drum cartridge

Abstract

To provide a structure that allows the parts count of a drum cartridge to be reduced, without supplying a voltage to a spring for pressing a developing cartridge against a photoreceptor drum.SOLUTION: This drum cartridge includes a first pressure member 93 for pressing a mounted developing cartridge against a photoreceptor drum. The first pressure member 93 includes a first spring 95 and an electroconductive part 97. The electroconductive part 97 is electrically connected to a developing roller in a state that the developing cartridge is mounted on the drum cartridge. Therefore, a voltage can be supplied to the developing roller via the electroconductive part 97. It is thereby made possible to reduce the parts count of the drum cartridge compared with the case where an electroconductive component for supplying a voltage to the developing roller 40 is provided separately from the electroconductive part 97. Furthermore, the first pressure member 93 includes an insulating part 96 between the first spring 95 and the electroconductive part 97. Thus, it is possible to prevent a voltage from being supplied to the first spring 95.SELECTED DRAWING: Figure 11

Description

[Technical Field]

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

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

[0003] The developer cartridge in Patent Document 1 is attached to a drum cartridge. The drum cartridge has a photosensitive drum. When the developer cartridge is attached to the drum cartridge, the photosensitive drum and the developer roller come into contact with each other. Then, the drum cartridge with the attached developer cartridge is attached to an image forming apparatus.

[0004] The drum cartridge has a member for pressing the developer cartridge against the photosensitive drum. The drum cartridge also has a member for supplying a bias voltage to the developer electrode of the developer roller. However, if the member for pressing the developer cartridge against the photosensitive drum and the member for supplying a bias voltage to the developer electrode of the developer roller are provided separately, there is a problem in that the number of parts in the drum cartridge increases.

[0005] The member for pressing the developer cartridge toward the photosensitive drum has a metal spring. In order to reduce the number of parts in the drum cartridge, it is conceivable to supply a bias voltage to the developer electrode of the developer roller via a spring, as in Patent Document 2. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-054058 [Patent Document 2] Japanese Patent Publication No. 2020-160224 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when a bias voltage is supplied to the developing electrode of the developing roller via a spring as in Patent Document 2 in order to reduce the number of parts in the drum cartridge, the voltage is supplied to the spring, so the insulation distance for the spring must be taken into consideration, which makes it difficult to arrange other parts around the spring.

[0008] An object of the present disclosure is to provide a structure that can reduce the number of parts of a drum cartridge without supplying voltage to a spring that presses a developer cartridge toward a photosensitive drum. [Means for solving the problem]

[0009] The first disclosure of the present application provides a developing cartridge comprising: a drum frame into which a developing cartridge having a developing roller and a developing electrode electrically connected to the developing roller can be attached; a photosensitive drum; a first pressing member that presses the developing electrode toward the photosensitive drum when the developing cartridge is attached to the drum frame, the first pressing member having a conductive portion that is electrically connected to the developing electrode when the developing cartridge is attached to the drum frame and a first spring that presses the conductive portion toward the photosensitive drum; and an electrode terminal that is electrically connected to the conductive portion when the developing cartridge is attached to the drum frame, wherein the first pressing member further has an insulating portion located between the conductive portion and the first spring.

[0010] A second disclosure of the present application is the drum cartridge of the first disclosure, characterized in that the conductive portion is made of conductive resin.

[0011] The third disclosure of the present application is a drum cartridge according to the first or second disclosure, characterized in that the drum cartridge is mountable in an image forming device having a main body electrode, and the electrode terminal contacts the main body electrode when the drum cartridge is mounted in the image forming device.

[0012] A fourth disclosure of the present application is a drum cartridge according to any one of the first to third disclosures, characterized in that the photosensitive drum is rotatable about a drum axis extending in a first direction, and the first spring presses the conductive portion toward the photosensitive drum in a second direction different from the first direction.

[0013] The fifth disclosure of the present application is a drum cartridge of the fourth disclosure, characterized in that one end of the first spring in the second direction is fixed to the drum frame, and the insulating part is fixed to the other end of the first spring in the second direction.

[0014] The sixth disclosure of the present application is the drum cartridge of the fifth disclosure, characterized in that the first spring is a coil spring that is expandable and contractible in the second direction, and the insulating portion has a first protrusion that is inserted into the other end of the first spring.

[0015] The seventh disclosure of the present application is the drum cartridge of the sixth disclosure, characterized in that the first protrusion is cylindrical, and the conductive portion has a second protrusion inserted inside the first protrusion, and a claw portion located on the outer surface of the second protrusion, which claw portion faces the first protrusion in the second direction.

[0016] The eighth disclosure of the present application is a drum cartridge according to any one of the fourth to seventh disclosures, characterized in that the electrode terminal is located on the drum frame, and when the developing cartridge is attached to the drum frame, the electrode terminal comes into contact with the conductive portion.

[0017] The ninth disclosure of the present application is the drum cartridge of the eighth disclosure, characterized in that the electrode terminal has an exposed portion located on the outer surface of the drum frame and a plate portion located on the inner surface of the drum frame, which plate portion contacts the conductive portion.

[0018] A tenth disclosure of the present application is the drum cartridge of the ninth disclosure, wherein the plate portion is elastically deformable.

[0019] An eleventh disclosure of the present application is the drum cartridge of the tenth disclosure, characterized in that the electrode terminal is a leaf spring.

[0020] The 12th disclosure of the present application is a drum cartridge according to the 10th or 11th disclosure, characterized in that the electrode terminal further has a fulcrum portion fixed to the drum frame, and the plate portion bends in the first direction around the fulcrum portion upon contact with the conductive portion.

[0021] A thirteenth disclosure of the present application is the drum cartridge of the twelfth disclosure, characterized in that the fulcrum portion is located at the end of the plate portion closest to the photosensitive drum in the second direction.

[0022] The 14th disclosure of the present application is the drum cartridge of the 13th disclosure, characterized in that when the developing cartridge is not attached to the drum frame, the position at which the conductive portion contacts the plate portion is a first contact position, and when the developing cartridge is attached to the drum frame and the developing roller is in contact with the photosensitive drum, the position at which the conductive portion contacts the plate portion is a second contact position that is farther from the fulcrum portion than the first contact position.

[0023] The 15th disclosure of the present application is a drum cartridge according to the 14th disclosure, characterized in that when the developing cartridge is attached to the drum frame, a separation operation can be performed by an external driving force to separate the developing roller from the photosensitive drum, and when the separation operation is performed, the position at which the conductive portion contacts the plate portion is a third contact position that is farther from the fulcrum portion than the second contact position.

[0024] The 16th disclosure of the present application is the drum cartridge of the 15th disclosure, characterized in that the conductive portion has a third protrusion that protrudes toward the electrode terminal and contacts the plate portion.

[0025] The 17th disclosure of the present application is a drum cartridge according to the 15th or 16th disclosure, characterized in that the plate portion has a curved portion located at the end farthest from the photosensitive drum of both end portions of the plate portion in the second direction, the curved portion curving in a direction intersecting the second direction, and when the separation operation is performed, the conductive portion contacts the curved portion.

[0026] An 18th disclosure of the present application is a drum cartridge according to any one of the 5th to 17th disclosures, characterized in that the first pressing member is located at one end of the drum frame in the first direction, and the drum cartridge further includes a second pressing member located at the other end of the drum frame in the first direction, which presses the developing cartridge toward the photosensitive drum when the developing cartridge is attached to the drum frame.

[0027] The 19th disclosure of the present application is the drum cartridge of the 18th disclosure, wherein the second pressing member has a contact portion that contacts the developing cartridge when the developing cartridge is attached to the drum frame, and a second spring that presses the contact portion toward the photosensitive drum, and the force with which the first spring presses the conductive portion in the second direction is greater than the force with which the second spring presses the contact portion in the second direction.

[0028] The 20th disclosure of the present application is a drum cartridge according to the 19th disclosure, characterized in that one end of the first spring in the second direction is fixed to the drum frame, one end of the second spring in the second direction is fixed to the drum frame, and one end of the first spring in the second direction is located closer to the photosensitive drum in the second direction than one end of the second spring in the second direction. [Effects of the Invention]

[0029] According to the first to twentieth disclosures of the present application, voltage can be supplied to the developing roller via the conductive portion of the drum cartridge. This allows the number of parts in the drum cartridge to be reduced compared to when a conductive part for supplying voltage to the developing roller is provided separately from the conductive portion. Furthermore, an insulating portion is provided between the conductive portion and the first spring. This prevents voltage from being supplied to the first spring.

[0030] Furthermore, according to the eighth disclosure of the present application, a voltage can be supplied from the electrode terminal of the drum cartridge to the developing roller via the conductive portion.

[0031] Furthermore, according to the ninth disclosure of the present application, the electrodes of the image forming device located outside the drum frame can be brought into contact with the exposed portions of the electrode terminals.

[0032] Furthermore, according to the tenth disclosure of the present application, the elastic force of the plate portion can stabilize the contact state of the electrode terminal with the conductive portion.

[0033] Furthermore, according to the seventeenth disclosure of the present application, during the separation operation, a force that assists the separation can be applied from the plate portion to the conductive portion.

[0034] According to the 19th disclosure of the present application, the resistance of the electrode terminal can be compensated for by making the pressing force of the first spring greater than the pressing force of the second spring, thereby evenly pressing both ends of the developer cartridge in the first direction toward the photosensitive drum. [Brief explanation of the drawings]

[0035] [Figure 1] FIG. 2 is a perspective view of a developing cartridge and a drum cartridge. [Figure 2] FIG. [Figure 3] FIG. 2 is a cross-sectional view of the developing cartridge. [Figure 4] FIG. 2 is a view of the developing cartridge as seen from the first outer surface side. [Figure 5] FIG. 2 is an exploded perspective view of the vicinity of a first outer surface of the developing cartridge. [Figure 6] FIG. 2 is a perspective view of the drum cartridge. [Figure 7] FIG. 2 is a view of the drum cartridge as seen from the first end side. [Figure 8] FIG. 2 is a cross-sectional view of the drum cartridge in the vicinity of a first pressing member. [Figure 9] 3A and 3B are cross-sectional views of the drum cartridge in the vicinity of both end portions in the first direction, with the developing cartridge attached thereto. [Figure 10] FIG. 2 is a view showing the state in which the developing cartridge is attached to the drum cartridge, viewed in a first direction. [Figure 11] 10 is a cross-sectional view of the vicinity of a first pressing member in a state in which the developing cartridge is attached to the drum cartridge. FIG. [Figure 12] 10 is a view of the developing cartridge and the photosensitive drum when a separating operation is performed, viewed in a first direction. FIG. [Figure 13] 10 is a cross-sectional view of the vicinity of a first pressing member in a state where a separating operation has been performed. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0036] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0037] In the following description, the direction in which the photosensitive drum extends is referred to as the "first direction." Furthermore, when the developer cartridge is attached to the drum cartridge, the direction in which the developing roller and the photosensitive drum are aligned is referred to as the "second direction." The first direction and the second direction intersect (preferably perpendicular to) each other.

[0038] <1. Overview of developing cartridges and drum cartridges> 1 is a perspective view of a developer cartridge 1 and a drum cartridge 2. The developer cartridge 1 and the 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.

[0039] The developer cartridge 1 can be attached to a drum cartridge 2. Furthermore, the drum cartridge 2 with the developer cartridge 1 attached can be attached to an image forming device. For example, four drum cartridges 2 with developer cartridges 1 attached can be attached to an image forming device. The four developer cartridges 1 contain developers of different colors (for example, cyan, magenta, yellow, and black). The developer is, for example, toner. The image forming device forms an image on the surface of printing paper using the developer supplied from the developer cartridge 1. However, the image forming device may be attached with one to three, or five or more drum cartridges 2 with developer cartridges 1 attached.

[0040] <2. About the developing cartridge> Fig. 2 is a perspective view of the developer cartridge 1. Fig. 3 is a cross-sectional view of the developer cartridge 1 cut along a plane perpendicular to the first direction. Fig. 4 is a view of the developer cartridge 1 as seen from the side of a first outer surface 11, which will be described later. As shown in Figs. 2 to 4, the developer cartridge 1 includes a casing 10, an agitator 20, a developer electrode 30, a developer roller 40, a supply roller 50, a gear portion 60, a first lever 70, and a lever holder 80.

[0041] The casing 10 is a housing capable of containing a developer. The casing 10 extends in a first direction. The casing 10 has a first outer surface 11 and a second outer surface 12. The first outer surface 11 is located at one end of the casing 10 in the first direction. The second outer surface 12 is located at the other end of the casing 10 in the first direction. The first outer surface 11 and the second outer surface 12 are spaced apart from each other in the first direction.

[0042] The casing 10 has a storage chamber 13. The developer is stored in the storage chamber 13. The casing 10 also has an opening 14. The opening 14 is located at one end of the casing 10 in the second direction. The external space of the casing 10 and the storage chamber 13 communicate with each other via the opening 14. The casing 10 may also have a handle located at the other end of the casing 10 in the second direction.

[0043] The agitator 20 has an agitator shaft 21 and blades 22. The agitator shaft 21 extends along the first direction. The blades 22 extend from the agitator shaft 21 toward the inner surface of the casing 10. That is, the blades 22 extend radially outward from the agitator shaft 21. A portion of the agitator shaft 21 and the blades 22 are located within the storage chamber 13 of the casing 10. The agitator gear of the gear unit 60 is fixed to one end of the agitator shaft 21 in the first direction. When the agitator gear rotates, the agitator shaft 21 and the blades 22 rotate about the agitator axis extending in the first direction. The rotation of the blades 22 agitates the developer in the storage chamber 13.

[0044] The developing electrode 30 is located on the first outer surface 11 of the casing 10. The developing electrode 30 has a plate shape. The developing electrode 30 extends along the first outer surface 11. The developing electrode 30 is fixed to the first outer surface 11. The developing electrode 30 is conductive. The developing electrode 30 is made of a material such as a metal or a conductive resin.

[0045] The development electrode 30 has a first bearing 31, a second bearing 32, a pressure-receiving surface 33, a boss 34 (not shown in FIG. 4), and an electrode protrusion 35. The first bearing 31 is a hole that penetrates in the first direction. The second bearing 32 is a hole that penetrates in the first direction. However, the first bearing 31 and the second bearing 32 may also be recesses that are recessed in the first direction. The pressure-receiving surface 33, the boss 34, and the electrode protrusion 35 will be described later.

[0046] The developing roller 40 is a roller that can rotate about a development axis that extends in the first direction. The developing roller 40 is located in the opening 14 of the casing 10.

[0047] The developing roller 40 has a developing roller main body 41 and a developing roller shaft 42. The developing roller main body 41 is a cylindrical part that extends in a first direction. The developing roller main body 41 is made of, for example, elastic rubber. The developing roller shaft 42 is a columnar part that extends in the first direction. The developing roller shaft 42 penetrates the developing roller main body 41 in the first direction. The developing roller main body 41 is fixed to the developing roller shaft 42. The developing roller shaft 42 is conductive. The developing roller shaft 42 is made of a metal or a conductive resin.

[0048] One end of the developing roller shaft 42 in the first direction is supported by the developing electrode 30. Specifically, one end of the developing roller shaft 42 in the first direction is inserted into the first bearing 31 of the developing electrode 30. Also, one end of the developing roller shaft 42 in the first direction contacts the developing electrode 30. Therefore, the developing roller shaft 42 is electrically connected to the developing electrode 30.

[0049] When the drum cartridge 2 with the developer cartridge 1 attached thereto is installed in an image forming apparatus, the image forming apparatus supplies a bias voltage to the developer roller shaft 42 via an electrode terminal 94, a conductive portion 97, and the developer electrode 30 (described later). Then, the developer is carried on the outer peripheral surface of the developer roller main body 41 due to the electrostatic force between the developer roller shaft 42 and the developer.

[0050] The developing roller gear of the gear portion 60 is fixed to the other end of the developing roller shaft 42 in the first direction. Therefore, when the developing roller gear rotates, the developing roller shaft 42 rotates about the development axis. Then, the developing roller main body 41 rotates about the development axis together with the developing roller shaft 42.

[0051] The developing roller shaft 42 does not have to penetrate the developing roller main body 41 in the first direction. For example, the developing roller shaft 42 may extend in the first direction from both ends of the developing roller main body 41 in the first direction.

[0052] The supply roller 50 is a roller that can rotate about a supply roller axis that extends in the first direction. The supply roller 50 is located between the agitator 20 and the developing roller 40 in the second direction.

[0053] The supply roller 50 has a supply roller main body 51 and a supply roller shaft 52. The supply roller main body 51 is a cylindrical part that extends in a first direction. The supply roller main body 51 is made of, for example, elastic rubber. The supply roller shaft 52 is a columnar part that extends in the first direction. The supply roller shaft 52 penetrates the supply roller main body 51 in the first direction. The supply roller main body 51 is fixed to the supply roller shaft 52. The supply roller shaft 52 is conductive. The supply roller shaft 52 is made of a metal or a conductive resin.

[0054] One end of the supply roller shaft 52 in the first direction is supported by the development electrode 30. Specifically, one end of the supply roller shaft 52 in the first direction is inserted into the second bearing 32 of the development electrode 30. Also, one end of the supply roller shaft 52 in the first direction contacts the development electrode 30. Therefore, the supply roller shaft 52 is electrically connected to the development electrode 30.

[0055] The supply roller gear of the gear unit 60 is fixed to the other end of the supply roller shaft 52 in the first direction. Therefore, when the supply roller gear rotates, the supply roller shaft 52 rotates about the supply roller axis. Then, the supply roller body 51 rotates about the supply roller axis together with the supply roller shaft 52.

[0056] The supply roller shaft 52 does not have to penetrate the supply roller main body 51 in the first direction. For example, the supply roller shaft 52 may extend in the first direction from both ends of the supply roller main body 51 in the first direction.

[0057] The outer peripheral surface of the developing roller main body 41 and the outer peripheral surface of the supply roller main body 51 come into contact with each other. The developer in the casing 10 is supplied to the developing roller 40 via the supply roller 50. The developing cartridge 1 also has a layer thickness regulating blade 45. The layer thickness regulating blade 45 shapes the developer carried on the outer peripheral surface of the developing roller main body 41 to a uniform thickness. The developer on the outer peripheral surface of the developing roller main body 41 is then supplied to a photosensitive drum 92 (described later) of the drum cartridge 2. At this time, the developer moves from the developing roller main body 41 to the photosensitive drum 92 in accordance with the electrostatic latent image formed on the outer peripheral surface of the photosensitive drum 92. As a result, the electrostatic latent image is visualized on the outer peripheral surface of the photosensitive drum 92.

[0058] The gear unit 60 is located on the second outer surface 12 of the casing 10. The gear unit 60 has a gear cover 61, a coupling, and multiple gears. The gear cover 61 is fixed to the second outer surface 12 of the casing 10. The multiple gears include the agitator gear, developing roller gear, and supply roller gear described above. At least some of the multiple gears are located between the second outer surface 12 and the gear cover 61.

[0059] The coupling is exposed from the gear cover 61. When the drum cartridge 2 with the developer cartridge 1 installed is installed in the image forming apparatus, the drive shaft of the image forming apparatus is connected to the coupling. Then, the rotation of the drive shaft is transmitted to the agitator gear, the developing roller gear, and the supply roller gear via the coupling.

[0060] The gears included in the gear unit 60 may transmit a rotational force by meshing of teeth, or may transmit a rotational force by friction.

[0061] The first lever 70 is located on the first outer surface 11 of the casing 10. The first lever 70 is movable relative to the casing 10.

[0062] Figure 5 is an exploded perspective view of the vicinity of the first outer surface of the developer cartridge 1. As shown in Figures 4 and 5, the first lever 70 has one end 71, the other end 72, a shaft 73, and a first hole 74. The one end 71 is located at one end of the first lever 70 in a third direction that intersects the first direction and the second direction. The other end 72 is located at the other end of the first lever 70 in the third direction. The one end 71 and the other end 72 are spaced apart in the third direction.

[0063] One end 71 of the first lever 70 has a first protrusion 75. The first protrusion 75 protrudes in a first direction. More specifically, the first protrusion 75 protrudes in the first direction, away from the first outer surface 11 of the casing 10. The first protrusion 75 has a concave surface 76. When the developer cartridge 1 is attached to the drum cartridge 2, the concave surface 76 is recessed toward a photosensitive drum 92 (described later) of the drum cartridge 2.

[0064] The other end 72 of the first lever 70 has a second protrusion 77. The second protrusion 77 protrudes in a first direction. More specifically, the second protrusion 77 protrudes in the first direction toward the first outer surface 11 of the casing 10.

[0065] The shaft 73 is located between the one end 71 and the other end 72 in the third direction. The shaft 73 protrudes from the first lever 70 in the first direction. More specifically, the shaft 73 protrudes in the first direction away from the first outer surface 11 of the casing 10. When the developer cartridge 1 is attached to the drum cartridge 2, the shaft 73 can come into contact with a drum frame 91 (described later) of the drum cartridge 2. The first lever 70 can rotate about the shaft 73 between a first position and a second position.

[0066] 4 and 5, the developing electrode 30 has a pressure receiving surface 33. The pressure receiving surface 33 is located farther from the developing roller 40 in the second direction than the other end 72 of the first lever 70. The pressure receiving surface 33 also faces the other end 72 of the first lever 70 in the second direction. Specifically, the pressure receiving surface 33 faces the second protrusion 77 of the first lever 70 in the second direction.

[0067] When one end 71 of the first lever 70 receives a driving force from the image forming apparatus while the developer cartridge 1 is attached to the drum cartridge 2, the first lever 70 rotates about the shaft 73. As a result, the other end 72 of the first lever 70 comes into contact with the pressure receiving surface 33. At this time, the shaft 73 of the first lever 70 functions as a fulcrum. The one end 71 of the first lever 70 functions as a point of force application. The other end 72 of the first lever 70 functions as a point of action.

[0068] The first hole 74 is located between the one end 71 and the other end 72 in the third direction. The first hole 74 overlaps with the shaft 73 in the first direction. The first hole 74 is recessed in the first direction from the surface of the first lever 70 facing the casing 10 toward the shaft 73. In this embodiment, the shape of the first hole 74 is a circle centered on an axis extending in the first direction. However, the first hole 74 may have a shape other than a circle, such as an ellipse or a polygon.

[0069] 5, the developing electrode 30 has a boss 34. The boss 34 extends in a first direction from a surface of the developing electrode 30 facing the first lever 70 toward the first lever 70. The developing electrode 30 is fixed to the casing 10. Therefore, the boss 34 is movable together with the casing 10.

[0070] The boss 34 fits into the first hole 74 of the first lever 70. The inner diameter of the first hole 74 is larger than the outer diameter of the boss 34. That is, the dimension of the first hole 74 in the second direction is larger than the dimension of the boss 34 in the second direction. Furthermore, the dimension of the first hole 74 in the third direction is larger than the dimension of the boss 34 in the third direction. Therefore, the first hole 74 is movable in the second and third directions relative to the boss 34. Furthermore, the first lever 70 is movable in the second and third directions relative to the developing electrode 30 and the casing 10 within the range of the dimensional difference between the boss 34 and the first hole 74.

[0071] The lever holder 80 is located on the first outer surface 11 of the casing 10. More specifically, the lever holder 80 is fixed to the first outer surface 11 of the casing 10. The lever holder 80 covers a portion of the first lever 70. That is, the portion of the first lever 70 is located between the first outer surface 11 of the casing 10 and the lever holder 80.

[0072] Furthermore, the lever holder 80 is located between the first protrusion 75 and the second protrusion 77 of the first lever 70 in the third direction. The first protrusion 75 and the lever holder 80 face each other in the third direction and can come into contact with each other. This prevents the first lever 70 from slipping out of the lever holder 80 in the third direction. In other words, the lever holder 80 holds the first lever 70 movably relative to the casing 10.

[0073] <3. About the drum cartridge> Next, a description will be given of the drum cartridge 2. Fig. 6 is a perspective view of the drum cartridge 2. Fig. 7 is a view of the drum cartridge 2 as seen from the first end 911 side, which will be described later.

[0074] As shown in FIGS. 6 and 7, the drum cartridge 2 includes a drum frame 91, a photosensitive drum 92, a first pressing member 93, an electrode terminal 94, and a second pressing member 98.

[0075] The drum frame 91 is a frame onto which the developing cartridge 1 can be attached. The drum frame 91 has a first end 911 and a second end 912. The first end 911 is located at one end of the drum frame 91 in the first direction. The second end 912 is located at the other end of the drum frame 91 in the first direction. The first end 911 and the second end 912 are spaced apart from each other in the first direction. The drum frame 91 extends in the first direction between the first end 911 and the second end 912.

[0076] When the developer cartridge 1 is attached to the drum frame 91, the first outer surface 11 of the developer cartridge 1 is located at a first end 911 of the drum frame 91. When the developer cartridge 1 is attached to the drum frame 91, the second outer surface 12 of the developer cartridge 1 is located at a second end 912 of the drum frame 91.

[0077] As shown in FIG. 7 , the drum frame 91 has a recess 913. The recess 913 is located at a first end 911 of the drum frame 91. The recess 913 recesses in a second direction toward the photosensitive drum 92. When the developer cartridge 1 is attached to the drum cartridge 2, the shaft 73 of the first lever 70 fits into the recess 913. The shaft 73 then comes into contact with the recess 913 in the direction toward the photosensitive drum 92.

[0078] The photosensitive drum 92 is a drum that can rotate about a drum axis that extends in the first direction. The photosensitive drum 92 is located at an end of the drum frame 91 in the second direction. One end of the photosensitive drum 92 in the first direction is rotatably supported by a first end 911 of the drum frame 91. The other end of the photosensitive drum 92 in the first direction is rotatably supported by a second end 912 of the drum frame 91. The photosensitive drum 92 has a cylindrical outer peripheral surface centered on the drum axis. The outer peripheral surface of the photosensitive drum 92 is covered with a photosensitive material. When the developer cartridge 1 is attached to the drum frame 91, the outer peripheral surface of the developing roller 40 comes into contact with the outer peripheral surface of the photosensitive drum 92.

[0079] The first pressing member 93 is a unit that presses the developer cartridge 1 toward the photosensitive drum 92 when the developer cartridge 1 is attached to the drum frame 91. The first pressing member 93 is located at a first end 911 of the drum frame 91.

[0080] 8 is a cross-sectional view of the drum cartridge 2 in the vicinity of the first pressing member 93. Fig. 8 shows cross sections along the first and second directions. As shown in Fig. 8, the first pressing member 93 has a first spring 95, an insulating portion 96, and a conductive portion 97.

[0081] The first spring 95 is an elastic member that can expand and contract in the second direction. The material of the first spring 95 is a metal that is a conductor. The first spring 95 in this embodiment is a coil spring. However, the first spring 95 may be another type of spring, such as a torsion spring or a leaf spring. One end of the first spring 95 in the second direction is fixed to the drum frame 91.

[0082] The insulating portion 96 is an insulating part. The insulating portion 96 is fixed to the other end of the first spring 95 in the second direction. Therefore, as the first spring 95 expands and contracts, the insulating portion 96 moves in the second direction relative to the drum frame 91. The insulating portion 96 is located between the first spring 95 and the conductive portion 97. The insulating portion 96 is made of a resin, which is an insulator. For example, the insulating portion 96 is made of polyacetal, which is lightweight and has excellent abrasion resistance.

[0083] The insulating portion 96 has an insulating end portion 961, an insulating wall portion 962, and a first protrusion 963. The insulating end portion 961 is a portion that extends in a direction intersecting the second direction. The insulating end portion 961 is plate-shaped. The insulating end portion 961 is located between the other end of the first spring 95 and a conductive end portion 971 (described later) of the conductive portion 97. The insulating wall portion 962 extends in the second direction from the outer periphery of the insulating end portion 961 toward one end of the first spring 95. The insulating end portion 961 and the insulating wall portion 962 cover the other end of the first spring 95.

[0084] The first protrusion 963 protrudes from the insulating end portion 961 toward the inside of the first spring 95. The first protrusion 963 extends in the second direction. The first protrusion 963 is cylindrical. The first protrusion 963 is inserted into the other end of the first spring 95. More specifically, the first protrusion 963 is press-fitted into the other end of the first spring 95. This fixes the insulating portion 96 to the other end of the first spring 95.

[0085] The conductive portion 97 is a component having electrical conductivity. The conductive portion 97 is fixed to the insulating portion 96. Therefore, the conductive portion 97 moves in the second direction together with the insulating portion 96 relative to the drum frame 91. A conductive resin is used as the material for the conductive portion 97. Using a conductive resin makes it possible to reduce the weight of the conductive portion 97 compared to when a metal is used. Furthermore, using a conductive resin makes it easier to manufacture a conductive portion 97 with a complex shape compared to when a metal is used. However, the conductive portion 97 may also be made of metal.

[0086] The conductive portion 97 has a conductive end portion 971, a conductive wall portion 972, a second protrusion 973, and a third protrusion 974. The conductive end portion 971 is a portion that extends in a direction intersecting the second direction. The conductive end portion 971 is plate-shaped. The conductive end portion 971 contacts the insulating end portion 961. The conductive wall portion 972 extends in the second direction from the outer periphery of the conductive end portion 971 toward one end of the first spring 95. The conductive end portion 971 and the conductive wall portion 972 cover a portion of the outer surface of the insulating portion 96.

[0087] The second protrusion 973 protrudes from the conductive end 971 toward the inside of the first protrusion 963. The second protrusion 973 extends in the second direction. The second protrusion 973 is cylindrical. The second protrusion 973 is inserted into the inside of the first protrusion 963. The conductive portion 97 also has a claw portion 975. The claw portion 975 is located on the outer circumferential surface of the second protrusion 973. More specifically, the claw portion 975 protrudes from the tip of the second protrusion 973 in a direction intersecting the second direction. On the other hand, the insulating portion 96 has a claw receiving portion 964. The claw receiving portion 964 is located on the inner circumferential surface of the first protrusion 963. More specifically, the claw receiving portion 964 extends from the tip of the first protrusion 963 toward the second protrusion 973. In the second direction, the claw receiving portion 964 is located closer to the conductive end 971 than the claw portion 975. The claw portion 975 and the claw receiving portion 964 face each other in the second direction.

[0088] The third protrusion 974 protrudes in the first direction from the outer surface of the conductive wall portion 972 toward the electrode terminal 94, which will be described later. The third protrusion 974 has an apex 976 and a tapered surface 977. The apex 976 is the portion of the third protrusion 974 that is farthest from the conductive wall portion 972 in the first direction. The tapered surface 977 is a surface that connects the conductive wall portion 972 and the apex 976. The tapered surface 977 extends obliquely with respect to the second direction. More specifically, the tapered surface 977 extends so as to approach the electrode terminal 94 in the first direction as it moves away from the photosensitive drum 92 in the second direction.

[0089] As shown in FIG. 5, the developing electrode 30 has an electrode protrusion 35. The electrode protrusion 35 protrudes in a first direction from the developing electrode 30. When the developing cartridge 1 is attached to the drum cartridge 2, the conductive end 971 of the conductive portion 97 comes into contact with the electrode protrusion 35 (see FIGS. 11 and 13). This electrically connects the conductive portion 97 and the developing electrode 30. That is, the conductive portion 97 is electrically connected to the developing roller shaft 42 via the developing electrode 30.

[0090] Furthermore, when the developer cartridge 1 is attached to the drum cartridge 2, the first spring 95 contracts in the second direction from its natural length. Therefore, the first spring 95 presses the conductive portion 97 in the second direction toward the photosensitive drum 92 due to its elastic repulsive force. As a result, the conductive portion 97 presses the developer electrode 30 in the second direction toward the photosensitive drum 92. This presses the casing 10 and the developer roller 40 of the developer cartridge 1 in the second direction toward the photosensitive drum 92. As a result, the outer circumferential surface of the developer roller 40 comes into contact with the outer circumferential surface of the photosensitive drum 92.

[0091] The electrode terminal 94 is a terminal that relays a voltage supplied from the image forming apparatus to the conductive portion 97. The electrode terminal 94 is located at a first end 911 of the drum frame 91. More specifically, the electrode terminal 94 is fixed to the first end 911 of the drum frame 91. The electrode terminal 94 is conductive. Specifically, the material of the electrode terminal 94 is a metal that is a conductor. The electrode terminal 94 in this embodiment is a leaf spring.

[0092] The electrode terminal 94 has an exposed portion 941 and a plate portion 942. The exposed portion 941 is located on the outer surface of the drum frame 91. More specifically, the exposed portion 941 is exposed on the outer surface of the first end portion 911. The image forming apparatus includes a main body electrode (not shown) for supplying a bias voltage. When the drum cartridge 2 is installed in the image forming apparatus, the exposed portion 941 comes into contact with the main body electrode of the image forming apparatus. This electrically connects the main body electrode of the image forming apparatus and the electrode terminal 94.

[0093] The plate portion 942 is located on the inner surface of the drum frame 91. The third protrusion 974 of the conductive portion 97 described above comes into contact with the plate portion 942. This electrically connects the electrode terminal 94 and the conductive portion 97. That is, the electrode terminal 94 is electrically connected to the developing roller shaft 42 via the conductive portion 97 and the developing electrode 30. The image forming apparatus supplies a bias voltage from the main body electrode to the developing roller shaft 42 via the electrode terminal 94, the conductive portion 97, and the developing electrode 30.

[0094] The electrode terminal 94 has a fulcrum portion 943 between the exposed portion 941 and the plate portion 942. The fulcrum portion 943 is fixed to the drum frame 91. Therefore, the fulcrum portion 943 is hardly displaced relative to the drum frame 91. The plate portion 942 extends from the fulcrum portion 943 in the second direction and in a direction away from the photosensitive drum 92. In other words, the fulcrum portion 943 is located at one of both ends of the plate portion 942 in the second direction that is closer to the photosensitive drum 92.

[0095] The plate portion 942 bends in the first direction around the fulcrum portion 943 due to contact with the conductive portion 97. In this manner, the plate portion 942 elastically deforms, and a pressing force acts between the electrode terminal 94 and the conductive portion 97. This makes it possible to stabilize the contact state of the electrode terminal 94 with the conductive portion 97.

[0096] As described above, the drum cartridge 2 of this embodiment supplies the bias voltage supplied to the electrode terminal 94 from the main body electrode of the image forming apparatus to the developer electrode 30 of the developer cartridge 1 via the conductive portion 97 of the first pressing member 93. In this way, there is no need to provide a conductive part for relaying the voltage between the electrode terminal 94 and the developer electrode 30, separate from the first pressing member 93. This makes it possible to reduce the number of parts in the drum cartridge 2. As a result, the drum cartridge 2 can be made more compact.

[0097] Furthermore, the first pressing member 93 has an insulating portion 96 between the conductive portion 97 and the first spring 95. This prevents voltage from being supplied to the first spring 95. Therefore, there is no need to consider the insulation distance for the first spring 95, making it easier to arrange other components around the first spring 95. This makes it easier to make the drum cartridge 2 more compact.

[0098] The second pressing member 98 is a unit that, together with the first pressing member 93, presses the developer cartridge 1 toward the photosensitive drum 92 when the developer cartridge 1 is attached to the drum frame 91. The second pressing member 98 is located at a second end 912 of the drum frame 91.

[0099] 9 is a cross-sectional view of the drum cartridge 2 in the vicinity of both ends in the first direction, with the developer cartridge 1 attached. Fig. 9 shows cross sections along the first and second directions. As shown in Fig. 9, the second pressing member 98 has a second spring 99 and a contact portion 100.

[0100] The second spring 99 is an elastic member that can expand and contract in the second direction. In this embodiment, the second spring 99 is a coil spring. However, the second spring 99 may be another type of spring, such as a torsion spring or a leaf spring. One end of the second spring 99 in the second direction is fixed to the drum frame 91.

[0101] The contact portion 100 is an insulating component. The contact portion 100 is fixed to the other end of the second spring 99 in the second direction. Therefore, as the second spring 99 expands and contracts, the contact portion 100 moves in the second direction relative to the drum frame 91.

[0102] When the developer cartridge 1 is attached to the drum cartridge 2, the contact portion 100 comes into contact with a portion of the casing 10 of the developer cartridge 1. Furthermore, when the developer cartridge 1 is attached to the drum cartridge 2, the second spring 99 contracts in the second direction from its natural length. Therefore, the second spring 99 presses the contact portion 100 in the second direction toward the photosensitive drum 92 due to its elastic repulsive force. As a result, the contact portion 100 presses the casing 10 in the second direction toward the photosensitive drum 92. This presses the casing 10 and the developing roller 40 of the developer cartridge 1 in the second direction toward the photosensitive drum 92. As a result, the outer peripheral surface of the developing roller 40 comes into contact with the outer peripheral surface of the photosensitive drum 92.

[0103] As described above, one end of the first spring 95 in the second direction and one end of the second spring 99 in the second direction are both fixed to the drum frame 91. However, one end of the first spring 95 in the second direction is located closer to the photosensitive drum 92 in the second direction than one end of the second spring 99 in the second direction. Then, when the developer cartridge 1 is attached to the drum cartridge 2, the length of the first spring 95 in the second direction is shorter than the length of the second spring 99 in the second direction. Therefore, the force with which the first spring 95 presses the conductive portion 97 in the second direction is greater than the force with which the second spring 99 presses the contact portion 100 in the second direction.

[0104] The conductive portion 97 receives an elastic force from the plate portion 942 of the electrode terminal 94. This elastic force includes a component in a direction away from the photosensitive drum 92 in the second direction. Frictional force also occurs between the conductive portion 97 and the electrode terminal 94. These elastic and frictional forces act as resistance when the first spring 95 presses the conductive portion 97. However, as described above, if the force with which the first spring 95 presses the conductive portion 97 in the second direction is greater than the force with which the second spring 99 presses the contact portion 100 in the second direction, the difference in force can offset the resistance. Therefore, the first spring 95 and the second spring 99 can evenly press both ends of the developer cartridge 1 in the first direction toward the photosensitive drum 92.

[0105] Note that one end of the first spring 95 in the second direction may be located at the same position in the second direction as one end of the second spring 99 in the second direction. The other end of the first spring 95 in the second direction may be located farther from the photosensitive drum 92 in the second direction than the other end of the second spring 99 in the second direction. Even in this case, when the developer cartridge 1 is attached to the drum cartridge 2, the length of the first spring 95 in the second direction can be made shorter than the length of the second spring 99 in the second direction. Therefore, the force with which the first spring 95 presses the conductive portion 97 in the second direction can be made greater than the force with which the second spring 99 presses the contact portion 100 in the second direction.

[0106] <4. Installing the developing cartridge> Fig. 10 is a view showing the developer cartridge 1 attached to the drum cartridge 2 as viewed in the first direction. Fig. 11 is a cross-sectional view of the vicinity of the first pressing member 93 when the developer cartridge 1 is attached to the drum cartridge 2. Fig. 11 shows cross sections along the first and second directions.

[0107] When the developer cartridge 1 is attached to the drum cartridge 2, the casing 10 of the developer cartridge 1 is inserted between the first end 911 and the second end 912 of the drum frame 91. Then, the outer peripheral surface of the developer roller 40 comes into contact with the outer peripheral surface of the photosensitive drum 92. Thereafter, the casing 10 of the developer cartridge 1 rotates around the developer roller 40 while maintaining the state in which the developer roller 40 is in contact with the photosensitive drum 92. As a result, the shaft 73 of the first lever 70 is positioned within the recess 913. Furthermore, when the casing 10 rotates around the developer roller 40, the electrode protrusion 35 of the developer electrode 30 comes into contact with the conductive portion 97 of the first pressing member 93.

[0108] 8, when the developer cartridge 1 is not attached to the drum frame 91, the length of the first spring 95 in the second direction is the first length. Furthermore, when the developer cartridge 1 is not attached to the drum frame 91, the position where the conductive portion 97 contacts the plate portion 942 of the electrode terminal 94 is the first contact position.

[0109] When the developer cartridge 1 is mounted in the drum frame 91 and the developer roller 40 comes into contact with the photosensitive drum 92, the first spring 95 contracts in the second direction, as shown in Figure 11. As a result, the length of the first spring 95 in the second direction becomes a second length that is shorter than the first length. The position at which the conductive portion 97 comes into contact with the plate portion 942 of the electrode terminal 94 is a second contact position that is farther from the fulcrum portion 943 in the second direction than the first contact position. The second contact position is farther from the photosensitive drum 92 in the second direction than the first contact position.

[0110] As the first spring 95 contracts from the first length to the second length, an elastic repulsive force is generated in the first spring 95. This causes the conductive portion 97 to press the developer cartridge 1 in the second direction toward the photosensitive drum 92. As a result, the outer peripheral surface of the developing roller 40 comes into contact with the outer peripheral surface of the photosensitive drum 92.

[0111] <5. Separation operation> After the drum cartridge 2 is installed in the image forming apparatus with the developer cartridge 1 attached, it can perform a separation operation by using a driving force supplied from the image forming apparatus. The separation operation is an operation for separating the developing roller 40 from the photosensitive drum 92. For example, when performing monochrome printing in the image forming apparatus, the drum cartridge 2 with the developer cartridge 1 of a color other than black installed performs the separation operation. However, there may also be cases where the drum cartridge 2 with the black developer cartridge 1 installed performs the separation operation.

[0112] Fig. 12 is a view of the developer cartridge 1 and the photosensitive drum 92 when the separating operation is performed, viewed in the first direction. Fig. 13 is a cross-sectional view of the vicinity of the first pressing member 93 when the separating operation is performed. Fig. 11 shows cross sections along the first and second directions.

[0113] When the developer cartridge 1 is attached to the drum cartridge 2, the developer roller 40 is disposed in a pressure contact position where it contacts the photosensitive drum 92. The position of the first lever 70 at this time is the first position. In the first position, the other end 72 of the first lever 70 is separated from the pressure receiving surface 33. Therefore, the other end 72 of the first lever 70 does not press the pressure receiving surface 33. In addition, the shaft 73 of the first lever 70 is in contact with the recess 913 of the drum frame 91.

[0114] When performing the separation operation, the image forming apparatus operates a first main body cam (not shown). This causes the first main body cam to come into contact with one end 71 of the first lever 70. More specifically, the first main body cam comes into contact with the concave surface 76 of the first lever 70. The first main body cam then presses the one end 71 of the first lever 70 in the second direction toward the photosensitive drum 92.

[0115] As a result, the first lever 70 rotates from the first position to the second position about the shaft 73 supported in the recess 913. As a result, the other end 72 of the first lever 70 comes into contact with the pressure receiving surface 33 of the casing 10. The other end 72 of the first lever 70 then presses the pressure receiving surface 33 of the casing 10 in the second direction, in a direction away from the photosensitive drum 92. As a result, the first outer surface 11 of the casing 10 moves in the second direction, in a direction away from the photosensitive drum 92.

[0116] The drum cartridge 2 also has a second lever (not shown). The second lever is located at a second end 912 of the drum frame 91. The second lever is rotatable about a lever shaft extending in the first direction. When the image forming apparatus performs a separation operation, it operates a second main body cam (not shown). This causes the second main body cam to contact one end of the second lever. The second main body cam then presses the one end of the second lever in the second direction toward the photosensitive drum 92. This causes the second lever to rotate about the lever shaft. This causes the other end of the second lever to contact the casing 10. The other end of the second lever then presses the casing 10 in the second direction, away from the photosensitive drum 92. As a result, the second outer surface 12 of the casing 10 moves in the second direction, away from the photosensitive drum 92.

[0117] In this way, on the first outer surface 11 of the casing 10, the first main body cam presses the first lever 70, and the first lever 70 presses the casing 10 in a direction away from the photosensitive drum 92. Furthermore, on the second outer surface 12 of the casing 10, the second main body cam presses the second lever, and the second lever presses the casing 10 in a direction away from the photosensitive drum 92. This allows the developing roller 40 to move in the second direction from a pressure contact position where it contacts the photosensitive drum 92 to a separated position where it is separated from the photosensitive drum 92.

[0118] The drum cartridge 2 does not necessarily have to have a second lever. For example, the developing cartridge 1 may have a second lever similar to the first lever 70 on the second outer surface 12.

[0119] When the separating operation is performed, the first spring 95 contracts in the second direction more than when the separating operation is not performed. As a result, as shown in FIG. 13 , the length of the first spring 95 in the second direction becomes a third length that is shorter than the second length. The position where the conductive portion 97 contacts the plate portion 942 of the electrode terminal 94 is a third contact position that is farther from the fulcrum portion 943 in the second direction than the second contact position. The third contact position is a position farther from the photosensitive drum 92 in the second direction than the second contact position.

[0120] In this embodiment, the plate portion 942 of the electrode terminal 94 has a curved portion 944. Of both end portions of the plate portion 942 in the second direction, the curved portion 944 is located at the end opposite the fulcrum portion 943. In other words, of both end portions of the plate portion 942 in the second direction, the curved portion 944 is located at the end farthest from the photosensitive drum 92. The curved portion 944 curves in a direction intersecting the second direction. Specifically, the curved portion 944 curves in a direction away from the second end 912 of the drum frame 91 in the first direction.

[0121] When the separating operation is not being performed, as shown in FIG. 11 , the third protrusion 974 of the conductive portion 97 contacts the flat surface of the plate portion 942. More specifically, the apex 976 of the third protrusion 974 contacts the flat surface of the plate portion 942. In contrast, when the separating operation is being performed, as shown in FIG. 13 , the third protrusion 974 of the conductive portion 97 contacts the curved portion 944. More specifically, the tapered surface 977 of the third protrusion 974 contacts the curved portion 944. As a result, when the separating operation is being performed, the component of the pressing force acting from the plate portion 942 on the third protrusion 974 in the second direction away from the photosensitive drum 92 is larger than when the separating operation is not being performed. Therefore, during the separating operation, a force assisting the separation can be applied from the plate portion 942 to the conductive portion 97. As a result, the separating operation can be performed more stably.

[0122] <6.Other> Although one embodiment of the present disclosure has been described above, the present disclosure is not limited to the above embodiment.

[0123] The detailed shape of the developing cartridge 1 may differ from the shape shown in the drawings of the present application. Furthermore, the elements appearing in the above-described embodiments and modifications may be combined as appropriate within the scope of not causing any contradiction. [Explanation of symbols]

[0124] 1 Developer cartridge 2 drum cartridges 10 Casing 20 Agitator 30 Development electrode 40 Developing roller 50 Supply roller 60 Gear section 70 First Lever 80 Lever holder 91 Drum Frame 92 Photosensitive drum 93 First pressing member 94 Electrode terminal 95 First Spring 96 Insulation section 97 Conductive part 98 Second pressing member 99 Second Spring 100 Contact part 941 Exposed part 942 Board part 943 Fulcrum 944 curved section 963 1st protrusion 973 2nd protrusion 974 Third protrusion 975 Claw

Claims

1. a drum frame into which a developer cartridge can be mounted, the developer cartridge having a developer roller and a developer electrode electrically connected to the developer roller; A photosensitive drum; a first pressing member that presses the developing electrode toward the photosensitive drum when the developing cartridge is attached to the drum frame, a conductive portion electrically connected to the developing electrode when the developing cartridge is attached to the drum frame; a first spring that presses the conductive portion toward the photosensitive drum; a first pressing member having an electrode terminal electrically connected to the conductive portion when the developing cartridge is attached to the drum frame; Equipped with The drum cartridge according to claim 1, wherein the first pressing member further includes an insulating portion located between the conductive portion and the first spring.

2. 2. The drum cartridge according to claim 1, The drum cartridge is characterized in that the conductive portion is made of a conductive resin.

3. 3. The drum cartridge according to claim 1, The drum cartridge is mountable in an image forming apparatus having a main body electrode, The electrode terminal is in contact with the main body electrode when the drum cartridge is mounted in the image forming apparatus.

4. 4. The drum cartridge according to claim 1, The photosensitive drum is rotatable about a drum axis extending in a first direction, The drum cartridge, wherein the first spring presses the conductive portion toward the photosensitive drum in a second direction different from the first direction.

5. 5. The drum cartridge according to claim 4, One end of the first spring in the second direction is fixed to the drum frame, The drum cartridge is characterized in that the insulating portion is fixed to the other end of the first spring in the second direction.

6. 6. The drum cartridge according to claim 5, the first spring is a coil spring that is expandable and contractible in the second direction, The insulating portion has a first protrusion that is inserted into the other end of the first spring.

7. 7. The drum cartridge according to claim 6, the first protrusion is cylindrical, The conductive portion is a second protrusion inserted inside the first protrusion; a claw portion located on an outer peripheral surface of the second protrusion, the claw portion facing the first protrusion in the second direction; A drum cartridge comprising:

8. 8. The drum cartridge according to claim 4, wherein: the electrode terminal is located on the drum frame; The drum cartridge, wherein the electrode terminal is in contact with the conductive portion when the developing cartridge is attached to the drum frame.

9. 9. The drum cartridge according to claim 8, The electrode terminal is an exposed portion located on the outer surface of the drum frame; a plate portion located on an inner surface of the drum frame and in contact with the conductive portion; A drum cartridge comprising:

10. 10. The drum cartridge according to claim 9, The drum cartridge is characterized in that the plate portion is elastically deformable.

11. 11. The drum cartridge according to claim 10, The drum cartridge is characterized in that the electrode terminal is a leaf spring.

12. 12. The drum cartridge according to claim 10 or 11, the electrode terminal further has a fulcrum portion fixed to the drum frame, The drum cartridge according to claim 1, wherein the plate portion is bent in the first direction around the fulcrum portion upon contact with the conductive portion.

13. 13. The drum cartridge according to claim 12, The drum cartridge is characterized in that the fulcrum portion is located at one of both end portions of the plate portion in the second direction, the end portion being closer to the photosensitive drum.

14. 14. The drum cartridge according to claim 13, a first contact position is a position where the conductive portion contacts the plate portion when the developing cartridge is not attached to the drum frame; A drum cartridge characterized in that, when the developing cartridge is attached to the drum frame and the developing roller is in contact with the photosensitive drum, the position at which the conductive portion contacts the plate portion is a second contact position that is farther from the fulcrum portion than the first contact position.

15. 15. The drum cartridge according to claim 14, a separating operation for separating the developing roller from the photosensitive drum by an external driving force when the developing cartridge is mounted on the drum frame; The drum cartridge is characterized in that, when the separating operation is performed, the position at which the conductive portion contacts the plate portion is a third contact position that is farther from the fulcrum portion than the second contact position.

16. 16. The drum cartridge according to claim 15, The conductive portion is a third protrusion protruding toward the electrode terminal and contacting the plate portion; A drum cartridge comprising:

17. 17. The drum cartridge according to claim 15 or 16, the plate portion has a curved portion located at an end farther from the photosensitive drum than both end portions of the plate portion in the second direction, the curved portion being curved in a direction intersecting the second direction, The drum cartridge according to claim 1, wherein the conductive portion is in contact with the curved portion when the separating operation is performed.

18. The drum cartridge according to any one of claims 5 to 17, the first pressing member is located at one end of the drum frame in the first direction, The drum cartridge is a second pressing member located at the other end of the drum frame in the first direction, the second pressing member pressing the developer cartridge toward the photosensitive drum when the developer cartridge is attached to the drum frame; The drum cartridge further comprises:

19. 19. The drum cartridge according to claim 18, The second pressing member is a contact portion that comes into contact with the developer cartridge when the developer cartridge is attached to the drum frame; a second spring that presses the contact portion toward the photosensitive drum; and a force with which the first spring presses the conductive portion in the second direction is greater than a force with which the second spring presses the contact portion in the second direction;

20. 20. The drum cartridge according to claim 19, One end of the first spring in the second direction is fixed to the drum frame, One end of the second spring in the second direction is fixed to the drum frame, A drum cartridge characterized in that one end of the first spring in the second direction is located closer to the photosensitive drum in the second direction than one end of the second spring in the second direction.

Images