Image forming device

Abstract

To provide an image forming apparatus that allows easy replacement of a first photoconductor drum and a second photoconductor drum.SOLUTION: An image forming apparatus 1 comprises a drawer 5 and a drum unit 6. The drum unit 6 has a plurality of photoconductor drums 61Y, 61M, 61C, 61K and a waste toner tube 65. The waste toner tube 65 allows passage of waste toner from the photoconductor drums 61Y, 61M, 61C, 61K. In a state in which the drawer 5 is located at a drawn position, the drum unit 6 can be mounted on the drawer 5.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to an image forming apparatus. [Background technology]

[0002] Conventionally, an image forming apparatus includes a main body housing and a drawer. The drawer is movable between a storage position and a pull-out position. When the drawer is in the storage position, the drawer is stored in the main body housing. When the drawer is in the pull-out position, the drawer is pulled out from the main body housing. The drawer has a first photosensitive drum and a second photosensitive drum (see Patent Document 1 below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-194583 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the image forming apparatus described in Patent Document 1, the drawer has a first photosensitive drum and a second photosensitive drum.

[0005] Therefore, when it is desired to replace the first and second photosensitive drums, it is necessary to replace the entire drawer, which is cumbersome.

[0006] Therefore, an object of the present disclosure is to provide an image forming apparatus in which the first photosensitive drum and the second photosensitive drum can be easily replaced. [Means for solving the problem]

[0007] (1) The image forming apparatus of the present disclosure includes a main body housing, a drawer, and a drum unit.

[0008] The drawer is movable between a storage position and an extended position. When the drawer is in the storage position, the drawer is stored in the main body housing. When the drawer is in the extended position, the drawer is extended from the main body housing.

[0009] The drum unit has a first photosensitive drum, a second photosensitive drum, and a waste toner tube. The waste toner tube allows the waste toner from the first photosensitive drum and the waste toner from the second photosensitive drum to pass through. When the drawer is in the pulled-out position, the drum unit can be attached to the drawer.

[0010] According to this configuration, the drum unit having the first photosensitive drum and the second photosensitive drum can be replaced with a new one in the drawer.

[0011] Therefore, the first photosensitive drum and the second photosensitive drum can be easily replaced.

[0012] The drum unit also has a waste toner tube.

[0013] Therefore, when the drum unit is removed from the drawer, the waste toner tube does not separate from the drum unit.

[0014] This can prevent waste toner from leaking during replacement of the drum unit.

[0015] (2) The first photosensitive drum is rotatable about a first axis extending in a first direction.

[0016] The drum unit may have a first drum side plate and a second drum side plate. The first drum side plate supports one end of the first photosensitive drum in the first direction. The second drum side plate supports the other end of the first photosensitive drum in the first direction.

[0017] The waste toner tube may be located between the first drum side plate and the second drum side plate in the first direction.

[0018] (3) When the drum unit is attached to the drawer, a portion of the waste toner tube may be located below the first drum side plate.

[0019] (4) The main body housing may have a first positioning plate and a second positioning plate. When the drum unit is attached to the drawer and the drawer is located at the storage position, the first positioning plate positions one end of the first photosensitive drum in the first direction relative to the main body housing. When the drum unit is attached to the drawer and the drawer is located at the storage position, the second positioning plate positions the other end of the first photosensitive drum in the first direction relative to the main body housing. When the drum unit is attached to the drawer and the drawer is located at the storage position, the waste toner tube may be located between the first positioning plate and the second positioning plate in the first direction.

[0020] (5) The drawer may include a positioning plate that positions the first photosensitive drum and the second photosensitive drum with respect to the drawer when the drum unit is attached to the drawer.

[0021] According to this configuration, with the drawer in the pulled-out position and the drum unit attached to the drawer, the positions of the first photosensitive drum and the second photosensitive drum can be determined by the positioning plate.

[0022] Then, by moving the drawer from the pulled-out position to the stored position, the first photosensitive drum and the second photosensitive drum can be stored in the main body housing with the positions of the first photosensitive drum and the second photosensitive drum being determined.

[0023] Therefore, compared to a configuration in which the first photosensitive drum and the second photosensitive drum are positioned relative to a positioning plate inside the main body housing when the drawer is placed in the storage position, the first photosensitive drum and the second photosensitive drum can be positioned relative to the main body housing more smoothly.

[0024] (6) The drum unit may have a first frame, a second frame, and a drum side plate. The first frame supports a first photosensitive drum. The second frame supports a second photosensitive drum. The drum side plate supports the first frame and the second frame. Each of the first frame and the second frame is movable relative to the drum side plate.

[0025] (7) The second photosensitive drum is rotatable about a second shaft extending in the first direction.

[0026] The first frame may have a first support portion. The first support portion supports one end of the first photosensitive drum in the first direction.

[0027] The second frame may have a second support portion. The second support portion supports one end of the second photosensitive drum in the first direction.

[0028] When the drum unit is attached to the drawer, the positioning plate comes into contact with the first support portion and the second support portion, thereby positioning the first support portion and the second support portion relative to the drawer.

[0029] (8) The drum side plate may have a first through hole and a second through hole.

[0030] The first support portion passes through the first through hole. The second support portion passes through the second through hole. The drum unit may have a first elastic member and a second elastic member. The first elastic member is located between an outer peripheral surface of the first support portion and an inner peripheral surface of the first through hole. The second elastic member is located between an outer peripheral surface of the second support portion and an inner peripheral surface of the second through hole.

[0031] (9) The drawer may further include a locking member. When the drum unit is attached to the drawer, the locking member is movable between a locked position and an unlocked position. When the locking member is in the locked position, the locking member locks the drum unit to the drawer. When the locking member is in the unlocked position, the locking member releases the lock of the drum unit from the drawer.

[0032] When the drum unit is attached to the drawer and the locking member is in the locked position, the locking member presses the first support portion and the second support portion toward the positioning plate.

[0033] (10) The locking member is rotatable about a shaft between a locked position and an unlocked position. The shaft extends in a direction from the storage position of the drawer to the pulled-out position.

[0034] (11) The locking member may have a plate shape.

[0035] (12) The locking member may have a first drum pressing member and a second drum pressing member.

[0036] When the drum unit is attached to the drawer and the locking member is in the locked position, the first drum pressing member presses the first support portion toward the positioning plate.

[0037] When the drum unit is attached to the drawer and the locking member is in the locked position, the second drum pressing member presses the second support portion toward the positioning plate.

[0038] (13) The first drum pressing member and the second drum pressing member may be springs.

[0039] (14) The locking member may have a first hole and a second hole.

[0040] When the drum unit is attached to the drawer and the locking member is in the locked position, the first support portion fits into the first hole, and when the drum unit is attached to the drawer and the locking member is in the locked position, the second support portion fits into the second hole.

[0041] (15) The drawer may include a second positioning plate. The second positioning plate is located on the opposite side of the first photosensitive drum and the second photosensitive drum in the first direction from the positioning plate when the drum unit is attached to the drawer. The second positioning plate, together with the positioning plate, positions the first photosensitive drum and the second photosensitive drum with respect to the drawer. The first frame has a third support portion. The third support portion supports the other end of the first photosensitive drum in the first direction. The second frame has a fourth support portion. The fourth support portion supports the other end of the second photosensitive drum in the first direction. When the drum unit is attached to the drawer, the second positioning plate positions the third support portion and the fourth support portion with respect to the drawer.

[0042] The drawer may further include a second locking member. The second locking member is movable between a second locking position and a second unlocking position when the drum unit is attached to the drawer. When the second locking member is located at the second locking position, the second locking member locks the drum unit to the drawer. When the second locking member is located at the second unlocking position, the second locking member unlocks the drum unit from the drawer. When the drum unit is attached to the drawer and the second locking member is located at the second locking position, the second locking member presses the third support portion and the fourth support portion toward the second positioning plate.

[0043] (16) The second locking member may have a third drum pressing member and a fourth drum pressing member.

[0044] When the drum unit is attached to the drawer and the second locking member is located at the second locking position, the third drum pressing member presses the third support portion toward the second positioning plate.

[0045] When the drum unit is attached to the drawer and the second locking member is located at the second locking position, the fourth drum pressing member presses the fourth support portion toward the second positioning plate.

[0046] (17) The second locking member may have a third hole and a fourth hole.

[0047] When the drum unit is attached to the drawer and the second locking member is in the second locking position, the third support portion fits into the third hole.

[0048] When the drum unit is attached to the drawer and the second locking member is in the second locking position, the fourth support portion fits into the fourth hole.

[0049] (18) The drum unit may further include a waste toner tube.

[0050] The waste toner tube allows the waste toner from the first photosensitive drum and the waste toner from the second photosensitive drum to pass through. The drum side plate supports the waste toner tube.

[0051] In such a configuration, the drum unit includes a waste toner tube.

[0052] Therefore, when the drum unit is removed from the drawer, the waste toner tube does not separate from the drum unit.

[0053] This can prevent waste toner from leaking during replacement of the drum unit.

[0054] (19) The first frame may have a first waste toner storage section and a first discharge section. The first waste toner storage section stores waste toner from the first photosensitive drum. The first discharge section may have a first discharge port. The first discharge port is capable of discharging the waste toner in the first waste toner storage section.

[0055] The second frame may have a second waste toner storage section and a second discharge section. The second waste toner storage section stores the waste toner from the second photosensitive drum. The second discharge section may have a second discharge port. The second discharge port is capable of discharging the waste toner in the second waste toner storage section.

[0056] The waste toner tube may have a first receiving port and a second receiving port. The first receiving port is capable of receiving the waste toner discharged from the first discharge port. The second receiving port is capable of receiving the waste toner discharged from the second discharge port.

[0057] The drum unit may have a first seal member and a second seal member. The first seal member has a through hole. The through hole communicates with the first discharge port and the first receiving port. The first seal member seals between the first frame and the waste toner tube. The second seal member has a through hole. The through hole communicates with the second discharge port and the second receiving port. The second seal member seals between the second frame and the waste toner tube.

[0058] According to this configuration, when the drum unit is removed from the drawer with the drawer in the pulled-out position, the first seal member and the second seal member can prevent the waste toner from leaking from the first frame and the second frame.

[0059] (20) The drum unit may have a first transport member and a second transport member.

[0060] The first transport member is located in the first waste toner storage unit and transports the waste toner in the first waste toner storage unit toward the first discharge port.

[0061] The second transport member is located in the second waste toner storage unit and transports the waste toner in the second waste toner storage unit toward the second discharge port.

[0062] (21) The main body housing may have a first positioning member.

[0063] When the drawer is in the storage position, the first positioning member positions one end of the drawer in the movement direction of the drawer relative to the main body housing.

[0064] The drawer may have a first positioned portion. When the drawer is in the storage position, the first positioned portion is positioned by the first positioning member.

[0065] (22) The first positioning member may have a cylindrical shape. The first positioned portion may be a notch. When the drawer is in the storage position, the first positioning member fits into the first positioned portion.

[0066] (23) The main housing may have a second positioning member. When the drawer is in the storage position, the second positioning member positions the other end of the drawer in the movement direction of the drawer relative to the main housing. The drawer may have a second positioned portion. When the drawer is in the storage position, the second positioned portion is positioned by the second positioning member.

[0067] (24) The second positioned portion may have a cylindrical shape. The second positioning member may be a notch. When the drawer is in the storage position, the second positioned portion fits into the second positioning member.

[0068] (25) The image forming apparatus may further include a first cartridge and a second cartridge. The first cartridge can accommodate toner to be supplied to the first photosensitive drum. The first cartridge can be attached to the drawer when the drawer is in the pulled-out position.

[0069] The second cartridge is capable of storing toner to be supplied to the second photosensitive drum. The second cartridge is attachable to the drawer when the drawer is in the pulled-out position.

[0070] (26) The drum unit may have a first cartridge guide and a second cartridge guide. The first cartridge guide guides the first cartridge. The second cartridge guide guides the second cartridge.

[0071] (27) The drawer may have a drum guide. The drum guide guides the drum unit.

[0072] (28) The first photosensitive drum is rotatable about a first axis. The first axis extends in a first direction. The drawer may have a first drawer side plate and a second drawer side plate. When the drum unit is attached to the drawer, the first drawer side plate supports one end of the drum unit in the first direction. When the drum unit is attached to the drawer, the second drawer side plate supports the other end of the drum unit in the first direction. The first drawer side plate may have a first inner surface and a second inner surface. When the drum unit is attached to the drawer, the first inner surface faces one end of the drum unit in the first direction. When the first cartridge is attached to the drawer, the second inner surface faces one end of the first cartridge in the first direction. The second drawer side plate may have a third inner surface and a fourth inner surface. When the drum unit is attached to the drawer, the third inner surface faces the other end of the drum unit in the first direction. When the first cartridge is attached to the drawer, the fourth inner surface faces the other end of the first cartridge in the first direction.

[0073] (29) The distance between the second inner surface and the fourth inner surface in the first direction may be longer than the distance between the first inner surface and the third inner surface in the first direction.

[0074] According to this configuration, the drum unit can easily pass between the second inner surface and the fourth inner surface.

[0075] This allows for smooth replacement of the drum unit.

[0076] (30) The drawer may have a first rib and a second rib. The first rib is located on a second inner surface of the first drawer side plate. When the first cartridge is installed in the drawer, the first rib supports one end of the first cartridge in the first direction. The second rib is located on a fourth inner surface of the second drawer side plate. When the first cartridge is installed in the drawer, the second rib supports the other end of the first cartridge in the first direction.

[0077] (31) The drum unit may have a first drum side plate and a second drum side plate. The first drum side plate supports one end of the first photosensitive drum in the first direction. The second drum side plate supports the other end of the first photosensitive drum in the first direction. The first rib may be located on the opposite side of the second drum side plate from the first drum side plate in the first direction. The second rib may be located on the opposite side of the first drum side plate from the second drum side plate in the first direction.

[0078] With this configuration, when the first cartridge is attached to the drawer, the first rib and the second rib can stably support the first cartridge, and when replacing the drum unit, the drum unit can be replaced by passing through between the first rib and the second rib.

[0079] (32) The first cartridge may have a first developing roller. When the drum unit is attached to the drawer and the first cartridge is attached to the drawer, the first developing roller comes into contact with the first photosensitive drum. The drawer may have a first developing roller and a second developing roller. The first developing roller presses one end of the first cartridge in the first direction toward the first photosensitive drum. The second developing roller presses the other end of the first cartridge in the first direction toward the first photosensitive drum.

[0080] (33) The first developer pressing member may be attached to a first rib, and the second developer pressing member may be attached to a second rib.

[0081] (34) The first developer pressing member may be located on the opposite side of the second drum side plate from the first drum side plate in the first direction. The second developer pressing member may be located on the opposite side of the first drum side plate from the second drum side plate in the first direction.

[0082] With this configuration, when the first cartridge is attached to the drawer, the first cartridge can be pressed against the first photosensitive drum by the first developer pressing member and the second developer pressing member, and when replacing the drum unit, the drum unit can be replaced through the gap between the first developer pressing member and the second developer pressing member.

[0083] (35) The first rib may have a first protrusion. When the first cartridge is attached to the drawer, the first protrusion contacts one end of the first cartridge in the first direction. The second rib may have a second protrusion. When the first cartridge is attached to the drawer, the second protrusion contacts the other end of the first cartridge in the first direction.

[0084] (36) The drawer may have a sheet guide. When the drum unit is attached to the drawer and the drawer is in the storage position, the sheet guide guides the sheet transported toward the first photosensitive drum.

[0085] (37) The image forming apparatus may further include a waste toner storage unit. The waste toner storage unit is capable of storing waste toner. When the drawer is in the storage position, the waste toner tube is connected to the waste toner storage unit. When the drawer is in the extended position, the waste toner tube is separated from the waste toner storage unit. Effect of the Invention

[0086] According to the image forming apparatus of the present disclosure, the first photosensitive drum and the second photosensitive drum can be easily replaced. [Brief description of the drawings]

[0087] [Figure 1] FIG. 1 is a schematic diagram of an image forming apparatus according to the first embodiment. [Diagram 2] FIG. 2 shows the drawer of FIG. 1 in the pulled-out position. [Diagram 3] FIG. 3 shows the drum unit of FIG. 2 removed from the drawer. [Figure 4] FIG. 4 is a cross-sectional view taken along line AA in FIG. [Diagram 5] FIG. 5 is a cross-sectional view of the drum unit, showing a cross section passing through the center in the first direction. [Figure 6] Figure 6A is a cross-sectional view of the drum unit taken through a waste toner tube, and Figure 6B is a side view of the drum unit. [Figure 7] FIG. 7 is an explanatory diagram for explaining the connection between the waste toner tube and the waste toner storage unit. [Figure 8] FIG. 8 is a side view of the drawer. [Figure 9] FIG. 9 is a side view of the drum unit removed from the drawer of the image forming apparatus according to the second embodiment. [Figure 10] FIG. 10 is a cross-sectional view of the drum unit of FIG. [Figure 11] 11 is a cross-sectional view of the drum unit shown in FIG. 10 taken along line AA. [Figure 12] 12 is a cross-sectional view of the drum unit shown in FIG. 10 taken along the line BB. [Figure 13] FIG. 13 is a cross-sectional view of the drawer removed from the main body housing, showing the drawer in the locked position. [Figure 14] FIG. 14 is a side view of the drawer of FIG. [Figure 15] FIG. 15 is a cross-sectional view of the drawer of FIG. 13 taken through the positioning plate. [Figure 16] FIG. 16 is a cross-sectional view of the drawer shown in the unlocked position. [Figure 17] FIG. 17 is a side view of the drawer of FIG. [Figure 18] FIG. 18 is a cross-sectional view of an image forming apparatus according to the second embodiment. [Figure 19] FIG. 19 shows the drawer of FIG. 20 in the pulled-out position. [Figure 20] FIG. 20 is a schematic diagram of an image forming apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0088] 1. Overview of image forming apparatus 1 An outline of an image forming apparatus 1 according to a first embodiment will be described with reference to FIGS.

[0089] As shown in FIG. 1, the image forming apparatus 1 includes a main body housing 2, a cover 3, a sheet storage section 4, a drawer 5, a drum unit 6, an exposure device 7, a plurality of cartridges 8Y, 8M, 8C, and 8K, a transfer device 9, and a fixing device 10.

[0090] 1.1 Main unit 2 The main body housing 2 accommodates a sheet storage section 4, a drawer 5, a drum unit 6, an exposure device 7, a plurality of cartridges 8Y, 8M, 8C, and 8K, a transfer device 9, and a fixing device 10. The main body housing 2 has an opening 21.

[0091] 1.2 Cover 3 The cover 3 is movable between a closed position (see FIG. 1) and an open position (see FIG. 2). When the cover 3 is located in the closed position as shown in FIG. 1, the cover 3 closes the opening 21. When the cover 3 is located in the open position as shown in FIG. 2, the opening 21 is open.

[0092] 1.3 Seat storage section 4 1, the sheet storage unit 4 is capable of storing a sheet S. The sheet S in the sheet storage unit 4 is transported toward a transfer device 9.

[0093] 1.4 Drawer 5 As shown in FIG. 2, when the cover 3 is in the open position, the drawer 5 is movable between the storage position (see FIG. 1) and the pull-out position (see FIG. 2) through the opening 21. The drawer 5 is movable in the direction in which the photosensitive drums 61Y, 61M, 61C, and 61K (see FIG. 1) are lined up. The photosensitive drums 61Y, 61M, 61C, and 61K will be described later. As shown in FIG. 1, when the drawer 5 is in the storage position, the entirety of the drawer 5 is stored in the main body housing 2. As shown in FIG. 2, when the drawer 5 is in the pull-out position, at least a portion of the drawer 5 is pulled out from the main body housing 2.

[0094] 1.5 Drum unit 6 As shown in FIG. 3, the drum unit 6 can be attached to the drawer 5 when the drawer 5 is in the pulled-out position.

[0095] As shown in FIG. 1, the drum unit 6 includes a plurality of photosensitive drums 61Y, 61M, 61C, and 61K, and a plurality of charging devices 62Y, 62M, 62C, and 62K.

[0096] 1.5.1 Photoconductor drums 61Y, 61M, 61C, 61K The photosensitive drum 61Y is rotatable about a first axis A1. The first axis A1 extends in a first direction. The photosensitive drum 61Y extends in the first direction.

[0097] The photosensitive drums 61Y, 61M, 61C, and 61K are aligned in a second direction. The second direction intersects with the first direction. Preferably, the second direction is perpendicular to the first direction.

[0098] The photosensitive drums 61M, 61C, and 61K will be described in the same manner as the photosensitive drum 61Y. Therefore, the description of the photosensitive drums 61M, 61C, and 61K will be omitted. That is, the photosensitive drum 61M is rotatable about a second shaft A12. The second shaft A12 extends in the first direction.

[0099] 1.5.2 Charging devices 62Y, 62M, 62C, 62K The charging device 62Y charges the circumferential surface of the photosensitive drum 61Y. The charging device 62M charges the circumferential surface of the photosensitive drum 61M. The charging device 62C charges the circumferential surface of the photosensitive drum 61C. The charging device 62K charges the circumferential surface of the photosensitive drum 61K.

[0100] In this embodiment, each of the charging devices 62Y, 62M, 62C, and 62K is a charging roller. Each of the charging devices 62Y, 62M, 62C, and 62K may be a Scorotron type charger.

[0101] 1.6 Exposure equipment 7 When the drum unit 6 is attached to the drawer 5 and the drawer 5 is in the storage position, the exposure device 7 can expose the peripheral surfaces of the photosensitive drums 61Y, 61M, 61C, and 61K to light. In this embodiment, the exposure device 7 is a laser scan unit.

[0102] 1.7 Cartridges 8Y, 8M, 8C, 8K 2, when the drawer 5 is in the pulled-out position, each of the cartridges 8Y, 8M, 8C, and 8K can be attached to the drawer 5. In particular, when the drawer 5 is in the pulled-out position and the drum unit 6 is attached to the drawer 5, each of the cartridges 8Y, 8M, 8C, and 8K can be attached to the drawer 5.

[0103] The cartridge 8Y can accommodate toner to be supplied to the photosensitive drum 61Y. The cartridge 8M can accommodate toner to be supplied to the photosensitive drum 61M. The cartridge 8C can accommodate toner to be supplied to the photosensitive drum 61C. The cartridge 8K can accommodate toner to be supplied to the photosensitive drum 61K.

[0104] As shown in FIG. 1, the cartridge 8Y includes a developing roller 81Y.

[0105] The developing roller 81Y can supply the toner in the cartridge 8Y to the photosensitive drum 61Y. When the drum unit 6 is attached to the drawer 5 and the cartridge 8Y is attached to the drawer 5, the developing roller 81Y comes into contact with the photosensitive drum 61Y. The developing roller 81Y may be separable from the photosensitive drum 61Y. When the drum unit 6 is attached to the drawer 5 and the cartridge 8Y is attached to the drawer 5, the developing roller 81Y extends in the first direction. The developing roller 81Y can rotate about the axis A2. When the drum unit 6 is attached to the drawer 5 and the cartridge 8Y is attached to the drawer 5, the axis A2 extends in the first direction.

[0106] Each of the cartridges 8M, 8C, and 8K will be described in the same manner as the cartridge 8Y, and therefore a description of the cartridges 8M, 8C, and 8K will be omitted.

[0107] 1.8 Transfer device 9 When the drum unit 6 is attached to the drawer 5 and the drawer 5 is in the storage position, the transfer device 9 is located below the photosensitive drums 61Y, 61M, 61C, and 61K. The transfer device 9 includes a belt 91 and transfer rollers 92Y, 92M, 92C, and 92K.

[0108] The belt 91 transports the sheet S from the sheet storage unit 4 toward the fixing device 10. When the drum unit 6 is attached to the drawer 5 and the drawer 5 is in the storage position, the belt 91 comes into contact with the photosensitive drums 61Y, 61M, 61C, and 61K.

[0109] The transfer roller 92Y transfers the toner on the photosensitive drum 61Y to the sheet S being transported by the belt 91. The transfer roller 92M transfers the toner on the photosensitive drum 61M to the sheet S being transported by the belt 91. The transfer roller 92C transfers the toner on the photosensitive drum 61C to the sheet S being transported by the belt 91. The transfer roller 92K transfers the toner on the photosensitive drum 61K to the sheet S being transported by the belt 91.

[0110] 1.9 Fixing device 10 The fixing device 10 applies heat and pressure to the sheet S onto which the toner has been transferred, thereby fixing the toner to the sheet S. The sheet S that has passed through the fixing device 10 is discharged onto the top surface of the main body housing 2.

[0111] 2. Drum unit 6 details The drum unit 6 will be described in detail with reference to FIGS. 2 and 4 to 7.

[0112] In addition to the photosensitive drums 61Y, 61M, 61C, 61K and charging devices 62Y, 62M, 62C, 62K described above, the drum unit 6 has a drum side plate 63A (see FIG. 4), a drum side plate 63B (see FIG. 4), drum cleaners 64Y, 64M, 64C, 64K (see FIG. 5), a waste toner tube 65 (see FIG. 6A), and a screw 66.

[0113] 2.1 Drum side panel 63A As shown in FIG. 4, the drum side plate 63A is located at one end of the drum unit 6 in the first direction. The drum side plate 63A extends in the second direction (see FIG. 6B) and the third direction. The third direction intersects with the first direction and the second direction. The third direction is perpendicular to the first direction and the second direction. The drum side plate 63A supports one end of the photosensitive drum 61Y in the first direction. The drum side plate 63A also supports one end of the photosensitive drum 61M (see FIG. 5) in the first direction, one end of the photosensitive drum 61C (see FIG. 5) in the first direction, and one end of the photosensitive drum 61K (see FIG. 5) in the first direction. The drum side plate 63A has an outer surface S1 and an inner surface S2. The inner surface S2 is located between the outer surface S1 and the drum side plate 63B in the first direction.

[0114] 6B, the drum side plate 63A has a plurality of protrusions 631Y, 631M, 631C, and 631K, and a plurality of cartridge guides 632Y, 632M, 632C, and 632K. In other words, the drum unit 6 has cartridge guides 632Y, 632M, 632C, and 632K.

[0115] As shown in Fig. 4, the protrusion 631Y is located on the outer surface S1 of the drum side plate 63A. The protrusion 631Y extends from the outer surface S1 of the drum side plate 63A. The protrusion 631Y may be attached to the outer surface S1 of the drum side plate 63A. In this embodiment, the protrusion 631Y has a cylindrical shape. The protrusion 631Y receives one end of the photosensitive drum 61Y in the first direction.

[0116] 6B, the protrusions 631Y, 631M, 631C, and 631K are aligned in the second direction. Each of the protrusions 631M, 631C, and 631K will be described in the same manner as the protrusion 631Y. Therefore, a description of each of the protrusions 631M, 631C, and 631K will be omitted.

[0117] The cartridge guide 632Y is located on the inner surface S2 (see FIG. 4) of the drum side plate 63A. When the cartridge 8Y is attached to the drawer 5 with the drum unit 6 attached to the drawer 5, a protrusion 85Y1 (see FIG. 4) of the cartridge 8Y fits into the cartridge guide 632Y. The protrusion 85Y1 will be described later. Thereby, when the cartridge 8Y is attached to the drawer 5 with the drum unit 6 attached to the drawer 5, the cartridge guide 632Y guides one end of the cartridge 8Y in the first direction. In this embodiment, the cartridge guide 632Y is a groove. The cartridge guide 632Y may be a rib.

[0118] The cartridge guides 632Y, 632M, 632C, and 632K are aligned in the second direction. When the cartridge 8M (see FIG. 2) is attached to the drawer 5 with the drum unit 6 attached to the drawer 5, the cartridge guide 632M guides one end of the cartridge 8M in the first direction. When the cartridge 8C (see FIG. 2) is attached to the drawer 5 with the drum unit 6 attached to the drawer 5, the cartridge guide 632C guides one end of the cartridge 8C in the first direction. When the cartridge 8K (see FIG. 2) is attached to the drawer 5 with the drum unit 6 attached to the drawer 5, the cartridge guide 632K guides one end of the cartridge 8K in the first direction.

[0119] Each of the cartridge guides 632M, 632C, and 632K will be described in the same manner as the cartridge guide 632Y, and therefore a description of each of the cartridge guides 632M, 632C, and 632K will be omitted.

[0120] 2.2 Drum side panel 63B As shown in FIG. 4, the drum side plate 63B is located at the other end of the drum unit 6 in the first direction. The drum side plate 63B is located away from the drum side plate 63A in the first direction. The drum side plate 63B extends in the second direction (see FIG. 5) and the third direction. The drum side plate 63B supports the other end of the photosensitive drum 61Y in the first direction. The drum side plate 63B also supports the other end of the photosensitive drum 61M (see FIG. 5) in the first direction, the other end of the photosensitive drum 61C (see FIG. 5) in the first direction, and the other end of the photosensitive drum 61K (see FIG. 5) in the first direction. The drum side plate 63B has an outer surface S3 and an inner surface S4.

[0121] The inner surface S4 is located between the outer surface S3 and the drum side plate 63A in the first direction.

[0122] The drum side plate 63B has a plurality of projections 633Y, 633M, 633C, and 633K (the projections 633M, 633C, and 633K are not shown) and a plurality of cartridge guides 634Y, 634M, 634C, and 634K (see FIG. 5).

[0123] The protrusion 633Y is located on the outer surface S3 of the drum side plate 63B. The protrusion 633Y extends from the outer surface S3 of the drum side plate 63B. The protrusion 633Y may be attached to the outer surface S3 of the drum side plate 63B. In this embodiment, the protrusion 633Y has a cylindrical shape. The protrusion 633Y receives the other end of the photosensitive drum 61Y in the first direction.

[0124] The protrusions 633Y, 633M, 633C, and 633K are aligned in the second direction. Each of the protrusions 633M, 633C, and 633K will be described in the same manner as the protrusion 633Y. Therefore, a description of each of the protrusions 633M, 633C, and 633K will be omitted.

[0125] As shown in FIG. 5, the cartridge guide 634Y is located on the inner surface S4 of the drum side plate 63B. When the cartridge 8Y is attached to the drawer 5 with the drum unit 6 attached to the drawer 5, the protrusion 85Y2 (see FIG. 4) of the cartridge 8Y fits into the cartridge guide 634Y. The protrusion 85Y2 will be described later. As a result, when the cartridge 8Y is attached to the drawer 5 with the drum unit 6 attached to the drawer 5, the cartridge guide 634Y guides the other end of the cartridge 8Y in the first direction. In this embodiment, the cartridge guide 634Y is a groove. The cartridge guide 634Y may be a rib.

[0126] The cartridge guides 634Y, 634M, 634C, and 634K are aligned in the second direction. When the cartridge 8M (see FIG. 2) is attached to the drawer 5 with the drum unit 6 attached to the drawer 5, the cartridge guide 634M guides the other end of the cartridge 8M in the first direction. When the cartridge 8C (see FIG. 2) is attached to the drawer 5 with the drum unit 6 attached to the drawer 5, the cartridge guide 634C guides the other end of the cartridge 8C in the first direction. When the cartridge 8K (see FIG. 2) is attached to the drawer 5 with the drum unit 6 attached to the drawer 5, the cartridge guide 634K guides the other end of the cartridge 8K in the first direction.

[0127] Each of the cartridge guides 634M, 634C, and 634K will be described in the same manner as the cartridge guide 634Y, and therefore a description of each of the cartridge guides 634M, 634C, and 634K will be omitted.

[0128] 2.3 Drum Cleaner 64Y, 64M, 64C, 64K The drum cleaner 64Y cleans the surface of the photosensitive drum 61Y. The drum cleaner 64Y includes a cleaning housing 641Y, a cleaning member 642Y, and a screw 643Y.

[0129] The cleaning housing 641Y is capable of containing waste toner from the photosensitive drum 61Y. The cleaning housing 641Y has an opening 6411Y.

[0130] The cleaning member 642Y cleans the surface of the photosensitive drum 61Y. The cleaning member 642Y is attached to a cleaning housing 641Y. An edge of the cleaning member 642Y contacts the surface of the photosensitive drum 61Y. Waste toner cleaned from the surface of the photosensitive drum 61Y by the cleaning member 642Y enters the cleaning housing 641Y through an opening 6411Y.

[0131] The screw 643Y is located in the cleaning housing 641Y. The screw 643Y transports the waste toner in the cleaning housing 641Y toward the waste toner tube 65 (see FIG. 6A). The screw 643Y extends in a first direction. The screw 643Y is rotatable about an axis A3. The axis A3 extends in the first direction. In this embodiment, the screw 643Y is an auger screw. The screw 643Y may be a shaftless screw.

[0132] The drum cleaner 64M cleans the surface of the photosensitive drum 61M. The drum cleaner 64C cleans the surface of the photosensitive drum 61C. The drum cleaner 64K cleans the surface of the photosensitive drum 61K.

[0133] Each of the drum cleaners 64M, 64C, and 64K will be described in the same manner as the drum cleaner 64Y, and therefore a description of each of the drum cleaners 64M, 64C, and 64K will be omitted.

[0134] 2.4 Waste Toner Tube 65 As shown in FIG. 6A, the waste toner tube 65 is connected to each of the drum cleaners 64Y, 64M, 64C, and 64K. The waste toner tube 65 allows the waste toner from the drum cleaner 64Y, the waste toner from the drum cleaner 64M, the waste toner from the drum cleaner 64C, and the waste toner from the drum cleaner 64K to pass through. In other words, the waste toner tube 65 allows the waste toner from the photosensitive drum 61Y, the waste toner from the photosensitive drum 61M, the waste toner from the photosensitive drum 61C, and the waste toner from the photosensitive drum 61K to pass through. The waste toner tube 65 extends in the second direction. The waste toner tube 65 has one end 65A and the other end 65B in the second direction. The other end 65B is located away from the one end 65A in the second direction. The waste toner tube 65 has a waste toner discharge port 651. The waste toner discharge port 651 is located at the other end 65B of the waste toner tube 65 in the second direction. The waste toner discharge port 651 is capable of discharging the waste toner in the waste toner tube 65.

[0135] 4, the waste toner tube 65 is located between the drum side plate 63A and the drum side plate 63B in the first direction. When the drum unit 6 is attached to the drawer 5, a part of the waste toner tube 65 is located below the drum side plate 63A. When the drum unit 6 is attached to the drawer 5 and the drawer 5 is located in the storage position, the waste toner tube 65 is located between the transfer device 9 and the drum side plate 63A in the first direction. When the drum unit 6 is attached to the drawer 5 and the drawer 5 is located in the storage position, the waste toner tube 65 is located between the belt 91 and the drum side plate 63A in the first direction.

[0136] When the drum unit 6 is attached to the drawer 5 and the drawer 5 is in the storage position, the waste toner pipe 65 is located between the positioning plates 22A and 22B in the first direction. The main body housing 2 has the positioning plates 22A and 22B.

[0137] When the drum unit 6 is attached to the drawer 5 and the drawer 5 is located at the storage position, the positioning plate 22A is located between the waste toner pipe 65 and the drum side plate 63A in the first direction. When the drum unit 6 is attached to the drawer 5 and the drawer 5 is located at the storage position, the positioning plate 22A positions one end of the photosensitive drum 61Y in the first direction relative to the main body housing 2. The positioning plate 22A extends in the second and third directions. The positioning plate 22A also positions one end of the photosensitive drum 61M in the first direction, one end of the photosensitive drum 61C in the first direction, and one end of the photosensitive drum 61K in the first direction relative to the main body housing 2.

[0138] The positioning plate 22B is located away from the positioning plate 22A in the first direction. The transfer device 9 is located between the positioning plate 22A and the positioning plate 22B in the first direction. When the drum unit 6 is attached to the drawer 5 and the drawer 5 is located at the storage position, the positioning plate 22B is located between the transfer device 9 and the drum side plate 63B in the first direction. When the drum unit 6 is attached to the drawer 5 and the drawer 5 is located at the storage position, the positioning plate 22B positions the other end of the photosensitive drum 61Y in the first direction relative to the main body housing 2. The positioning plate 22B extends in the second direction and the third direction. The positioning plate 22B also positions the other end of the photosensitive drum 61M in the first direction, the other end of the photosensitive drum 61C in the first direction, and the other end of the photosensitive drum 61K in the first direction relative to the main body housing 2.

[0139] As shown in FIG. 7, when the drum unit 6 is attached to the drawer 5 and the drawer 5 is located in the storage position, the waste toner tube 65 is connected to the waste toner storage unit 11. The image forming apparatus 1 further includes the waste toner storage unit 11. The waste toner storage unit 11 is located inside the main body housing 2. When the waste toner tube 65 is connected to the waste toner storage unit 11, the waste toner discharged from the waste toner discharge port 651 (see FIG. 6A) enters the waste toner storage unit 11. The waste toner storage unit 11 is capable of storing waste toner. As shown in FIG. 2, when the drum unit 6 is attached to the drawer 5 and the drawer 5 is located in the pulled-out position, the waste toner tube 65 is separated from the waste toner storage unit 11.

[0140] 2.5 Screw 66 As shown in FIG. 6A, the screw 66 is located in the waste toner tube 65. The screw 66 transports the waste toner in the waste toner tube 65 toward the waste toner discharge port 651. The screw 66 extends in a second direction. The screw 66 is rotatable about an axis A4. The axis A4 extends in the second direction. In this embodiment, the screw 66 is an auger screw. The screw 66 may be a shaftless screw.

[0141] 3. Cartridge 8Y Details The cartridge 8Y will be described in detail with reference to FIGS.

[0142] As shown in FIG. 4, the cartridge 8Y has, in addition to the developing roller 81Y described above, a cartridge housing 82Y, two ribs 83Y1 and 83Y2, two protrusions 84Y1 and 84Y2, and two protrusions 85Y1 and 85Y2.

[0143] 3.1 Cartridge housing 82Y The cartridge housing 82Y is capable of containing toner. The cartridge housing 82Y extends in a first direction. The cartridge housing 82Y has one side surface S11 in the first direction and the other side surface S12 in the first direction.

[0144] 3.2 Ribs 83Y1, 83Y2 The rib 83Y1 is located on a side surface S11 of the cartridge 8Y. The rib 83Y1 extends from the side surface S11. The rib 83Y1 may be attached to the side surface S11. When the cartridge 8Y is attached to the drawer 5, the rib 83Y1 extends in the third direction.

[0145] The rib 83Y2 is located on a side surface S12 of the cartridge 8Y. The rib 83Y2 extends from the side surface S12. The rib 83Y2 may be attached to the side surface S12. When the cartridge 8Y is attached to the drawer 5, the rib 83Y2 extends in the third direction.

[0146] 3.3 Protrusion 84Y1, 84Y2 The protrusion 84Y1 is located on a side surface S11 of the cartridge 8Y. The protrusion 84Y1 extends from the side surface S11. The protrusion 84Y1 extends in a first direction. The protrusion 84Y1 may be attached to the side surface S11. When the drum unit 6 and the cartridge 8Y are attached to the drawer 5, the protrusion 84Y1 is located on the opposite side of the photosensitive drum 61Y (see FIG. 1) with respect to the developing roller 81Y (see FIG. 1). The protrusion 84Y1 is located away from the rib 83Y1.

[0147] The protrusion 84Y2 is located on a side surface S12 of the cartridge 8Y. The protrusion 84Y2 extends from the side surface S12. The protrusion 84Y2 extends in the first direction. The protrusion 84Y2 may be attached to the side surface S12. When the drum unit 6 and the cartridge 8Y are attached to the drawer 5, the protrusion 84Y2 is located on the opposite side of the photosensitive drum 61Y (see FIG. 1) with respect to the developing roller 81Y (see FIG. 1). The protrusion 84Y2 is located away from the rib 83Y2.

[0148] 3.4 Protrusion 85Y1, 85Y2 The protrusion 85Y1 is located on a side surface S11 of the cartridge 8Y. The protrusion 85Y1 extends from the side surface S11. The protrusion 85Y1 extends in a first direction. The protrusion 85Y1 may be attached to the side surface S11. The protrusion 85Y1 extends along an axis A2 (see FIG. 1). The protrusion 85Y1 may be a shaft of the developing roller 81Y. The protrusion 85Y1 has a cylindrical shape.

[0149] The protrusion 85Y2 is located on the side surface S12 of the cartridge 8Y. The protrusion 85Y2 extends from the side surface S12. The protrusion 85Y2 extends in the first direction. The protrusion 85Y2 may be attached to the side surface S12. The protrusion 85Y2 extends along the axis A2 (see FIG. 1). The protrusion 85Y2 may be the shaft of the developing roller 81Y. The protrusion 85Y2 has a cylindrical shape.

[0150] 4. Details of Drawer 5 The drawer 5 will be described in detail with reference to FIGS. 1 to 4 and 8. FIG.

[0151] Drawer 5 has drawer side panel 51A (see Figure 4), drawer side panel 51B (see Figure 4), multiple ribs 52Y, 52M, 52C, 52K (see Figure 8), multiple ribs 53Y, 53M, 53C, 53K (see Figure 1), multiple developer pressing members 54Y, 54M, 54C, 54K (see Figure 8), multiple developer pressing members 55Y, 55M, 55C, 55K (see Figure 1), and a sheet guide 56 (see Figure 1).

[0152] 4.1 Drawer side panel 51A 4, the drawer side panel 51A is located at one end of the drawer 5 in the first direction. The drawer side panel 51A extends in the second direction (see FIG. 8) and the third direction. The drawer side panel 51A has an outer surface S21, an inner surface S31, and an inner surface S32.

[0153] The outer surface S21 is located on the opposite side of the drawer side plate 51B from the inner surface S31 in the first direction.

[0154] The inner surface S31 is located between the outer surface S21 and the drum side plate 63A in the first direction. The inner surface S31 is located between the inner surface S32 and the drum side plate 63A in the first direction. When the drum unit 6 is attached to the drawer 5, the inner surface S31 faces one end of the drum unit 6 in the first direction.

[0155] The inner surface S32 is located above the inner surface S31 in the third direction. The inner surface S32 is located away from the inner surface S31 in the first direction. The inner surface S32 is located between the outer surface S21 and the inner surface S31 in the first direction. When the cartridge 8Y is attached to the drawer 5, the inner surface S32 faces one end of the cartridge 8Y in the first direction.

[0156] 8, the drawer side plate 51A has a plurality of drum guides 511Y, 511M, 511C, and 511K. In other words, the drawer 5 has the drum guides 511Y, 511M, 511C, and 511K.

[0157] The drum guides 511Y, 511M, 511C, and 511K are located on the inner surface S31 (see FIG. 4). The drum guides 511Y, 511M, 511C, and 511K are located between the inner surface S32 (see FIG. 4) and the drum side plate 63A (see FIG. 4) in the first direction. The drum guides 511Y, 511M, 511C, and 511K are aligned in the second direction. Each of the drum guides 511Y, 511M, 511C, and 511K extends in the third direction.

[0158] As shown in FIG. 3, when the drum unit 6 is attached to the drawer 5, the drum guide 511Y guides the protrusion 631Y of the drum unit 6, the drum guide 511M guides the protrusion 631M of the drum unit 6, the drum guide 511C guides the protrusion 631C of the drum unit 6, and the drum guide 511K guides the protrusion 631K of the drum unit 6.

[0159] As shown in Figures 2 and 4, when the drum unit 6 is attached to the drawer 5, the protrusion 631Y of the drum unit 6 fits into the drum guide 511Y, the protrusion 631M of the drum unit 6 fits into the drum guide 511M, the protrusion 631C of the drum unit 6 fits into the drum guide 511C, and the protrusion 631K of the drum unit 6 fits into the drum guide 511K, so that the drawer side panel 51A supports one end of the drum unit 6 in the first direction.

[0160] 4.2 Drawer side panel 51B 4, the drawer side panel 51B is located at the other end of the drawer 5 in the first direction. The drawer side panel 51B is located away from the drawer side panel 51A in the first direction. The drawer side panel 51B extends in the second and third directions. The drawer side panel 51B has an outer surface S22, an inner surface S41, and an inner surface S42.

[0161] The outer surface S22 is located on the opposite side of the drawer side panel 51A from the inner surface S41 in the first direction.

[0162] The inner surface S41 is located between the outer surface S22 and the drum side plate 63B in the first direction. The inner surface S41 is located between the inner surface S42 and the drum side plate 63B in the first direction. When the drum unit 6 is attached to the drawer 5, the inner surface S41 faces the other end of the drum unit 6 in the first direction.

[0163] The inner surface S42 is located above the inner surface S41 in the third direction. The inner surface S42 is located away from the inner surface S41 in the first direction. The inner surface S42 is located between the outer surface S22 and the inner surface S41 in the first direction. When the cartridge 8Y is attached to the drawer 5, the inner surface S42 faces the other end of the cartridge 8Y in the first direction.

[0164] A distance D1 between the inner surface S32 and the inner surface S42 in the first direction is longer than a distance D2 between the inner surface S31 and the inner surface S41 in the first direction.

[0165] Similar to the drawer side plate 51A, the drawer side plate 51B has a plurality of drum guides 512Y, 512M, 512C, and 512K. The drum guides 512M, 512C, and 512K are not shown.

[0166] The drum guides 512Y, 512M, 512C, and 512K are located on the inner surface S41. The drum guides 512Y, 512M, 512C, and 512K are located between the inner surface S42 and the drum side plate 63B in the first direction. The drum guide 512Y has the same shape as the drum guide 511Y (see FIG. 8), the drum guide 512M has the same shape as the drum guide 511M (see FIG. 8), the drum guide 512C has the same shape as the drum guide 511C (see FIG. 8), and the drum guide 512K has the same shape as the drum guide 511K (see FIG. 8).

[0167] When the drum unit 6 is attached to the drawer 5, the drum guide 512Y guides the protrusion 633Y of the drum unit 6, the drum guide 512M guides the protrusion 633M of the drum unit 6, the drum guide 512C guides the protrusion 633C of the drum unit 6, and the drum guide 512K guides the protrusion 633K of the drum unit 6.

[0168] When the drum unit 6 is attached to the drawer 5, the protrusion 633Y of the drum unit 6 fits into the drum guide 512Y, the protrusion 633M of the drum unit 6 fits into the drum guide 512M, the protrusion 633C of the drum unit 6 fits into the drum guide 512C, and the protrusion 633K of the drum unit 6 fits into the drum guide 512K, so that the drawer side panel 51B supports the other end of the drum unit 6 in the first direction.

[0169] 4.3 Ribs 52Y, 52M, 52C, 52K As shown in Fig. 4, the rib 52Y is located on the inner surface S32 of the drawer side plate 51A. The rib 52Y extends from the inner surface S32 of the drawer side plate 51A. The rib 52Y extends in the first direction and the third direction. The rib 52Y may be attached to the inner surface S32 of the drawer side plate 51A. The rib 52Y is located on the opposite side of the drum side plate 63A from the drum side plate 63B in the first direction.

[0170] As shown in FIG. 8, in this embodiment, the rib 52Y has a protrusion 521Y.

[0171] The protrusion 521Y is attached to the rib 52Y. In this embodiment, the protrusion 521Y has wheels. The protrusion 521Y may extend from the drawer side panel 51A.

[0172] 4, when the cartridge 8Y is attached to the drawer 5, the protrusion 521Y comes into contact with one end of the cartridge 8Y in the first direction. More specifically, when the cartridge 8Y is attached to the drawer 5, the protrusion 521Y comes into contact with a rib 83Y1 of the cartridge 8Y. As a result, when the cartridge 8Y is attached to the drawer 5, the rib 52Y supports one end of the cartridge 8Y in the first direction.

[0173] 8, the ribs 52Y, 52M, 52C, and 52K are aligned in the second direction. Each of the ribs 52M, 52C, and 52K will be described in the same manner as the rib 52Y. Therefore, a description of each of the ribs 52M, 52C, and 52K will be omitted.

[0174] 4.4 Ribs 53Y, 53M, 53C, 53K 4, the rib 53Y is located away from the rib 52Y in the first direction. The drum unit 6 is attached to the drawer 5 by passing between the rib 52Y and the rib 53Y.

[0175] The rib 53Y is located on the inner surface S42 of the drawer side plate 51B. The rib 53Y extends from the inner surface S42 of the drawer side plate 51B. The rib 53Y extends in the first direction and the third direction. The rib 53Y may be attached to the inner surface S42 of the drawer side plate 51B. The rib 53Y is located on the opposite side of the drum side plate 63A to the drum side plate 63B in the first direction.

[0176] As shown in FIG. 1, in this embodiment, the rib 53Y has a protrusion 531Y.

[0177] The protrusion 531Y is attached to the rib 53Y. In this embodiment, the protrusion 531Y has wheels. The protrusion 531Y may extend from the drawer side plate 51B.

[0178] As shown in FIG. 4, the protrusion 531Y is located away from the protrusion 521Y in the first direction. The drum unit 6 is attached to the drawer 5 through between the protrusion 521Y and the protrusion 531Y. When the cartridge 8Y is attached to the drawer 5, the protrusion 531Y comes into contact with the other end of the cartridge 8Y in the first direction. More specifically, when the cartridge 8Y is attached to the drawer 5, the protrusion 531Y comes into contact with the rib 83Y2 of the cartridge 8Y. Thus, when the cartridge 8Y is attached to the drawer 5, the rib 53Y supports the other end of the cartridge 8Y in the first direction.

[0179] 1, the ribs 53Y, 53M, 53C, and 53K are aligned in the second direction. Each of the ribs 53M, 53C, and 53K will be described in the same manner as the rib 53Y. Therefore, a description of each of the ribs 53M, 53C, and 53K will be omitted.

[0180] 4.5 Developing Pressing Members 54Y, 54M, 54C, 54K 4, in this embodiment, the developer pressing member 54Y is attached to the rib 52Y. The developer pressing member 54Y may be attached to the drawer side plate 51A. When the drum unit 6 is attached to the drawer 5, the developer pressing member 54Y is located on the opposite side of the drum side plate 63A from the drum side plate 63B in the first direction.

[0181] With the drum unit 6 and the cartridge 8Y attached to the drawer 5, the developer pressing member 54Y presses one end of the cartridge 8Y in the first direction toward the photosensitive drum 61Y. More specifically, the developer pressing member 54Y presses a protrusion 84Y1 of the cartridge 8Y toward the photosensitive drum 61Y.

[0182] The developing device pressing members 54M, 54C, and 54K (see FIG. 8) will be described in the same manner as the developing device pressing member 54Y, and therefore, the description of the developing device pressing members 54M, 54C, and 54K will be omitted.

[0183] 4.6 Developing Pressing Members 55Y, 55M, 55C, 55K The developer pressing member 55Y is positioned away from the developer pressing member 54Y in the first direction. The drum unit 6 is attached to the drawer 5 through between the developer pressing member 54Y and the developer pressing member 55Y.

[0184] In this embodiment, the developer pressing member 55Y is attached to the rib 53Y. The developer pressing member 55Y may be attached to the drawer side plate 51B. When the drum unit 6 is attached to the drawer 5, the developer pressing member 55Y is located on the opposite side of the drum side plate 63A with respect to the drum side plate 63B in the first direction.

[0185] With the drum unit 6 and the cartridge 8Y attached to the drawer 5, the developer pressing member 55Y presses the other end of the cartridge 8Y in the first direction toward the photosensitive drum 61Y. More specifically, the developer pressing member 55Y presses the protrusion 84Y2 of the cartridge 8Y toward the photosensitive drum 61Y.

[0186] The developing device pressing members 55M, 55C, and 55K (see FIG. 1) will be described in the same manner as the developing device pressing member 55Y. Therefore, the description of the developing device pressing members 55M, 55C, and 55K will be omitted.

[0187] 4.7 Seat guide 56 1, when the drum unit 6 is attached to the drawer 5, the sheet guide 56 is located on the opposite side of the photosensitive drum 61M with respect to the photosensitive drum 61Y. When the drum unit 6 is attached to the drawer 5 and the drawer 5 is located in the storage position, the sheet guide 56 guides the sheet S transported toward the photosensitive drum 61Y. More specifically, the sheet guide 56 guides the sheet S transported toward the photosensitive drum 61Y toward the belt 91.

[0188] 5. Effects (1) According to the image forming apparatus 1, the drum unit 6 having the photosensitive drums 61Y, 61M, 61C, and 61K (see FIG. 1) can be replaced with a new one in the drawer 5 as shown in FIG.

[0189] Therefore, the photosensitive drums 61Y, 61M, 61C, and 61K can be easily replaced.

[0190] The drum unit 6 also has a waste toner tube 65 .

[0191] Therefore, when the drum unit 6 is removed from the drawer 5, the waste toner tube 65 is not separated from the drum unit 6.

[0192] This can prevent the waste toner from leaking during replacement of the drum unit 6.

[0193] (2) According to the image forming apparatus 1, as shown in FIG. 4, the distance D1 between the inner surface S32 and the inner surface S42 in the first direction is longer than the distance D2 between the inner surface S31 and the inner surface S41 in the first direction.

[0194] This allows the drum unit 6 to easily pass between the inner surface S32 and the inner surface S42.

[0195] Therefore, the drum unit 6 can be replaced smoothly.

[0196] (3) According to the image forming apparatus 1, as shown in Fig. 4, the rib 52Y is located on the opposite side of the drum side plate 63A from the drum side plate 63B in the first direction. The rib 53Y is located on the opposite side of the drum side plate 63B from the drum side plate 63A in the first direction.

[0197] As a result, when the cartridge 8Y is attached to the drawer 5, the cartridge 8Y can be stably supported by the ribs 52Y and 53Y, and when replacing the drum unit 6, the drum unit 6 can be replaced through the gap between the ribs 52Y and 53Y.

[0198] (4) According to the image forming apparatus 1, as shown in Fig. 4, the developing device pressing member 54Y is located on the opposite side of the drum side plate 63B from the drum side plate 63A in the first direction. The developing device pressing member 55Y is located on the opposite side of the drum side plate 63B from the drum side plate 63A in the first direction.

[0199] As a result, when the cartridge 8Y is attached to the drawer 5, the cartridge 8Y can be pressed against the photosensitive drum 61Y by the developer pressing member 54Y and the developer pressing member 55Y, and when replacing the drum unit 6, the drum unit 6 can be replaced through the gap between the developer pressing member 54Y and the developer pressing member 55Y.

[0200] 6. Second embodiment Next, a second embodiment will be described with reference to Figures 9 to 20. In the second embodiment, the same members as those in the first embodiment are given the same reference numerals, and the description thereof will be omitted.

[0201] 6.1 Drum Unit 20 Details The drum unit 20 includes a drum side plate 201A (see FIG. 9), a drum side plate 201B (see FIG. 10), a plurality of frames 202Y, 202M, 202C, and 202K (see FIG. 11), a plurality of elastic members 203Y, 203M, 203C, and 203K (see FIG. 9), a plurality of elastic members 204Y (see FIG. 10), 204M, 204C, and 204K, a waste toner tube 205 (see FIG. 9), and a plurality of seal members 206Y, 206M, 206C, and 206K (see FIG. 11). The elastic members 204M, 204C, and 204K are not shown.

[0202] 6.1.1 Drum side panel 201A As shown in FIG. 10, the drum side plate 201A is located at one end of the drum unit 20 in the first direction. As shown in FIG. 9, the drum side plate 201A extends in the second direction and the third direction. The third direction intersects with the first direction and the second direction. Preferably, the third direction is perpendicular to the first direction and the second direction. The drum side plate 201A supports the frames 202Y, 202M, 202C, and 202K. More specifically, as shown in FIG. 11, the drum side plate 201A supports one end of each of the frames 202Y, 202M, 202C, and 202K in the first direction. As shown in FIG. 9, the drum side plate 201A has a plurality of through holes 2011Y, 2011M, 2011C, and 2011K.

[0203] The through holes 2011Y, 2011M, 2011C, and 2011K are aligned in the second direction. In other words, the through holes 2011Y, 2011M, 2011C, and 2011K are aligned in the movement direction of the drawer 30 (see FIGS. 1 and 2). Each of the through holes 2011Y, 2011M, 2011C, and 2011K has a circular shape.

[0204] 6.1.2 Drum side panel 201B As shown in FIG. 10, the drum side plate 201B is located at the other end of the drum unit 20 in the first direction. The drum side plate 201B is located away from the drum side plate 201A in the first direction. The drum side plate 201B extends in the second direction and the third direction. The drum side plate 201B supports the frames 202Y, 202M, 202C, and 202K (see FIG. 11) together with the drum side plate 201A. In detail, the drum side plate 201B supports the other end of each of the frames 202Y, 202M, 202C, and 202K in the first direction. The drum side plate 201B has a plurality of through holes 2012Y, 2012M, 2012C, and 2012K. The through holes 2012M, 2012C, and 2012K are not shown.

[0205] The through holes 2012Y, 2012M, 2012C, and 2012K are aligned in the second direction. In other words, the through holes 2012Y, 2012M, 2012C, and 2012K are aligned in the movement direction of the drawer 30 (see FIG. 19). Each of the through holes 2012Y, 2012M, 2012C, and 2012K has a circular shape.

[0206] 6.1.3 Frame 202Y 12, the frame 202Y supports the above-mentioned photosensitive drum 61Y and the charging device 62Y. The frame 202Y has the above-mentioned drum cleaner 64Y. In other words, the frame 202Y has a cleaning housing 641Y as a first waste toner storage unit and a screw 643Y as a first conveying member.

[0207] The frame 202Y extends in the first direction. As shown in Fig. 10, the frame 202Y includes a frame side plate 2021Y, a frame side plate 2022Y, a support portion 2023Y, a support portion 2024Y, and a discharge portion 2025Y (see Fig. 11).

[0208] 6.1.3.1 Frame side panel 2021Y The frame side plate 2021Y is located at one end of the frame 202Y in the first direction. As shown in Fig. 11, the frame side plate 2021Y extends in the second and third directions. As shown in Fig. 12, the frame side plate 2021Y has the above-mentioned cartridge guide 632Y.

[0209] 6.1.3.2 Frame side panel 2022Y As shown in Fig. 10, the frame side plate 2022Y is located at the other end of the frame 202Y in the first direction. The frame side plate 2022Y is located away from the frame side plate 2021Y in the first direction. The frame side plate 2022Y extends in the second direction and the third direction. The frame side plate 2022Y has the above-mentioned cartridge guide 634Y (see Fig. 5).

[0210] 6.1.3.3 Support part 2023Y The support portion 2023Y is located on the opposite side of the frame side plate 2022Y with respect to the frame side plate 2021Y in the first direction. The support portion 2023Y extends from the frame side plate 2021Y. The support portion 2023Y may be attached to the frame side plate 2021Y. The support portion 2023Y extends in the first direction. The support portion 2023Y has a cylindrical shape. The support portion 2023Y supports one end of the photosensitive drum 61Y in the first direction.

[0211] The support portion 2023Y fits into the through hole 2011Y of the drum side plate 201A. The support portion 2023Y passes through the through hole 2011Y of the drum side plate 201A. The outer peripheral surface of the support portion 2023Y is spaced apart from the inner peripheral surface of the through hole 2011Y of the drum side plate 201A. This allows the frame 202Y to move relative to the drum side plate 201A.

[0212] 6.1.3.4 Support part 2024Y The support portion 2024Y is located on the opposite side of the frame side plate 2022Y from the frame side plate 2021Y in the first direction. The support portion 2024Y extends from the frame side plate 2022Y. The support portion 2024Y may be attached to the frame side plate 2022Y. The support portion 2024Y extends in the first direction. The support portion 2024Y has a cylindrical shape. The support portion 2024Y supports the other end portion of the photosensitive drum 61Y in the first direction.

[0213] The support portion 2024Y fits into the through hole 2012Y of the drum side plate 201B. The support portion 2024Y passes through the through hole 2012Y of the drum side plate 201B. The outer peripheral surface of the support portion 2024Y is spaced apart from the inner peripheral surface of the through hole 2012Y of the drum side plate 201B. This allows the frame 202Y to move relative to the drum side plate 201B.

[0214] 6.1.3.5 Discharge section 2025Y As shown in FIG. 11, the discharge portion 2025Y is located on the opposite side of the frame side plate 2022Y (see FIG. 10) with respect to the frame side plate 2021Y in the first direction. The discharge portion 2025Y is located away from the support portion 2023Y. The discharge portion 2025Y extends from the frame side plate 2021Y. The discharge portion 2025Y may be attached to the frame side plate 2021Y. The discharge portion 2025Y is located between the frame side plate 2021Y (see FIG. 10) and the drum side plate 201A (see FIG. 10) in the first direction. The discharge portion 2025Y extends in the first direction. In this embodiment, the discharge portion 2025Y has a cylindrical shape. The discharge portion 2025Y communicates with the cleaning housing 641Y. One end of the screw 643Y in the first direction is located within the discharge portion 2025Y. The discharge section 2025Y has a discharge port 2026Y. The screw 643Y transports the waste toner in the cleaning housing 641Y toward the discharge port 2026Y. The discharge port 2026Y can discharge the toner in the cleaning housing 641Y.

[0215] 6.1.4 Frames 202M, 202C, 202K Frames 202Y, 202M, 202C, and 202K are aligned in the second direction. Frames 202M, 202C, and 202K will be described similarly to frame 202Y.

[0216] Specifically, as shown in FIG. 11, the frame 202M supports the above-mentioned photosensitive drum 61M and the charging device 62M (see FIG. 12). The frame 202M has the above-mentioned drum cleaner 64M. In other words, the frame 202M has a cleaning housing 641M as a second waste toner storage section and a screw 643M as a second conveying member. The screw 643M is located inside the cleaning housing 641M. Furthermore, the frame 202M has a support portion 2023M (see FIG. 9), a support portion 2024M, and a discharge portion 2025M. Note that the support portion 2024M is not shown.

[0217] As shown in Fig. 9, the support portion 2023M supports one end of the photosensitive drum 61M in the first direction. The support portion 2023M passes through a through hole 2011M of the drum side plate 201A. As shown in Fig. 11, the frame 202M is movable relative to the drum side plate 201A.

[0218] The support portion 2024M supports the other end of the photosensitive drum 61M in the first direction. The support portion 2024M passes through a through hole 2012M in the drum side plate 201B (see FIG. 10). The frame 202M is movable relative to the drum side plate 201B (see FIG. 10).

[0219] 11, the discharge portion 2025M has a discharge port 2026M. The screw 643M transports the waste toner in the cleaning housing 641M toward the discharge port 2026M. The discharge port 2026M can discharge the waste toner in the cleaning housing 641M.

[0220] 6.1.5 Elastic members 203Y, 203M, 203C, 203K As shown in FIG. 9, the elastic member 203Y is located between the outer peripheral surface of the support portion 2023Y and the inner peripheral surface of the through hole 2011Y. The elastic member 203Y extends in the circumferential direction of the support portion 2023Y. The elastic member 203M is located between the outer peripheral surface of the support portion 2023M and the inner peripheral surface of the through hole 2011M. The elastic member 203M extends in the circumferential direction of the support portion 2023M. The elastic member 203C is located between the outer peripheral surface of the support portion 2023C and the inner peripheral surface of the through hole 2011C. The elastic member 203C extends in the circumferential direction of the support portion 2023C. The elastic member 203K is located between the outer peripheral surface of the support portion 2023K and the inner peripheral surface of the through hole 2011K. The elastic member 203K extends in the circumferential direction of the support portion 2023K.

[0221] In this embodiment, the elastic members 203Y, 203M, 203C, and 203K are made of sponge.

[0222] 6.1.6 Elastic members 204Y, 204M, 204C, 204K The description of the elastic members 204Y (see FIG. 10), 204M, 204C, and 204K is similar to the description of the elastic members 203Y, 203M, 203C, and 203K, so the description of the elastic members 204M, 204C, and 204K will be omitted.

[0223] 6.1.7 Waste Toner Tube 205 11, the waste toner pipe 205 is located at the lower end of the drum unit 20. The waste toner pipe 205 is attached to the lower end of the drum side plate 201A. In this way, the drum side plate 201A supports the waste toner pipe 205. The waste toner pipe 205 is located below each of the discharge portions 2025Y, 2025M, 2025C, and 2025K. The waste toner pipe 205 is located away from each of the discharge portions 2025Y, 2025M, 2025C, and 2025K in the third direction.

[0224] Waste toner tube 205 allows the passage of waste toner from discharge portion 2025Y, waste toner from discharge portion 2025M, waste toner from discharge portion 2025C, and waste toner from discharge portion 2025K. Waste toner tube 205 extends in the second direction. Waste toner tube 205 has a plurality of receiving openings 2051Y, 2051M, 2051C, and 2051K.

[0225] The receiving openings 2051Y, 2051M, 2051C, and 2051K are aligned in the second direction. The receiving opening 2051Y can receive the waste toner discharged from the discharge opening 2026Y. The receiving opening 2051M can receive the waste toner discharged from the discharge opening 2026M. The receiving opening 2051C can receive the waste toner discharged from the discharge opening 2026C. The receiving opening 2051K can receive the waste toner discharged from the discharge opening 2026K.

[0226] 6.1.8 Seal members 206Y, 206M, 206C, 206K The seal member 206Y is located between the discharge portion 2025Y and the waste toner tube 205. The seal member 206Y seals between the waste toner tube 205 and the discharge portion 2025Y. In other words, the seal member 206Y seals between the waste toner tube 205 and the frame 202Y. The seal member 206Y extends in the third direction. One end of the seal member 206Y in the third direction contacts the discharge portion 2025Y. The other end of the waste toner tube 205 in the third direction contacts the waste toner tube 205. The seal member 206Y has a through hole 2061Y. The through hole 2061Y communicates with the discharge port 2026Y and the receiving port 2051Y. In this embodiment, the seal member 206Y is made of an elastic material such as a sponge.

[0227] The seal member 206M is located between the discharge portion 2025M and the waste toner pipe 205. The seal member 206M provides a seal between the waste toner pipe 205 and the frame 202M. The seal member 206M has a through hole 2061M. The through hole 2061M communicates with the discharge port 2026M and the receiving port 2051M.

[0228] The seal member 206C is located between the discharge portion 2025C and the waste toner tube 205. The seal member 206C provides a seal between the waste toner tube 205 and the frame 202C. The seal member 206C has a through hole 2061C. The through hole 2061C communicates with the discharge port 2026C and the receiving port 2051C.

[0229] The seal member 206K is located between the discharge portion 2025K and the waste toner pipe 205. The seal member 206K provides a seal between the waste toner pipe 205 and the frame 202K. The seal member 206K has a through hole 2061K. The through hole 2061K communicates with the discharge port 2026K and the receiving port 2051K.

[0230] The seal members 206M, 206C, and 206K can be explained in the same manner as the seal member 206Y, and therefore, explanations of the seal members 206M, 206C, and 206K will be omitted.

[0231] 7. Details of Drawer 30 The drawer 30 will now be described in detail with reference to FIGS.

[0232] As shown in FIG. 13, drawer 30 has drawer side panel 301A, drawer side panel 301B, positioning plate 302A, positioning plate 302B, locking member 303A, locking member 303B, first positioned portion 304 (see FIG. 15), and second positioned portion 305 (see FIG. 15).

[0233] 7.1 Drawer side panel 301A As shown in FIG. 16, the drawer side panel 301A has a recess 311 in addition to the outer surface S21, the inner surface S31, and the inner surface S32 described above.

[0234] The recess 311 is recessed from the outer surface S21 toward the inner surface S31 in the first direction. As shown in Fig. 17, the recess 311 communicates with the lower ends of the drum guides 511Y, 511M, 511C, and 511K.

[0235] 14, in this embodiment, when the drum unit 20 is attached to the drawer 30, the drum guide 511Y guides the support portion 2023Y. When the drum unit 20 is attached to the drawer 30, the support portion 2023Y fits into the drum guide 511Y.

[0236] The drum guides 511M, 511C, and 511K will be described in the same manner as the drum guide 511Y. Therefore, the description of the drum guides 511M, 511C, and 511K will be omitted.

[0237] 7.2 Drawer side panel 301B As shown in FIG. 13, the drawer side panel 301B is positioned away from the drawer side panel 301A in the first direction.

[0238] The drawer side panel 301B will be described in the same manner as the drawer side panel 301A, and therefore a description of the drawer side panel 301B will be omitted.

[0239] 7.3 Positioning plate 302A The positioning plate 302A is located on the inner surface S31 of the drawer side plate 301A. The positioning plate 302A is attached to the inner surface S31 of the drawer side plate 301A. When the drum unit 20 is attached to the drawer 30, the positioning plate 302A is located on the opposite side of the frame side plate 2021Y with respect to the drum side plate 201A in the first direction.

[0240] 15, the positioning plate 302A extends in the second direction. In this embodiment, the positioning plate 302A is made of a metal such as iron or stainless steel. The positioning plate 302A has a plurality of recesses 331Y, 331M, 331C, and 331K.

[0241] When the drum unit 20 is attached to the drawer 30, the support portion 2023Y fits into the recess 331Y, the support portion 2023M fits into the recess 331M, the support portion 2023C fits into the recess 331C, and the support portion 2023K fits into the recess 331K.

[0242] When the drum unit 20 is attached to the drawer 30, the positioning plate 302A comes into contact with the support portion 2023Y, whereby the positioning plate 302A positions the support portion 2023Y relative to the drawer 30. As a result, when the drum unit 20 is attached to the drawer 30, the positioning plate 302A positions the photosensitive drum 61Y relative to the drawer 30.

[0243] Furthermore, when the drum unit 20 is attached to the drawer 30, the positioning plate 302A comes into contact with the support portion 2023M, whereby the positioning plate 302A positions the support portion 2023M relative to the drawer 30. As a result, when the drum unit 20 is attached to the drawer 30, the positioning plate 302A positions the photosensitive drum 61M relative to the drawer 30.

[0244] Furthermore, when the drum unit 20 is attached to the drawer 30, the positioning plate 302A comes into contact with the support portion 2023C, whereby the positioning plate 302A positions the support portion 2023C relative to the drawer 30. As a result, when the drum unit 20 is attached to the drawer 30, the positioning plate 302A positions the photosensitive drum 61C relative to the drawer 30.

[0245] Furthermore, when the drum unit 20 is attached to the drawer 30, the positioning plate 302A comes into contact with the support portion 2023K, whereby the positioning plate 302A positions the support portion 2023K relative to the drawer 30. As a result, when the drum unit 20 is attached to the drawer 30, the positioning plate 302A positions the photosensitive drum 61K relative to the drawer 30.

[0246] 7.4 Positioning plate 302B As shown in FIG. 13, the positioning plate 302B is located away from the positioning plate 302A in the first direction. The positioning plate 302B is located on the inner surface S41 of the drawer side plate 301B. The positioning plate 302B is attached to the inner surface S41 of the drawer side plate 301B. When the drum unit 20 is attached to the drawer 30, the positioning plate 302B is located on the opposite side of the frame side plate 2022Y with respect to the drum side plate 201B in the first direction. When the drum unit 20 is attached to the drawer 30, the positioning plate 302B is located on the opposite side of the positioning plate 302A with respect to the photosensitive drums 61Y, 61M, 61C, and 61K (see FIG. 12) in the first direction.

[0247] The positioning plate 302B extends in the second direction. In this embodiment, the positioning plate 302B has the same shape as the positioning plate 302A. The positioning plate 302B may have a different shape from the positioning plate 302A. The positioning plate 302B has a plurality of recesses 332Y, 332M, 332C, and 332K. The recesses 332M, 332C, and 332K are not shown.

[0248] When the drum unit 20 is attached to the drawer 30, the support portion 2024Y fits into the recess 332Y, the support portion 2024M fits into the recess 332M, the support portion 2024C fits into the recess 332C, and the support portion 2024K fits into the recess 332K. Thus, the positioning plate 302B, together with the positioning plate 302A, positions the photosensitive drums 61Y, 61M, 61C, and 61K relative to the drawer 30.

[0249] 7.5 Locking member 303A The locking member 303a is attached to the outer surface S21 of the drawer side panel 301A. As shown in Figs. 13 and 16, when the drum unit 20 is attached to the drawer 30, the locking member 303A is movable between a locked position (see Fig. 13) and an unlocked position (see Fig. 16). The locking member 303A is rotatable about an axis A5 between the locked position (see Fig. 13) and the unlocked position (see Fig. 16). The axis A5 extends in a direction from the storage position (see Fig. 1) of the drawer 30 toward the pulled-out position (see Fig. 2).

[0250] 13, when the drawer 30 is in the locked position, the locking member 303A locks the drum unit 20 to the drawer 30. When the locking member 303A is in the locked position, the locking member 303A is located in the recess 311. When the locking member 303A is in the locked position, the locking member 303a extends in the third direction.

[0251] 16, when the drawer 30 is in the unlocked position, the locking member 303A unlocks the drum unit 20 from the drawer 30. When the locking member 303A is in the unlocked position, a part of the locking member 303a is located outside the recess 311. When the locking member 303A is in the unlocked position, the locking member 303a extends in the first direction.

[0252] As shown in FIG. 14, the locking member 303A extends in the second direction. The locking member 303A has a plate shape. As shown in FIG. 13, the locking member 303A has a first surface S5 and a second surface S6. When the locking member 303A is in the locked position, the second surface S6 is located between the drum side plate 201A and the first surface S5 in the first direction. As shown in FIG. 14, the locking member 303A has a plurality of holes 351Y, 351M, 351C, 351K, a plurality of drum pressing members 352Y, 352M, 352C, 352K, and a handle 353.

[0253] 7.5.1 Hole 351Y, 351M, 351C, 351K The holes 351Y, 351M, 351C, and 351K are aligned in the second direction. Each of the holes 351Y, 351M, 351C, and 351K has a circular shape. In this embodiment, each of the holes 351Y, 351M, 351C, and 351K is a through hole.

[0254] As shown in FIG. 13, when the drum unit 20 is attached to the drawer 30 and the locking member 303A is located at the locking position, the support portion 2023Y of the frame 202Y fits into the hole 351Y. When the locking member 303A is located at the locking position, the support portion 2023Y passes through the hole 351Y. When the drum unit 20 is attached to the drawer 30 and the locking member 303A is located at the locking position, the coupling 610Y of the photosensitive drum 61Y is exposed through the hole 351Y. The coupling 610Y is located at one end of the photosensitive drum 61Y in the first direction. The photosensitive drum 61Y has a coupling 610Y. When the drawer 30 is located at the storage position, the main body coupling 400Y fits into the coupling 610Y.

[0255] As shown in FIG. 14, when the drum unit 20 is attached to the drawer 30 and the locking member 303A is in the locked position, the support portion 2023M of the frame 202M fits into the hole 351M, the support portion 2023C of the frame 202C fits into the hole 351C, and the support portion 2023K of the frame 202K fits into the hole 351K.

[0256] The holes 351M, 351C, and 351K will be described in the same manner as the hole 351Y, and therefore a description of the holes 351M, 351C, and 351K will be omitted.

[0257] 7.5.2 Drum pressing members 352Y, 352M, 352C, 352K 14, the drum pressing member 352Y is located at the upper end of the hole 351Y. The drum pressing member 352M is located at the upper end of the hole 351M. The drum pressing member 352C is located at the upper end of the hole 351C. The drum pressing member 352K is located at the upper end of the hole 351K.

[0258] As shown in FIG. 15, when the drum unit 20 is attached to the drawer 30 and the locking member 303A is positioned in the locked position, the drum pressing member 352Y presses the support portion 2023Y toward the recess 331Y of the positioning plate 302A, the drum pressing member 352M presses the support portion 2023M toward the recess 331M of the positioning plate 302A, the drum pressing member 352C presses the support portion 2023C toward the recess 331C of the positioning plate 302A, and the drum pressing member 352K presses the support portion 2023K toward the recess 331K of the positioning plate 302A. As a result, when the drum unit 20 is attached to the drawer 30 and the locking member 303A is in the locked position, the locking member 303A presses the support portions 2023Y, 2023M, 2023C, and 2023K toward the positioning plate 302A.

[0259] In this embodiment, the drum pressing members 352Y, 352M, 352C, and 352K are springs.

[0260] 7.5.3 Handle 353 As shown in FIG. 13, the handle 353 is attached to the first surface S5 of the locking member 303A. The handle 353 may extend from the first surface S5. The handle 353 is rotatable about an axis A6. The axis A6 extends parallel to the axis A5. When the locking member 303A is in the locked position, the handle 353 is located away from the axis A5 in the third direction. When the locking member 303A is in the locked position, the handle 353 is attached to the opposite side of the hole 351Y with respect to the axis A5 in the third direction.

[0261] 7.6 Locking member 303B The locking member 303B is attached to the drawer side plate 301B. The locking member 303B is attached to the outer surface S22 of the drawer side plate 301B.

[0262] Locking member 303B is described similarly to locking member 303A.

[0263] In detail, the lock member 303B has a plurality of holes 361Y, 361M, 361C, and 361K, a plurality of drum pressing members 362Y, 362M, 362C, and 362K, and a handle 363. Note that the holes 361M, 361C, and 361K and the drum pressing members 362M, 362C, and 362K are not shown in the figure.

[0264] 13 and 16, when the drum unit 20 is attached to the drawer 30, the locking member 303B is movable between a second lock position (see FIG. 13) and a second unlocked position (see FIG. 16). When the locking member 303B is located at the second lock position as shown in FIG. 13, the locking member 303B locks the drum unit 20 to the drawer 30. When the locking member 303B is located at the second unlocked position as shown in FIG. 16, the locking member 303B releases the lock of the drum unit 20 to the drawer 30.

[0265] 13, when the drum unit 20 is attached to the drawer and the locking member 303B is located at the second lock position, the support portion 2024Y fits into the hole 361Y, the support portion 2024M fits into the hole 361M, the support portion 2024C fits into the hole 361C, and the support portion 2024K fits into the hole 361K. As a result, when the drum unit 20 is attached to the drawer 30 and the locking member 303B is located at the second lock position, the locking member 303B presses the support portions 2024Y, 2024M, 2024C, and 2024K toward the positioning plate 302B.

[0266] 7.7 First positioned part 304 As shown in Fig. 15, the first positioned portion 304 is located at one end of the drawer 30 in the second direction. The first positioned portion 304 is a notch. More specifically, the first positioned portion 304 is located at one end of the positioning plate 302A in the second direction. In other words, the positioning plate 302A has the first positioned portion 304. In addition, the positioning plate 302B (see Fig. 18) also has the first positioned portion 304.

[0267] 7.8 Second positioned part 305 The second positioned portion 305 is located at the other end of the drawer 30 in the second direction. The second positioned portion 305 has a cylindrical shape. The second positioned portion 305 extends in the first direction. The second positioned portion 305 is made of a metal such as iron or stainless steel. The second positioned portion 305 is connected to the positioning plate 302A. The second positioned portion 305 protrudes from the outer surface S21 of the drawer side plate 301A in the first direction. The second positioned portion 305 is also connected to the positioning plate 302B (see FIG. 13).

[0268] 8. Details of the main body 40 The main body housing 40 has a side plate 41A (see FIG. 18), a side plate 41B (see FIG. 18), a first positioning member 42 (see FIG. 19), and a second positioning member 43 (see FIG. 19).

[0269] 8.1 Side plate 41A As shown in Fig. 18, the side plate 41A is located inside the main body housing 40. When the drawer 30 is in the storage position, the side plate 41A faces the drawer side plate 301A. The side plate 41A is made of a metal such as iron or stainless steel. The side plate 41A extends in the third direction and the second direction (see Fig. 19).

[0270] 8.2 Side plate 41B The side plate 41B is located within the main housing 40. The side plate 41B is located away from the side plate 41A in the first direction. When the drawer 30 is in the storage position, the side plate 41B is located on the opposite side of the drawer 30 from the side plate 41A. When the drawer 30 is in the storage position, the side plate 41B faces the drawer side plate 301B. The side plate 41B is made of a metal such as iron or stainless steel. The side plate 41B extends in the third direction. As shown in FIG. 19, the side plate 41B extends in the second direction.

[0271] 8.3 First positioning member 42 The first positioning member 42 is located at one end of the side plate 41B in the second direction. The first positioning member 42 extends in the first direction. The first positioning member 42 has a cylindrical shape. In this embodiment, the first positioning member 42 is attached to the side plate 41B. The first positioning member 42 may extend from the side plate 41B. The first positioning member 42 is also located on the side plate 41A (see FIG. 18).

[0272] 20, when the drawer 30 is in the storage position, the first positioning member 42 fits into the first positioned portion 304. As a result, when the drawer 30 is in the storage position, the first positioned portion 304 is positioned by the first positioning member 42. When the drawer 30 is in the storage position, the first positioning member 42 positions one end of the drawer 30 in the movement direction of the drawer 30 relative to the main housing 40.

[0273] As shown in FIG. 19, when the drawer 30 is in the pulled-out position, the first positioned portion 304 moves away from the first positioning member 42.

[0274] 8.4 Second positioning member 43 The second positioning member 43 is located at the other end of the side plate 41B in the second direction. The second positioning member 43 is a notch. More specifically, in this embodiment, the second positioning member 43 is provided on the side plate 41B. In other words, the side plate 41B has the second positioning member 43. The side plate 41A (see FIG. 18) also has the second positioning member 43.

[0275] 20, when the drawer 30 is in the storage position, the second positioned portion 305 fits into the second positioning member 43. As a result, when the drawer 30 is in the storage position, the second positioned portion 305 is positioned by the second positioning member 43. When the drawer 30 is in the storage position, the second positioning member 43 positions the other end of the drawer 30 in the movement direction of the drawer 30 relative to the main housing 40.

[0276] As shown in FIG. 19, when the drawer 30 is in the pulled-out position, the second positioned portion 305 moves away from the second positioning member 43.

[0277] 9. Effects of the Second Embodiment (1) In the image forming device 1, as shown in FIG. 19, when the drawer 30 is in the pulled-out position and the drum unit 6 is attached to the drawer 5, the positions of the photosensitive drum 61Y and the photosensitive drum 61M can be determined by the positioning plate 302A (see FIG. 15).

[0278] 20, by moving the drawer 30 from the pulled-out position to the stored position, the photosensitive drums 61Y and 61M can be stored in the main body housing 40 with the positions of the photosensitive drums 61Y and 61M determined.

[0279] Therefore, compared to the first embodiment (see FIG. 4) in which the photosensitive drums 61Y and 61M are positioned relative to the positioning plate 22A inside the main body housing 2 when the drawer 5 is placed in the storage position, the image forming apparatus 1 of the second embodiment can smoothly position the photosensitive drums 61Y and 61M relative to the main body housing 40.

[0280] (2) In image forming apparatus 1, as shown in FIG. 19, when drawer 30 is in the pulled-out position and drum unit 20 is removed from drawer 30, sealing members 206Y and 206M (see FIG. 11) can prevent waste toner from leaking from frames 202Y and 202M.

[0281] 10. Variations (1) The cartridge 8Y may be a toner cartridge that does not have the developing roller 81Y. In this case, the drum unit 20 may have a developing device that has the developing roller 81Y.

[0282] (2) The transfer device 9 may be of an intermediate transfer type.

[0283] (3) The cartridge 8Y may not have the ribs 83Y1, 83Y2. In this case, the rib 52Y of the drawer 5 may support one end of the cartridge housing 82Y in the first direction. The one end of the cartridge housing 82Y may be a gear cover. Furthermore, the rib 53Y of the drawer 5 may support the other end of the cartridge housing 82Y in the first direction. The other end of the cartridge housing 82Y may be a gear cover.

[0284] (4) The cartridge 8Y may not have the protrusions 84Y1, 84Y2. In this case, the developer pressing member 54Y of the drawer 5 may press one end of the cartridge housing 82Y in the first direction. The one end of the cartridge housing 82Y may be a gear cover. Furthermore, the developer pressing member 54Y of the drawer 5 may press the other end of the cartridge housing 82Y in the first direction. The other end of the cartridge housing 82Y may be a gear cover. [Explanation of symbols]

[0285] 1. Image forming device 2 Main unit 5 Drawer 6 Drum Unit 8Y Cartridge (1st Cartridge) 8M Cartridge (2nd Cartridge) 11 Waste toner storage compartment 20 Drum unit 22A Positioning plate (first positioning plate) 22B Positioning plate (second positioning plate) 30 Drawer 40 Main unit housing 42 First positioning member 43 Second positioning member 51A Drawer side panel (first drawer side panel) 51B Drawer side panel (second drawer side panel) 52Y Rib (First Rib) 53Y Rib (2nd Rib) 54Y developing press member (first developing press member) 55Y developing press member (second developing press member) 56 Seat guide 61Y Photosensitive drum (first photosensitive drum) 61M Photosensitive drum (second photosensitive drum) 63A Drum side panel (first drum side panel) 63B Drum side panel (second drum side panel) 65 Waste Toner Tube 81Y Developing roller 201A Drum side panel 202Y Frame (1st Frame) 202M frame (2nd frame) 203Y Elastic member (first elastic member) 203M Elastic member (second elastic member) 205 Waste toner tube 206Y Sealing member (first sealing member) 206M Sealing material (second sealing material) 302A Positioning plate 302B Positioning plate (second positioning plate) 303A Locking member (first locking member) 303B Locking member (second locking member) 304 1st positioned part 305 Second positioned part 351Y hole (1st hole) 351M hole (2nd hole) 352Y Drum pressing member (first drum pressing member) 352M Drum pressing member (second drum pressing member) 361Y hole (3rd hole) 361M hole (4th hole) 362Y Drum pressing member (third drum pressing member) 362M Drum pressing member (fourth drum pressing member) 511Y Drum Guide 632Y Cartridge Guide (1st Cartridge Guide) 632M Cartridge Guide (Second Cartridge Guide) 641Y Cleaning housing (1st waste toner storage unit) 641M Cleaning unit (second waste toner storage unit) 643Y Screw (first conveying member) 643M Screw (second conveying member) 2011Y Through hole (1st through hole) 2011M Through hole (second through hole) 2023Y Support part (1st support part) 2023M Support part (2nd support part) 2024Y Support part (3rd support part) 2024M Support part (4th support part) 2025Y Discharge section (1st discharge section) 2025M Discharge section (2nd discharge section) 2026Y Discharge port (1st discharge port) 2026M Discharge port (2nd discharge port) 2051Y Intake (1st Intake) 2051M Inlet (2nd intake) A1 First axis A5 axis A12 2nd axis D1 Distance D2 distance S Seat S31 Inside S32 Inside S41 Inside S42 Inside

Claims

1. A main body housing; a drawer movable between a storage position in which the drawer is stored in the main body housing and a pull-out position in which the drawer is pulled out from the main body housing; a drum unit including a first photosensitive drum, a second photosensitive drum, and a waste toner tube through which waste toner from the first photosensitive drum and waste toner from the second photosensitive drum pass, the drum unit being attachable to the drawer when the drawer is in the pulled-out position; An image forming apparatus comprising:

2. the first photosensitive drum is rotatable about a first axis extending in a first direction; The drum unit includes: a first drum side plate supporting one end of the first photosensitive drum in the first direction; a second drum side plate that supports the other end of the first photosensitive drum in the first direction; having 2 . The image forming apparatus according to claim 1 , wherein the waste toner pipe is located between the first drum side plate and the second drum side plate in the first direction.

3. 3. The image forming apparatus according to claim 2, wherein a portion of the waste toner pipe is located below the first drum side plate when the drum unit is attached to the drawer.

4. the first photosensitive drum is rotatable about a first axis extending in a first direction; The main body housing includes: a first positioning plate that positions one end of the first photosensitive drum in the first direction relative to the main body housing when the drum unit is attached to the drawer and the drawer is located at the storage position; a second positioning plate that positions the other end of the first photosensitive drum in the first direction relative to the main body housing when the drum unit is attached to the drawer and the drawer is located at the storage position, 4. The image forming apparatus according to claim 1, wherein when the drum unit is attached to the drawer and the drawer is located in the storage position, the waste toner tube is located between the first positioning plate and the second positioning plate in the first direction.

5. The drawer comprises: The image forming apparatus according to claim 1 , further comprising a positioning plate for positioning the first photosensitive drum and the second photosensitive drum with respect to the drawer when the drum unit is attached to the drawer.

6. The drum unit includes: a first frame supporting the first photosensitive drum; a second frame supporting the second photosensitive drum; a drum side plate supporting the first frame and the second frame; having The image forming apparatus according to claim 5 , wherein each of the first frame and the second frame is movable relative to the drum side plate.

7. An image forming apparatus as described in claim 6, wherein the drum side panel supports the waste toner tube.

8. The first frame is a first waste toner storage unit that stores waste toner from the first photosensitive drum; a first discharge section having a first discharge port capable of discharging the waste toner in the first waste toner storage section, The second frame is a second waste toner storage unit that stores waste toner from the second photosensitive drum; a second discharge section having a second discharge port capable of discharging the waste toner in the second waste toner storage section, The waste toner pipe is a first receiving opening capable of receiving the waste toner discharged from the first discharge opening; a second receiving opening capable of receiving the waste toner discharged from the second discharge opening; having The drum unit includes: a first seal member having a through hole communicating with the first discharge port and the first receiving port, and sealing between the first frame and the waste toner tube; a second seal member having a through hole communicating with the second discharge port and the second receiving port, and sealing between the second frame and the waste toner tube; The image forming apparatus according to claim 7 .

9. The drum unit includes: a first conveying member located in the first waste toner storage unit and configured to convey the waste toner in the first waste toner storage unit toward the first discharge port; a second conveying member located in the second waste toner storage unit and configured to convey the waste toner in the second waste toner storage unit toward the second discharge port; The image forming apparatus according to claim 8 .

10. Further comprising a waste toner storage section capable of storing the waste toner, 10. The image forming apparatus according to claim 1, wherein the waste toner tube is connected to the waste toner storage unit when the drawer is in the storage position, and is separated from the waste toner storage unit when the drawer is in the extended position.

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