Drum unit

Abstract

To provide a drum unit capable of housing a cleaner in a drum frame when a wire is not cleaned.SOLUTION: A drum frame has a guide frame 73 positioned at one end portion in a first direction, and an electrifier frame 77 supporting an electrifier 80. The electrifier 80 has a cleaner 83. The cleaner 83 moves in the first direction along a wire 81 to clean the wire 81. In a state where the cleaner 83 is positioned at one end portion in the first direction, the cleaner 83 is positioned between the guide frame 73 and the electrifier frame 77 in a second direction. The cleaner 83 also has an operation portion 85. In a state where the cleaner 83 is positioned at one end portion in the first direction, the operation portion 85 protrudes from between the guide frame 73 and the electrifier frame 77 in a third direction.SELECTED DRAWING: Figure 10

Description

[Technical field]

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

[0002] Conventionally, electrophotographic image forming apparatuses such as laser printers and LED printers are known. A conventional image forming apparatus is described in, for example, Patent Document 1. The image forming apparatus of Patent Document 1 includes a developing cartridge having a developing roller and a drum unit having a photosensitive drum. The developing cartridge is attached to the drum unit. Furthermore, the drum unit with the developing cartridge attached is attached to the image forming apparatus. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-079134 A Summary of the Invention [Problem to be solved by the invention]

[0004] Furthermore, the drum unit of Patent Document 1 has a scorotron charger. The scorotron charger has a charging wire and a cleaner. The cleaner moves along the wire, thereby cleaning the wire. In a drum unit having this type of charger, a space is required to place the cleaner when the wire is not being cleaned.

[0005] An object of the present disclosure is to provide a drum unit in which a cleaner can be stored in the drum frame when wire cleaning is not being performed. [Means for solving the problem]

[0006] The first disclosure is a drum unit including a photosensitive drum rotatable about a drum axis extending in a first direction, a drum frame having the photosensitive drum, the drum frame having the photosensitive drum positioned at one end in a second direction intersecting the first direction, and a charger that charges the surface of the photosensitive drum, the drum frame having a guide frame positioned at one end in the first direction and a charger frame supporting the charger, the charger having a wire extending in the first direction and a cleaner that cleans the wire by moving along the wire in the first direction, and when the cleaner is positioned at one end in the first direction, the cleaner is positioned between the guide frame and the charger frame in the second direction, and has an operating portion that protrudes from between the guide frame and the charger frame in a third direction intersecting the first direction and the second direction.

[0007] The second disclosure is the drum unit of the first disclosure, characterized in that the drum frame has an installation space in which a developing cartridge having a developing roller is disposed when the developing cartridge is mounted on the drum frame, the developing roller contacts the photosensitive drum when the developing cartridge is disposed in the installation space, the cleaner has a clip that clamps the wire, and the operating portion extends from the clip toward the installation space.

[0008] A third disclosure is the drum unit of the second disclosure, characterized in that when the cleaner is positioned at one end in the first direction, the operating portion protrudes from between the guide frame and the charger frame toward the mounting space.

[0009] A fourth disclosure is the drum unit of the second or third disclosure, characterized in that the charger frame has a rail extending in the first direction and supporting the operating portion.

[0010] A fifth disclosure is the drum unit of the fourth disclosure, wherein the operating portion has an operating portion groove recessed in the second direction, and an end of the rail in the second direction fits into the operating portion groove.

[0011] A sixth disclosure is the drum unit of the fifth disclosure, wherein the operating part has an operating part protrusion facing the operating part groove, and an end of the rail in the second direction is positioned between the operating part groove and the operating part protrusion in the second direction, and has a rail groove into which the operating part protrusion fits.

[0012] A seventh disclosure is a drum unit according to any one of the first to sixth disclosures, characterized in that the charger further has a grid positioned between the photosensitive drum and the wire, and the cleaner further has a film in contact with the grid.

[0013] The eighth disclosure is a drum unit of the first disclosure, comprising a first photosensitive drum which is the photosensitive drum, and a second photosensitive drum located away from the first photosensitive drum in the third direction, the drum frame having a first mounting space in which a first developing cartridge having a first developing roller in contact with the first photosensitive drum is disposed, and a second mounting space in which a second developing cartridge having a second developing roller in contact with the second photosensitive drum is disposed, and the charger frame and the charger are located between the first mounting space and the second mounting space in the third direction.

[0014] A ninth disclosure is a drum unit of the eighth disclosure, further comprising a pressing member that presses the second developing cartridge toward the second photosensitive drum, and when the cleaner is located at one end in the first direction, the cleaner is located between the pressing member and the charger frame in the second direction.

[0015] A tenth disclosure is the drum unit of the ninth disclosure, wherein the pressing member is located on the guide frame.

[0016] An eleventh disclosure is the drum unit of the first disclosure, characterized in that the guide frame has a guide groove into which a part of a developing cartridge having a developing roller is inserted when the developing cartridge is attached. Effect of the Invention

[0017] According to the first to eleventh disclosures, the cleaner can be disposed in the space between the guide frame and the charger frame, which allows the cleaner to be stored in the drum frame when the wire is not being cleaned.

[0018] Also, according to the second disclosure, with the developer cartridge removed, it is possible to operate a cleaner that cleans the charger that charges the photosensitive drum that is in contact with the developer roller of the developer cartridge.

[0019] According to the fourth disclosure, the charger frame supports the operation unit. This makes it possible to suppress bending of the operation unit. Also, the operation unit can be moved in the first direction while suppressing bending of the operation unit.

[0020] Furthermore, according to the fifth disclosure, the rail fits into the operation portion groove, so that bending of the operation portion can be further suppressed.

[0021] Moreover, according to the sixth disclosure, it is possible to prevent the operating part from coming off the rail.

[0022] Also, according to the seventh disclosure, not only the wires but also the grids can be cleaned. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a schematic diagram of an image forming apparatus. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4]2 is a cross-sectional view of the developing cartridge taken along a plane perpendicular to a first direction. FIG. [Diagram 5] FIG. [Figure 6] 2 is a perspective view of a first metal plate, a first guide frame, and a first pressing member. FIG. [Figure 7] FIG. 2 is a partial perspective view of the drum unit in the vicinity of a first pressing member. [Figure 8] 13 is a perspective view of a second metal plate, a second guide frame, and a second pressing member. FIG. [Figure 9] FIG. 4 is a partial perspective view of the drum unit in the vicinity of a second pressing member. [Figure 10] FIG. 4 is a perspective view of a first pressing member. [Figure 11] FIG. 4 is a perspective view of a first pressing member. [Figure 12] 4 is a cross-sectional view of the drum unit and the developing cartridge during installation of the developing cartridge to the drum unit, or during removal of the developing cartridge from the drum unit. FIG. [Figure 13] 2 is a cross-sectional view of the drum unit and the developing cartridge in a state where the developing cartridge is attached to the drum unit. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0025] In the following description, the direction in which the drum shaft of the photosensitive drum extends is referred to as the "first direction." The direction in which one end of the drum frame where the photosensitive drum is located is aligned with the other end of the drum frame is referred to as the "second direction." The direction in which the operating part of the cleaner protrudes is referred to as the "third direction."

[0026] The first direction and the second direction intersect with each other. For example, the first direction and the second direction are perpendicular to each other. The second direction and the third direction intersect with each other. For example, the second direction and the third direction are perpendicular to each other. The third direction and the first direction intersect with each other. For example, the third direction and the first direction are perpendicular to each other.

[0027] <1. Configuration of image forming device> FIG. 1 is a schematic diagram of an image forming apparatus 100. The image forming apparatus 100 is an electrophotographic printer. Specifically, the image forming apparatus 100 is a laser printer or an LED printer. As shown in FIG. 1, the image forming apparatus 100 includes a main body frame 101, a drum unit 2, and four developing cartridges 1.

[0028] The four developing cartridges 1 can be attached to the drum unit 2. Furthermore, the drum unit 2 to which the four developing cartridges 1 are attached can be attached to the main body frame 101. The drum unit 2 is attached to the main body frame 101 by moving in the third direction relative to the main body frame 101.

[0029] As an example, the four developer cartridges 1 are arranged in the third direction in the following order: developer cartridge 1 containing yellow toner, developer cartridge 1 containing magenta toner, developer cartridge 1 containing cyan toner, and developer cartridge 1 containing black toner. The image forming device 100 prints an image on the surface of a printing paper using toner supplied from the developer cartridges 1.

[0030] <2. Structure of the developing cartridge> Figures 2 and 3 are perspective views of the developing cartridge 1. Figure 4 is a cross-sectional view of the developing cartridge 1 cut along a plane perpendicular to the first direction. As shown in Figures 2 to 4, the developing cartridge 1 includes a housing 10, a developing roller 20, a gear unit 40, and a memory assembly 50.

[0031] <2-1. Cabinet> The housing 10 is a container capable of storing toner. The housing 10 has a first end surface 11 and a second end surface 12. The first end surface 11 is located at one end of the housing 10 in the first direction. The second end surface 12 is located at the other end of the housing 10 in the first direction. The first end surface 11 and the second end surface 12 are separated from each other in the first direction.

[0032] A storage chamber 13 is provided inside the housing 10. The toner is stored in the storage chamber 13. As shown in Fig. 4, the housing 10 has an opening 14. The opening 14 is located at one end of the housing 10 in the second direction. The external space of the housing 10 and the storage chamber 13 communicate with each other via the opening 14.

[0033] The housing 10 has a first outer surface 16 and a second outer surface 17. The first outer surface 16 is located at one end of the housing 10 in the third direction. The second outer surface 17 is located at the other end of the housing 10 in the third direction. The first outer surface 16 and the second outer surface 17 are spaced apart from each other in the third direction. The opening 14 is located closer to the first outer surface 16 than to the second outer surface 17 in the third direction.

[0034] The housing 10 also has a first recess 181 and a first protrusion 182. The first recess 181 and the first protrusion 182 are located at one end of the second outer surface 17 in the first direction. The first recess 181 is recessed in the second direction from the second outer surface 17 toward the first outer surface 16. The first protrusion 182 protrudes from the first recess 181 in the third direction toward the opposite side to the first outer surface 16. When the developing cartridge 1 is attached to the drum unit 2, the first protrusion 182 faces a first pressing member 91, which will be described later, in the third direction.

[0035] The housing 10 also has a second recess 191 and a second protrusion 192. The second recess 191 and the second protrusion 192 are located at the other end of the second outer surface 17 in the first direction. The second recess 191 is recessed in the third direction from the second outer surface 17 toward the first outer surface 16. The second protrusion 192 protrudes in the third direction from the second recess 191 toward the opposite side to the first outer surface 16. When the developing cartridge 1 is attached to the drum unit 2, the second protrusion 192 faces a second pressing member 92, which will be described later, in the third direction.

[0036] <2-2. Developing roller> The developing roller 20 is a roller that can rotate about a developing shaft extending in the first direction. The developing roller 20 is located in the opening 14 of the housing 10. That is, the developing roller 20 is located at one end of the housing 10 in the second direction. The developing roller 20 has a developing roller main body 21 and a developing shaft 22. The developing roller main body 21 is a cylindrical member that extends in the first direction. The developing roller main body 21 is made of, for example, elastic rubber. The developing shaft 22 is a columnar member that penetrates the developing roller main body 21 and extends in the first direction. The developing roller main body 21 is fixed to the developing shaft 22. The developing shaft 22 is made of metal or conductive resin.

[0037] One end of the developing shaft 22 in the first direction is attached to a developing roller gear included in the gear unit 40. The other end of the developing shaft 22 in the first direction is supported by a second end surface 12 of the housing 10 via a bearing. When the developing roller gear rotates, the developing shaft 22 and the developing roller main body 21 rotate about the developing axis. The toner in the housing 10 is carried on the outer circumferential surface of the developing roller main body 21.

[0038] 2 and 3, the developer cartridge 1 has a first collar 23 and a second collar 24. The first collar 23 is attached to one end of the developer shaft 22 in the first direction. The second collar 24 is attached to the other end of the developer shaft 22 in the first direction. The first collar 23 and the second collar 24 have cylindrical outer circumferential surfaces centered on the development shaft. The first collar 23 and the second collar 24 may be rotatable about the development shaft 22.

[0039] <2-3. Gear section> The gear unit 40 is located on the first end surface 11 of the housing 10. The gear unit 40 has a gear cover 41, a coupling 42, and a plurality of gears. The gear cover 41 is attached to the first end surface 11 of the housing 10. Specifically, the gear cover 41 is fixed to the first end surface 11 of the housing 10 by screws.

[0040] The multiple gears include the developing roller gear described above. The coupling 42 and the multiple gears are each rotatable about an axis extending in the first direction. At least some of the multiple gears are located between the first end surface 11 of the housing 10 and the gear cover 41 in the first direction. That is, at least some of the multiple gears are covered by the gear cover 41.

[0041] The coupling 42 is exposed from the gear cover 41. When the drum unit 2 in which the developing cartridge 1 is mounted is mounted to the image forming apparatus 100, the drive shaft of the image forming apparatus 100 is connected to the coupling 42. Then, the rotation of the drive shaft is transmitted to multiple gears via the coupling 42.

[0042] <2-4.Memory Assembly> The memory assembly 50 is located on the second end surface 12 of the housing 10. As shown in FIG.

[0043] The memory 51 is a storage medium that stores information about the developing cartridge 1. The memory 51 is, for example, an IC chip. For example, information about the specifications or lifespan of the developing cartridge 1 is stored in the memory 51. The memory 51 has an electrical contact surface 511. The electrical contact surface 511 is electrically connected to a memory element of the memory 51. The electrical contact surface 511 is located at one end of the holder 52 in the third direction. In this embodiment, the memory 51 having the electrical contact surface 511 is held at one end of the holder 52 in the third direction. However, of the memory 51, only the electrical contact surface 511 may be held by the holder 52, and the memory element of the memory 51 may be held in another part of the developing cartridge 1.

[0044] The holder cover 53 is attached to the second end surface 12 of the housing 10. At least a portion of the holder 52 is covered by the holder cover 53. The holder 52 is located between the second end surface 12 of the housing 10 and the holder cover 53. The holder 52 is movable in a first direction, a second direction, and a third direction relative to the housing 10 and the holder cover 53. Therefore, the electrical contact surface 511 of the memory 51 is also movable in a first direction, a second direction, and a third direction relative to the housing 10 and the holder cover 53.

[0045] <3. Drum unit configuration> 5 is a perspective view of the drum unit 2. The drum unit 2 has four photosensitive drums 60, a drum frame 70, a charger 80, four first pressing members 91, and four second pressing members 92.

[0046] <3-1. Photoconductor drum> The photosensitive drum 60 is a drum that is rotatable about a drum axis D that extends in the first direction. The photosensitive drum 60 is located at one end of the drum frame 70 in the second direction. The photosensitive drum 60 has a cylindrical outer circumferential surface centered on the drum axis D. The outer circumferential surface of the photosensitive drum 60 is covered with a photosensitive material.

[0047] The four photoconductor drums 60 are arranged in the third direction. As an example, the four photoconductor drums 60 are arranged in the third direction in the following order: photoconductor drum 60 corresponding to yellow toner, photoconductor drum 60 corresponding to magenta toner, photoconductor drum 60 corresponding to cyan toner, and photoconductor drum 60 corresponding to black toner.

[0048] The photoconductor drum 60 corresponding to the yellow toner and the photoconductor drum 60 corresponding to the magenta toner are arranged at an interval in the third direction. The photoconductor drum 60 corresponding to the magenta toner and the photoconductor drum 60 corresponding to the cyan toner are arranged at an interval in the third direction. The photoconductor drum 60 corresponding to the cyan toner and the photoconductor drum 60 corresponding to the black toner are arranged at an interval in the third direction.

[0049] <3-2. Drum frame> The drum frame 70 supports the four photosensitive drums 60 rotatably about a drum axis D. The drum frame 70 has a first side frame 71, a first metal plate 72, a first guide frame 73, a second side frame 74, a second metal plate 75, a second guide frame 76, and four charger frames 77. The first guide frame 73 is an example of a guide frame.

[0050] Fig. 6 is a perspective view of the first metal plate 72, the first guide frame 73, and a first pressing member 91 (described later). Fig. 7 is a partial perspective view of the drum unit 2 in the vicinity of the first guide frame 73.

[0051] The first side frame 71, the first metal plate 72, and the first guide frame 73 are located at one end of the drum frame 70 in the first direction. The first side frame 71 and the first guide frame 73 are made of resin. The first metal plate 72 is made of metal that is more rigid than resin.

[0052] The first metal plate 72 extends in the second and third directions. The first side frame 71 is fixed to an outer surface of the first metal plate 72 in the first direction. The first guide frame 73 is fixed to an inner surface of the first metal plate 72 in the first direction.

[0053] Fig. 8 is a perspective view of the second metal plate 75, the second guide frame 76, and a second pressing member 92 (described later). Fig. 9 is a partial perspective view of the drum unit 2 in the vicinity of the second guide frame 76.

[0054] The second side frame 74, the second metal plate 75, and the second guide frame 76 are located at the other end of the drum frame 70 in the first direction. The second side frame 74 and the second guide frame 76 are made of resin. The second metal plate 75 is made of a metal that is more rigid than resin.

[0055] The second metal plate 75 extends in the second and third directions. The second side frame 74 is fixed to an outer surface of the second metal plate 75 in the first direction. The second guide frame 76 is fixed to an inner surface of the second metal plate 75 in the first direction.

[0056] The inner surface of the first metal plate 72 in the first direction refers to the surface facing the developing cartridge 1 when the developing cartridge 1 is attached to the drum unit 2, and the outer surface of the first metal plate 72 in the first direction refers to the surface opposite to the inner surface of the first metal plate 72 in the first direction. The same is true for the second metal plate 75. Therefore, the inner surface of the first metal plate 72 in the first direction and the inner surface of the second metal plate 75 in the first direction face each other in the first direction.

[0057] The charger frame 77 is a frame that supports the charger 80. The charger frame 77 is made of resin. The four charger frames 77 are arranged at intervals in the third direction. Each charger frame 77 extends in the first direction between the first guide frame 73 and the second guide frame 76. One end of the charger frame 77 in the first direction is connected to the first guide frame 73. The other end of the charger frame 77 in the first direction is connected to the second guide frame 76.

[0058] Fig. 10 is a partial vertical cross-sectional view of the drum unit 2. Fig. 10 shows a cross section perpendicular to the first direction at one end of the drum frame 70 in the first direction. Four developer cartridges 1 are mounted to the drum frame 70. More specifically, the drum frame 70 has four mounting spaces 78. The four mounting spaces 78 are aligned in the third direction. When the developer cartridges 1 are mounted to the drum frame 70, the developer cartridges 1 are disposed in the mounting spaces 78.

[0059] When the developer cartridge 1 is disposed in the mounting space 78, the developer cartridge 1 is located between the first metal plate 72 and the second metal plate 75 in the first direction. When the developer cartridge 1 is disposed in the mounting space 78, a part of the developer cartridge 1 is adjacent to the charger frame 77 in the third direction. When the developer cartridge 1 is disposed in the mounting space 78, the developer roller 20 contacts the photosensitive drum 60. More specifically, the outer circumferential surface of the developer roller 20 contacts the outer circumferential surface of the photosensitive drum 60. This allows the toner carried on the outer circumferential surface of the developer roller 20 to be supplied to the photosensitive drum 60.

[0060] As shown in FIGS. 6, 7, and 10, the first guide frame 73 has a first guide groove 731. The first guide groove 731 is recessed toward the photosensitive drum 60 in the direction in which the photosensitive drum 60 and the developing roller 20 contact each other. When the developing cartridge 1 is attached to the drum frame 70, a portion of the developing cartridge 1 is inserted into the first guide groove 731. Specifically, the first collar 23 of the developing cartridge 1 is inserted into the first guide groove 731. This allows the developing cartridge 1 to be guided relative to the drum frame 70.

[0061] As shown in FIGS. 8 and 9, the second guide frame 76 has a second guide groove 761. The second guide groove 761 is recessed toward the photosensitive drum 60 in the direction in which the photosensitive drum 60 and the developing roller 20 contact each other. When the developing cartridge 1 is attached to the drum frame 70, a portion of the developing cartridge 1 is inserted into the second guide groove 761. Specifically, the second collar 24 of the developing cartridge 1 is inserted into the second guide groove 761. This allows the developing cartridge 1 to be guided relative to the drum frame 70.

[0062] As shown in FIG. 9, the drum frame 70 includes an electrical contact 79. The electrical contact 79 is attached to the second side frame 74. When the developing cartridge 1 is attached to the drum frame 70, the electrical contact surface 511 of the memory 51 comes into contact with the electrical contact 79. This electrically connects the memory 51 and the electrical contact 79. When the drum frame 70 with the developing cartridge 1 attached thereto is attached to the main body frame 101, the electrical contact 79 is electrically connected to the control unit of the image forming apparatus 100. This allows the control unit of the image forming apparatus 100 to perform at least one of reading information from the memory 51 and writing information to the memory 51.

[0063] <3-3.Charger> The chargers 80 are devices that charge the surfaces of the photoconductor drums 60. The four chargers 80 are aligned in the third direction. The chargers 80 are supported by a charger frame 77.

[0064] The charger 80 and the charger frame 77 are located between adjacent mounting spaces 78 in the third direction. That is, if one of the four photosensitive drums 60 is defined as a "first photosensitive drum", the photosensitive drum 60 located away from the first photosensitive drum in the third direction is defined as a "second photosensitive drum", the developing roller 20 in contact with the first photosensitive drum is defined as a "first developing roller", the developing roller 20 in contact with the second photosensitive drum is defined as a "second developing roller", the developing cartridge 1 having the first developing roller is defined as a "first developing cartridge", the developing cartridge 1 having the second developing roller is defined as a "second developing cartridge", the mounting space 78 in which the first developing cartridge is disposed is defined as a "first mounting space", and the mounting space in which the second developing cartridge is disposed is defined as a "second mounting space", the charger 80 and the charger frame 77 are located between the first mounting space and the second mounting space in the third direction.

[0065] 10, the charger 80 has a wire 81 and a grid 82. The wire 81 and the grid 82 are located near the outer circumferential surface of the photoconductor drum 60.

[0066] The wire 81 is a metal wire. The wire 81 extends in a first direction along the outer circumferential surface of the photoconductor drum 60. The wire 81 is disposed at a distance from the outer circumferential surface of the photoconductor drum 60. One end of the wire 81 in the first direction is supported by one end of the charger frame 77 in the first direction. The other end of the wire 81 in the first direction is supported by the other end of the charger frame 77 in the first direction.

[0067] The grid 82 is a metal plate having a plurality of holes. The grid 82 extends in the first direction along the outer circumferential surface of the photoconductor drum 60. The grid 82 is located between the outer circumferential surface of the photoconductor drum 60 and the wire 81. The grid 82 is disposed at a distance from the outer circumferential surface of the photoconductor drum 60. The wire 81 is disposed at a distance from the grid 82. One end of the grid 82 in the first direction is supported by one end of the charger frame 77 in the first direction. The other end of the grid 82 in the first direction is supported by the other end of the charger frame 77 in the first direction.

[0068] With the drum unit 2 attached to the main body frame 101, the wire 81 and the grid 82 are electrically connected to a control unit of the image forming apparatus 100. When the image forming apparatus 100 performs printing, the control unit applies a voltage between the wire 81 and the grid 82. This causes a corona discharge between the wire 81 and the grid 82. As a result, the outer circumferential surface of the photoconductor drum 60 is charged.

[0069] The charger 80 also has a cleaner 83. The cleaner 83 is capable of moving in a first direction along the wire 81 while being in contact with the wire 81. When the cleaner 83 moves in the first direction, the wire 81 is cleaned. Specifically, when the cleaner 83 moves in the first direction, the toner or dust adhering to the wire 81 is wiped off by the cleaner 83.

[0070] FIG. 11 is a perspective view of cleaner 83. FIG. 12 is a view of cleaner 83 viewed in a first direction. As shown in FIGS. 11 and 12, cleaner 83 has clip 84. Clip 84 clamps wire 81. Specifically, clip 84 has two claws 841 and sponge 842. Wire 81 is clamped between two claws 841 via sponge 842. When cleaner 83 moves in the first direction relative to wire 81, sponge 842 rubs against wire 81. This causes toner or dust adhering to wire 81 to be wiped off.

[0071] The cleaner 83 also has an operating part 85. The operating part 85 extends from the clip 84 toward the mounting space 78. A tip of the operating part 85 is exposed in the mounting space 78. A user of the image forming apparatus 100 can operate the operating part 85 with the developer cartridge 1 removed from the mounting space 78. When the operating part 85 is moved in a first direction relative to the charger frame 77, the clip 84 also moves in the first direction relative to the charger frame 77 together with the operating part 85.

[0072] The operation unit 85 extends toward the mounting space 78 in which the developer cartridge 1 having the developing roller 20 that contacts the photosensitive drum 60 that is charged by the wire 81 cleaned by the cleaner 83 is disposed. Therefore, when the operation unit 85 moves in the first direction with the developer cartridge 1 removed from the mounting space 78, the wire 81 that charges the photosensitive drum 60 that contacts the developing roller 20 of the developer cartridge 1 can be cleaned. In other words, the charger 80 of the color corresponding to the developer cartridge 1 removed from the mounting space 78 can be cleaned.

[0073] The cleaner 83 is stored in one end of the drum frame 70 in the first direction. Figure 13 is a partial vertical cross-sectional view of the drum unit 2 in a state in which the cleaner 83 is stored in one end of the drum frame 70 in the first direction. Figure 13 shows a cross section perpendicular to the first direction.

[0074] 13, when the cleaner 83 is located at one end in the first direction, it is located between the first guide frame 73 and the charger frame 77 in the second direction. When the cleaner 83 is located at one end in the first direction, the operation unit 85 protrudes from between the first guide frame 73 and the charger frame 77 toward the mounting space 78 in the third direction. In this way, the cleaner 83 can be disposed in the space between the first guide frame 73 and the charger frame 77. This allows the cleaner 83 to be stored at one end of the drum frame 70 in the first direction when cleaning of the wire 81 is not performed.

[0075] The charger frame 77 has a rail 771. The rail 771 protrudes in the second direction from the charger frame 77 toward the other end of the drum frame 70 in the second direction. The rail 771 also extends in the first direction between one end of the charger frame 77 in the first direction and the other end of the charger frame 77 in the first direction. The operation unit 85 is supported by the rail 771. This suppresses bending of the operation unit 85. Also, the operation unit 85 can be moved in the first direction along the rail 771 while suppressing bending of the operation unit 85.

[0076] 11 to 13, operation unit 85 has operation unit groove 851. Operation unit groove 851 is recessed in the second direction from a surface of operation unit 85 facing rail 771 toward the opposite surface of operation unit 85. An end of rail 771 in the second direction fits into operation unit groove 851. This further suppresses bending of operation unit 85.

[0077] 12 and 13, the operation unit 85 has an operation unit protrusion 852. The operation unit protrusion 852 faces the operation unit groove 851 in the second direction. The end of the rail 771 in the second direction is located between the operation unit groove 851 and the operation unit protrusion 852 in the second direction. The rail 771 also has a rail groove 772. The rail groove 772 is located at the end of the rail 771 in the second direction. The operation unit protrusion 852 fits into the rail groove 772. In this way, the rail 771 fits into the operation unit groove 851, and further, the operation unit protrusion 852 fits into the rail groove 772. This prevents the operation unit 85 from coming off the rail 771.

[0078] As shown in FIGS. 11 to 13, the cleaner 83 has a film 86. The film 86 spreads from the cleaner 83 toward the grid 82. The film 86 spreads in a direction intersecting the first direction. The film 86 comes into contact with the grid 82. When the cleaner 83 moves in the first direction relative to the charger frame 77, the film 86 also moves in the first direction together with the operation unit 85 and the clip 84. Then, the film 86 rubs against the grid 82, thereby wiping off the toner or dust adhering to the grid 82. This allows the grid 82 to be cleaned.

[0079] <3-4. Pressing member> The first pressing member 91 and the second pressing member 92 are members that press the developing cartridge 1 toward the photosensitive drum 60 in a state in which the developing cartridge 1 is attached to the drum frame 70. The first pressing member 91 is an example of a pressing member.

[0080] As shown in FIG. 6 and FIG. 7, the first pressing member 91 is located on the first guide frame 73. In a state where the developing cartridge 1 is attached to the drum frame 70, the first pressing member 91 faces the first protrusion 182 of the housing 10 in the third direction. The first pressing member 91 is rotatable about a pressing shaft extending in the first direction. The drum unit 2 further includes a first elastic member 93. The first elastic member 93 is a spring that is expandable and contractible in a rotational direction about the pressing shaft. The first elastic member 93 is, for example, a torsion coil spring. In a state where the developing cartridge 1 is attached to the drum frame 70, the first elastic member 93 biases the first pressing member 91 toward the developing cartridge 1. As a result, the first pressing member 91 presses the first protrusion 182 of the developing cartridge 1. As a result, the developing roller 20 is pressed against the photosensitive drum 60.

[0081] As shown in FIG. 8 and FIG. 9, the second pressing member 92 is located on the second guide frame 76. In a state where the developing cartridge 1 is attached to the drum frame 70, the second pressing member 92 faces the second protrusion 192 of the housing 10 in the third direction. The second pressing member 92 is rotatable about a pressing shaft extending in the first direction. The drum unit 2 further includes a second elastic member 94. The second elastic member 94 is a spring that is expandable and contractible in a rotational direction about the pressing shaft. The second elastic member 94 is, for example, a torsion coil spring. In a state where the developing cartridge 1 is attached to the drum frame 70, the second elastic member 94 biases the second pressing member 92 toward the developing cartridge 1. As a result, the second pressing member 92 presses the second protrusion 192 of the developing cartridge 1. As a result, the developing roller 20 is pressed against the photosensitive drum 60.

[0082] As shown in FIG. 10, the charger 80, the charger frame 77, the first pressing member 91, and the second pressing member 92 are located between adjacent mounting spaces 78 in the third direction. That is, if one of the four photosensitive drums 60 is defined as the "first photosensitive drum," the photosensitive drum 60 located away from the first photosensitive drum in the third direction is defined as the "second photosensitive drum," the developing roller 20 in contact with the first photosensitive drum is defined as the "first developing roller," the developing roller 20 in contact with the second photosensitive drum is defined as the "second developing roller," the developing cartridge 1 having the first developing roller is defined as the "first developing cartridge," the developing cartridge 1 having the second developing roller is defined as the "second developing cartridge," the mounting space 78 in which the first developing cartridge is disposed is defined as the "first mounting space," and the mounting space in which the second developing cartridge is disposed is defined as the "second mounting space," then the charger 80, the charger frame 77, the first pressing member 91, and the second pressing member 92 are positioned between the first mounting space and the second mounting space in the third direction.

[0083] In this case, the charger 80 located between the first and second mounting spaces charges the first photosensitive drum, whereas the first and second pressing members 91 and 92 located between the first and second mounting spaces press the second developing cartridge toward the second photosensitive drum, not toward the first photosensitive drum.

[0084] In a state in which the cleaner 83 located between the first mounting space and the second mounting space is located at one end of the drum frame 70 in the first direction, the cleaner 83 is located in the second direction between the first pressing member 91 located between the first mounting space and the second mounting space and the charger frame 77 located between the first mounting space and the second mounting space. This allows the first pressing member 91 and the cleaner 83 to be disposed at one end of the drum frame 70 in the first direction.

[0085] <4. Modifications> Although one embodiment has been described above, the present disclosure is not limited to the above embodiment.

[0086] In the above embodiment, the number of developer cartridges 1 that can be attached to the drum unit 2 is four. However, the number of developer cartridges 1 that can be attached to the drum unit 2 may be one to three, or may be five or more.

[0087] Furthermore, the elements appearing in the above-described embodiment and modified examples may be combined as appropriate or some may be deleted to the extent that no contradictions arise. [Explanation of symbols]

[0088] 1 Developer cartridge 2 Drum Unit 20 Developing roller 60 Photoconductor drum 70 Drum Frame 73 First guide frame 77 Charger Frame 78 Installation space 80 Charger 81 Wire 82 Grid 83 Cleaner 84 clips 85 Control section 86 Film 91 First pressing member 100 Image forming device 771 Rail 841 Claws

Claims

1. a photosensitive drum rotatable about a drum axis extending in a first direction; a drum frame having the photosensitive drum, the photosensitive drum being positioned at one end in a second direction intersecting with the first direction; a charger for charging the surface of the photosensitive drum; A drum unit comprising: The drum frame is A guide frame located at one end in the first direction; a charger frame supporting the charger; having The charger is A wire extending in the first direction; a cleaner adapted to move along the wire in the first direction to clean the wire; having a drum unit characterized in that, when the cleaner is located at one end in the first direction, the cleaner is located between the guide frame and the charger frame in the second direction, and has an operating portion that protrudes from between the guide frame and the charger frame in a third direction that intersects the first direction and the second direction.

2. 2. The drum unit according to claim 1, the drum frame has a mounting space in which a developing cartridge having a developing roller is disposed when the developing cartridge is mounted on the drum frame; When the developer cartridge is disposed in the mounting space, the developer roller contacts the photosensitive drum, The cleaner comprises: A clip that holds the wire having The drum unit according to claim 1, wherein the operation portion extends from the clip toward the mounting space.

3. 3. The drum unit according to claim 2, a drum unit, characterized in that, when the cleaner is located at one end in the first direction, the operation portion protrudes from between the guide frame and the charger frame toward the mounting space.

4. 4. The drum unit according to claim 2, The charger frame is A rail extending in the first direction supports the operating unit. A drum unit comprising:

5. 5. The drum unit according to claim 4, The operation portion has an operation portion groove recessed in the second direction, A drum unit, characterized in that an end of the rail in the second direction fits into the operation portion groove.

6. 6. The drum unit according to claim 5, The operation portion has an operation portion protrusion facing the operation portion groove, A drum unit characterized in that an end of the rail in the second direction is located between the operation portion groove and the operation portion protrusion in the second direction and has a rail groove into which the operation portion protrusion fits.

7. 4. The drum unit according to claim 1, The charger is A grid located between the photoconductor drum and the wire. and The cleaner comprises: A film in contact with the grid The drum unit further comprises:

8. 2. The drum unit according to claim 1, A first photoconductor drum, which is the photoconductor drum; a second photoconductor drum located away from the first photoconductor drum in the third direction; Equipped with The drum frame is a first mounting space in which a first developing cartridge having a first developing roller in contact with the first photosensitive drum is disposed; a second mounting space in which a second developing cartridge having a second developing roller in contact with the second photosensitive drum is disposed; having the charger frame and the charger are located between the first mounting space and the second mounting space in the third direction.

9. 9. The drum unit according to claim 8, A pressing member that presses the second developing cartridge toward the second photosensitive drum. and a drum unit comprising: a first end portion of the cleaner disposed between the pressing member and the charger frame in the second direction; and a second end portion of the cleaner disposed between the pressing member and the charger frame in the second direction.

10. 10. The drum unit according to claim 9, The pressing member is located on the guide frame.

11. 2. The drum unit according to claim 1, The guide frame is A guide groove into which a part of a developing cartridge having a developing roller is inserted when the developing cartridge is mounted. A drum unit comprising:

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