Developing cartridge

Abstract

This further develops the conventional configuration of image forming apparatuses. [Solution] The housing 10 of the developing cartridge 1 has a first outer surface 11 and a second outer surface 12. The first outer surface 11 and the second outer surface 12 are separated in a first direction. The developing cartridge 1 is also equipped with a detection gear 58 or a holder 92 on the first outer surface 11. When viewing the developing cartridge 1 from the second outer surface side 12 in the first direction, at least a part of the detection gear 58 or holder 92 is located outside the housing 10.

Description

Technical Field

[0001] The present disclosure relates to a developing cartridge. Background Art

[0002] Conventionally, electrophotographic image forming apparatuses such as laser printers and LED printers are known. A conventional image forming apparatus is described, for example, in Patent Document 1. The image forming apparatus of Patent Document 1 includes a developing cartridge and a drum cartridge (photoreceptor cartridge). The developing cartridge is mounted to the drum cartridge. Further, the drum cartridge with the developing cartridge mounted thereon is mounted to a main body frame of the image forming apparatus. Prior Art Literature Patent Literature

[0003] Patent Document 1 Japanese Unexamined Patent Application Publication No. 2014-016480 Summary of the Invention Problem to be Solved by the Invention

[0004] However, the developing cartridge of Patent Document 1 still has room for further improvement. An object of the present disclosure is to further develop the conventional configuration. Means for Solving the Problem

[0005] The first disclosure is a toner housing having a first outer surface and a second outer surface separated from the first outer surface in a first direction; a developing roller rotatable about a developing shaft extending in the first direction; an agitator rotatable about an agitator shaft extending in the first direction; a coupling gear located on the first outer surface; an idler gear located on the first outer surface and meshing with the coupling gear; an agitator gear located on the first outer surface and connected to the agitator, which meshes with the idler gear; and a detection gear located on the first outer surface and meshing with the idler gear, which disengages from the idler gear when rotated, wherein at least a portion of the detection gear is located outside the housing when the developing cartridge is viewed in the first direction from the second outer surface side.

[0006] A second disclosure is a developing cartridge comprising a housing for containing toner, the housing having a first outer surface and a second outer surface separated from the first outer surface in a first direction; a developing roller rotatable about a developing axis extending in the first direction; a memory having an electrical contact surface; and a holder for holding the electrical contact surface, the holder located on the first outer surface and movable relative to the housing, characterized in that, when the developing cartridge is viewed in the first direction from the second outer surface side, at least a portion of the holder is located outside the housing. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide a new image forming apparatus that further develops the prior art. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view of the developing cartridge and drum cartridge. [Figure 2] This is a perspective view of the developing cartridge and drum cartridge. [Figure 3] This is a perspective view of a developing cartridge. [Figure 4] This is a view of the developing cartridge with the gear cover removed, as seen from the first direction. [Figure 5] This is a partial perspective view of the developing cartridge with the gear cover removed. [Figure 6] This diagram shows the area around the gear section of the developing cartridge, viewed from directions intersecting the first and second directions. [Figure 7] This is a cross-sectional view of the developing cartridge and drum cartridge with the developing cartridge mounted on the drum cartridge. [Figure 8] This is a cross-sectional view of the developing cartridge and drum cartridge with the developing cartridge mounted on the drum cartridge. [Figure 9] This is a view of the developing cartridge from the second outer surface side towards the first direction. [Figure 10] This is an exploded perspective view of the developing electrode, feed electrode, and bearing. [Figure 11] This is a cross-sectional view of a developing cartridge mounted on a drum cartridge. [Figure 12] This is a perspective view of the developing cartridge and developing roller cover. [Figure 13] This is a perspective view of the developing roller cover. [Figure 14] This is a perspective view of the developing cartridge and drum cartridge. [Figure 15] This is a perspective view of the developing cartridge and drum cartridge. [Figure 16] This is a perspective view of the developing cartridge and drum cartridge. [Figure 17] This is a perspective view of the developing cartridge and drum cartridge. [Figure 18] This is a perspective view of the developing cartridge with the cover removed. [Figure 19] This is a view of the developing cartridge with the cover removed, as seen from the first direction. [Figure 20] This is a perspective view of the holder. [Figure 21] It is a view of the holder viewed from a direction orthogonal to the first direction. [Figure 22] It is an exploded perspective view of the holder. [Figure 23] It is a perspective view of the developing cartridge with the holder disassembled. [Figure 24] It is a view of the developing cartridge viewed in the second direction from the first end side of the holder. [Figure 25] It is a cross-sectional view of the developing cartridge and the drum cartridge in a process where the developing cartridge is mounted to the drum cartridge. [Figure 26] It is a cross-sectional view of the developing cartridge and the drum cartridge in a process where the developing cartridge is mounted to the drum cartridge. [Figure 27] It is a cross-sectional view of the developing cartridge and the drum cartridge in a process where the developing cartridge is mounted to the drum cartridge. [Figure 28] It is a cross-sectional view of the developing cartridge and the drum cartridge in a process where the developing cartridge is mounted to the drum cartridge. [Figure 29] It is a view of the developing cartridge viewed in the first direction from the second outer surface side. [Figure 30] It is an exploded perspective view of the developing electrode, the supply electrode, and the bearing. [Figure 31] It is a cross-sectional view of the developing cartridge mounted to the drum cartridge. [Figure 32] It is a perspective view of the developing cartridge and the developing roller cover. [Figure 33] It is a perspective view of the developing roller cover. [Figure 34] It is a perspective view of the holder cover. DETAILED DESCRIPTION OF EMBODIMENTS

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0010] In the following, the direction in which the first outer surface 11 and the second outer surface 12 of the housing 10 of the developing cartridge 1 are aligned will be referred to as the "first direction." The direction in which one end of the housing 10 where the developing roller 30 is located is aligned with the other end of the housing 10 will be referred to as the "second direction." The direction in which the projection 65 of the drum frame 60 extends will be referred to as the "third direction."

[0011] The first and second directions intersect each other. For example, the first and second directions are perpendicular to each other. The first and third directions intersect each other. For example, the first and third directions are perpendicular to each other. The second and third directions intersect each other. For example, the second and third directions are perpendicular to each other.

[0012] <1. First Embodiment> First, the first embodiment will be described.

[0013] <1-1. Overview of Developing Cartridges and Drum Cartridges> Figures 1 and 2 are perspective views of the developing cartridge 1 and drum cartridge 2 of the first embodiment. Figure 1 shows the developing cartridge 1 mounted on the drum cartridge 2. Figure 2 shows the developing cartridge 1 removed from the drum cartridge 2.

[0014] The developer cartridge 1 and drum cartridge 2 are 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 is detachable from the drum cartridge 2. The drum cartridge 2, with the developer cartridge 1 attached, is also detachable from the main frame of the image forming apparatus. The image forming apparatus forms an image on the printing paper using toner supplied from the developer cartridge 1.

[0015] <1-2. About the developing cartridge> Figure 3 is a perspective view of the developing cartridge 1. As shown in Figures 1 to 3, the developing cartridge 1 comprises a housing 10, an agitator 20, a developing roller 30, a supply roller 40, and a gear section 50.

[0016] The housing 10 is a container for housing toner, which is a developer. The housing 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 housing 10 in a first direction. The second outer surface 12 is located at the other end of the housing 10 in a first direction. The first outer surface 11 and the second outer surface 12 are separated from each other in a first direction.

[0017] The housing 10 houses the toner cartridge. As shown in Figure 2, the housing 10 also has an opening 13. The opening 13 is located at one end of the housing 10 in the second direction. The space inside the housing 10 and the space outside are in communication through the opening 13. The housing 10 also has a toner handle 14. The toner handle 14 is located at the other end of the housing 10 in the second direction.

[0018] The housing 10 has a positioning projection 121. When the developing cartridge 1 is mounted on the drum cartridge 2, the positioning projection 121 is inserted into a hole provided in the drum cartridge 2. By inserting the positioning projection 121 into the hole provided in the drum cartridge 2, the developing cartridge 1 is positioned in a first direction relative to the drum cartridge 2. The housing 10 also has a housing projection 124. When the developing cartridge 1 is mounted on the drum cartridge 2, the housing projection 124 is inserted into a drum frame hole 60A provided in the drum cartridge 2.

[0019] The agitator 20 is located inside the housing 10. As shown in Figure 3, the agitator 20 has blades 21. The agitator 20 is rotatable about an agitator shaft L1 (see Figure 4) that extends in a first direction. When the agitator 20 rotates about the agitator shaft L1, the toner inside the housing 10 is agitated by the blades 21.

[0020] The developing roller 30 is a roller that can rotate around the developing shaft L2 (see Figure 4) extending in the first direction. The developing roller 30 is supported by the housing 10. The developing roller 30 is located in the opening 13. That is, the developing roller 30 is located at one end of the housing 10 in the second direction. The developing roller 30 has a cylindrical outer surface extending in the first direction. A portion of the outer surface of the developing roller 30 is exposed to the outside of the housing 10.

[0021] The supply roller 40 is a roller that can rotate about a supply shaft L3 (see Figure 4) extending in a first direction. The supply roller 40 is supported by the housing 10. The supply roller 40 is located inside the housing 10. More specifically, the supply roller 40 is located between the developer roller 30 and the agitator 20. The supply roller 40 has a cylindrical outer surface extending in a first direction. The outer surface of the developer roller 30 and the outer surface of the supply roller 40 are in contact with each other. Toner inside the housing 10 is supplied to the outer surface of the developer roller 30 via the outer surface of the supply roller 40. As a result, toner is carried on the outer surface of the developer roller 30.

[0022] The gear section 50 is located on the first outer surface 11 of the housing 10. The gear section 50 includes a gear cover 51, a coupling 52, and a plurality of gears. The gear cover 51 is attached to the first outer surface 11 of the housing 10. Specifically, the gear cover 51 is fixed to the first outer surface 11 of the housing 10 by screws. The plurality of gears are located between the first outer surface 11 and the gear cover 51 in a first direction. That is, the plurality of gears are covered by the gear cover 51. The coupling 52 is exposed from the gear cover 51.

[0023] The gear cover 51 is fixed to the housing 10 by three screws: a first screw 18, a second screw 19, and a third screw 191. The housing 10 has a first outer surface 11 with a first screw hole 16, a second screw hole 17, and a third screw hole 192. The first screw 18 is fastened to the first screw hole 16 through a hole formed in the gear cover 51. The second screw 19 is fastened to the second screw hole 17 through a hole formed in the gear cover 51. The third screw 191 is fastened to the third screw hole 192 through a hole formed in the gear cover 51. This fixes the gear cover 51 to the housing 10.

[0024] The coupling 52 is a rotatable component about a coupling shaft L4 (see Figure 4) that extends in the first direction. When the drum cartridge 2 with the developing cartridge 1 attached is mounted on the main frame, the drive shaft of the image forming apparatus is inserted into the coupling 52. This allows the coupling 52 to rotate together with the drive shaft about the coupling shaft L4. The image forming apparatus transmits driving force to multiple gears via the coupling 52.

[0025] Figure 4 is a view of the developing cartridge 1 with the gear cover 51 removed, as seen in the first direction. Figure 5 is a partial perspective view of the developing cartridge 1 with the gear cover 51 removed. Figure 6 is a view of the area around the gear section 50 of the developing cartridge 1, as seen from directions intersecting the first and second directions. As shown in Figures 4 to 6, the gears of the gear section 50 include a coupling gear 53, a developing roller gear 54, a supply roller gear 55, an idler gear 56, an agitator gear 57, and a detection gear 58.

[0026] The coupling gear 53 is located on the first outer surface 11 of the housing 10. The coupling gear 53 is housed inside the gear cover 51. The coupling 52 and the coupling gear 53 are integrally molded parts. Therefore, the coupling gear 53 rotates together with the coupling 52 around the coupling shaft L4.

[0027] The coupling gear 53 comprises a large-diameter coupling gear 531 and a small-diameter coupling gear 532. The diameter of the small-diameter coupling gear 532, centered on the coupling shaft L4, is smaller than the diameter of the large-diameter coupling gear 531, also centered on the coupling shaft L4. In the first direction, the small-diameter coupling gear 532 is located between the coupling 52 and the large-diameter coupling gear 531. The large-diameter coupling gear 531 and the small-diameter coupling gear 532 have multiple teeth around their entire outer circumference. However, the teeth of the coupling gear 53 are not shown in the figures of this disclosure.

[0028] The developing roller gear 54 is located on the first outer surface 11 of the housing 10. The developing roller gear 54 is housed inside the gear cover 51. The developing roller gear 54 is connected to one end of the developing roller 30 in a first direction. The developing roller gear 54 has multiple teeth around its entire circumference. However, the teeth of the developing roller gear 54 are not shown in the figures of this disclosure.

[0029] The developing roller gear 54 meshes with the coupling gear 53. More specifically, the developing roller gear 54 meshes with the large-diameter coupling gear 531. The developing roller gear 54 rotates in conjunction with the rotation of the large-diameter coupling gear 531. As the developing roller gear 54 rotates, the developing roller 30 also rotates along with the developing roller gear 54 around the developing shaft L2.

[0030] The supply roller gear 55 is located on the first outer surface 11 of the housing 10. The supply roller gear 55 is housed inside the gear cover 51. The supply roller gear 55 is connected to one end of the supply roller 40 in the first direction. The supply roller gear 55 has multiple teeth around its entire circumference. However, the teeth of the supply roller gear 55 are not shown in the figures of this disclosure.

[0031] The supply roller gear 55 meshes with the coupling gear 53. More specifically, the supply roller gear 55 meshes with the small-diameter coupling gear 532. The supply roller gear 55 rotates in conjunction with the rotation of the small-diameter coupling gear 532. As the supply roller gear 55 rotates, the supply roller 40 also rotates along with the supply roller gear 55 around the supply shaft L3.

[0032] The idler gear 56 is located on the first outer surface 11 of the housing 10. The idler gear 56 is housed inside the gear cover 51. The idler gear 56 is located between the agitator gear 57 and the protrusion 15, which will be described later. The idler gear 56 is rotatable about the idler shaft L5 which extends in the first direction.

[0033] The idler gear 56 includes a large-diameter idler gear 561 and a small-diameter idler gear 562. The diameter of the small-diameter idler gear 562, centered on the idler shaft L5, is smaller than the diameter of the large-diameter idler gear 561, also centered on the idler shaft L5. In the first direction, the small-diameter idler gear 562 is located between the first outer surface 11 of the housing 10 and the large-diameter idler gear 561. Both the large-diameter idler gear 561 and the small-diameter idler gear 562 have multiple teeth around their entire outer circumference.

[0034] The idler gear 56 meshes with the coupling gear 53. More specifically, the large-diameter idler gear 561 meshes with the small-diameter coupling gear 532. The idler gear 56 rotates in conjunction with the rotation of the coupling gear 53.

[0035] The agitator gear 57 is located on the first outer surface 11 of the housing 10. The agitator gear 57 is housed inside the gear cover 51. The agitator gear 57 is connected to one end of the agitator 20 in a first direction. The agitator gear 57 has multiple teeth around its entire circumference. However, the teeth of the agitator gear 57 are not shown in the figures of this disclosure.

[0036] The agitator gear 57 meshes with the idler gear 56. More specifically, the agitator gear 57 meshes with the small-diameter idler gear 562. The agitator gear 57 rotates in conjunction with the rotation of the small-diameter idler gear 562. As the agitator gear 57 rotates, the agitator 20 also rotates along with the agitator gear 57 around the agitator shaft L1.

[0037] Here, the ratio of the rotational speeds of the developing roller 30, the supply roller 40, and the agitator 20 is determined according to the gear ratio of each gear in the gear section 50. The rotational speed of the developing roller 30 is greater than that of the supply roller 40. Specifically, the rotational speed of the developing roller 30 is approximately 1.5 times that of the supply roller 40. For example, when a printing operation is performed in the image forming apparatus, the rotational speed of the developing roller 30 is in the range of 250 rpm to 300 rpm, while the rotational speed of the supply roller 40 is in the range of 165 rpm to 200 rpm. Also, the rotational speed of the supply roller 40 is greater than that of the agitator 20. For example, when a printing operation is performed in the image forming apparatus, the rotational speed of the supply roller 40 is in the range of 165 rpm to 200 rpm, while the rotational speed of the agitator 20 is in the range of 50 rpm to 90 rpm. However, the ratio of each rotational speed may be appropriately changed according to the diameter of each roller, the characteristics of the material, the characteristics of the toner, etc.

[0038] The detection gear 58 is located on the first outer surface 11 of the housing 10. A portion of the detection gear 58 is located inside the gear cover 51. The other portion of the detection gear 58 is exposed to the outside of the gear cover 51. The detection gear 58 is rotatable about a detection shaft L6 that extends in a first direction. A portion of the outer circumference of the detection gear 58 has a recess 581 that is recessed radially inward. The portion of the outer circumference of the detection gear 58 other than the recess 581 has multiple teeth.

[0039] As shown in Figure 5, in the first direction, the agitator gear 57 is located between the first outer surface 11 of the housing 10 and the detection gear 58. That is, in the first direction, the detection gear 58 is located further from the first outer surface 11 of the housing 10 than the agitator gear 57.

[0040] Figures 7 and 8 are cross-sectional views of the developing cartridge 1 and drum cartridge 2 with the developing cartridge 1 mounted on the drum cartridge 2. Figures 7 and 8 show a cross-section including the detection gear 58 and perpendicular to the first direction.

[0041] When the developing cartridge 1 is unused, the detection gear 58 is in the first rotation position. In this case, as shown in Figure 7, the detection gear 58 meshes with the idler gear 56. More specifically, the detection gear 58 meshes with the small-diameter idler gear 562. When the drum cartridge 2 with the developing cartridge 1 installed is mounted in the image forming apparatus and driving force is supplied from the image forming apparatus to the gear section 50, the detection gear 58 rotates in conjunction with the rotation of the idler gear 56. However, when the detection gear 58 rotates to the second rotation position, the meshing between the idler gear 56 and the detection gear 58 disengages, as shown in Figure 8. At that point, the detection gear 58 stops rotating further.

[0042] The image forming apparatus has a sensor that detects the rotation of a detection gear 58. When a drum cartridge 2 with a developing cartridge 1 attached is installed in the image forming apparatus, the sensor detects whether or not the detection gear 58 rotates from a first rotation position to a second rotation position. This allows the image forming apparatus to identify whether the developing cartridge 1 is unused or has already been used. Specifically, if the sensor detects that the detection gear 58 has rotated from the first rotation position to the second rotation position, the image forming apparatus identifies that the developing cartridge 1 is unused. If the sensor does not detect that the detection gear 58 has rotated from the first rotation position to the second rotation position, the image forming apparatus identifies that the developing cartridge 1 has already been used.

[0043] The sensor can be configured, for example, with a swingable lever and an optical sensor. In this case, the lever contacts the detection gear 58 and swings according to the shape of the recess 581. The optical sensor detects the swing of the lever. In this way, the image forming apparatus can detect whether or not the detection gear 58 has rotated from the first rotation position to the second rotation position in response to the detection signal from the optical sensor.

[0044] <1-3. About Drum Cartridges> As shown in Figures 1 and 2, the drum cartridge 2 comprises a drum frame 60 and a photoreceptor drum 70. The drum cartridge 2 also has a charger for charging the photoreceptor drum 70 and a transfer roller that contacts the photoreceptor drum 70. During printing, the paper passes between the photoreceptor drum 70 and the transfer roller.

[0045] The drum frame 60 includes a first side frame 61, a second side frame 62, a connecting frame 63, and a drum handle 64. The first side frame 61 is located at one end of the drum frame 60 in a first direction. The second side frame 62 is located at the other end of the drum frame 60 in a first direction. The first side frame 61 and the second side frame 62 are separated from each other in a first direction. The connecting frame 63 connects the first side frame 61 and the second side frame 62 in a first direction.

[0046] The drum handle 64 is located at the end of the drum frame 60 opposite to the photoreceptor drum 70 in the second direction. As shown in Figure 1, when the developing cartridge 1 is mounted on the drum frame 60, the toner handle 14 overlaps with the drum handle 64. This allows the user to grasp both the toner handle 14 and the drum handle 64 simultaneously.

[0047] The developing cartridge 1 is detachable from the drum frame 60. When the developing cartridge 1 is mounted on the drum frame 60, it is positioned between the first side frame 61 and the second side frame 62 in a first direction.

[0048] The photoreceptor drum 70 is a drum that can rotate about a drum axis L7 extending in a first direction. The photoreceptor drum 70 is supported by a drum frame 60. In the first direction, the photoreceptor drum 70 is located between a first side frame 61 and a second side frame 62. In the second direction, the photoreceptor drum 70 is located at one end of the drum frame 60.

[0049] The photoreceptor drum 70 has a cylindrical outer surface extending in a first direction. The outer surface of the photoreceptor drum 70 is covered with a photosensitive material. When the drum cartridge 2 is mounted on the main frame of the image forming apparatus, the photoreceptor drum 70 receives a driving force from the image forming apparatus. More specifically, the photoreceptor drum 70 has a drum gear at the end of the drum frame 60 closer to one end in the first direction. When the drum cartridge 2 is mounted on the image forming apparatus, the drum gear meshes with the gear of the image forming apparatus and receives a driving force. As a result, the photoreceptor drum 70 rotates around the drum axis L7.

[0050] The photoreceptor drum 70 has a drum shaft 71. The drum shaft 71 protrudes from one end and the other end of the drum frame 60 in a first direction. When mounted in the image forming apparatus, the drum shaft 71 is guided along a groove in the main frame. When mounted in the image forming apparatus, the drum shaft 71 contacts the grounding terminal of the image forming apparatus.

[0051] The charger is a scorotron charger having wires and a grid. The drum cartridge 2 has a wire electrode electrically connected to the wires and a grid electrode electrically connected to the grid. The wire electrode and the grid electrode are configured to contact the electrodes of the image forming apparatus and receive power when the drum cartridge 2 is mounted on the image forming apparatus. The wire electrode and the grid electrode are located at the other end of the drum frame 60 in the first direction.

[0052] The drum cartridge 2 has a transfer electrode electrically connected to a transfer roller. The transfer electrode is configured to contact the electrode of the image forming apparatus and receive power when the drum cartridge 2 is mounted in the image forming apparatus. The transfer electrode is located at the other end of the drum frame 60 in the first direction.

[0053] With the developing cartridge 1 mounted on the drum frame 60, the developing roller 30 and the photoreceptor drum 70 are aligned in a second direction. More specifically, with the developing cartridge 1 mounted on the drum frame 60, the outer surface of the developing roller 30 and the outer surface of the photoreceptor drum 70 are in contact with each other.

[0054] Toner is supplied from the outer surface of the developing roller 30 to the outer surface of the photoreceptor drum 70. At this time, the toner moves from the developing roller 30 to the photoreceptor drum 70 in accordance with the electrostatic latent image formed on the outer surface of the photoreceptor drum 70. As a result, an image is formed on the outer surface of the photoreceptor drum 70 using toner. Subsequently, the image is transferred from the photoreceptor drum 70 to the printing paper using toner.

[0055] <1-4. Regarding development pressure> Next, we will explain the structure in which the developing roller 30 is pressed toward the photosensitive drum 70 when the developing cartridge 1 is mounted on the drum cartridge 2.

[0056] As shown in Figures 7 and 8, the drum cartridge 2 includes a pressing member 80. The pressing member 80 is a member that presses the developing cartridge 1 toward the photoreceptor drum 70 when the developing cartridge 1 is mounted on the drum cartridge 2. The pressing member 80 is provided on the first side frame 61. A similar pressing member may also be provided on the second side frame 62.

[0057] Furthermore, as shown in Figures 7 and 8, the drum cartridge 2 has a compression spring 81. The compression spring 81 is located between the pressing member 80 and the first side frame 61. The compression spring 81 is an elastic member that can expand and contract in a second direction. One end of the compression spring 81 in the second direction is connected to the pressing member 80. The other end of the compression spring 81 in the second direction is connected to the first side frame 61.

[0058] As shown in Figures 4, 7, and 8, the housing 10 of the developing cartridge 1 has a protrusion 15. The protrusion 15 is a projection that extends in a first direction from the first outer surface 11 toward the outside of the housing 10. When the developing cartridge 1 is mounted on the drum cartridge 2, the protrusion 15 comes into contact with the pressing member 80, as shown in Figures 7 and 8. Then, due to the elastic force of the pressing spring 81, the protrusion 15 receives a pressing force in a second direction toward the photoreceptor drum 70 from the pressing member 80. As a result, the developing roller 30 and the photoreceptor drum 70 come into contact with each other. The developing roller 30 is also pressed toward the photoreceptor drum 70 in the second direction.

[0059] The protrusion 15 is located outside the first outer surface 11 of the housing 10 in the first direction, rather than between the first outer surface 11 and the second outer surface 12 in the first direction. This allows the protrusion 15 to be positioned closer to the developing roller 30 in the second direction than if it were placed between the first outer surface 11 and the second outer surface 12 in the first direction. Therefore, it is possible to prevent the external dimensions of the housing 10 in the second direction from being increased by the protrusion 15. In addition, since the internal space of the housing 10 in the second direction is not narrowed by the protrusion 15, the volume of the internal space of the housing 10 can be secured.

[0060] The gear cover 51 has a gear cover opening 511. The protrusion 15 and the gear cover opening 511 are aligned in a second direction. A portion of the protrusion 15 is exposed to the outside of the gear cover 51 through the gear cover opening 511. Therefore, when the developing cartridge 1 is mounted on the drum cartridge 2, the pressing member 80 can press the portion of the protrusion 15 that is exposed from the gear cover 51. Also, at least a portion of the detection gear 58 is exposed from the gear cover opening 511.

[0061] The protrusion 15 has a rib 151 that protrudes in a direction away from the developing roller 30 in the second direction. When the developing cartridge 1 is mounted on the drum cartridge 2, the pressing member 80 contacts the outer surface of the rib 151. As a result, the portion of the outer surface of the protrusion 15 that is pressed by the pressing member 80 is limited to the outer surface of the rib 151. Therefore, it is possible to suppress variations in the direction of the pressing force received by the protrusion 15.

[0062] In the first direction, at least a portion of the protrusion 15 is located in the same position as the coupling gear 53, idler gear 56, agitator gear 57, or detection gear 58. That is, at least a portion of the protrusion 15 is located on the same plane perpendicular to the first direction as the coupling gear 53, idler gear 56, agitator gear 57, or detection gear 58. In this way, the length of the developing cartridge 1 in the first direction can be reduced compared to when the protrusion 15 and the coupling gear 53, idler gear 56, agitator gear 57, or detection gear 58 are located in different positions in the first direction.

[0063] In this embodiment, in the first direction, at least a portion of the protrusion 15 is located at the same position as the detection gear 58. That is, at least a portion of the protrusion 15 is located on the same plane perpendicular to the first direction as the detection gear 58. Therefore, the length of the developing cartridge 1 in the first direction can be reduced compared to when the protrusion 15 and the detection gear 58 are located at different positions in the first direction.

[0064] As shown by the dashed lines in Figures 7 and 8, the developer cartridge 1 has a sponge 41. The sponge 41 is located at one end of the supply roller 40 in the first direction. The sponge 41 prevents toner from leaking out of the housing 10 along the shaft of the supply roller 40 to the outside of the housing 10.

[0065] The sponge 41 is held by the protrusion 15. Specifically, the protrusion 15 has a rectangular recessed supply seal holder 152 on the side opposite to the rib 151 in the second direction. The sponge 41 is held by the supply seal holder 152. In other words, in the structure of this embodiment, the protrusion 15 plays two roles: receiving pressure from the pressing member 80 and holding the sponge 41. This makes the housing 10 smaller than when the part that receives pressure from the pressing member 80 and the part that holds the sponge 41 are provided separately. Also, the shape of the first outer surface 11 of the housing 10 can be simplified compared to when the part that receives pressure from the pressing member 80 and the part that holds the sponge 41 are provided separately.

[0066] Figure 9 is a view of the developer cartridge 1 from the second outer surface 12 side in the first direction. As shown in Figure 9, the housing 10 of the developer cartridge 1 has a toner filling port 122. The toner filling port 122 is an opening for filling toner into the housing 10. The toner filling port 122 penetrates the second outer surface 12 of the housing 10 in the first direction. The developer cartridge 1 also has a cap 123. The cap 123 is attached to the toner filling port 122. This closes the toner filling port 122.

[0067] Furthermore, as shown in Figure 9, the developing cartridge 1 further comprises a developing electrode 22, a supply electrode 23, and a bearing 24. The developing electrode 22, the supply electrode 23, and the bearing 24 are located on the second outer surface 12 of the housing 10. The developing electrode 22, the supply electrode 23, and the bearing 24 are mounted on the second outer surface 12 of the housing 10.

[0068] The developing electrode 22 is an electrode for applying a voltage to the developing roller 30. More specifically, the developing roller 30 has a developing roller shaft 31. The developing roller shaft 31 extends in a first direction along the developing axis L2. The developing roller shaft 31 is made of a conductive metal or conductive resin. The developing electrode 22 is in contact with the developing roller shaft 31. This causes the developing electrode 22 and the developing roller shaft 31 to be electrically connected to each other.

[0069] When the drum cartridge 2, with the developing cartridge 1 installed, is mounted on the main frame of the image forming apparatus, the developing electrode 22 comes into contact with the electrode of the image forming apparatus. As a result, a voltage is applied from the electrode of the image forming apparatus to the developing roller shaft 31 via the developing electrode 22. The toner inside the housing 10 is supported on the outer surface of the developing roller 30 by the electrostatic force caused by the voltage applied to the developing roller shaft 31.

[0070] The supply electrode 23 is an electrode for applying a voltage to the supply roller 40. More specifically, the supply roller 40 has a supply roller shaft 42. The supply roller shaft 42 extends in a first direction along the supply axis L3. The supply roller shaft 42 is made of a conductive metal or conductive resin. The supply electrode 23 is in contact with the supply roller shaft 42. This causes the supply electrode 23 and the supply roller shaft 42 to be electrically connected to each other.

[0071] When the drum cartridge 2, with the developing cartridge 1 attached, is mounted on the main frame of the image forming apparatus, the supply electrode 23 comes into contact with the electrode of the image forming apparatus. As a result, a voltage is applied from the electrode of the image forming apparatus to the supply roller shaft 42 via the supply electrode 23. The toner inside the housing 10 is supported on the outer surface of the supply roller 40 by the electrostatic force caused by the voltage applied to the supply roller shaft 42.

[0072] Furthermore, the voltage applied by the image forming apparatus to the supply roller shaft 42 via the supply electrode 23 is greater than the voltage applied to the developing roller shaft 31 via the developing electrode 22. For example, when the image forming apparatus applies a voltage of 200V to 500V to the developing roller shaft 31, it applies a voltage 100V greater to the supply roller shaft 42, i.e., a voltage of 300V to 600V.

[0073] The bearing 24 is a member that supports the developing roller 30 and the supply roller 40 in a rotatable manner. Figure 10 is an exploded perspective view of the developing electrode 22, the supply electrode 23, and the bearing 24. As shown in Figure 10, the bearing 24 has a bearing hole 241 and a bearing recess 242. The bearing hole 241 is a circular hole that penetrates the bearing 24 in a first direction. The end of the developing roller shaft 31 in the first direction is inserted into the bearing hole 241. This allows the developing roller 30 to be rotatably supported on the bearing 24 with respect to the developing axis L2. The end of the developing roller shaft 31 in the first direction is exposed to the outside through the bearing hole 241.

[0074] The bearing recess 242 is a circular recess formed on the surface of the bearing 24 facing the housing 10. The end of the supply roller shaft 42 in the first direction is inserted into the bearing recess 242. This allows the supply roller 40 to be rotatably supported on the supply shaft L3 relative to the bearing 24. The bearing recess 242 does not penetrate the bearing 24. Therefore, the end of the supply roller shaft 42 in the first direction is covered by the bearing 24.

[0075] The developing electrode 22, the supply electrode 23, and the bearing 24 are fixed to the second outer surface 12 of the housing 10 by a common screw 25 shown in Figure 10. Specifically, the supply electrode 23, the bearing 24, and the developing electrode 22 are stacked in this order in the first direction, starting from the side closest to the housing 10, and the screw 25 passes through the developing electrode 22, the bearing 24, and the supply electrode 23. Then, by fastening the screw 25 to the housing 10, the developing electrode 22, the bearing 24, and the supply electrode 23 are fixed in place, sandwiched between the second outer surface 12 of the housing 10 and the head of the screw 25.

[0076] The bearing 24 is made of resin, which is an insulator. Therefore, by interposing the bearing 24 between the developing electrode 22 and the supply electrode 23, it is possible to prevent electrical conductivity between the developing electrode 22 and the supply electrode 23.

[0077] As shown in Figure 9, when the developing cartridge 1 is viewed in the first direction from the second outer surface 12 side, at least a portion of the detection gear 58 is located outside the housing 10. That is, when the developing cartridge 1 is viewed in the first direction from the second outer surface 12 side, at least a portion of the detection gear 58 protrudes outward beyond the outer shape of the housing 10. In this way, when the developing cartridge 1 is viewed in the first direction from the second outer surface 12 side, the detection gear 58 and other gears can be arranged over a wider area than if the entire detection gear 58 were placed inside the outer shape of the housing 10.

[0078] As shown in Figures 1 and 2, the drum cartridge 2 has a locking lever 66. The locking lever 66 is a lever that prevents the developing cartridge 1 from coming off the drum frame 60 when the developing cartridge 1 is mounted on the drum frame 60. The locking lever 66 is attached to the drum frame 60.

[0079] The lock lever 66 is rotatable relative to the drum frame 60 about a pivot axis L8 (see Figure 11) extending in a first direction. The lock lever 66 rotates between a locked position and a released position. The drum cartridge 2 also has a spring (not shown). The spring biases the lock lever 66 from the released position to the locked position. The spring may be, for example, a resin spring molded integrally with the lock lever 66, or it may be a separate component such as a coil spring or torsion spring.

[0080] As shown in Figure 9, the developing cartridge 1 has a first protrusion 26 and a second protrusion 27. The first protrusion 26 and the second protrusion 27 are located on the second outer surface 12 of the housing 10. The first protrusion 26 and the second protrusion 27 protrude in a first direction toward the outside of the housing 10 from the second outer surface 12. The first protrusion 26 and the second protrusion 27 are connected.

[0081] Figure 11 is a cross-sectional view of the developing cartridge 1 mounted on the drum cartridge 2. Figure 11 shows a cross-section including the lock lever 66 and perpendicular to the first direction. As shown in Figure 11, the lock lever 66 has a first lever arm 661 and a second lever arm 662. The first lever arm 661 and the second lever arm 662 are located on opposite sides of each other with respect to the pivot axis L8 of the lock lever 66.

[0082] When the developing cartridge 1 is mounted on the drum cartridge 2, the lock lever 66 is positioned in the locked position (position shown in Figure 11) by the biasing force of the spring. At this time, the first lever arm 661 engages with the first projection 26. Specifically, the first projection 26 is positioned between the first lever arm 661 and the pivot shaft L8. This prevents the developing cartridge 1 from coming off the drum frame 60.

[0083] To remove the developing cartridge 1 from the drum cartridge 2, the user presses the first lever arm 661, thereby rotating the lock lever 66 from the locked position to the released position. This disengages the first lever arm 661 from the first projection 26. This allows the developing cartridge 1 to be removed from the drum frame 60.

[0084] Furthermore, when the lock lever 66 is rotated from the locked position to the released position, the second lever arm 662 comes into contact with the second projection 27. The second lever arm 662 then pushes the second projection 27 away from the drum frame 60. This allows the developing cartridge 1 to be lifted away from the drum frame 60. As a result, the developing cartridge 1 can be easily removed from the drum frame 60.

[0085] Furthermore, the developing cartridge 1 has a developing roller cover 28. The developing roller cover 28 is a component that protects the developing roller 30 when the developing cartridge 1 is transported. Figure 12 is a perspective view of the developing cartridge 1 and the developing roller cover 28. Figure 13 is a perspective view of the developing roller cover 28.

[0086] The developing roller cover 28 is cup-shaped and opens towards the developing roller 30. The developing roller cover 28 is detachable from the developing cartridge 1. When the developing roller cover 28 is attached to the developing cartridge 1, it covers the developing roller 30. The developing cartridge 1 is transported with the developing roller cover 28 attached. This protects the developing roller 30. When using the developing cartridge 1, the developing roller cover 28 is removed.

[0087] As shown in Figure 13, the developing roller cover 28 has four claws 281. Two of the four claws 281 are located at one end of the developing roller cover 28 in the first direction. The other two of the four claws 281 are located at the other end of the developing roller cover 28 in the first direction. Each claw 281 engages with a recess, hole, or step provided in the developing cartridge 1. This allows the developing roller cover 28 to be mounted on the developing cartridge 1.

[0088] <2. Second Embodiment> Next, a second embodiment will be described.

[0089] <2-1. Overview of Developer Cartridges and Drum Cartridges> Figures 14 to 17 are perspective views of the developing cartridge 1 and drum cartridge 2 of the second embodiment. Figure 14 shows the developing cartridge 1 mounted on the drum cartridge 2. Figure 15 shows the developing cartridge 1 mounted on the drum cartridge 2 from a different angle than Figure 14. Figure 16 shows the developing cartridge 1 removed from the drum cartridge 2. Figure 17 shows the developing cartridge 1 removed from the drum cartridge 2 from a different angle than Figure 16.

[0090] The developer cartridge 1 and drum cartridge 2 are 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 mounted on the drum cartridge 2. The drum cartridge 2 with the developer cartridge 1 mounted can also be mounted on the main frame of the image forming apparatus. The image forming apparatus forms an image on the printing paper using toner supplied from the developer cartridge 1.

[0091] <2-2. About the developing cartridge> As shown in Figures 14 to 17, the developing cartridge 1 comprises a housing 10, an agitator 20, a developing roller 30, a supply roller 40, a gear section 50, a memory 90, and a holder 92.

[0092] The housing 10 is a container capable of holding toner, which is a developer. The housing 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 housing 10 in a first direction. The second outer surface 12 is located at the other end of the housing 10 in a first direction. The first outer surface 11 and the second outer surface 12 are separated from each other in a first direction. The housing 10 also has a toner handle 14. The toner handle 14 is located at one end of the housing 10 in a second direction.

[0093] The agitator 20 is located inside the housing 10. The agitator 20 has blades 21. The agitator 20 is rotatable about an agitator shaft L1 (see Figure 18) that extends in a first direction. When the agitator 20 rotates about the agitator shaft L1, the toner inside the housing 10 is agitated by the blades 21.

[0094] The developing roller 30 is a roller that can rotate around a developing axis L2 extending in a first direction. The developing roller 30 is supported by the housing 10. The developing roller 30 is located at the other end of the housing 10 in a second direction. Toner inside the housing 10 is supplied to the outer surface of the developing roller 30 via a supply roller (not shown). As a result, toner is carried on the outer surface of the developing roller 30.

[0095] The gear section 50 is located on the first outer surface 11 of the housing 10. The gear section 50 has a plurality of gears and a gear cover 51. The gear cover 51 is attached to the first outer surface 11 of the housing 10. More specifically, the gear cover 51 is fixed to the first outer surface 11 of the housing 10 by a first screw 18, a second screw 19, and a third screw 191. The method for fixing the gear cover 51 to the housing 10 will be described later.

[0096] Multiple gears are located between the first outer surface 11 and the gear cover 51 in the first direction. That is, the multiple gears are covered by the gear cover 51. With the drum cartridge 2, into which the developing cartridge 1 is mounted, attached to the main frame, the image forming apparatus supplies driving force to the agitator 20, developing roller 30, and supply roller 40 via the multiple gears of the gear section 50. As a result, the agitator 20, developing roller 30, and supply roller 40 rotate.

[0097] Figure 18 is a perspective view of the developing cartridge 1 with the gear cover 51 removed. Figure 19 is a view of the developing cartridge 1 with the gear cover 51 removed, viewed in a first direction. As shown in Figures 18 and 19, the gears of the gear section 50 include an agitator gear 57, a coupling gear 53, an idler gear 56, a developing roller gear 54, and a supply roller gear 55.

[0098] The agitator gear 57 is attached to one end of the agitator 20 in the first direction. When the agitator gear 57 rotates, the agitator 20 also rotates with the agitator gear 57 around the agitator axis L1.

[0099] The developing roller gear 54 is attached to one end of the developing roller 30 in the first direction. When the developing roller gear 54 rotates, the developing roller 30 also rotates together with the developing roller gear 54 around the developing shaft L2 that extends in the first direction.

[0100] The supply roller gear 55 is attached to one end of the supply roller 40 in the first direction. When the supply roller gear 55 rotates, the supply roller 40 also rotates together with the supply roller gear 55 on the axis of rotation extending in the first direction.

[0101] The coupling gear 53 meshes with the idler gear 56, the developing roller gear 54, and the supply roller gear 55. The idler gear 56 meshes with the agitator gear 57. When the coupling gear 53 receives driving force from the image forming apparatus, the developing roller gear 54, the supply roller gear 55, and the idler gear 56 rotate. When the idler gear 56 rotates, the agitator gear 57 also rotates. The coupling gear 53 is a stepped gear having a large-diameter coupling gear 531 and a small-diameter coupling gear 532, similar to the first embodiment. Similarly, the idler gear 56 is a stepped gear having a large-diameter idler gear 561 and a small-diameter idler gear 562, similar to the first embodiment.

[0102] Here, the ratio of the rotational speeds of the developing roller 30, the supply roller 40, and the agitator 20 is determined according to the gear ratio of each gear in the gear section 50. The rotational speed of the developing roller 30 is greater than that of the supply roller 40. Specifically, the rotational speed of the developing roller 30 is approximately 1.5 times that of the supply roller 40. For example, when a printing operation is performed in the image forming apparatus, the rotational speed of the developing roller 30 is in the range of 250 rpm to 300 rpm, while the rotational speed of the supply roller 40 is in the range of 165 rpm to 200 rpm. Also, the rotational speed of the supply roller 40 is greater than that of the agitator 20. For example, when a printing operation is performed in the image forming apparatus, the rotational speed of the supply roller 40 is in the range of 165 rpm to 200 rpm, while the rotational speed of the agitator 20 is in the range of 50 rpm to 90 rpm. However, the ratio of each rotational speed may be appropriately changed according to the diameter of each roller, the characteristics of the material, the characteristics of the toner, etc.

[0103] In the second embodiment, the developing cartridge 1 does not have a detection gear, but it does have a memory 90. Also, in the first embodiment, the image forming apparatus had a sensor that detected the rotation of the detection gear 58, but in the second embodiment, it has an electrode that contacts the electrical contact surface 91 of the memory 90.

[0104] Memory 90 is a storage medium that stores information about the developing cartridge 1. Memory 90 is located on the first outer surface 11 of the housing 10. Memory 90 is, for example, an IC chip. Memory 90 stores at least one of the identification information and lifespan information of the developing cartridge 1. The identification information is information for identifying the developing cartridge 1. The identification information is, for example, the serial number of the developing cartridge 1. The lifespan information is information that represents the lifespan of the developing cartridge 1. The lifespan information is, for example, the cumulative number of rotations of the developing roller 30.

[0105] As shown in Figures 17 and 18, the memory 90 has an electrical contact surface 91. The electrical contact surface 91 is a metal surface that is a conductor. The electrical contact surface 91 is electrically connected to the memory elements of the memory 90. The electrical contact surface 91 is a surface that intersects with respect to a second direction. For example, the electrical contact surface 91 is a surface that is perpendicular to the second direction. When the developing cartridge 1 is mounted on the drum cartridge 2, the electrical contact surface 91 is exposed from the drum frame 60. When the drum cartridge 2 with the developing cartridge 1 mounted is mounted on the image forming apparatus, the electrical contact surface 91 comes into contact with the electrodes of the image forming apparatus. This allows the control unit of the image forming apparatus to communicate with the memory 90.

[0106] The holder 92 is a unit that holds the memory 90. The holder 92 is located on the first outer surface 11 of the housing 10. Figure 20 is a perspective view of the holder 92. Figure 21 is a view of the holder 92 from a direction perpendicular to the first direction. Figure 22 is an exploded perspective view of the holder 92. As shown in Figures 20 to 22, the holder 92 has a first holder 921, a second holder 922, and a spring 93.

[0107] The first holder 921 has a first end 930, which is one end of the holder 92 in the second direction. The second holder 922 has a second end 940, which is the other end of the holder 92 in the second direction. The first end 930 and the second end 940 are separated from each other in the second direction. The first end 930 is further from the developing roller 30 than the second end 940.

[0108] The first holder 921 is movable in a second direction relative to the second holder 922. Therefore, the first end portion 930 is movable in a second direction relative to the second end portion 940. As the first holder 921 moves in a second direction relative to the second holder 922, the length of the holder 92 in the second direction changes. Specifically, the length of the holder 92 in the second direction changes between a first length and a second length that is shorter than the first length.

[0109] In this embodiment, the first holder 921 is cup-shaped and opens in a second direction toward the second holder 922. The second holder 922 is inserted inside the first holder 921. The first holder 921 also has a through hole 931. The through hole 931 penetrates a portion of the first holder 921 in a first direction. The second holder 922 has claws 941. The claws 941 protrude from a portion of the second holder 922 in a first direction. The claws 941 are inserted into the through hole 931. This prevents the second holder 922 from coming out of the first holder 921 in a second direction.

[0110] The memory 90 is located at the first end 930 of the holder 92. Therefore, the electrical contact surface 91 is located at the first end 930 of the holder 92. In this embodiment, the entire memory 90 is held at the first end 930 of the holder 92. However, only the electrical contact surface 91 of the memory 90 may be held at the first end 930 of the holder 92, and the memory elements of the memory 90 may be held in a part of the developing cartridge 1 other than the holder 92. In that case, it is sufficient that the memory elements of the memory 90 and the electrical contact surface 91 are electrically connected by a conductor.

[0111] The spring 93 is an elastic member that can expand and contract in a second direction. The spring 93 is, for example, a coil spring. One end of the spring 93 in the second direction is in contact with the first holder 921. The other end of the spring 93 in the second direction is in contact with the second holder 922. The spring 93 is positioned between the first end 930 and the second end 940 when it is compressed in the second direction from its natural length. Therefore, the elastic force of the spring 93 constantly biases the holder 92 from the second length toward the first length.

[0112] The holder 92 is positioned between the first outer surface 11 of the housing 10 and the gear cover 51 in the first direction. The holder 92 is attached to the housing 10 and the gear cover 51. The holder 92 is movable in the second and third directions relative to the housing 10 and the gear cover 51. The structure for attaching the holder 92 to the housing 10 and the gear cover 51 will be described later.

[0113] <2-3. About Drum Cartridges> As shown in Figures 14 to 17, the drum cartridge 2 comprises a drum frame 60, a photoreceptor drum 70, and a pressing member 80. The drum cartridge 2 also has a charger for charging the photoreceptor drum 70 and a transfer roller that contacts the photoreceptor drum 70. When printing, the paper passes between the photoreceptor drum 70 and the transfer roller.

[0114] The drum frame 60 includes a first side frame 61, a second side frame 62, a connecting frame 63, and a drum handle 64. The first side frame 61 is located at one end of the drum frame 60 in a first direction. The second side frame 62 is located at the other end of the drum frame 60 in a first direction. The first side frame 61 and the second side frame 62 are separated from each other in a first direction. The connecting frame 63 connects the first side frame 61 and the second side frame 62 in a first direction. The drum handle 64 is located at one end of the drum frame 60 in a second direction.

[0115] In the first embodiment, the drum cartridge 2 had a drum frame hole 60A, but the drum cartridge 2 of the second embodiment does not have a hole in the same position. With this configuration, even if one attempts to install the developing cartridge 1 of the first embodiment, the housing projection 124 will interfere, thus preventing the drum cartridge 2 of the first embodiment from being unintentionally installed on the drum frame 60 of the second embodiment.

[0116] The developing cartridge 1 can be mounted on the drum frame 60. When the developing cartridge 1 is mounted on the drum frame 60, it is positioned between the first side frame 61 and the second side frame 62 in a first direction.

[0117] The photoreceptor drum 70 is a drum that can rotate about a drum axis L7 extending in a first direction. The photoreceptor drum 70 is supported by a drum frame 60. In the first direction, the photoreceptor drum 70 is located between the first side frame 61 and the second side frame 62. In the second direction, the photoreceptor drum 70 is located at the other end of the drum frame 60.

[0118] The photoreceptor drum 70 has a cylindrical outer surface. The outer surface of the photoreceptor drum 70 is covered with a photosensitive material. When the drum cartridge 2 is mounted on the main frame of the image forming apparatus, the photoreceptor drum 70 receives a driving force from the image forming apparatus. More specifically, the photoreceptor drum 70 has a drum gear at the end of the drum frame 60 closer to one end in the first direction. When the drum cartridge 2 is mounted on the image forming apparatus, the drum gear meshes with the gear of the image forming apparatus and receives a driving force. As a result, the photoreceptor drum 70 rotates around the drum axis L7.

[0119] The photoreceptor drum 70 has a drum shaft 71. The drum shaft 71 protrudes from one end and the other end of the drum frame 60 in a first direction. When mounted in the image forming apparatus, the drum shaft 71 is guided along a groove in the main frame. When mounted in the image forming apparatus, the drum shaft 71 contacts the grounding terminal of the image forming apparatus.

[0120] The charger is a scorotron charger having wires and a grid. The drum cartridge 2 has a wire electrode electrically connected to the wires and a grid electrode electrically connected to the grid. The wire electrode and the grid electrode are configured to contact the electrodes of the image forming apparatus and receive power when the drum cartridge 2 is mounted on the image forming apparatus. The wire electrode and the grid electrode are located at the other end of the drum frame 60 in the first direction.

[0121] The drum cartridge 2 has a transfer electrode electrically connected to a transfer roller. The transfer electrode is configured to contact the electrode of the image forming apparatus and receive power when the drum cartridge 2 is mounted in the image forming apparatus. The transfer electrode is located at the other end of the drum frame 60 in the first direction.

[0122] With the developing cartridge 1 mounted on the drum frame 60, the developing roller 30 and the photoreceptor drum 70 are aligned in a second direction. More specifically, with the developing cartridge 1 mounted on the drum frame 60, the outer surface of the developing roller 30 and the outer surface of the photoreceptor drum 70 are in contact with each other.

[0123] Toner is supplied from the outer surface of the developing roller 30 to the outer surface of the photoreceptor drum 70. At this time, the toner moves from the developing roller 30 to the photoreceptor drum 70 in accordance with the electrostatic latent image formed on the outer surface of the photoreceptor drum 70. As a result, an image is formed on the outer surface of the photoreceptor drum 70 using toner. Subsequently, the image is transferred from the photoreceptor drum 70 to the printing paper using toner.

[0124] The pressing member 80 is a member that presses the developing cartridge 1 toward the photoreceptor drum 70 when the developing cartridge 1 is mounted on the drum cartridge 2. As shown in Figure 16, the pressing member 80 is attached to the first side frame 61. The drum cartridge 2 also has a pressing spring 81 (see Figures 25 and 28). The pressing spring 81 is located between the pressing member 80 and the first side frame 61.

[0125] On the other hand, as shown in Figures 17 to 19, the housing 10 of the developing cartridge 1 has a protrusion 15. When the developing cartridge 1 is mounted on the drum cartridge 2, the pressing member 80 comes into contact with the protrusion 15. Then, due to the elastic force of the pressing spring 81, the pressing member 80 presses the protrusion 15 toward the photoreceptor drum 70. As a result, the developing roller 30 and the photoreceptor drum 70 come into contact with each other.

[0126] <2-4. About the holder> Next, the holder 92 of the developing cartridge 1 will be described in more detail. Figure 23 is a perspective view of the developing cartridge 1 with the holder 92 disassembled. Figure 24 is a view of the developing cartridge 1 from the first end 930 side of the holder 92 in the second direction.

[0127] As shown in Figures 20, 22, and 23, the holder 92 has a hole 94. More specifically, the first holder 921 has a hole 94 extending in a first direction. The hole 94 penetrates the first holder 921 in a first direction. On the other hand, as shown in Figures 18, 19, and 23, the housing 10 has a first boss 160. The first boss 160 extends outward from the outer surface of the housing 10 in a first direction. More specifically, the first boss 160 extends in a first direction from the first outer surface 11 of the housing 10 toward the gear cover 51. The shape of the first boss 160 is, for example, cylindrical. However, the shape of the first boss 160 may be other shapes, such as a prismatic shape. The first boss 160 is inserted into the hole 94 of the holder 92.

[0128] The size of the hole 94 in the second direction is larger than the size of the first boss 160 in the second direction. Therefore, with the first boss 160 inserted into the hole 94, the holder 92 is movable in the second direction relative to the first boss 160. This allows the holder 92 to move in the second direction relative to the housing 10 and the gear cover 51. When the holder 92 moves in the second direction relative to the housing 10 and the gear cover 51, the electrical contact surface 91 of the memory 90 also moves in the second direction relative to the housing 10 and the gear cover 51 along with the holder 92.

[0129] Furthermore, the size of the hole 94 in the third direction is larger than the size of the first boss 160 in the third direction. Therefore, with the first boss 160 inserted into the hole 94, the holder 92 is movable in the third direction relative to the first boss 160. This allows the holder 92 to move in the third direction relative to the housing 10 and the gear cover 51. When the holder 92 moves in the third direction relative to the housing 10 and the gear cover 51, the electrical contact surface 91 of the memory 90 also moves in the third direction relative to the housing 10 and the gear cover 51 along with the holder 92.

[0130] The first boss 160 has a first screw hole 16. The first screw hole 16 is a hole through which a first screw 18 for attaching the gear cover 51 to the housing 10 is fastened. The first screw hole 16 extends in a first direction from the tip of the first boss 160 in a first direction, along the central axis of the first boss 160. The first screw 18 is fastened to the first screw hole 16 through a hole formed in the gear cover 51. A portion of the gear cover 51 is then sandwiched between the head of the first screw 18 and the first boss 160. This attaches the gear cover 51 to the housing 10.

[0131] The gear cover 51 may have not only the first screw 18, but also a second screw 19 and a third screw 191. In other words, the gear cover 51 may be fixed by three screws. The housing 10 has a second screw hole 17 and a third screw hole 192 at positions different from the first screw hole 16 on the first outer surface 11. The second screw 19 is fastened to the second screw hole 17 through a hole formed in the gear cover 51. The third screw 191 is fastened to the third screw hole 192 through a hole formed in the gear cover 51. By fixing the gear cover 51 to the housing 10 with these three screws 18, 19, and 191, the gear cover 51 can be more firmly fixed to the housing 10.

[0132] The first boss 160 has two functions: receiving the first screw 18 for attaching the gear cover 51 to the housing 10, and holding the holder 92. By giving the first boss 160 two functions in this way, the number of parts in the developing cartridge 1 can be reduced compared to when the two functions are realized by separate parts.

[0133] Furthermore, the first boss 160 into which the first screw 18 is inserted has high strength. Therefore, the first boss 160 into which the first screw 18 is inserted is resistant to deformation. Also, the hole 94 into which the first boss 160 of the holder 92 is inserted is a through hole, not a recess. That is, the high-strength first boss 160 penetrates the hole 94 of the holder 92. This prevents the holder 92 from tilting relative to the housing 10 and the gear cover 51 in the first direction.

[0134] Furthermore, as shown in Figure 21, the holder 92 has a second boss 95. The second boss 95 extends in a first direction from the outer surface of the holder 92 toward the housing 10. More specifically, the second boss 95 extends in a first direction from the outer surface of the first holder 921 toward the housing 10. On the other hand, as shown in Figure 23, the housing 10 has a housing-side recess 10A. The housing-side recess 10A is recessed in a first direction from the first outer surface 11 of the housing 10. The second boss 95 is inserted into the housing-side recess 10A.

[0135] In this way, by inserting the second boss 95 into the housing-side recess 10A, the tilting of the holder 92 relative to the housing 10 and gear cover 51 in the first direction is further suppressed. The size of the recess in the second direction is larger than the size of the second boss 95 in the second direction. Therefore, even when the second boss 95 is inserted into the housing-side recess 10A, it does not prevent the holder 92 from moving in the second direction relative to the housing 10 and gear cover 51. Also, the size of the housing-side recess 10A in the third direction is larger than the size of the second boss 95 in the third direction. Therefore, even when the second boss 95 is inserted into the housing-side recess 10A, it does not prevent the holder 92 from moving in the third direction relative to the housing 10 and gear cover 51.

[0136] Figures 25 to 28 are cross-sectional views of the developing cartridge 1 and drum cartridge 2 during the process of the developing cartridge 1 being mounted onto the drum cartridge 2. Figures 25 to 28 show cross-sections passing through the holder 92 and perpendicular to the first direction.

[0137] The holder 92 is partially covered by the gear cover 51. Specifically, of the first end 930 and second end 940 of the holder 92, the second end 940 is covered by the gear cover 51, and the first end 930 is located outside the gear cover 51. In the first direction, the second end 940 is located between the first outer surface 11 of the housing 10 and the gear cover 51. In the second direction, the second end 940 is located inside the gear cover 51. In the second direction, the first end 930 is located outside the gear cover 51. In the second direction, the first end 930 is located outside the housing 10. Also, in the second direction, the second end 940 is located between the multiple gears of the gear section 50 and the first end 930.

[0138] Thus, in this embodiment, in the second direction, a portion of the holder 92 is located inside the gear cover 51. Therefore, the dimensions of the developing cartridge 1 in the second direction can be reduced compared to when the entire holder 92 is located outside the gear cover 51.

[0139] As shown in Figures 25 to 28, the gear cover 51 has a gear cover opening 511. The gear cover opening 511 is a hole that penetrates a portion of the gear cover 51 in a second direction. The holder 92 is positioned in the gear cover opening 511. The gear cover 51 also has an annular opening edge 512 which is the edge of the gear cover opening 511. The opening edge 512 faces the holder 92 in the rotational direction around the first boss 160. Therefore, when the holder 92 rotates around the first boss 160, the holder 92 comes into contact with the opening edge 512. This restricts the rotation of the holder 92 around the first boss 160.

[0140] As shown in Figures 20 to 22, the holder 92 has a protruding wall 932. Specifically, the first holder 921 has a protruding wall 932. The protruding wall 932 protrudes from the first end 930 of the holder 92 in a direction away from the housing 10 in a first direction. In a second direction, the protruding wall 932 is located on the outside of the gear cover 51. The protruding wall 932 also faces the opening edge 512 of the gear cover 51 in a second direction. The protruding wall 932 is capable of contacting the opening edge 512 of the gear cover 51 in a second direction. This prevents the first end 930 of the holder 92 from entering the interior of the gear cover 51.

[0141] The gears of the gear section 50 and the holder 92 are at least partially overlapping in the first direction. The second end 940 of the holder 92 is aligned with at least some of the gears of the gear section 50 in the second direction. In this embodiment, the agitator gear 57 and the holder 92 are positioned at the same location in the first direction. The second end 940 of the holder 92 is aligned with the agitator gear 57 in the second direction. More specifically, the second end 940 of the holder 92 and the end faces of the teeth of the agitator gear 57 face each other in the second direction. This reduces the dimensions of the developing cartridge 1 in the first direction compared to when the agitator gear 57 and the holder 92 are positioned at different locations in the first direction.

[0142] As shown in Figures 25 to 28, the drum frame 60 has a projection 65. The projection 65 extends from the first side frame 61 in a third direction. In the third direction, the projection 65 protrudes away from the pressing member 80. When the developing cartridge 1 is mounted on the drum cartridge 2, the projection 65 is inserted into the gear cover 51 through the gear cover opening 511. That is, the projection 65 is inserted between the first outer surface 11 of the housing 10 and the gear cover 51. At this time, the projection 65 is inserted between the holder 92 and the agitator gear 57 in a second direction. As a result, the projection 65 restricts the position of the holder 92 in the second direction.

[0143] As shown in Figure 27, in this embodiment, during the process of mounting the developing cartridge 1 onto the drum cartridge 2, the projection 65 contacts the second end 940 of the holder 92. This causes the holder 92 to move in the second direction relative to the housing 10. Then, once the mounting of the developing cartridge 1 onto the drum cartridge 2 is complete, the projection 65 contacts the second end 940 of the holder 92, as shown in Figure 28. This positions the holder 92 in the second direction relative to the drum frame 60 and the housing 10.

[0144] When the developing cartridge 1 is mounted on the drum cartridge 2, the projection 65 is located between the holder 92 and the agitator gear 57 in the second direction. Also, the projection 65 is located between the first outer surface 11 and the gear cover 51 in the first direction.

[0145] As shown in Figure 28, when the projection 65 is in contact with the second end 940 of the holder 92, the electrical contact surface 91 is movable in the second direction. More specifically, when the spring 93 expands or contracts in the second direction, the electrical contact surface 91 moves in the second direction relative to the projection 65.

[0146] When no external force is applied to the holder 92, the spring 93 is at its first length. When an external force is applied to the holder 92 in the direction from the first end 930 to the second end 940, the second end 940 is supported by the projection 65, the first end 930 moves toward the second end 940, and the spring 93 is compressed. As a result, the electrical contact surface 91 becomes movable relative to the projection 65.

[0147] As shown in Figures 20 to 22, the holder 92 has a first guide surface 96 and a second guide surface 97. Specifically, the first holder 921 has the first guide surface 96, and the second holder 922 has the second guide surface 97. The first guide surface 96 and the second guide surface 97 are guide surfaces for guiding the holder 92 relative to the drum frame 60 during the process of mounting the developing cartridge 1 onto the drum cartridge 2.

[0148] The first guide surface 96 and the second guide surface 97 are inclined with respect to the second and third directions. More specifically, the first guide surface 96 and the second guide surface 97 are surfaces that extend away from the first end 930 in the second direction and approach the second end 940 in the third direction.

[0149] In the process of mounting the developing cartridge 1 onto the drum cartridge 2, first, the first guide surface 96 contacts the projection 65. Then, the first guide surface 96 moves along the projection 65. Subsequently, as shown in Figure 26, the second guide surface 97 contacts the projection 65. Then, the second guide surface 97 moves along the projection 65. As a result, the holder 92 moves in the second direction to the space opposite the agitator gear 57 relative to the projection 65. Consequently, the projection 65 can be inserted between the second end 940 of the holder 92 and the agitator gear 57.

[0150] Furthermore, the positions of the convex portion 15 and the holder 92 in the first direction overlap at least partially. Also, as shown in Figure 19, the holder 92 and the convex portion 15 are aligned in a direction intersecting the first direction. For this reason, the dimensions of the developing cartridge 1 in the first direction can be reduced compared to when the convex portion 15 and the holder 92 are positioned at different locations in the first direction.

[0151] Figure 29 is a view of the developer cartridge 1 from the second outer surface 12 side in the first direction. As shown in Figure 29, the housing 10 of the developer cartridge 1 has a toner filling port 122. The toner filling port 122 is an opening for filling toner into the housing 10. The toner filling port 122 penetrates the second outer surface 12 of the housing 10 in the first direction. The developer cartridge 1 also has a cap, which is not shown in Figure 29. The cap is attached to the toner filling port 122. This closes the toner filling port 122.

[0152] Furthermore, as shown in Figure 29, the developing cartridge 1 further comprises a developing electrode 22, a supply electrode 23, and a bearing 24. The developing electrode 22, the supply electrode 23, and the bearing 24 are located on the second outer surface 12 of the housing 10. The developing electrode 22, the supply electrode 23, and the bearing 24 are attached to the second outer surface 12 of the housing 10.

[0153] The developing electrode 22 is an electrode for applying a voltage to the developing roller 30. More specifically, the developing roller 30 has a developing roller shaft 31. The developing roller shaft 31 extends in a first direction along the developing axis L2. The developing roller shaft 31 is made of a conductive metal or conductive resin. The developing electrode 22 is in contact with the developing roller shaft 31. This causes the developing electrode 22 and the developing roller shaft 31 to be electrically connected to each other.

[0154] When the drum cartridge 2, with the developing cartridge 1 installed, is mounted on the main frame of the image forming apparatus, the developing electrode 22 comes into contact with the electrode of the image forming apparatus. As a result, a voltage is applied from the electrode of the image forming apparatus to the developing roller shaft 31 via the developing electrode 22. The toner inside the housing 10 is supported on the outer surface of the developing roller 30 by the electrostatic force caused by the voltage applied to the developing roller shaft 31.

[0155] The supply electrode 23 is an electrode for applying a voltage to the supply roller 40. More specifically, the supply roller 40 has a supply roller shaft 42. The supply roller shaft 42 extends in a first direction along the supply axis L3. The supply roller shaft 42 is made of a conductive metal or conductive resin. The supply electrode 23 is in contact with the supply roller shaft 42. This causes the supply electrode 23 and the supply roller shaft 42 to be electrically connected to each other.

[0156] When the drum cartridge 2, with the developing cartridge 1 attached, is mounted on the main frame of the image forming apparatus, the supply electrode 23 comes into contact with the electrode of the image forming apparatus. As a result, a voltage is applied from the electrode of the image forming apparatus to the supply roller shaft 42 via the supply electrode 23. The toner inside the housing 10 is supported on the outer surface of the supply roller 40 by the electrostatic force caused by the voltage applied to the supply roller shaft 42.

[0157] Furthermore, the voltage applied by the image forming apparatus to the supply roller shaft 42 via the supply electrode 23 is greater than the voltage applied to the developing roller shaft 31 via the developing electrode 22. For example, when the image forming apparatus applies a voltage of 200V to 500V to the developing roller shaft 31, it applies a voltage 100V greater to the supply roller shaft 42, i.e., a voltage of 300V to 600V.

[0158] The bearing 24 is a member that supports the developing roller 30 and the supply roller 40 in a rotatable manner. Figure 30 is an exploded perspective view of the developing electrode 22, the supply electrode 23, and the bearing 24. As shown in Figure 30, the bearing 24 has a bearing hole 241 and a bearing recess 242. The bearing hole 241 is a circular hole that penetrates the bearing 24 in a first direction. The end of the developing roller shaft 31 in the first direction is inserted into the bearing hole 241. This allows the developing roller 30 to be rotatably supported on the bearing 24 with respect to the developing axis L2. The end of the developing roller shaft 31 in the first direction is exposed to the outside through the bearing hole 241.

[0159] The bearing recess 242 is a circular recess formed on the surface of the bearing 24 facing the housing 10. The end of the supply roller shaft 42 in the first direction is inserted into the bearing recess 242. This allows the supply roller 40 to be rotatably supported on the supply shaft L3 relative to the bearing 24. The bearing recess 242 does not penetrate the bearing 24. Therefore, the end of the supply roller shaft 42 in the first direction is covered by the bearing 24.

[0160] The developing electrode 22, the supply electrode 23, and the bearing 24 are fixed to the second outer surface 12 of the housing 10 by a common screw 25 as shown in Figure 30. Specifically, the supply electrode 23, the bearing 24, and the developing electrode 22 are stacked in this order in the first direction, starting from the side closest to the housing 10, and the screw 25 passes through the developing electrode 22, the bearing 24, and the supply electrode 23. Then, by fastening the screw 25 to the housing 10, the developing electrode 22, the bearing 24, and the supply electrode 23 are fixed in place, sandwiched between the second outer surface 12 of the housing 10 and the head of the screw 25.

[0161] The bearing 24 is made of resin, which is an insulator. Therefore, by interposing the bearing 24 between the developing electrode 22 and the supply electrode 23, it is possible to prevent electrical conductivity between the developing electrode 22 and the supply electrode 23.

[0162] As shown in Figure 29, when viewing the developing cartridge 1 in the first direction from the second outer surface 12 side, at least a portion of the holder 92 is located outside the housing 10. That is, when viewing the developing cartridge 1 in the first direction from the second outer surface 12 side, at least a portion of the holder 92 protrudes outward beyond the outer shape of the housing 10. In this way, when viewing the developing cartridge 1 in the first direction from the second outer surface 12 side, the holder 92 and the multiple gears of the gear section 50 can be arranged over a wider area than if the entire holder 92 were placed inside the outer shape of the housing 10.

[0163] As shown in Figures 14 and 16, the drum cartridge 2 has a locking lever 66. The locking lever 66 is a lever that prevents the developing cartridge 1 from coming off the drum frame 60 when the developing cartridge 1 is mounted on the drum frame 60. The locking lever 66 is attached to the drum frame 60.

[0164] The lock lever 66 is rotatable relative to the drum frame 60 about a pivot axis L8 (see Figure 31) extending in a first direction. The lock lever 66 rotates between a locked position and a released position. The drum cartridge 2 also has a spring (not shown). The spring biases the lock lever 66 from the released position to the locked position. The spring may be, for example, a resin spring molded integrally with the lock lever 66, or it may be a separate component such as a coil spring or torsion spring.

[0165] As shown in Figure 29, the developing cartridge 1 has a first protrusion 26 and a second protrusion 27. The first protrusion 26 and the second protrusion 27 are located on the second outer surface 12 of the housing 10. The first protrusion 26 and the second protrusion 27 protrude in a first direction toward the outside of the housing 10 from the second outer surface 12. The first protrusion 26 and the second protrusion 27 are connected.

[0166] Figure 31 is a cross-sectional view of the developing cartridge 1 mounted on the drum cartridge 2. Figure 31 includes the lock lever 66 and shows a cross-section perpendicular to the first direction. As shown in Figure 31, the lock lever 66 has a first lever arm 661 and a second lever arm 662. The first lever arm 661 and the second lever arm 662 are located on opposite sides of each other with respect to the pivot axis L8 of the lock lever 66.

[0167] When the developing cartridge 1 is mounted on the drum cartridge 2, the lock lever 66 is positioned in the locked position (position shown in Figure 31) by the biasing force of the spring. At this time, the first lever arm 661 engages with the first projection 26. Specifically, the first projection 26 is positioned between the first lever arm 661 and the pivot shaft L8. This prevents the developing cartridge 1 from coming off the drum frame 60.

[0168] To remove the developing cartridge 1 from the drum cartridge 2, the user presses the first lever arm 661, thereby rotating the lock lever 66 from the locked position to the released position. This disengages the first lever arm 661 from the first projection 26. This allows the developing cartridge 1 to be removed from the drum frame 60.

[0169] Furthermore, when the lock lever 66 is rotated from the locked position to the released position, the second lever arm 662 comes into contact with the second projection 27. The second lever arm 662 then pushes the second projection 27 away from the drum frame 60. This allows the developing cartridge 1 to be lifted away from the drum frame 60. As a result, the developing cartridge 1 can be easily removed from the drum frame 60.

[0170] Furthermore, the developing cartridge 1 has a developing roller cover 28 and a holder cover 29. The developing roller cover 28 is a component for protecting the developing roller 30 when the developing cartridge 1 is transported. The holder cover 29 is a component for protecting the memory 90 and the holder 92 when the developing cartridge 1 is transported. Figure 32 is a perspective view of the developing cartridge 1, the developing roller cover 28, and the holder cover 29. Figure 33 is a perspective view of the developing roller cover 28. Figure 34 is a perspective view of the holder cover 29.

[0171] The developing roller cover 28 is cup-shaped and opens towards the developing roller 30. The developing roller cover 28 is detachable from the developing cartridge 1. When the developing roller cover 28 is attached to the developing cartridge 1, it covers the developing roller 30. The developing cartridge 1 is transported with the developing roller cover 28 attached. This protects the developing roller 30. When using the developing cartridge 1, the developing roller cover 28 is removed.

[0172] As shown in Figure 33, the developing roller cover 28 has four claws 281. Two of the four claws 281 are located at one end of the developing roller cover 28 in the first direction. The other two of the four claws 281 are located at the other end of the developing roller cover 28 in the first direction. Each claw 281 engages with a recess, hole, or step provided in the developing cartridge 1. This allows the developing roller cover 28 to be mounted on the developing cartridge 1.

[0173] The holder cover 29 is cup-shaped and opens towards the holder 92. The holder cover 29 is detachable from the developing cartridge 1. When the holder cover 29 is attached to the developing cartridge 1, it covers the holder 92. The developing cartridge 1 is transported with the holder cover 29 attached. This restricts the range of movement of the holder 92 relative to the housing 10. As a result, the memory 90 and the holder 92 are protected. When the developing cartridge 1 is in use, the holder cover 29 is removed.

[0174] As shown in Figure 34, the holder cover 29 has claws 291. The claws 291 are projections provided on the inner surface of the holder cover 29. The claws 291 engage with recesses, holes, or steps provided in the developing cartridge 1. This allows the holder cover 29 to be attached to the developing cartridge 1.

[0175] <3. Variant> Although one embodiment has been described above, this disclosure is not limited to the above embodiment.

[0176] In the first and second embodiments described above, the gear cover 51 was a single integrated part, but it is not limited to this. For example, the gear cover 51 may consist of two parts: a first cover that covers a plurality of gears, and a second cover that covers the second end 940 of the holder 92.

[0177] In the second embodiment described above, the holder 92 included a first holder 921, a second holder 922, and a spring 93, but is not limited to this. For example, the holder 92 does not have to have a spring 93.

[0178] Alternatively, the first end portion 930 that holds the electrical contact surface 91 and the second end portion 940 that aligns with the gear may be made up of a single integrated part.

[0179] Alternatively, the holder 92 may not have a second holder 922, and the spring 93 may be in direct contact with the projection 65.

[0180] Furthermore, in the second embodiment described above, the spring 93 was a coil spring, but it is not limited to this. For example, the spring 93 may be a leaf spring or the like.

[0181] Furthermore, in the second embodiment described above, the first holder 921 of the holder 92 had a hole 94, but it is not limited to this. For example, the second holder 922 may have a hole, and the holder 92 may be movable relative to the housing 10 with the first boss 160 of the housing inserted into the hole of the second holder 922.

[0182] Furthermore, in the second embodiment described above, the holder 92 had a hole 94 and the housing 10 had a first boss 160, but the invention is not limited to this. For example, the gear cover 51 may have a hole, and the holder 92 may have a boss into which the gear cover 51 is inserted.

[0183] Furthermore, in the second embodiment described above, the ribs constituting the hole 94 of the holder 92 were connected, but this is not limited to this. For example, a portion of the ribs constituting the hole 94 may be cut off, as long as it is within the range held by the first boss 160.

[0184] Furthermore, in the first and second embodiments described above, the surface of the protrusion 15 that contacts the pressing member 80 protruded in a direction away from the developing roller 30 in the second direction. However, the surface of the protrusion 15 that contacts the pressing member 80 does not necessarily have to protrude in a direction away from the developing roller 30 in the second direction. For example, the surface of the protrusion 15 that contacts the pressing member 80 may be a flat surface. Alternatively, the surface of the protrusion 15 that contacts the pressing member 80 may be recessed toward the developing roller 30 in the second direction.

[0185] The gear section 50 does not necessarily have to be configured as described in the first and second embodiments above. The number of gears included in the gear section 50, the position of the gears, the type of gears, the shape of the gears, etc., may be changed as appropriate without departing from the spirit of the present invention.

[0186] Furthermore, the elements that appear in the above embodiments and modifications may be combined as appropriate, or some elements may be omitted, to the extent that no contradictions arise. [Explanation of Symbols]

[0187] 1: Developing cartridge 2: Drum cartridge 10: Cabinet 11: 1st outer surface 12 :Second outer surface 15: Convex part 20: Agitator 21: Feather 30: Developing Roller 40: Supply roller 41: Sponge 50: Gear section 51: Gear cover 53: Coupling Gear 54: Developing roller gear 55: Supply Roller Gear 56: Idol Gear 57: Agitator Gear 58: Detection gear 60: Drum frame 65: Protrusion 70: Photoconductor Drum 80: Pressing member 90: Memory 91: Electrical contact surface 92: Holder 93: Spring 94: Hole 95: Second Boss 96: First guide surface 97: Second guide surface 921: First holder 922: Second holder 160: First Boss 511: Gear cover opening 930: First end 940: Second end

Claims

1. A housing for toner, The first outer surface and A second outer surface located away from the first outer surface in a first direction, A housing having, A developing roller that is rotatable with respect to the developing axis extending in the first direction, A rotatable agitator with respect to an agitator shaft extending in the first direction, The coupling gear located on the first outer surface, An idler gear located on the first outer surface and meshing with the coupling gear, An agitator gear located on the first outer surface and connected to the agitator, comprising an agitator gear that meshes with the idler gear, A detection gear located on the first outer surface and meshing with the idler gear, wherein the detection gear disengages from the idler gear when it rotates, A developing cartridge equipped with, A developing cartridge characterized in that, when the developing cartridge is viewed from the second outer surface side in the first direction, at least a portion of the detection gear is located outside the housing.

2. A housing for toner, The first outer surface and A second outer surface located away from the first outer surface in a first direction, A housing having, A developing roller that is rotatable with respect to the developing axis extending in the first direction, A memory having an electrical contact surface, A holder for holding the electrical contact surface, the holder being located on the first outer surface and movable relative to the housing, A developing cartridge equipped with, A developing cartridge characterized in that, when the developing cartridge is viewed from the second outer surface side in the first direction, at least a part of the holder is located outside the housing.

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