Drum cartridges and developing cartridges

Abstract

To provide a construction that can reduce the number of components in a drum cartridge.SOLUTION: A drum cartridge 2 comprises a photoreceptor drum 92 and a movable member 95. The photoreceptor drum is rotatable with respect to an axis extending in a first direction. The movable member 95 is electrically conductive. When a developing cartridge 1 is mounted to the drum cartridge 2, the movable member 95 presses a developing electrode 60 of the developing cartridge 1 toward the photoreceptor drum 92. Also, a voltage can be supplied to the developing electrode 60 of the developing cartridge 1 via the movable member 95 of the drum cartridge 2. This makes it possible to reduce the number of components of the drum cartridge 2 more than when providing a conductive component for supplying the voltage to the developing electrode 60, in addition to the movable member 95.SELECTED DRAWING: Figure 12

Description

[Technical Field]

[0001] The present disclosure relates to a drum cartridge and a developing 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. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-54058 Summary of the Invention [Problem to be solved by the invention]

[0005] 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, the number of parts in the drum cartridge increases.

[0006] An object of the present disclosure is to provide a drum cartridge with a structure that can reduce the number of parts. [Means for solving the problem]

[0007] The first disclosure of the present application is a drum cartridge into which a developing cartridge can be attached, comprising a photosensitive drum rotatable about an axis extending in a first direction, and a conductive movable member, wherein when the developing cartridge is attached to the drum cartridge, the movable member presses the developing electrode of the developing cartridge toward the photosensitive drum.

[0008] A second disclosure of the present application is the drum cartridge of the first disclosure, further comprising a conductive elastic member that presses the movable member toward the photosensitive drum.

[0009] A third disclosure of the present application is the drum cartridge of the second disclosure, characterized in that the elastic member is a spring.

[0010] A fourth disclosure of the present application is the drum cartridge of the third disclosure, characterized in that the elastic member is a coil spring.

[0011] The fifth disclosure of the present application is a developer cartridge that can be attached to a drum cartridge of any one of the first to fourth disclosures, comprising: a developer roller having a developer roller shaft extending in a first direction; a casing that can contain developer; and a developer electrode that has a first end and a second end that is farther from the developer roller shaft than the first end, the first end being electrically connected to the developer roller shaft, and the movable member presses the second end of the developer electrode toward the photosensitive drum.

[0012] The sixth disclosure of the present application is a developing cartridge according to the fifth disclosure, characterized in that the casing extends in a second direction intersecting the first direction, the developing roller is located at one end of the casing in the second direction, and the second end of the developing electrode is farther from the one end of the casing in the second direction than the first end.

[0013] A seventh disclosure of the present application is the developer cartridge according to the fifth or sixth disclosure, characterized in that the developer electrode is rotatable about a rotation axis extending in the first direction relative to the first end portion.

[0014] The eighth disclosure of the present application is a developer cartridge according to the seventh disclosure, characterized in that the developer electrode is rotatable about the rotation axis between a first position and a second position, and the casing has a first regulating surface that contacts the second end of the developer electrode when the developer electrode is in the first position, and a second regulating surface that contacts the second end of the developer electrode when the developer electrode is in the second position.

[0015] The ninth disclosure of the present application is a developer cartridge according to the seventh disclosure, characterized in that the second end of the developer electrode has a hole extending in the first direction, the casing has a casing shaft inserted into the hole, and in the rotation direction of the second end about the rotation axis, the length of the hole is longer than the length of the casing shaft.

[0016] The 10th disclosure of the present application is a developer cartridge according to the 9th disclosure, characterized in that the hole has a first inner surface and a second inner surface spaced from the first inner surface in the rotational direction, and when the developer electrode is in the first position, the casing shaft contacts the first inner surface, and when the developer electrode is in the second position, the casing shaft contacts the second inner surface.

[0017] An eleventh disclosure of the present application is the developing cartridge according to any one of the fifth to tenth disclosures, characterized in that the developing roller shaft is conductive.

[0018] A twelfth disclosure of the present application is the developer cartridge according to any one of the fifth to eleventh disclosures, characterized in that the developer electrode is conductive.

[0019] A thirteenth disclosure of the present application is the developer cartridge of the twelfth disclosure, characterized in that the developer electrode is made of a conductive resin.

[0020] The 14th disclosure of the present application is a developer cartridge according to any one of the 5th to 13th disclosures, characterized in that the casing has a first outer surface located at one end in the first direction, and the developer electrode extends along the first outer surface between the first end and the second end.

[0021] A fifteenth disclosure of the present application is the developer cartridge of the fourteenth disclosure, characterized in that the developer electrode is a first bearing that rotatably supports the developer roller shaft.

[0022] The 16th disclosure of the present application is a developer cartridge according to any one of the 5th to 14th disclosures, characterized in that the developer electrode has an axial hole extending in the first direction and having a cylindrical inner surface, and the developer roller shaft is inserted into the axial hole.

[0023] The 17th disclosure of the present application is a developing cartridge according to the 15th disclosure, characterized in that the casing further has a second outer surface located at the other end in the first direction, and the developing cartridge further includes a second bearing extending along the second outer surface between a third end and a fourth end farther from the developing roller shaft than the third end and being rotatable about the rotation axis relative to the casing.

[0024] The 18th disclosure of the present application is a developing cartridge according to any one of the 5th to 17th disclosures, characterized in that when the developing cartridge is attached to the drum cartridge, the first end of the developing electrode contacts a part of the drum cartridge.

[0025] The 19th disclosure of the present application is a developer cartridge according to the 18th disclosure, characterized in that when the developer cartridge is attached to the drum cartridge, the second end of the developer electrode contacts another part of the drum cartridge. [Effects of the Invention]

[0026] According to the first to nineteenth disclosures of the present application, a voltage can be supplied to the developing electrode of the developing cartridge via the movable member of the drum cartridge, which reduces the number of parts in the drum cartridge compared to when a conductive part for supplying voltage to the developing electrode is provided separately from the movable member. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 2 is a perspective view of a developing cartridge and a drum cartridge. [Figure 2] FIG. 2 is a perspective view showing a state in which the developing cartridge is attached to the drum cartridge. [Figure 3] FIG. [Figure 4] FIG. 2 is an exploded perspective view of the developing cartridge in the vicinity of a first outer surface of the casing. [Figure 5] 10 is an exploded perspective view of the developing cartridge in the vicinity of a second outer surface of the casing. FIG. [Figure 6] 2 is an exploded front view of the developing cartridge in the vicinity of a first outer surface of the casing. FIG. [Figure 7] 10A and 10B are diagrams illustrating the rotation of a first bearing. [Figure 8] 3 is a cross-sectional view of the developing cartridge and the drum cartridge when the developing cartridge is attached to the drum cartridge. FIG. [Figure 9] 3 is a cross-sectional view of the developing cartridge and the drum cartridge when the developing cartridge is attached to the drum cartridge. FIG. [Figure 10] 3 is a cross-sectional view of the developing cartridge and the drum cartridge when the developing cartridge is attached to the drum cartridge. FIG. [Figure 11] 3 is a cross-sectional view of the developing cartridge and the drum cartridge when the developing cartridge is attached to the drum cartridge. FIG. [Figure 12] FIG. 2 is a side view of the developing cartridge and the drum cartridge in a state where the developing cartridge is attached to the drum cartridge. [Figure 13] FIG. 2 is a side view of the drum cartridge. [Figure 14] 10 is a cross-sectional view of the developer cartridge and the drum cartridge during the separating operation. FIG. [Figure 15] FIG. 10 is a side view of a drum cartridge according to a first modified example. [Figure 16] FIG. 10 is a side view of a first bearing of a second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0029] In the following description, the direction in which the developing roller 30 of the developing cartridge 1 extends will be referred to as the "first direction." Furthermore, the direction in which the agitator 20 of the developing cartridge 1 and the developing roller 30 are aligned will be referred to as the "second direction." The first direction and the second direction intersect (preferably perpendicular to) each other.

[0030] <1. Overview of developing cartridges and drum cartridges> FIG. 1 is a perspective view of a developer cartridge 1 and a drum cartridge 2. FIG. 2 is a perspective view showing the developer cartridge 1 attached to the 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.

[0031] As shown in FIGS. 1 and 2, a developer cartridge 1 is used together with a drum cartridge 2. The developer cartridge 1 is attachable to the drum cartridge 2. The developer cartridge 1 is attached to the image forming device while attached to the drum cartridge 2. The image forming device can accommodate, for example, four developer cartridges 1. The four developer cartridges 1 contain developers (e.g., toner) of different colors (e.g., cyan, magenta, yellow, and black). The image forming device forms an image on the recording surface of printing paper using the developer supplied from the developer cartridges 1. However, the number of developer cartridges 1 that can be attached to the image forming device may be one to three, or may be five or more.

[0032] <2. About the developing cartridge> Fig. 3 is an exploded perspective view of the developer cartridge 1. Fig. 4 is an exploded perspective view of the developer cartridge 1 in the vicinity of the first outer surface 11 of the casing 10. Fig. 5 is an exploded perspective view of the developer cartridge 1 in the vicinity of the second outer surface 12 of the casing 10. As shown in Figs. 1 to 5, the developer cartridge 1 includes a casing 10, an agitator 20, a development roller 30, a supply roller 40, a gear unit 50, a first bearing 60, and a second bearing 70.

[0033] The casing 10 is a housing capable of containing a developer. The casing 10 has a first outer surface 11 and a second outer surface 12. The first outer surface 11 is located at one end of the casing 10 in the first direction. The second outer surface 12 is located at the other end of the casing 10 in the first direction. The first outer surface 11 and the second outer surface 12 are spaced apart from each other in the first direction. The casing 10 extends in the first direction between the first outer surface 11 and the second outer surface 12, and also extends in the second direction.

[0034] A storage chamber 13 is provided inside the casing 10. The developer is stored in the storage chamber 13. The casing 10 also has an opening 14. The opening 14 is located at one end of the casing 10 in the second direction. The external space of the casing 10 and the storage chamber 13 communicate with each other via the opening 14. The casing 10 may have a handle on the outer surface of the other end in the second direction.

[0035] The agitator 20 has an agitator shaft 21 and blades 22. The agitator shaft 21 extends along a first direction. The blades 22 extend from the agitator shaft 21 toward the inner surface of the casing 10. A portion of the agitator shaft 21 and the blades 22 are disposed within the storage chamber 13 of the casing 10. An agitator gear 51 included in a gear unit 50 is attached to the end of the agitator shaft 21 in the first direction. The agitator shaft 21 is fixed to the agitator gear 51 so as not to rotate relative to it. When the agitator gear 51 rotates, the agitator shaft 21 and the blades 22 rotate about a rotation axis extending in the first direction. The rotation of the blades 22 agitates the developer in the storage chamber 13.

[0036] The developing roller 30 is a roller that can rotate about a rotation axis (first axis) A1 that extends in the first direction. The developing roller 30 is located in the opening 14 of the casing 10. In other words, the developing roller 30 is located at one end of the casing 10 in the second direction. The developing roller 30 has a developing roller main body 31 and a developing roller shaft 32. The developing roller main body 31 is a cylindrical member that extends in the first direction. The developing roller main body 31 is made of, for example, elastic rubber. The developing roller shaft 32 is a cylindrical member that penetrates the developing roller main body 31 and extends in the first direction. The developing roller shaft 32 is conductive. The developing roller shaft 32 is made of a metal or a conductive resin.

[0037] The developing roller main body 31 is fixed to the developing roller shaft 32 so as not to rotate relative to it. A developing roller gear 52 included in the gear unit 50 is attached to the end of the developing roller shaft 32 in the first direction. The developing roller shaft 32 is fixed to the developing roller gear 52 so as not to rotate relative to it. Therefore, when the developing roller gear 52 rotates, the developing roller shaft 32 also rotates, and the developing roller main body 31 rotates together with the developing roller shaft 32.

[0038] The developing roller shaft 32 does not have to penetrate the developing roller main body 31 in the first direction. For example, the developing roller shaft 32 may extend in the first direction from both ends of the developing roller main body 31 in the first direction.

[0039] The supply roller 40 is a roller that can rotate about a rotation axis (second axis) that extends in the first direction. The supply roller 40 is located between the agitator 20 and the developing roller 30. The supply roller 40 has a supply roller main body 41 and a supply roller shaft 42. The supply roller main body 41 is a cylindrical member that extends in the first direction. The supply roller main body 41 is made of, for example, elastic rubber. The supply roller shaft 42 is a cylindrical member that penetrates the supply roller main body 41 and extends in the first direction.

[0040] Supply roller body 41 is fixed to supply roller shaft 42 so as not to rotate relative to it. Furthermore, supply roller gear 53, which is included in gear unit 50, is attached to the end of supply roller shaft 42 in the first direction. Supply roller shaft 42 is fixed to supply roller gear 53 so as not to rotate relative to it. Therefore, when supply roller gear 53 rotates, supply roller shaft 42 also rotates, and supply roller body 41 rotates together with supply roller shaft 42.

[0041] The supply roller shaft 42 does not have to penetrate the supply roller main body 41 in the first direction. For example, the supply roller shaft 42 may extend in the first direction from both ends of the supply roller main body 41 in the first direction.

[0042] When the developer cartridge 1 receives a driving force, developer is supplied from the storage chamber 13 in the casing 10 to the outer circumferential surface of the developer roller 30 via the supply roller 40. At this time, the developer is frictionally charged between the supply roller 40 and the developer roller 30. Meanwhile, a bias voltage is applied to the developer roller shaft 32 of the developer roller 30. Therefore, the developer is attracted to the outer circumferential surface of the developer roller body 31 by the electrostatic force between the developer roller shaft 32 and the developer.

[0043] The developing cartridge 1 also has a layer thickness regulating blade (not shown). The layer thickness regulating blade shapes the developer supplied to the outer peripheral surface of the developing roller main body 31 to a uniform thickness. The developer on the outer peripheral surface of the developing roller main body 31 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 31 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.

[0044] The gear portion 50 is located on the second outer surface 12 of the casing 10. As shown in FIG. 5 , the gear portion 50 includes the above-mentioned agitator gear 51, developing roller gear 52, and supply roller gear 53, as well as a plurality of idle gears 56, a coupling 54, and a gear cover 55. The gear cover 55, together with the casing 10, constitutes the housing of the developer cartridge 1. The gear cover 55 is fixed to the second outer surface 12 of the casing 10, for example, by screws. At least some of the multiple gears are located between the second outer surface 12 and the gear cover 55.

[0045] The coupling 54 has an engagement portion 541 that is recessed in the first direction. The engagement portion 541 is exposed from the gear cover 55. When the developer cartridge 1 attached to the drum cartridge 2 is attached to the image forming apparatus, the drive shaft of the image forming apparatus is connected to the engagement portion 541 of the coupling 54. Then, the rotation of the drive shaft is transmitted to the agitator gear 51, the plurality of idle gears 56, the developing roller gear 52, and the supply roller gear 53 via the coupling 54.

[0046] The gears included in the gear unit 50 may transmit a rotational force by meshing of teeth, or may transmit a rotational force by friction.

[0047] 6 is an exploded front view of the developing cartridge 1 in the vicinity of the first outer surface 11 of the casing 10. As shown in FIGS. 1, 4, and 6, the first bearing 60 is located on the first outer surface 11 of the casing 10. The first bearing 60 rotatably supports one end of the developing roller shaft 32 in the first direction.

[0048] The first bearing 60 has a first end 61 and a second end 62. The second end 62 is farther from the developing roller shaft 32 than the first end 61. The second end 62 is farther from one end of the casing 10 in the second direction than the first end 61. The first bearing 60 extends along the first outer surface 11 of the casing 10 between the first end 61 and the second end 62.

[0049] The first bearing 60 has a first arm 63 and a second arm 64. The second arm 64 is farther from the developing roller shaft 32 than the first arm 63. Furthermore, the second arm 64 is farther from one end of the casing 10 in the second direction than the first arm 63. The first arm 63 has the first end 61 described above. The second arm 64 has the second end 62 described above. The first arm 63 extends, for example, linearly along the first outer surface 11 of the casing 10. The second arm 64 extends, for example, linearly along the first outer surface 11 of the casing 10. However, the first arm 63 is bent with respect to the second arm 64. The angle formed between the first arm 63 and the second arm 64 is an obtuse angle.

[0050] In this embodiment, the first arm 63 and the second arm 64 are integrally formed. However, the first arm 63 and the second arm 64 may be separate parts. In that case, it is sufficient that the first arm 63 and the second arm 64 are fixed to each other.

[0051] The first bearing 60 has a first shaft hole 65. The first shaft hole 65 extends in the first direction at a first end 61 of the first bearing 60. The first shaft hole 65 may be a through-hole that penetrates the first end 61 in the first direction, or it may not penetrate the first end 61. The first shaft hole 65 has a cylindrical inner circumferential surface. One end of the developing roller shaft 32 in the first direction is inserted into the first shaft hole 65. This allows one end of the developing roller shaft 32 in the first direction to be rotatably supported about a rotation axis (first axis) A1 that extends in the first direction. The first bearing 60 is also rotatable about the rotation axis A1 with respect to the casing 10. Specifically, the second end 62 is rotatable about the rotation axis A1 with respect to the first end 61.

[0052] The first bearing 60 is a conductive development electrode. The first bearing 60 is made of, for example, a conductive resin. However, the first bearing 60 may also be made of a metal. A first end 61 of the first bearing 60 contacts one end of the development roller shaft 32 in the first direction. Therefore, the first end 61 of the first bearing 60 is electrically connected to the development roller shaft 32.

[0053] As shown in FIG. 4, the casing 10 has a casing recess 15. The inner surface of the casing recess 15 includes a first restriction surface 151 and a second restriction surface 152. The first restriction surface 151 and the second restriction surface 152 are spaced apart in the rotation direction of the second end 62 about the rotation axis A1. Also, as shown in FIG. 6, the first bearing 60 has a bearing shaft 66. The bearing shaft 66 protrudes from the second end 62 of the first bearing 60 toward the other side in the first direction. The bearing shaft 66 is inserted into the casing recess 15.

[0054] 7 is a diagram showing the rotation of the first bearing 60. The first bearing 60 is rotatable about the rotation axis A1 between a first position shown in the upper diagram of FIG. 7 and a second position shown in the lower diagram of FIG. 7. When the first bearing 60 is in the first position, the bearing shaft 66 contacts the first restriction surface 151. On the other hand, when the first bearing 60 is in the second position, the bearing shaft 66 contacts the second restriction surface 152. This limits the rotation range of the first bearing 60.

[0055] The first bearing 60 also has a first hole 67. The first hole 67 extends in the second direction between the first end 61 and the second end 62. The first hole 67 also penetrates the first bearing 60 in the rotation direction about the rotation axis A1. However, the first hole 67 does not have to penetrate the first bearing 60. When the developer cartridge 1 is attached to the drum cartridge 2, the first hole 67 allows insertion of a first lever 97 of the drum cartridge 2, which will be described later.

[0056] As shown in FIG. 3 , the second bearing 70 is located on the second outer surface 12 of the casing 10. More specifically, the second bearing 70 is located on the outer surface of the gear cover 55. The first bearing 60 and the second bearing 70 are positioned to overlap in the first direction. The second bearing 70 rotatably supports the other end of the developing roller shaft 32 in the first direction. The second bearing 70 has a third end 71 and a fourth end 72. The fourth end 72 is farther from the developing roller shaft 32 than the third end 71. Furthermore, the fourth end 72 is farther from one end of the casing 10 in the second direction than the third end 71. The second bearing 70 extends along the second outer surface 12 of the casing 10 between the third end 71 and the fourth end 72.

[0057] The second bearing 70 has a third arm 73 and a fourth arm 74. The fourth arm 74 is farther from the developing roller shaft 32 than the third arm 73. Furthermore, the fourth arm 74 is farther from one end of the casing 10 in the second direction than the third arm 73. The third arm 73 has the third end 71 described above. The fourth arm 74 has the fourth end 72 described above. The third arm 73 extends, for example, linearly along the second outer surface 12 of the casing 10. The fourth arm 74 extends, for example, linearly along the second outer surface 12 of the casing 10. However, the third arm 73 is curved with respect to the fourth arm 74. The angle formed between the third arm 73 and the fourth arm 74 is an obtuse angle.

[0058] In this embodiment, the third arm 73 and the fourth arm 74 are integrally formed. However, the third arm 73 and the fourth arm 74 may be separate parts. In that case, it is sufficient that the third arm 73 and the fourth arm 74 are fixed to each other.

[0059] The second bearing 70 has a second shaft hole 75. The second shaft hole 75 extends in the first direction at a third end 71 of the second bearing 70. The second shaft hole 75 may be a through-hole that penetrates the third end 71 in the first direction, or it may not penetrate the third end 71. The second shaft hole 75 has a cylindrical inner circumferential surface. The other end of the developing roller shaft 32 in the first direction is inserted into the second shaft hole 75. This allows the other end of the developing roller shaft 32 in the first direction to be rotatably supported about a rotation axis (first axis) A1 that extends in the first direction. The second bearing 70 is also rotatable about the rotation axis A1 with respect to the casing 10. Specifically, the fourth end 72 is rotatable about the rotation axis A1 with respect to the third end 71.

[0060] As shown in FIG. 3 , the gear cover 55 has a gear cover protrusion 550. The gear cover protrusion 550 protrudes from the gear cover 55 toward the other side in the first direction. The second bearing 70 also has a hook portion 76. The hook portion 76 protrudes from the outer surface of the second bearing 70 in the direction of rotation of the fourth end portion 72 about the rotation axis A1. The second bearing 70 also has a third restriction surface 761 located at the base end of the hook portion 76 and a fourth restriction surface 762 located at the tip of the hook portion 76. The third restriction surface 761 and the fourth restriction surface 762 are spaced apart in the direction of rotation of the fourth end portion 72 about the rotation axis A1.

[0061] The second bearing 70 is rotatable about the rotation axis A1 between a third position and a fourth position. When the second bearing 70 is in the third position, a third restriction surface 761 of the second bearing 70 contacts the gear cover protrusion 550. On the other hand, when the second bearing 70 is in the second position, a fourth restriction surface 762 of the second bearing 70 contacts the gear cover protrusion 550. This limits the rotation range of the second bearing 70.

[0062] The second bearing 70 also has a third hole 77. The third hole 77 extends in the second direction between the third end 71 and the fourth end 72. The third hole 77 also penetrates the second bearing 70 in the rotation direction about the rotation axis A1. However, the third hole 77 does not have to penetrate the second bearing 70. When the developer cartridge 1 is attached to the drum cartridge 2, the third hole 77 allows insertion of a second lever of the drum cartridge 2, which will be described later. The first hole 67 of the first bearing 60 and the third hole 77 of the second bearing 70 are positioned to overlap in the first direction.

[0063] <3. Structure of the drum cartridge> As shown in FIGS. 1 and 2, the drum cartridge 2 includes a drum frame 91 and a photosensitive drum 92. The developer cartridge 1 is attached to the drum frame 91. The photosensitive drum 92 is a cylindrical drum that is rotatable about a rotation axis that extends in a first direction. The outer peripheral surface of the photosensitive drum 92 is covered with a photosensitive material. The photosensitive drum 92 is located at one end of the drum frame 91 in the second direction. When the developer cartridge 1 is attached to the drum frame 91, the outer peripheral surface of the developer roller 30 comes into contact with the outer peripheral surface of the photosensitive drum 92.

[0064] 8 to 11 are cross-sectional views of the developer cartridge 1 and the drum cartridge 2 when the developer cartridge 1 is attached to the drum cartridge 2. FIGS. 8 to 11 show cross sections of the developer cartridge 1 and the drum cartridge 2 taken along the line SS in FIG. 6. As shown in FIGS. 8 to 11, the drum cartridge 2 has a first guide surface 93 and a second guide surface 94. The first guide surface 93 and the second guide surface 94 are located at one end of the drum frame 91 in the first direction. The first guide surface 93 and the second guide surface 94 are spaced apart from each other in the rotation direction about the rotation axis of the photosensitive drum 92. The drum cartridge 2 also has a third guide surface (not shown) and a fourth guide surface (not shown) at the other end of the drum frame 91 in the first direction, similar to the first guide surface 93 and the second guide surface 94.

[0065] As shown in FIGS. 8 to 11 , the drum cartridge 2 includes a first movable member 95 and a first coil spring 96. The first movable member 95 and the first coil spring 96 are conductive. The first movable member 95 is made of, for example, conductive resin. The first coil spring 96 is made of, for example, metal. The first movable member 95 and the first coil spring 96 are located at one end of the drum frame 91 in the first direction. The first coil spring 96 is an elastic member that can expand and contract in the second direction. One end of the first coil spring 96 in the second direction is connected to the first movable member 95. The other end of the first coil spring 96 in the second direction is connected to the drum frame 91. When the developer cartridge 1 is attached to the drum cartridge 2, the first movable member 95 presses the second end 62 of the first bearing 60 toward the photosensitive drum 92 due to the elastic force of the first coil spring 96.

[0066] The drum cartridge 2 also includes a second movable member (not shown) and a second coil spring (not shown). The second movable member and the second coil spring are located at the other end of the drum frame 91 in the first direction. When the developer cartridge 1 is attached to the drum cartridge 2, the second movable member presses the fourth end 72 of the second bearing 70 toward the photosensitive drum 92 due to the elastic force of the second coil spring.

[0067] The drum cartridge 2 may include other types of elastic members instead of the first coil spring 96 and the second coil spring. For example, the drum cartridge 2 may include, as the elastic member, a spring other than a coil spring, such as a torsion spring or a leaf spring, or rubber.

[0068] As shown in FIGS. 8 to 11, the drum cartridge 2 also includes a first lever 97. The first lever 97 is located at one end of the drum frame 91 in the first direction. The first lever 97 is located between the first movable member 95 and the photosensitive drum 92. The first lever 97 is rotatable about a rotation axis extending in the first direction. When the developer cartridge 1 is attached to the drum cartridge 2, the first lever 97 is inserted into the first hole 67 of the first bearing 60.

[0069] The drum cartridge 2 also includes a second lever (not shown). The second lever is located at the other end of the drum frame 91 in the first direction. The second lever is located between the second movable member and the photosensitive drum 92. The second lever is rotatable about a rotation axis extending in the first direction. When the developing cartridge 1 is attached to the drum cartridge 2, the second lever is inserted into the third hole 77 of the second bearing 70.

[0070] <4. Installing the developing cartridge> When the developer cartridge 1 is attached to the drum cartridge 2, as shown in FIGS. 8 to 11, the developer cartridge 1 moves relative to the drum cartridge 2 so that the developer roller 30 approaches the photosensitive drum 92. At this time, as shown in FIGS. 9 to 11, the first end 61 of the first bearing 60 comes into contact with the second guide surface 94 and moves along the second guide surface 94. Accordingly, the first bearing 60 rotates about the rotation axis A1 from the first position to the second position. Similarly, the third end 71 of the second bearing 70 comes into contact with the fourth guide surface and moves along the fourth guide surface. Accordingly, the second bearing 70 rotates about the rotation axis A1 from the third position to the fourth position.

[0071] In this way, when the developer cartridge 1 is attached to the drum cartridge 2, the first bearing 60 and the second bearing 70 rotate about the rotation axis A1 of the developer roller 30. Therefore, the first bearing 60 can be disposed between the photosensitive drum 92 and the first movable member 95, and the second bearing 70 can be disposed between the photosensitive drum 92 and the second movable member, without rotating the casing 10 relative to the drum frame 91. Therefore, a user of the image forming apparatus can move the developer roller 30 closer to the photosensitive drum 92 without rotating the casing 10.

[0072] When the first bearing 60 is disposed between the photosensitive drum 92 and the first movable member 95, the first movable member 95 comes into contact with the second end 62 of the first bearing 60. Then, due to the elastic force of the first coil spring 96, the first movable member 95 presses the second end 62 of the first bearing 60 toward the photosensitive drum 92. As a result, as shown in FIG. 11 , the first end 61 of the first bearing 60 comes into contact with the first guide surface 93, and the other portion of the first bearing 60 comes into contact with the second guide surface 94. This fixes the position of the first bearing 60 relative to the drum frame 91.

[0073] Similarly, the second movable member presses the fourth end 72 of the second bearing 70 toward the photosensitive drum 92. As a result, the third end 71 of the second bearing 70 contacts the third guide surface, and the other portion of the second bearing 70 contacts the fourth guide surface. This fixes the position of the second bearing 70 relative to the drum frame 91.

[0074] Furthermore, with the positions of the first bearing 60 and the second bearing 70 fixed relative to the drum frame 91, the first movable member 95 presses the first bearing 60, and the second movable member presses the second bearing 70. This causes the outer peripheral surface of the developing roller 30 to come into contact with the outer peripheral surface of the photosensitive drum 92. The developing roller 30 is then pressed against the photosensitive drum 92.

[0075] As described above, in this embodiment, the first bearing 60 has a first end 61 and a second end 62, and the second end 62 is rotatable relative to the first end 61. Furthermore, the second bearing 70 has a third end 71 and a fourth end 72, and the fourth end 72 is rotatable relative to the third end 71. Therefore, the developing roller 30 can be positioned relative to the photosensitive drum 92 by utilizing the first end 61 and the second end 62 of the first bearing 60 and the third end 71 and the fourth end 72 of the second bearing 70.

[0076] In this embodiment, when the developer cartridge 1 is attached to the drum cartridge 2, the first bearing 60 and the second bearing 70 rotate about the rotation axis A1. Similarly, when the developer cartridge 1 is removed from the drum cartridge 2, the first bearing 60 and the second bearing 70 rotate about the rotation axis A1. Therefore, the developer cartridge 1 can be smoothly attached to and removed from the drum cartridge 2 by rotating the first bearing 60 and the second bearing 70 without rotating the casing 10.

[0077] <5. Voltage supply> Figure 12 is a side view of the developer cartridge 1 and the drum cartridge 2 in a state in which the developer cartridge 1 is attached to the drum cartridge 2. However, in Figure 12, the drum frame 91 is indicated by a two-dot chain line.

[0078] The first movable member 95 and the first coil spring 96 are conductive. The first movable member 95 is made of, for example, a conductive resin. The first coil spring 96 is made of, for example, a metal. As shown in FIG. 12 , the drum cartridge 2 includes an electrode terminal 98 that is in electrical contact with the first coil spring 96. As shown in FIGS. 1 and 2 , the electrode terminal 98 is exposed on the outer surface of the drum frame 91. As described above, the developing roller shaft 32 and the first bearing 60 are also conductive. Therefore, when the developing cartridge 1 is installed in the drum cartridge 2 and the first movable member 95 contacts the first bearing 60, the electrode terminal 98, the first coil spring 96, the first movable member 95, the first bearing 60, and the developing roller shaft 32 are electrically connected to one another.

[0079] When the developer cartridge 1 attached to the drum cartridge 2 is installed in an image forming apparatus, the electrode terminal of the image forming apparatus comes into contact with the electrode terminal 98 of the drum cartridge 2. Then, a bias voltage is supplied from the image forming apparatus to the developer roller shaft 32 via the electrode terminal 98, the first coil spring 96, the first movable member 95, and the first bearing 60. As a result, the developer is attracted to the outer circumferential surface of the developer roller body 31 by electrostatic force due to the bias voltage.

[0080] In this manner, in this embodiment, the bias voltage is supplied to the first bearing 60 of the developer cartridge 1 via the first movable member 95 of the drum cartridge 2. In this manner, the number of parts of the drum cartridge 2 can be reduced compared to when a conductive part for supplying voltage to the first bearing 60 is provided separately from the first movable member 95. Therefore, the drum cartridge 2 can be made smaller.

[0081] Furthermore, the first bearing 60 of this embodiment performs multiple functions: (1) a function as a bearing that rotatably supports the developing roller shaft 32, (2) a function as a positioning member that positions the developing roller 30 with respect to the photosensitive drum 92 when the developing cartridge 1 is attached to the drum cartridge 2, and (3) a function as a developing electrode that supplies a bias voltage to the developing roller shaft 32. Therefore, compared to when these functions are realized by separate members, the number of parts of the developing cartridge 1 can be reduced and the developing cartridge 1 can be made smaller.

[0082] <6. Separation operation> After the developer cartridge 1 is installed in the image forming apparatus while attached to the drum cartridge 2, it can perform a separation operation by a driving force supplied from the image forming apparatus. The separation operation is an operation for temporarily separating the developer roller 30 from the photosensitive drum 92. For example, when monochrome printing is performed in the image forming apparatus, the developer cartridges 1 of each color other than black perform the separation operation. However, there may be cases where only the black developer cartridge 1 performs the separation operation.

[0083] 11, when the developer cartridge 1 is attached to the drum cartridge 2, the developer cartridge 1 is disposed at a contact position where the developer roller 30 contacts the photosensitive drum 92. At this time, the first lever 97 of the drum cartridge 2 is inserted into the first hole 67 of the first bearing 60. In addition, the second lever (not shown) of the drum cartridge 2 is inserted into the third hole 77 of the second bearing 70.

[0084] FIG. 13 is a side view of the drum cartridge 2. In FIG. 13, the drum frame 91 is indicated by a two-dot chain line. As shown in FIG. 13, the drum cartridge 2 includes a first cam 99. The first cam 99 is located between the photosensitive drum 92 and the first lever 97 in the second direction. In addition, the first cam 99 is located between the first guide surface 93, the second guide surface 94, and the drum frame 91 in the first direction. When performing the separation operation, the first cam 99 rotates about a rotation axis extending in the first direction due to a driving force supplied from the image forming apparatus. As a result, the protrusion 991 of the first cam 99 presses the protrusion 971 of the first lever 97, causing the first lever 97 to rotate about the rotation axis extending in the first direction from the position indicated by the solid line in FIG. 13 to the position indicated by the two-dot chain line. The drum cartridge 2 also includes a second cam similar to the first cam 99 to rotate the second lever.

[0085] FIG. 14 is a cross-sectional view of the developer cartridge 1 and the drum cartridge 2 during the separating operation. FIG. 14 shows a cross-section of the developer cartridge 1 and the drum cartridge 2 at a position corresponding to the broken line SS in FIG. 6. When the first cam 99 rotates the first lever 97, the first lever 97 presses the inner surface 670 of the first hole 67 of the first bearing 60. Specifically, the first lever 97 presses the second end 62 of the first bearing 60 in a direction away from the photosensitive drum 92 against the compressive force of the first coil spring 96. When the second lever rotates the second cam, the second lever presses the inner surface of the third hole 77 of the second bearing 70. Specifically, the second lever presses the fourth end 72 of the second bearing 70 in a direction away from the photosensitive drum 92 against the compressive force of the second coil spring.

[0086] As a result, the casing 10 and the developing roller 30 move together with the first bearing 60 and the second bearing 70 in a direction away from the photosensitive drum 92. As a result, the outer circumferential surface of the developing roller 30 moves away from the outer circumferential surface of the photosensitive drum 92. In other words, the developing cartridge 1 moves from the contact position to the separated position relative to the drum cartridge 2.

[0087] In this manner, in this embodiment, the developer cartridge 1 can be moved from the contact position to the separated position by pressing the first bearing 60 and the second bearing 70. This allows the number of parts in the developer cartridge 1 to be reduced compared to when a member that receives the pressing force during the separating operation is provided in addition to the first bearing 60 and the second bearing 70. This allows the developer cartridge 1 to be made smaller.

[0088] Furthermore, the first bearing 60 is rotatable about the rotation axis A1. Therefore, the first lever 97 can press the inner surface 670 of the first hole 67 of the first bearing 60 in the optimal direction without rotating the casing 10. Similarly, the second bearing 70 is also rotatable about the rotation axis A1. Therefore, the second lever can press the inner surface 670 of the third hole 77 of the second bearing 70 in the optimal direction without rotating the casing 10.

[0089] Furthermore, when the developer cartridge 1 moves from the contact position to the separated position, the first bearing 60 moves along the second guide surface 94. Furthermore, the second bearing 70 moves along the fourth guide surface. This allows the first lever 97 to press the first bearing 60 while maintaining the position of the first bearing 60 centered on the rotation axis A1. Furthermore, the second lever can press the second bearing 70 while maintaining the position of the second bearing 70 centered on the rotation axis A1.

[0090] <7. Variations> Although one embodiment of the present disclosure has been described above, the present disclosure is not limited to the above embodiment. Various modifications will be described below, focusing on differences from the above embodiment.

[0091] <7-1. First modified example> The first modified example is another example of a mechanism for operating the first lever 97 of the drum cartridge 2. FIG. 15 is a side view of the drum cartridge 2 of the first modified example. In FIG. 15, the drum frame 91 is indicated by a two-dot chain line. In the example of FIG. 15, the drum cartridge 2 does not have a first cam 99. The first lever 97 has a protrusion 972 for receiving drive from the image forming apparatus. When performing a separating operation, the image forming apparatus presses the protrusion 972 of the first lever 97. This causes the first lever 97 to rotate about a rotation axis extending in the first direction. In this way, omitting the first cam 99 can further reduce the number of parts of the developing cartridge 1.

[0092] <7-2. Second modified example> The second modified example is another example of a structure for limiting the rotation range of the first bearing 60. Fig. 16 is a side view of the first bearing 60 of the second modified example. In the example of Fig. 16, the first bearing 60 has a second hole 68 in the second end 62. The second hole 68 extends in the first direction from the surface of the second end 62 of the first bearing 60 on the other side in the first direction toward the surface on one side in the first direction.

[0093] 16 , the casing 10 has a casing shaft 16. The casing shaft 16 extends in the first direction from the first outer surface 11 of the casing 10 toward one side in the first direction. The casing shaft 16 is inserted into the second hole 68 of the first bearing 60.

[0094] 16, in the rotation direction of the second end portion 62 about the rotation axis A1, the length d1 of the second hole 68 is longer than the length d2 of the casing shaft 16. The second hole 68 has a first inner surface 681 and a second inner surface 682. The first inner surface 681 and the second inner surface 682 are spaced apart in the rotation direction.

[0095] As in the above embodiment, the first bearing 60 is rotatable about the rotation axis A1 between a first position (the position indicated by the two-dot chain line in FIG. 16) and a second position (the position indicated by the solid line in FIG. 15). When the first bearing 60 is in the first position, the casing shaft 16 contacts the first inner surface 681. On the other hand, when the first bearing 60 is in the second position, the casing shaft 16 contacts the second inner surface 682. This limits the rotation range of the first bearing 60.

[0096] <7-3. Other variations> In the above embodiment, the developer cartridge 1 includes a first bearing and a second bearing. The first bearing and the second bearing have the same shape and are both rotatable relative to the casing 10. However, the second bearing may have a different shape from the first bearing. The second bearing may also be non-rotatable relative to the casing 10. The developer cartridge 1 may not include a second bearing. In that case, it is sufficient that the first bearing is disposed at either end of the casing 10 in the first direction.

[0097] In the above embodiment, the developer cartridge 1 is attached to the drum cartridge 2 having one photosensitive drum 92. However, the developer cartridge 1 may be attached to a drum cartridge having multiple photosensitive drums 92.

[0098] Furthermore, the detailed shape of the developing cartridge 1 may differ from the shape shown in each drawing of the present application. Furthermore, the elements appearing in the above-described embodiments and modifications may be combined as appropriate within the scope of not causing any contradiction. [Explanation of symbols]

[0099] 1 Developer cartridge 2 drum cartridges 10 Casing 11 First outer surface 12 Second outer surface 13 Containment Room 14 Aperture 15 Casing recess 16 Casing shaft 20 Agitator 30 Developing roller 31 Developing roller body 32 Developing roller shaft 40 Supply roller 41 Supply roller body 42 Supply roller shaft 50 Gear section 51 Agitator gear 52 Developing roller gear 53 Supply roller gear 54 Coupling 55 gear cover 60 First bearing 61 First end 62 Second end 63 First Arm 64 Second Arm 65 First shaft hole 66 Bearing shaft 67 Hole 1 68 2nd hole 70 Second bearing 71 Third end 72 4th end 73 Third Arm 74 4th Arm 75 Second shaft hole 76 Hook part 77 Hole 3 91 Drum Frame 92 Photosensitive drum 93 First guide surface 94 Second guide surface 95 First movable member 96 First coil spring 97 First Lever 98 Electrode terminal 99 First Cam A1 rotation axis

Claims

1. A cartridge unit including a developing cartridge and a drum cartridge into which the developing cartridge can be attached, The drum cartridge is a photosensitive drum rotatable about an axis extending in a first direction; a conductive coil spring; a conductive movable member; An electrode terminal; Equipped with The developing cartridge is a developing roller having a developing roller shaft extending in the first direction, the developing roller being movable between a position in contact with the photosensitive drum and a position spaced apart from the photosensitive drum when the developing cartridge is attached to the drum cartridge; a casing capable of containing a developer; a developing electrode having a first end, a second end that is farther from the developing roller shaft than the first end, and a pressed surface that receives a pressing force from the drum cartridge for moving the developing roller from a position in contact with the photosensitive drum to a position spaced apart from the photosensitive drum, the first end being electrically connected to the developing roller shaft; Equipped with When the developer cartridge is attached to the drum cartridge, the movable member presses the second end of the developer electrode toward the photosensitive drum by the elastic force of the coil spring so that the developer roller is urged toward the photosensitive drum, a developing roller shaft that is supplied with a bias voltage via the electrode terminal, the coil spring, the movable member, and the developing electrode;

2. 2. The cartridge unit according to claim 1, The cartridge unit is characterized in that the coil spring presses the movable member toward the photosensitive drum.

3. 2. The cartridge unit according to claim 1, The casing extends in a second direction intersecting the first direction, the developing roller is located at one end of the casing in the second direction, a cartridge unit, wherein the second end of the developing electrode is farther from the one end of the casing in the second direction than the first end of the developing electrode is.

4. 4. The cartridge unit according to claim 3, The cartridge unit, wherein the developing electrode is rotatable relative to the first end about a rotation axis extending in the first direction.

5. 5. The cartridge unit according to claim 4, the development electrode is rotatable about the rotation axis between a first position and a second position; The casing comprises: a first regulating surface that comes into contact with the second end of the developing electrode when the developing electrode is in the first position; a second regulating surface that comes into contact with the second end of the developing electrode when the developing electrode is in the second position; A cartridge unit comprising:

6. 5. The cartridge unit according to claim 4, the second end of the development electrode has a hole extending in the first direction; the casing has a casing shaft inserted into the hole; A cartridge unit, characterized in that the length of the hole in the rotation direction of the second end about the rotation axis is longer than the length of the casing shaft.

7. 7. The cartridge unit according to claim 6, the development electrode is rotatable about the rotation axis between a first position and a second position; The hole is A first inner surface; a second inner surface spaced apart from the first inner surface in the rotation direction; and When the development electrode is in the first position, the casing shaft contacts the first inner surface; When the development electrode is in the second position, the casing shaft contacts the second inner surface. A cartridge unit characterized by:

8. 8. The cartridge unit according to claim 1, The cartridge unit is characterized in that the developing roller shaft is conductive.

9. 9. The cartridge unit according to claim 1, A cartridge unit, wherein the developing electrode is conductive.

10. 10. The cartridge unit according to claim 9, A cartridge unit, wherein the developing electrode is made of a conductive resin.

11. 11. The cartridge unit according to claim 1, The casing comprises: a first outer surface located at one end in the first direction; and The cartridge unit, wherein the developer electrode extends along the first outer surface between the first end and the second end.

12. 12. The cartridge unit according to claim 11, The cartridge unit is characterized in that the developing electrode is a first bearing that rotatably supports the developing roller shaft.

13. 13. A cartridge unit according to any one of claims 1 to 12, The development electrode is a shaft hole extending in the first direction and having a cylindrical inner peripheral surface; and A cartridge unit, wherein the developing roller shaft is inserted into the shaft hole.

14. 13. The cartridge unit according to claim 12, The casing comprises: a second outer surface located at the other end in the first direction; and The developing cartridge is a second bearing extending along the second outer surface between a third end and a fourth end that is farther from the developing roller shaft than the third end, and rotatable about the rotation axis of the developing electrode relative to the casing; A cartridge unit further comprising:

15. 15. A cartridge unit according to any one of claims 1 to 14, a cartridge unit, wherein when the developer cartridge is attached to the drum cartridge, the first end of the developer electrode contacts a part of the drum cartridge.

16. 16. The cartridge unit according to claim 15, a cartridge unit, wherein when the developer cartridge is attached to the drum cartridge, the second end of the developer electrode contacts another portion of the drum cartridge.

Images