried on the outer circumferential surface of the developer roller main body 31 due to the electrostatic force between the developer roller shaft 32 and the developer.

[0041] The first collar 50 is located on the first outer surface 11 of the casing 10. The first collar 50 is non-conductive. Specifically, the first collar 50 is made of non-conductive resin. The first collar 50 is cap-shaped. That is, the first collar 50 has a first hole 51. The first hole 51 is a recess that is recessed in the first direction. The first hole 51 has a cylindrical inner circumferential surface. One end of the developing roller shaft 32 in the first direction is inserted into the first hole 51. As a result, the first collar 50 is attached to one end of the developing roller shaft 32 in the first direction. The first collar 50 also covers one end of the developing roller shaft 32 in the first direction.

[0042] The first collar 50 has a first engagement portion 52. The first engagement portion 52 engages with the electrode 40. This prevents the first collar 50 from coming off the developing roller shaft 32 in the first direction away from the casing 10.

[0043] The structure of the first collar 50 will be described in more detail later.

[0044] The gear portion 60 is located on the second outer surface 12 of the casing 10. The gear portion 60 has a gear cover 61, a coupling 62, and multiple gears. The gear cover 61, together with the casing 10, constitutes the housing of the developer cartridge 1. The gear cover 61 is fixed to the second outer surface 12 of the casing 10. The multiple gears include an agitator gear fixed to the agitator shaft 21 and a developing roller gear fixed to the developing roller shaft 32. At least some of the multiple gears are located between the second outer surface 12 and the gear cover 61.

[0045] The coupling 62 is exposed from the gear cover 61. When the developer cartridge 1 attached to the drum cartridge is attached to the image forming apparatus, the drive shaft of the image forming apparatus is connected to the coupling 62. Then, the rotation of the drive shaft is transmitted to the agitator gear and the developing roller gear via the coupling 62. Note that the multiple gears included in the gear unit 60 may transmit rotational force by meshing of teeth or by friction.

[0046] The second collar 70 is located on the second outer surface 12 of the casing 10. More specifically, the second collar 70 is located on the outer surface of the gear cover 61. That is, in the first direction, the gear cover 61 is located between the casing 10 and the second collar 70. The second collar 70 is non-conductive. Specifically, the second collar 70 is made of a non-conductive resin.

[0047] 3, the second collar 70 has a first end 71 and a second end 72. The second end 72 is farther from the developing roller shaft 32 than the first end 71. The second end 72 is farther in the second direction from one end of the casing 10 in the second direction than the first end 71. The second collar 70 extends along the second outer surface 12 of the casing 10 between the first end 71 and the second end 72.

[0048] The second collar 70 has a second hole 73. The second hole 73 penetrates the second collar 70 in the first direction. However, the second hole 73 may be a recess that is recessed in the first direction. The second hole 73 has a cylindrical inner circumferential surface. The other end of the developing roller shaft 32 in the first direction is inserted into the second hole 73. As a result, the second collar 70 is attached to the other end of the developing roller shaft 32 in the first direction. The second collar 70 also covers the other end of the developing roller shaft 32 in the first direction. The second collar 70 is rotatable about the developing roller shaft 32 with respect to the casing 10. Specifically, the second end 72 of the second collar 70 is rotatable about the developing roller shaft 32 with respect to the first end 71.

[0049] The gear cover 61 also has a second engagement portion 63. The second engagement portion 63 protrudes from the outer surface of the gear cover 61 in the first direction toward the second collar 70. The second engagement portion 63 engages with the second collar 70. This prevents the second collar 70 from coming off the developing roller shaft 32 in a direction away from the casing 10 in the first direction.

[0050] The second collar 70 has a through hole 74. The through hole 74 penetrates the second collar 70 in the first direction. The through hole 74 has a first stopper surface 741 and a second stopper surface 742. The first stopper surface 741 and the second stopper surface 742 are spaced apart in the rotation direction of the second end 72 around the developing roller shaft 32. The above-mentioned second engagement portion 63 is inserted into the through hole 74.

[0051] The second collar 70 is rotatable about the developing roller shaft 32 between a first rotation position and a second rotation position. When the second collar 70 is in the first rotation position, the second engagement portion 63 contacts the first stopper surface 741. On the other hand, when the second collar 70 is in the second rotation position, the second engagement portion 63 contacts the second stopper surface 742. This limits the rotation range of the second collar 70.

[0052] After the developer cartridge 1 is installed in the drum cartridge and then mounted in the image forming apparatus, a separation operation can be performed by a driving force supplied from the image forming apparatus. The separation operation is an operation that temporarily separates the developer roller 30 from the photosensitive drum. When performing the separation operation, the image forming apparatus presses a cam provided on the drum cartridge. This causes the cam to rotate and contact the second collar 70. The cam then presses the second collar 70 in the second direction, away from the photosensitive drum. This moves the casing 10 and the developer roller 30 from a pressure contact position where they are in contact with the photosensitive drum to a separation position where they are away from the photosensitive drum.

[0053] The structure of the second collar 70 will be described in more detail later.

[0054] <2. Structure around the first color> Next, a more detailed structure in the vicinity of the first collar 50 will be described. Fig. 5 is a perspective view of the vicinity of the first collar 50. Fig. 6 is a cross-sectional view of the vicinity of the first collar 50. Fig. 6 is a cross-sectional view taken along line AA in Fig. 2.

[0055] As shown in Figures 5 and 6, the first collar 50 has an end wall portion 53, a peripheral wall portion 54, and a first engagement portion 52. The end wall portion 53 is disk-shaped. The end wall portion 53 covers the end surface of one end of the developing roller shaft 32 in the first direction. The peripheral wall portion 54 extends in the first direction from the outer periphery of the end wall portion 53 toward the casing 10. The peripheral wall portion 54 is cylindrical and centered on the developing roller shaft 32. The peripheral wall portion 54 covers the outer periphery of one end of the developing roller shaft 32 in the first direction. The space inside the peripheral wall portion 54 becomes the first hole 51 described above.

[0056] In this way, one end of the developing roller shaft 32 in the first direction is covered by the non-conductive first collar 50. Therefore, one end of the developing roller shaft 32 in the first direction is not exposed. Therefore, even if the developing cartridge 1 is made compact, it is easy to keep the one end of the developing roller shaft 32, which is conductive, insulated from other components in the image forming apparatus.

[0057] The peripheral wall portion 54 has a notch 541. The notch 541 is formed in a portion of the peripheral wall portion 54 that is centered on the developing roller shaft 32. The first engagement portion 52 is located outside the notch 541 in the radial direction of the developing roller 30. In other words, the first engagement portion 52 is located on the opposite side of the notch 541 from the developing roller shaft 32 in the second direction.

[0058] The first engagement portion 52 has a first arm 521 and a first claw 522. The first arm 521 extends in a first direction from the edge of the end wall portion 53 toward the casing 10. More specifically, the first arm 521 has a first portion 521a and a second portion 521b. The first portion 521a extends in the first direction while moving away from the developing roller shaft 32 in the second direction. That is, the first portion 521a extends in the first direction from the edge of the end wall portion 53 while spreading outward in the radial direction of the developing roller 30. The second portion 521b extends linearly from the tip of the first portion 521a along the first direction.

[0059] The first claw 522 protrudes in the second direction from the tip of the first arm 521. More specifically, the first claw 522 protrudes in the second direction away from the developing roller shaft 32. That is, the first claw 522 protrudes in the second direction away from one end of the casing 10. Furthermore, the first claw 522 protrudes in the radial direction of the developing roller 30 away from the developing roller shaft 32.

[0060] On the other hand, the electrode 40 has a protrusion 42 and a first claw receiving portion 43. The protrusion 42 protrudes in the first direction from one end face of the electrode 40 in the first direction. The first claw receiving portion 43 protrudes in the second direction from the protrusion 42 toward the first collar 50. The first claw receiving portion 43 faces the first arm 521 in the second direction. There is a gap between the first claw receiving portion 43 and the casing 10 in the first direction.

[0061] The first claw 522 can engage with the first claw receiving portion 43 of the electrode 40. Specifically, the first claw 522 is inserted into the gap between the first claw receiving portion 43 and the casing 10. One end surface of the first claw 522 in the first direction comes into contact with the first claw receiving portion 43. This prevents the first collar 50 from coming off the developing roller shaft 32 in a direction away from the casing 10 in the first direction.

[0062] In this way, the first claw 522 engages with the electrode 40 located outside the developing roller shaft 32, rather than with the developing roller shaft 32. In this way, there is no need to provide a groove serving as a claw receiving portion in the developing roller shaft 32. This makes it possible to reduce the length of the developing roller shaft 32 in the first direction. Furthermore, the length of the first arm 521 can be secured more than when the first claw 522 is engaged with the developing roller shaft 32. This allows the first arm 521 to bend well when the engagement of the first claw 522 with the first claw receiving portion 43 is released.

[0063] When recycling the developer cartridge 1, the first collar 50 is removed from the developer roller shaft 32. The operation of removing the first collar 50 from the developer roller shaft 32 will be described below.

[0064] When removing the first collar 50 from the developing roller shaft 32, first, a jig 90 is inserted between the first claw receiving portion 43 and the first arm 521. Figure 7 is a cross-sectional view of the vicinity of the first collar 50 with the jig 90 inserted. When the jig 90 is inserted between the first claw receiving portion 43 and the first arm 521, the first arm 521 bends, and the first claw 522 moves from a first position (position in Figure 6) where it engages with the first claw receiving portion 43 to a second position (position in Figure 7) where it is separated from the first claw receiving portion 43. This releases the engagement of the first claw 522 with the first claw receiving portion 43.

[0065] Thereafter, with the first claw 522 remaining in the second position, the first collar 50 moves in the first direction away from the casing 10. As a result, the first collar 50 is removed from one end of the developing roller shaft 32 in the first direction.

[0066] The first claw receiving portion 43 has a first tapered surface 431. The first tapered surface 431 faces the first arm 521 in the second direction. The first tapered surface 431 is inclined with respect to the first direction. More specifically, the first tapered surface 431 approaches the first arm 521 in the second direction as it approaches the first claw 522 in the first direction. Therefore, by simply inserting a jig 90 between the first tapered surface 431 and the first arm 521 and pushing the jig 90 along the first tapered surface 431, the first arm 521 can be bent and the first claw 522 can be moved from the first position to the second position.

[0067] The first arm 521 and the first claw 522 are provided on the first collar 50 made of non-conductive resin, rather than on the electrode 40 made of conductive resin. Non-conductive resin is more flexible than conductive resin. Therefore, by providing the first arm 521 and the first claw 522 on the first collar 50, the first arm 521 can be bent favorably. Therefore, breaking of the first arm 521 when the first collar 50 is removed from the developing roller shaft 32 can be prevented.

[0068] Furthermore, in the structure of this embodiment, the first collar 50 has a notch 541. The first arm 521 and the first claw 522 are positioned on the opposite side of the notch 541 from the developing roller shaft 32 in the second direction. This allows the positions of the first arm 521 and the first claw 522 to be closer to the developing roller shaft 32 than when the notch 541 is not present. This allows the first collar 50 to be made more compact.

[0069] When the first claw 522 approaches the developing roller shaft 32 closer than the second position, the first arm 521 comes into contact with the developing roller shaft 32. This prevents the first arm 521 from bending excessively. That is, the outer surface of the developing roller shaft 32 serves as a restricting surface that restricts the bending of the first arm 521. Therefore, the first arm 521 can be further prevented from breaking.

[0070] <3. Structure around the second color> Next, a more detailed structure in the vicinity of the second collar 70 will be described. Fig. 8 is a perspective view of the vicinity of the second collar 70. Fig. 9 is a cross-sectional view of the vicinity of the second collar 70. Fig. 9 is a cross-sectional view taken along line BB in Fig. 3.

[0071] As described above, the second collar 70 has the through hole 74. The through hole 74 penetrates the second collar 70 in the first direction. The gear cover 61 also has the second engagement portion 63. The second engagement portion 63 is inserted into the through hole 74.

[0072] The second engagement portion 63 has a second arm 631 and a second claw 632. The second arm 631 extends in a first direction from the outer surface of the gear cover 61 toward the second collar 70. That is, the second arm 631 extends in the first direction away from the casing 10. The second claw 632 protrudes in the second direction from the tip of the second arm 631. More specifically, the second claw 632 protrudes in the second direction away from the developing roller shaft 32. That is, the second claw 632 protrudes in the second direction away from one end of the casing 10. Furthermore, the second claw 632 protrudes in the radial direction of the developing roller 30 away from the developing roller shaft 32.

[0073] On the other hand, the second collar 70 has a second claw receiving portion 75. The second claw receiving portion 75 is located in the through hole 74. More specifically, the second claw receiving portion 75 protrudes from the inner surface of the through hole 74 toward the inside of the through hole 74. The second claw receiving portion 75 also protrudes from the inner surface of the through hole 74 toward the second arm 631. The second claw receiving portion 75 also protrudes in the second direction toward the developing roller shaft 32. The second claw receiving portion 75 faces the second arm 631 in the second direction.

[0074] The second claw 632 can engage with the second claw receiving portion 75 of the second collar 70. Specifically, the second claw receiving portion 75 is inserted between the casing 10 and the second claw 632. One end surface of the second claw 632 in the first direction comes into contact with the second claw receiving portion 75. This prevents the second collar 70 from coming off the developing roller shaft 32 in a direction away from the casing 10 in the first direction.

[0075] In this way, the second collar 70 does not engage with the developing roller shaft 32, but rather engages with the second claw 632 extending from the gear cover 61 on the outside of the developing roller shaft 32. In this way, there is no need to provide a groove for engagement in the developing roller shaft 32. This makes it possible to reduce the length of the developing roller shaft 32 in the first direction. Furthermore, the length of the second arm 631 can be secured more than when the second collar 70 is engaged with the developing roller shaft 32. This allows the second arm 631 to bend smoothly when the engagement of the second claw 632 with the second claw receiving portion 75 is released.

[0076] When recycling the developer cartridge 1, the second collar 70 is removed from the developing roller shaft 32. The operation of removing the second collar 70 from the developing roller shaft 32 will be described below.

[0077] When removing the second collar 70 from the developing roller shaft 32, first, a jig 90 is inserted between the inner surface of the through hole 74 of the second collar 70 and the second claw 632. FIG. 10 is a cross-sectional view of the vicinity of the second collar 70 with the jig 90 inserted. When the jig 90 is inserted between the inner surface of the through hole 74 of the second collar 70 and the second claw 632, the second arm 631 bends, and the second claw 632 moves from the third position (position in FIG. 9) where it engages with the second claw receiving portion 75 to the fourth position (position in FIG. 10) where it is separated from the second claw receiving portion 75. This releases the engagement of the second claw 632 with the second claw receiving portion 75.

[0078] Thereafter, with the second claw 632 remaining in the fourth position, the second collar 70 moves in the first direction away from the casing 10. As a result, the second collar 70 is removed from the other end of the developing roller shaft 32 in the first direction.

[0079] The second claw 632 has a second tapered surface 633. The second tapered surface 633 faces the inner surface of the through hole 74 of the second collar 70 in the second direction. The second tapered surface 633 is inclined with respect to the first direction. More specifically, the second tapered surface 633 approaches the inner surface of the through hole 74 of the second collar 70 in the second direction as it approaches the second claw receiving portion 75 in the first direction. Therefore, simply by inserting the jig 90 between the second tapered surface 633 and the inner surface of the through hole 74 of the second collar 70 and pushing the jig 90 along the second tapered surface 633, the second arm 631 can be bent and the second claw 632 can be moved from the third position to the fourth position.

[0080] The second arm 631 and the second claw 632 are provided on the gear cover 61, which is made of non-conductive resin rather than conductive resin. Non-conductive resin is more flexible than conductive resin. Therefore, by providing the second arm 631 and the second claw 632 on the gear cover 61, the second arm 631 can be bent favorably. Therefore, breaking of the second arm 631 when the second collar 70 is removed from the developing roller shaft 32 can be prevented.

[0081] When the second claw 632 approaches the developing roller shaft 32 closer than the fourth position, the second arm 631 comes into contact with the inner surface of the through hole 74 of the second collar 70. This prevents the second arm 631 from bending excessively. That is, the inner surface of the through hole 74 of the second collar 70 serves as a restricting surface that restricts the bending of the second arm 631. This further reduces the risk of the second arm 631 breaking.

[0082] <4. Modifications> The developing cartridge 1 may be attached to a drum cartridge having one photosensitive drum or may be attached to a drum cartridge having multiple photosensitive drums. The developing cartridge 1 may also be attached directly to an image forming apparatus.

[0083] Furthermore, the detailed shape of the developing cartridge 1 may differ from the shape shown in each drawing of the present application. Furthermore, the elements appearing in the above-described embodiments and modifications may be combined as appropriate within the scope of not causing any contradiction. [Explanation of symbols]

[0084] 1 Developer cartridge 10 Casing 20 Agitator 30 Developing roller 32 Developing roller shaft 40 electrodes 43 First claw receiving part 50 First Color 53 End wall 54 Peripheral wall section 60 Gear section 61 Gear cover 70 Second Color 74 Through Hole 75 Second claw receiving part 431 First tapered surface 521 First Arm 522 First Claw 541 Notch 631 Second Arm 632 Second Claw 633 Second tapered surface

Claims

1. A developer cartridge, a housing capable of accommodating a developer; a developer roller having a developer roller shaft extending in a first direction; an electrode located at one end of the housing in the first direction, the electrode being electrically connected to the developing roller shaft and made of a conductive resin; a first collar covering one end of the developing roller shaft in the first direction, the first collar being made of a non-conductive resin; Equipped with The first color is a first arm extending in the first direction; a first claw engageable with the electrode, the first claw protruding from the first arm in a direction away from the developing roller shaft; and The developing cartridge, wherein the first claw is movable between a first position where it can engage with the electrode and a second position where it is separated from the electrode.

2. 2. The developing cartridge according to claim 1, The developing cartridge is characterized in that the developing roller shaft is made of metal.

3. 3. The developing cartridge according to claim 1, The developing cartridge, wherein the first claw protrudes in a radial direction of the developing roller in a direction away from the developing roller shaft.

4. 4. The developing cartridge according to claim 1, The developing cartridge, wherein the first claw is inserted between the housing and the electrode in the first direction.

5. 5. The developing cartridge according to claim 1, the developing roller is located at one end of the housing in a second direction intersecting with the first direction, The developing cartridge, wherein the first claw protrudes in a direction away from the one end of the housing in the second direction.

6. 6. The developing cartridge according to claim 5, The first color is an end wall portion covering the end surface of the one end portion of the developing roller shaft; a peripheral wall portion covering an outer peripheral surface of the one end portion of the developing roller shaft, the peripheral wall portion having a notch; and a developing cartridge, wherein the first arm and the first claw are located on an opposite side of the developing roller shaft with respect to the notch in the second direction;

7. 7. The developing cartridge according to claim 6, The developing cartridge, wherein the first arm extends in the first direction from an edge of the end wall portion toward the housing.

8. 8. The developing cartridge according to claim 5, The electrode is a first tapered surface facing the first arm in the second direction, the first tapered surface approaching the first arm in the second direction as it approaches the first claw in the first direction; A developing cartridge comprising:

9. 9. The developing cartridge according to claim 5, a second collar covering the other end of the developing roller shaft in the first direction, the second collar being made of a non-conductive resin; a gear cover located at the other end of the housing in the first direction, the gear cover being located between the housing and the second collar in the first direction; Furthermore, The gear cover is a second arm extending in the first direction; a second claw protruding from the second arm in a direction away from the developing roller shaft; and The second color is a claw receiving portion inserted between the housing and the second claw A developing cartridge comprising:

10. 10. The developing cartridge according to claim 9, The developing cartridge, wherein the second claw protrudes in a direction away from the one end of the housing in the second direction.

11. 11. The developing cartridge according to claim 9 or 10, The developing cartridge, wherein the second arm extends in the first direction away from the housing.

12. 12. The developing cartridge according to claim 9, The second color is a through hole penetrating in the first direction, the through hole in which the claw receiving portion is located; and The developing cartridge, wherein the second arm and the second claw are inserted into the through hole.

13. 13. The developing cartridge according to claim 12, The second claw is a second tapered surface facing an inner surface of the through hole of the second collar in the second direction, the second tapered surface approaching the inner surface in the second direction as it approaches the pawl receiving portion in the first direction; A developing cartridge comprising:

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