Image forming device

Abstract

To provide an image forming apparatus that can prevent a reduction in the accuracy of positioning a photoconductor drum in a body housing.SOLUTION: An image forming apparatus 1 comprises a drum cartridge 5Y, a developing cartridge 6Y, and a drawer 4. The drawer 4 includes a lock member 43Y. With the drum cartridge 5Y attached to the drawer 4, the lock member 43Y is movable between a lock position and a lock release position. With the lock member 43Y located at the lock position, the lock member 43Y locks a photoconductor drum 11Y to the drawer 4. With the lock member 43Y located at the lock release position, the lock member 43Y releases the lock of the photoconductor drum 11Y to the drawer 4.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] 2. Description of the Related Art Conventionally, there has been known an image forming apparatus in which a drum cartridge having a photosensitive drum and a developing cartridge having a developing roller are detachably attachable to a drawer (see Patent Document 1 below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-86729 A Summary of the Invention [Problem to be solved by the invention]

[0004] In an image forming apparatus as described in Patent Document 1, when an operator inserts or removes a developing cartridge into or from a drawer while the drum cartridge is attached to the drawer, the drum cartridge may move relative to the drawer. If the drum cartridge moves relative to the drawer, the positioning accuracy of the photosensitive drum within the main body housing may decrease.

[0005] In view of the above, an object of the present disclosure is to provide an image forming apparatus capable of suppressing a decrease in the positioning accuracy of a photosensitive drum within a main body housing. [Means for solving the problem]

[0006] (1) The image forming apparatus of the present disclosure includes a main body housing, a drum cartridge, a developing cartridge, and a drawer. The drum cartridge has a photosensitive drum. The developing cartridge has a developing roller. The drawer is movable between an inner position and an outer position. When the drawer is in the inner position, the drawer is located inside the main body housing. When the drawer is in the outer position, the drawer is located outside the main body housing. The drum cartridge and the developing cartridge are each detachable from the drawer.

[0007] The drawer includes a locking member. When the drum cartridge is attached to the drawer, the locking member is movable between a locked position and an unlocked position. When the locking member is located at the locked position, the locking member locks the photosensitive drum to the drawer. When the locking member is located at the unlocked position, the locking member releases the lock of the photosensitive drum from the drawer.

[0008] According to this configuration, when replacing the developer cartridge with the drum cartridge attached to the drawer, the developer cartridge can be replaced with respect to the drawer with the photosensitive drum locked to the drawer by the locking member.

[0009] Therefore, the photosensitive drum can be prevented from moving relative to the drawer during the replacement of the developing cartridge.

[0010] As a result, it is possible to suppress a decrease in the positioning accuracy of the photosensitive drum within the main body housing.

[0011] (2) The photosensitive drum is rotatable about a drum shaft. The drum shaft extends in the axial direction. The locking member may be rotatable about a first shaft between a locked position and an unlocked position. The first shaft may extend in the axial direction.

[0012] According to this configuration, when the locking member is moved between the locked position and the unlocked position, it is not necessary to move the locking member in the axial direction.

[0013] Therefore, it is possible to save space in the axial direction.

[0014] (3) The locking member may be rotatable about the drum shaft between a locked position and an unlocked position.

[0015] According to this configuration, the range of movement of the locking member relative to the photosensitive drum can be reduced.

[0016] Therefore, it is possible to prevent the drawer from becoming large due to the provision of the locking member.

[0017] (4) The locking member may have a disk shape. The locking member may have a lock guide and a through hole. The locking guide extends in a radial direction of the locking member. The through hole is located in the center of the locking member. The through hole is circular. The through hole is located within the locking guide. (5) The drawer may have a drawer guide. When the drum cartridge is attached to the drawer, the drawer guide guides one end of the photosensitive drum in the axial direction of the photosensitive drum. The locking member may have a lock guide. When the drum cartridge is attached to the drawer, one end of the photosensitive drum fits into the lock guide. When the locking member is in the locked position, the lock guide extends in a direction intersecting the extension direction of the drawer guide. When the locking member is in the unlocked position, the lock guide extends in the extension direction of the drawer guide and is connected to the drawer guide.

[0018] With this configuration, when the drum cartridge is attached to the drawer with the locking member in the unlocked position, one end of the photosensitive drum in the axial direction can be guided by the drawer guide and the locking guide, allowing it to be smoothly fitted into the locking member.

[0019] Furthermore, when the drum cartridge is attached to the drawer and the locking member is in the locked position, one end of the photosensitive drum in the axial direction can be locked to the drawer by the locking guide.

[0020] (6) The locking member may have a locking portion. When the locking member is in the locked position, the locking portion locks the photosensitive drum to the drawer. When the drum cartridge is installed in the drawer and the locking member is in the locked position, the locking portion is located between one end of the photosensitive drum and the drawer guide. When the drum cartridge is installed in the drawer and the locking member is in the unlocked position, the locking portion retracts from between one end of the photosensitive drum and the drawer guide.

[0021] According to this configuration, when the drum cartridge is attached to the drawer and the locking member is in the locked position, one end of the photosensitive drum in the axial direction can be locked to the drawer by the locking portion.

[0022] (7) The drawer may have a positioning plate. When the drum cartridge is installed in the drawer, the positioning plate comes into contact with one end of the photosensitive drum to determine the position of the photosensitive drum. The locking member may have a pressing member. When the drum cartridge is installed in the drawer, the pressing member presses one end of the photosensitive drum toward the positioning plate.

[0023] According to this configuration, the locking member can be used to press one end of the photosensitive drum against the positioning plate.

[0024] (8) The locking member may have a spring. When the drum cartridge is attached to the drawer, the spring presses the pressing member toward one end of the photosensitive drum.

[0025] (9) The positioning plate may have a recess. When the drum cartridge is attached to the drawer, one end of the photosensitive drum fits into the recess. When the drum cartridge is attached to the drawer, the pressing member may press the one end of the photosensitive drum toward the recess of the positioning plate.

[0026] (10) The main body housing has a positioning member. When the drawer is located at the inner position, the positioning member positions the positioning plate on the main body housing. The positioning plate has a positioned portion. When the drawer is located at the inner position, the positioned portion comes into contact with the positioning member.

[0027] (11) The positioning member may have a cylindrical shape. The positioned portion may be a notch. When the drawer is located at the inner position, the positioning member fits into the notch.

[0028] (12) The drawer may further include a lever that moves the locking member between a locked position and an unlocked position. The lever is movable together with the locking member.

[0029] (13) The drawer may have a side plate. The side plate may have an inner surface, an outer surface, and a through hole. When the drum cartridge is attached to the drawer, the inner surface faces the drum cartridge. When the drum cartridge is attached to the drawer, the outer surface is located on the opposite side of the drum cartridge from the inner surface. The through hole passes from the inner surface to the outer surface. The locking member may be located within the through hole of the side plate. The lever may be located outside the outer surface of the side plate.

[0030] With this configuration, an operator can operate the locking member from outside the side plate.

[0031] Therefore, the operator can move the locking member smoothly.

[0032] (14) When the locking member is in the locked position, the lever may be movable between a first position and a second position. When the lever is in the first position, the lever extends along an outer surface of the side plate. When the lever is in the second position, the lever protrudes from the outer surface of the side plate. When the locking member is in the locked position and the lever is in the first position, the lever is locked with respect to the side plate. When the locking member is in the locked position and the lever is in the second position, the lever is unlocked with respect to the side plate.

[0033] With this configuration, the locking member can be locked in the locked position by using the lever.

[0034] (15) The lever may have a protrusion. The side plate may have a hole. When the locking member is in the locked position and the lever is in the first position, the protrusion of the lever fits into the hole in the side plate, thereby locking the lever to the side plate. When the locking member is in the locked position and the lever is in the second position, the protrusion of the lever comes out of the hole in the side plate, thereby unlocking the lever from the side plate.

[0035] (16) The main housing may have an abutment portion. When the drawer is moved from the outer position to the inner position with the drawer in the outer position and the lever in the second position, the lever abuts against the abutment portion.

[0036] According to this configuration, it is possible to prevent the drawer from being positioned at the inner position when the lever is in the second position.

[0037] Therefore, when an operator moves the drawer from the outer position to the inner position, the operator can be prompted to place the lock member in the lock position and the lever in the first position.

[0038] (17) The photosensitive drum may have a coupling. The coupling is located at one end of the photosensitive drum. The locking member may have a through hole. When the drum cartridge is attached to the drawer, the coupling is exposed from the through hole. When the drum cartridge is attached to the drawer and the lever is located at the second position, the lever may cover at least a portion of the coupling in the axial direction of the photosensitive drum.

[0039] According to this configuration, when the drawer is positioned at the inner position with the lever positioned at the second position, the main body coupling can be prevented from fitting into the coupling by the lever.

[0040] Therefore, it is possible to prevent image formation from being started in a state in which the photosensitive drum is not locked in the drawer.

[0041] (18) When the drum cartridge is installed in the drawer and the lever is in the second position, the lever may extend in a radial direction of the photosensitive drum. The lever has a first end and a second end in the direction in which the lever extends. The second end may be located on the opposite side of the through hole from the first end.

[0042] (19) The drawer may have a developer guide that guides the developer cartridge when the developer cartridge is attached to the drawer.

[0043] (20) The drawer may have a developer pressing member. When the drum cartridge and the developer cartridge are attached to the drawer, the developer pressing member presses the developer cartridge against the photosensitive drum.

[0044] (21) The drawer may have a developer pressing spring. When the developer cartridge is attached to the drawer, the developer pressing spring presses the developer pressing member toward the developer cartridge.

[0045] (22) The lock guide has a first end and a second end. When the lock member is in the unlocked position, the first end of the lock guide is connected to the drawer guide. The second end of the lock guide is located away from the first end of the lock guide in the direction in which the lock guide extends. When the lock member is in the locked position, the first end of the lock guide may be located between the second end of the lock guide and the developer pressing member in the direction in which the lock guide extends.

[0046] With this configuration, when the drum cartridge and the developing cartridge are attached to the drawer, the force transmitted from the developing pressing member to the drum cartridge via the developing cartridge is applied in a direction from the first end of the lock guide toward the second end of the lock guide.

[0047] Therefore, it is possible to prevent the one end of the photosensitive drum from coming off the lock guide due to the force from the developing device pressing member.

[0048] (23) The drum cartridge may have a first handle. When the drum cartridge is attached to the drawer, the first handle may be housed within the drawer. The developing cartridge may have a second handle. When the developing cartridge is attached to the drawer, the second handle may protrude outside the drawer.

[0049] With this configuration, when an operator attempts to replace the developing cartridge while the drum cartridge and developing cartridge are attached to the drawer, the operator can easily notice the second handle of the developing cartridge compared to the first handle of the drum cartridge.

[0050] Therefore, when an operator attempts to replace the developing cartridge while the drum cartridge and the developing cartridge are attached to the drawer, the operator can be prevented from accidentally removing the drum cartridge. Effect of the Invention

[0051] According to the image forming apparatus of the present disclosure, it is possible to suppress a decrease in the positioning accuracy of the photosensitive drum within the main body housing. [Brief description of the drawings]

[0052] [Figure 1] FIG. 1 is a schematic diagram of an image forming apparatus. [Diagram 2] FIG. 2 is an explanatory diagram for explaining the movement of the drawer shown in FIG. 1, showing a state in which the cover is in the cover open position and the drawer is in the outer position. [Diagram 3] 3A and 3B are a side view and a cross-sectional view of the drum cartridge. [Figure 4] 4 is a cross-sectional view of the drawer and the drum cartridge shown in FIG. 2 taken along line AA. [Diagram 5] FIG. 5 is a side view of the drawer shown in FIG. [Figure 6] FIG. 6 is a cross-sectional view of the drawer shown in FIG. 4, showing the inner surface of one side plate 41A. [Figure 7] FIG. 7 is a cross-sectional view of the drawer shown in FIG. 4, showing the inner surface of the other side plate 41B. [Figure 8] FIG. 8 is a cross-sectional view of the drawer shown in FIG. 6, showing the locking member in the unlocked position. [Figure 9] FIG. 9 is a side view of the drawer shown in FIG. 5 with the locking member in the unlocked position. [Figure 10] FIG. 10 is a front view of the developing cartridge. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0053] 1. Image forming device 1 An outline of image forming apparatus 1 will be described with reference to FIGS. 1 to 3A.

[0054] As shown in FIG. 1, the image forming apparatus 1 includes a main body housing 2, a sheet cassette 3, a drawer 4, multiple drum cartridges 5Y, 5M, 5C, and 5K, multiple developing cartridges 6Y, 6M, 6C, and 6K, an exposure device 7, a belt unit 8, a transfer roller 9, and a fixing device 10.

[0055] 1.1 Main unit 2 The main body housing 2 houses a sheet cassette 3, a drawer 4, drum cartridges 5Y, 5M, 5C, and 5K, developing cartridges 6Y, 6M, 6C, and 6K, an exposure device 7, a belt unit 8, a transfer roller 9, and a fixing device 10. The main body housing 2 has an opening 21, a cover 22, and positioning members 23A and 23B.

[0056] The opening 21 is located on one side wall of the main body housing 2 in the first direction.

[0057] The cover 22 is movable between a cover closed position (see FIG. 1) and a cover open position (see FIG. 2). As shown in FIG. 1, when the cover 22 is located at the cover closed position, the cover 22 closes the opening 21. As shown in FIG. 2, when the cover 22 is located at the cover open position, the opening 21 is open.

[0058] The positioning member 23A extends in the axial direction. The axial direction will be described later. The positioning member 23A has a cylindrical shape. The positioning member 23A is made of a metal such as stainless steel or iron. The positioning member 23A positions one end of the drawer 4 in the main housing 2 in the first direction.

[0059] Positioning member 23B is located away from positioning member 23A in the first direction. Positioning member 23B has a notch. Positioning member 23A positions the other end of drawer 4 in main housing 2 in the first direction.

[0060] 1.2 Sheet cassette 3 1, the sheet cassette 3 is capable of housing a sheet S. The sheet S in the sheet cassette 3 is transported toward a transfer roller 9.

[0061] 1.3 Drawer 4 As shown in Fig. 2, when the cover 22 is in the cover open position, the drawer 4 is movable in a first direction between an inner position (see Fig. 1) and an outer position (see Fig. 2) through the opening 21. As shown in Fig. 1, when the drawer 4 is in the inner position, the entirety of the drawer 4 is located inside the main body housing 2. As shown in Fig. 2, when the drawer 4 is in the outer position, at least a part of the drawer 4 is located outside the main body housing 2.

[0062] 1.4 Drum Cartridges 5Y, 5M, 5C, 5K Each of the drum cartridges 5Y, 5M, 5C, and 5K is detachably attached to the drawer 4. More specifically, each of the drum cartridges 5Y, 5M, 5C, and 5K is detachably attached to the drawer 4 when the drawer 4 is in the outer position.

[0063] The drum cartridges 5M, 5C, and 5K will be described in the same manner as the drum cartridge 5Y, and therefore, in the following description, the description of the drum cartridges 5M, 5C, and 5K will be omitted.

[0064] As shown in FIG. 1, the drum cartridge 5Y includes a photosensitive drum 11Y and a charging device 12Y.

[0065] 1.4.1 Photosensitive drum 11Y The photosensitive drum 11Y extends in an axial direction. When the drum cartridge 5Y is attached to the drawer 4, the axial direction intersects with the first direction. Preferably, when the drum cartridge 5Y is attached to the drawer 4, the axial direction is perpendicular to the first direction. The photosensitive drum 11Y is rotatable about a drum axis A1. The drum axis A1 extends in the axial direction. As shown in FIG. 3A, the photosensitive drum 11Y has a coupling 111Y.

[0066] The coupling 111Y is located at one end of the photosensitive drum 11Y in the axial direction. The coupling 111Y rotates together with the photosensitive drum 11Y. When the drum cartridge 5Y is attached to the drawer 4 and the drawer 4 is located at the inner position, a main body coupling (not shown) fits into the coupling 111Y. The coupling 111Y rotates by receiving power from a main body coupling (not shown).

[0067] 1.4.2 Charging device 12Y 1, the charging device 12Y charges the peripheral surface of the photosensitive drum 11Y. In this embodiment, the charging device 12Y is a charging roller. The charging device 12Y may be a scorotron type charger.

[0068] 1.5 Developing cartridges 6Y, 6M, 6C, 6K Each of the developing cartridges 6Y, 6M, 6C, and 6K is detachable from the drawer 4. More specifically, each of the developing cartridges 6Y, 6M, 6C, and 6K is detachable from the drawer 4 when the drawer 4 is in the outer position.

[0069] The developing cartridge 6Y can supply toner to the photosensitive drum 11Y. The developing cartridge 6M can supply toner to the photosensitive drum 11M. The developing cartridge 6C can supply toner to the photosensitive drum 11C. The developing cartridge 6K can supply toner to the photosensitive drum 11K.

[0070] The description of each of the developing cartridges 6M, 6C, and 6K is the same as the description of the developing cartridge 6Y, so in the following description, the description of the developing cartridges 6M, 6C, and 6K will be omitted.

[0071] The developing cartridge 6Y includes a developing housing 61Y and a developing roller 62Y.

[0072] 1.5.1 Developer housing 61Y The developing housing 61Y accommodates the toner to be supplied to the photosensitive drum 11Y. The developing housing 61Y supports the developing roller 62Y.

[0073] 1.5.2 Developing roller 62Y The developing roller 62Y can supply toner in the developing housing 61Y to the photosensitive drum 11Y. The developing roller 62Y contacts the photosensitive drum 11Y. The developing roller 62Y may be separable from the photosensitive drum 11Y. The developing roller 62Y extends in the axial direction. The developing roller 62Y can rotate about a developing shaft A2. The developing shaft A2 extends in the axial direction.

[0074] 1.6 Exposure equipment 7 When the drum cartridges 5Y, 5M, 5C, and 5K are attached to the drawer 4 and the drawer 4 is located in the inner position, the exposure device 7 can expose the peripheral surfaces of the photosensitive drums 11Y, 11M, 11C, and 11K to light. In this embodiment, the exposure device 7 is a laser scan unit.

[0075] 1.7 Belt unit 8 When the drum cartridges 5Y, 5M, 5C, and 5K are attached to the drawer 4 and the drawer 4 is located in the inner position, the belt unit 8 is located below the drum cartridges 5Y, 5M, 5C, and 5K. The belt unit 8 includes an intermediate transfer belt 81 and a plurality of transfer rollers 82Y, 82M, 82C, and 82K.

[0076] When the drum cartridges 5Y, 5M, 5C, and 5K are attached to the drawer 4 and the drawer 4 is located at the inner position, the intermediate transfer belt 81 contacts the photosensitive drums 11Y, 11M, 11C, and 11K.

[0077] The transfer roller 82Y transfers the toner on the photosensitive drum 11Y to the intermediate transfer belt 81. The transfer roller 82M transfers the toner on the photosensitive drum 11M to the intermediate transfer belt 81. The transfer roller 82C transfers the toner on the photosensitive drum 11C to the intermediate transfer belt 81. The transfer roller 82K transfers the toner on the photosensitive drum 11K to the intermediate transfer belt 81.

[0078] 1.8 Transfer roller 9 The transfer roller 9 transfers the toner on the intermediate transfer belt 81 onto the sheet S. More specifically, the sheet S transported from the sheet cassette 3 toward the transfer roller 9 passes between the transfer roller 9 and the intermediate transfer belt 81 and is transported to the fixing device 10. At this time, the transfer roller 9 transfers the toner on the intermediate transfer belt 81 onto the sheet S.

[0079] 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.

[0080] 2. Details of the 5Y drum cartridge Next, the drum cartridge 5Y will be described in detail with reference to FIGS. 3A to 4.

[0081] As shown in FIGS. 3A and 3B, the drum cartridge 5Y has a drum frame 51 and a first handle 52, in addition to the above-mentioned photosensitive drum 11Y and charging device 12Y.

[0082] 2.1 Drum Frame 51 The drum frame 51 supports the photosensitive drum 11Y and the charging device 12Y. As shown in Fig. 4, the drum frame 51 has drum side plates 511A and 511B and cylindrical portions 512A and 512B.

[0083] 2.1.1 Drum side panels 511A, 511B 3A and 4, the drum side plate 511A is located at one end of the drum cartridge 5Y in the axial direction. The drum side plate 511A 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 511B in the axial direction.

[0084] 3B and 4, the drum side plate 511B is located at the other end of the drum cartridge 5Y in the axial direction. The drum side plate 511B is located away from the drum side plate 511A in the axial direction. The drum side plate 511B has an outer surface S11 and an inner surface S12. The inner surface S12 is located between the outer surface S11 and the drum side plate 511A in the axial direction.

[0085] 2.1.2 Cylindrical portions 512A, 512B As shown in Fig. 3A and Fig. 4, the cylindrical portion 512A is located on the opposite side of the drum side plate 511A from the drum side plate 511B in the axial direction. The cylindrical portion 512A extends from the outer surface S1 of the drum side plate 511A. The cylindrical portion 512A may be attached to the drum side plate 511A. The cylindrical portion 512A extends in the axial direction. The cylindrical portion 512A receives one end of the photosensitive drum 11Y in the axial direction.

[0086] As shown in Fig. 3B and Fig. 4, the cylindrical portion 512B is located on the opposite side of the drum side plate 511B from the drum side plate 511A in the axial direction. The cylindrical portion 512B extends from the outer surface S11 of the drum side plate 511B. The cylindrical portion 512B may be attached to the drum side plate 511B. The cylindrical portion 512B extends in the axial direction. The cylindrical portion 512B receives the other end of the photosensitive drum 11Y in the axial direction.

[0087] 2.2 First handle 52 3A and 3B, when the drum cartridge 5Y is attached to the drawer 4, the first handle 52 is located at the upper end of the drum frame 51. When the drum cartridge 5Y is attached to the drawer 4, the first handle 52 extends upward from the drum frame 51. The first handle 52 may be attached to the drum frame 51.

[0088] 2, when the drum cartridge 5Y is attached to the drawer 4, the first handle 52 is housed within the drawer 4. In other words, when the drum cartridge 5Y is attached to the drawer 4, the first handle 52 is located below the upper end of the drawer 4. When an operator removes the drum cartridge 5Y from the drawer 4 with the drum cartridge 5Y attached to the drawer 4, the first handle 52 is gripped by the operator.

[0089] 3. Details of Drawer 4 The drawer 4 will be described in detail with reference to FIGS.

[0090] In the following description of the drawer 4, the "axial direction" refers to the "axial direction" in a state in which the drum cartridge 5Y is attached to the drawer 4.

[0091] As shown in FIGS. 4 to 7, the drawer 4 includes two side plates 41A and 41B (see FIG. 4), two positioning plates 42A and 42B (see FIG. 4), a positioning shaft 42C, a plurality of locking members 43Y, 43M, 43C and 43K (see FIG. 5), a plurality of levers 44Y, 44M, 44C and 44K (see FIG. 5), and a plurality of locking members 45Y, 45M, 45C and 45K (see FIG. 7). ), a plurality of levers 46Y (see FIG. 4), 46M, 46C, 46K, a plurality of developer pressing members 47Y, 47M, 47C, 47K (see FIG. 6), a plurality of developer pressing members 48Y, 48M, 48C, 48K (see FIG. 7), a plurality of developer pressing springs 49Y, 49M, 49C, 49K (see FIG. 6), and a plurality of developer pressing springs 50Y, 50M, 50C, 50K (see FIG. 7).

[0092] It should be noted that the levers 46M, 46C, and 46K are not shown in the figure.

[0093] 3.1 Side plate 41A As shown in FIG. 4, the side plate 41A is located at one end of the drawer 4 in the axial direction. When the drum cartridge 5Y is attached to the drawer 4, the side plate 41A faces the drum side plate 511A in the axial direction. When the drum cartridge 5Y is attached to the drawer 4, the side plate 41A faces the drum side plate 511B in the axial direction with respect to the drum side plate 511A. The side plate 41A has an outer surface S21 and an inner surface S22. When the drum cartridge 5Y is attached to the drawer 4, the outer surface S21 faces the drum cartridge 5Y with respect to the inner surface S22 in the axial direction. The inner surface S22 is located between the outer surface S21 and the side plate 41B in the axial direction. When the drum cartridge 5Y is attached to the drawer 4, the inner surface S22 faces the drum cartridge 5Y.

[0094] As shown in Figures 5 and 6, side plate 41A has a plurality of drawer guides 411Y, 411M, 411C, 411K (see Figure 6), a plurality of through holes 412Y, 412M, 412C, 412K (see Figure 6), a plurality of development guides 413Y, 413M, 413C, 413K (see Figure 6), a plurality of holes 414Y (see Figure 5), a plurality of holes 414M (see Figure 5), a plurality of holes 414C (see Figure 5), and a plurality of holes 414K (see Figure 5).

[0095] In other words, the drawer 4 has a plurality of drawer guides 411Y, 411M, 411C, 411K, a plurality of through holes 412Y, 412M, 412C, 412K, a plurality of development guides 413Y, 413M, 413C, 413K, a plurality of holes 414Y, a plurality of holes 414M, a plurality of holes 414C, and a plurality of holes 414K.

[0096] 3.1.1 Drawer Guide 411Y, 411M, 411C, 411K As shown in FIG. 6, the drawer guides 411Y, 411M, 411C, and 411K are aligned in the first direction at intervals from one another.

[0097] 4, the drawer guide 411Y guides the installation of the drum cartridge 5Y into the drawer 4. More specifically, the drawer guide 411Y guides one end of the photosensitive drum 11Y in the axial direction when the drum cartridge 5Y is installed in the drawer 4. The drawer guide 411Y is located on the inner surface S22 of the side plate 41A.

[0098] As shown in FIG. 6, the drawer guide 411Y extends in a second direction. The second direction intersects with the first direction and the axial direction. More specifically, the second direction is perpendicular to the first direction and the axial direction. The drawer guide 411Y has one end E1 and the other end E2 in the second direction. The other end E2 is located between the one end E1 and the locking member 43Y in the second direction. The drawer guide 411Y is a recess. The drawer guide 411Y may be a rib. When the drum cartridge 5Y is attached to the drawer 4, the cylindrical portion 512A (see FIG. 4) of the drum cartridge 5Y fits into the drawer guide 411Y.

[0099] The description of each of the drawer guides 411M, 411C, and 411K is similar to the description of the drawer guide 411Y, so the description of the drawer guides 411M, 411C, and 411K will be omitted.

[0100] 3.1.2 Through hole 412Y, 412M, 412C, 412K 4 and 6, the through hole 412Y is located on the other side of the drawer guide 411Y in the second direction. In other words, the through hole 412Y is located on the opposite side of the one end E1 of the drawer guide 411Y with respect to the other end E2 of the drawer guide 411Y in the second direction. The through hole 412Y has a circular shape. The through hole 412Y penetrates from the inner surface S22 (see FIG. 4) of the side plate 41A to the outer surface S21 (see FIG. 4) of the side plate 41A.

[0101] The description of each of the through holes 412M, 412C, and 412K is similar to the description of the through hole 412Y, and therefore the description of each of the through holes 412M, 412C, and 412K will be omitted.

[0102] 3.1.3 Development Guide 413Y, 413M, 413C, 413K As shown in FIG. 6, the developing guide 413Y is located on the inner surface S22 of the side plate 41A. The developing guide 413Y is located between the drawer guide 411Y and the drawer guide 411M. The developing guide 413Y is located between the drawer guide 411Y and the developing roller pressing member 47Y. The developing guide 413Y extends in the second direction. When the developing cartridge 6Y is attached to the drawer 4, the developing guide 413Y guides the developing cartridge 6Y. In detail, when the developing cartridge 6Y is attached to the drawer 4, the protrusion 63A (see FIG. 10) of the developing cartridge 6Y fits into the developing guide 413Y. The protrusion 63A will be described later. When the developing cartridge 6Y is attached to the drawer 4, the developing guide 413Y guides the protrusion 63A. As a result, when the developing cartridge 6Y is attached to the drawer 4, the developing guide 413Y guides one end of the developing roller 62Y in the axial direction.

[0103] The developing guide 413M is positioned between the drawer guide 411M and the drawer guide 411C. The developing guide 413M is positioned between the drawer guide 411M and the developing pressing member 47M. When the developing cartridge 6M is attached to the drawer 4, the developing guide 413M guides the developing cartridge 6M.

[0104] The developing guide 413C is located between the drawer guide 411C and the drawer guide 411K. The developing guide 413C is located between the drawer guide 411C and the developing pressing member 47C. When the developing cartridge 6C is attached to the drawer 4, the developing guide 413C guides the developing cartridge 6C.

[0105] The developing guide 413K is located on the opposite side of the drawer guide 411K from the drawer guide 411C. The developing guide 413K is located between the drawer guide 411K and the developing cartridge pressing member 47K. When the developing cartridge 6K is attached to the drawer 4, the developing guide 413K guides the developing cartridge 6K.

[0106] The description of each of the developing guides 413M, 413C, and 413K is similar to the description of the developing guide 413Y, so the description of each of the developing guides 413M, 413C, and 413K will be omitted.

[0107] 3.1.4 Hole 414Y, 414M, 414C, 414K 4 and 5, the hole 414Y is located on the outer surface S21 of the side plate 41A. The hole 414Y is located on the edge of the through hole 412M. The hole 414Y is recessed from the outer surface S21 toward the inner surface S22 in the axial direction. The hole 414Y may be a through hole.

[0108] The description of each of the holes 414M, 414C, and 414K is similar to the description of the hole 414Y, so the description of each of the holes 414M, 414C, and 414K will be omitted.

[0109] 3.2 Side plate 41B As shown in FIG. 4, the side plate 41B is located at the other end of the drawer 4 in the axial direction. The side plate 41B is located away from the side plate 41A in the axial direction. When the drum cartridge 5Y is attached to the drawer 4, the side plate 41B faces the drum side plate 511B in the axial direction. When the drum cartridge 5Y is attached to the drawer 4, the side plate 41B is located on the opposite side of the drum side plate 511B from the drum side plate 511A in the axial direction. The side plate 41B has an outer surface S31 and an inner surface S32. The inner surface S32 is located between the outer surface S31 and the side plate 41A in the axial direction.

[0110] 4 and 7, side plate 41B has a plurality of drawer guides 415Y, 415M, 415C, and 415K (see FIG. 7), a plurality of through holes 416Y, 416M, 416C, and 416K (see FIG. 7), a plurality of developing guides 417Y, 417M, 417C, and 417K (see FIG. 7), a plurality of holes 418Y (see FIG. 4), a plurality of holes 418M, a plurality of holes 418C, and a plurality of holes 418K. Note that holes 418M, 418C, and 418K are not shown.

[0111] 3.2.1 Drawer Guide 415Y, 415M, 415C, 415K As shown in FIG. 7, the drawer guides 415Y, 415M, 415C, and 415K are aligned in the first direction at intervals from one another.

[0112] As shown in FIG. 4, the drawer guide 415Y, together with the drawer guide 411Y, guides the installation of the drum cartridge 5Y into the drawer 4. The drawer guide 415Y is located on the inner surface S32 of the side plate 41B. The drawer guide 415Y extends in the second direction. The drawer guide 415Y is a recess. The drawer guide 415Y may be a rib. When the drum cartridge 5Y is installed in the drawer 4, the cylindrical portion 512B of the drum cartridge 5Y fits into the drawer guide 415Y.

[0113] The description of each of the drawer guides 415M, 415C, and 415K is similar to the description of the drawer guide 415Y, so the description of the drawer guides 415M, 415C, and 415K will be omitted.

[0114] 3.2.2 Through holes 416Y, 416M, 416C, 416K 4 and 7, the through hole 416Y is located on the other side of the drawer guide 415Y in the second direction. The through hole 416Y has a circular shape. The through hole 416Y penetrates from the inner surface S32 of the side plate 41B to the outer surface S31 of the side plate 41B.

[0115] The description of each of the through holes 416M, 416C, and 416K is similar to the description of the through hole 416Y, so the description of each of the through holes 416M, 416C, and 416K will be omitted.

[0116] 3.2.3 Development Guide 417Y, 417M, 417C, 417K As shown in FIG. 7, each of the developing guides 417Y, 417M, 417C, and 417K is located on the inner surface S32 of the side plate 41B.

[0117] The description of each of the developing guides 417Y, 417M, 417C, and 417K is the same as the description of the developing guide 413Y (see FIG. 6), so the description of each of the developing guides 417Y, 417M, 417C, and 417K will be omitted.

[0118] 3.2.3 Holes 418Y, 418M, 418C, 418K As shown in Fig. 4, the hole 418Y is located on the outer surface S31 of the side plate 41B. The hole 418Y is located on the edge of the through hole 416Y, similar to the hole 414Y (see Fig. 5). The hole 418Y is recessed from the outer surface S31 toward the inner surface S32 in the axial direction. The hole 418Y may be a through hole.

[0119] The explanation for each of the holes 418M, 418C, and 418K is similar to the explanation for the hole 418Y, so the explanation for the holes 418M, 418C, and 418K will be omitted.

[0120] 3.3 Positioning plate 42A 4, the positioning plate 42A is located at one end of the drawer 4 in the axial direction. The positioning plate 42A is located inside the inner surface S22 of the side plate 41A in the axial direction. In other words, the positioning plate 42A is located between the side plate 41A and the side plate 41B in the axial direction.

[0121] 6, the positioning plate 42A extends in a first direction. The positioning plate 42A is made of a metal such as stainless steel or iron.

[0122] As shown in FIG. 4, when the drum cartridges 5Y, 5M, 5C, and 5K are attached to the drawer 4, the positioning plate 42A comes into contact with one end of each of the photosensitive drums 11Y, 11M, 11C, and 11K to determine the positions of the photosensitive drums 11Y, 11M, 11C, and 11K.

[0123] In detail, as shown in FIG. 6, the positioning plate 42A has a plurality of recesses 421Y, 421M, 421C, and 421K, and a positioned portion 422.

[0124] 3.3.1 Recesses 421Y, 421M, 421C, 421K When the drum cartridge 5Y is attached to the drawer 4, one end of the photosensitive drum 11Y (see FIG. 6) fits into the recess 421Y. The recess 421Y overlaps with the locking member 43Y in the axial direction. More specifically, when the locking member 43Y is in the locked position, the recess 421Y overlaps with the locking guide 431 of the locking member 43Y in the axial direction. The locking position and the locking guide 431 will be described later.

[0125] The recesses 421Y, 421M, 421C, and 421K are arranged in the first direction at intervals from one another. The description of the recesses 421M, 421C, and 421K is the same as the description of the recess 421Y. Therefore, the description of the recesses 421M, 421C, and 421K will be omitted.

[0126] 3.3.2 Positioned portion 422 When the drawer 4 is located at the inner position, the positioned portion 422 is positioned by the positioning member 23A of the main body housing 2. In other words, when the drawer 4 is located at the inner position, the positioning member 23A of the main body housing 2 positions the positioning plate 42A to the main body housing 2.

[0127] The positioned portion 422 is located at one end of the positioning plate 42A in the first direction. When the drawer 4 is located at the inner position, the positioned portion 422 comes into contact with the positioning member 23A. In this embodiment, the positioned portion 422 is a notch. When the drawer 4 is located at the inner position, the positioning member 23A of the main housing 2 fits into the notch, which is the positioned portion 422.

[0128] 3.4 Positioning plate 42B 4, the positioning plate 42B is located at the other end of the drawer 4 in the axial direction. The positioning plate 42B is located inside the inner surface S32 of the side plate 41B in the axial direction. In other words, the positioning plate 42B is located between the side plate 41A and the side plate 41B in the axial direction. When the drum cartridges 5Y, 5M, 5C, and 5K are attached to the drawer 4, the positioning plate 42B comes into contact with the other ends of the photosensitive drums 11Y, 11M, 11C, and 11K, respectively, to determine the positions of the photosensitive drums 11Y, 11M, 11C, and 11K.

[0129] 7, the positioning plate 42B extends in the first direction. The description of the positioning plate 42B is similar to the description of the positioning plate 42A. Therefore, the description of the positioning plate 42B will be omitted.

[0130] 3.5 Positioning shaft 42C As shown in FIG. 1, the positioning shaft 42C is located at the other end of the drawer 4 in the first direction. The positioning shaft 42C extends in the axial direction. When the drawer 4 is located at the inner position, the positioning shaft 42C fits into a notch of the positioning member 23B of the main body housing 2. This positions the other end of the drawer 4 in the first direction relative to the main body housing 2. The positioning shaft 42C has a cylindrical shape. The positioning shaft 42C is made of a metal such as stainless steel or iron. In this embodiment, the positioning shaft 42C penetrates the other end of the positioning plate 42A in the first direction and the other end of the side plate 41A in the first direction. The positioning shaft 42C may extend from the side plate 41A of the drawer 4.

[0131] 3.6 Locking members 43Y, 43M, 43C, 43K As shown in FIG. 5, the locking member 43Y is located in the through hole 412Y of the side plate 41A. The locking member 43Y has a disk shape. When the drum cartridge 5Y is attached to the drawer 4, the locking member 43Y is movable between a locked position (see FIG. 6) and an unlocked position (see FIG. 8). The locking member 43Y is rotatable between the locked position and the unlocked position about a first axis A11 (see FIG. 4). The first axis A11 extends in the axial direction. In this embodiment, the first axis A11 coincides with the drum axis A1 (see FIG. 4). That is, the locking member 43Y is rotatable between the locked position and the unlocked position about the drum axis A1. The first axis A11 may be misaligned with the drum axis A1.

[0132] 6, when the locking member 43Y is located at the locked position with the drum cartridge 5Y attached to the drawer 4, the locking member 43Y locks the photosensitive drum 11Y to the drawer 4. "Locking the photosensitive drum 11Y to the drawer 4" means preventing the photosensitive drum 11Y from moving in the direction in which the drum cartridge 5Y is removed from the drawer 4.

[0133] As shown in FIG. 8, when the drum cartridge 5Y is attached to the drawer 4 and the lock member 43Y is located at the unlocking position, the lock of the photosensitive drum 11Y with respect to the drawer 4 is released.

[0134] 4, the locking member 43Y has an outer surface S41 and an inner surface S42. The inner surface S42 is located between the outer surface S41 and the side plate 41B of the drawer 4 in the axial direction. When the drum cartridge 5Y is attached to the drawer 4, the inner surface S42 faces the outer surface S1 of the drum side plate 511A.

[0135] As shown in FIG. 6, the locking member 43Y includes a locking guide 431, a locking portion 432, a through hole 433, a pressing member 434, and a spring 435.

[0136] The locking members 43M, 43C, and 43K will be described in the same manner as the locking member 43Y, and therefore a description of the locking members 43M, 43C, and 43K will be omitted.

[0137] 3.6.1 Lock Guide 431 The lock guide 431 extends in the radial direction of the lock member 43Y. The lock guide 431 has a first end E11 and a second end E12 in the direction in which the lock guide 431 extends. The second end E12 is located away from the first end E11 in the direction in which the lock guide 431 extends. When the drum cartridge 5Y is attached to the drawer 4, the cylindrical portion 512A (see FIG. 3A) of the drum cartridge 5Y fits into the lock guide 431. As a result, when the drum cartridge 5Y is attached to the drawer 4, one end (see FIG. 4) of the photosensitive drum 11Y in the axial direction fits into the lock guide 431.

[0138] When the locking member 43Y is in the locked position, the locking guide 431 extends in a first direction. In other words, when the locking member 43Y is in the locked position, the locking guide 431 extends in a direction intersecting the direction in which the drawer guide 411Y extends. When the locking member 43Y is in the locked position, the locking guide 431 is not connected to the drawer guide 411Y. When the locking member 43Y is in the locked position, in the direction in which the locking guide 431 extends, the first end E11 of the locking guide 431 is located between the second end E12 of the locking guide 431 and the developer pressing member 47Y.

[0139] Therefore, when the drum cartridge 5Y is attached to the drawer 4 and the locking member 43Y is located at the locking position, if the drum cartridge 5Y moves in the second direction, the cylindrical portion 512A does not come out of the lock guide 431. As a result, when the drum cartridge 5Y is attached to the drawer 4 and the locking member 43Y is located at the locking position, the drum cartridge 5Y cannot be removed from the drawer 4.

[0140] 8, when the locking member 43Y is in the unlocked position, the lock guide 431 extends in the same direction as the drawer guide 411Y. When the locking member 43Y is in the unlocked position, the lock guide 431 is connected to the drawer guide 411Y. More specifically, when the locking member 43Y is in the unlocked position, the first end E11 of the lock guide 431 is connected to the drawer guide 411Y.

[0141] Therefore, when the drum cartridge 5Y is attached to the drawer 4 and the locking member 43Y is located at the unlocking position, when the drum cartridge 5Y moves in the second direction, the cylindrical portion 512A comes out of the lock guide 431. As a result, when the drum cartridge 5Y is attached to the drawer 4 and the locking member 43Y is located at the unlocking position, the drum cartridge 5Y can be removed from the drawer 4.

[0142] 3.6.2 Locking part 432 4 and 6, the lock portion 432 is a part of the lock member 43Y. In this embodiment, the lock portion 432 is a wall that defines the lock guide 431.

[0143] When the locking member 43Y is in the locked position, the locking portion 432 extends in the first direction (see FIG. 6). In other words, when the locking member 43Y is in the locked position, the locking portion 432 extends in a direction intersecting the direction in which the drawer guide 411Y extends. When the drum cartridge 5Y is attached to the drawer 4 and the locking member 43Y is in the locked position, the locking portion 432 is located between one end of the photosensitive drum 11Y and the drawer guide 411Y. Therefore, when the drum cartridge 5Y is attached to the drawer 4 and the locking member 43Y is in the locked position, if the drum cartridge 5Y moves in the second direction, the cylindrical portion 512A does not come out of the locking guide 431. As a result, when the drum cartridge 5Y is attached to the drawer 4 and the locking member 43Y is in the locked position, the locking portion 432 locks the photosensitive drum 11Y to the drawer 4.

[0144] 8, when the locking member 43Y is in the unlocked position, the locking portion 432 extends in the direction in which the drawer guide 411Y extends. When the drum cartridge 5Y is attached to the drawer 4 and the locking member 43Y is in the unlocked position, the locking portion 432 retreats from between one end of the photosensitive drum 11Y and the drawer guide 411Y. Therefore, when the drum cartridge 5Y is attached to the drawer 4 and the locking member 43Y is in the unlocked position, and the drum cartridge 5Y moves in the second direction, the cylindrical portion 512A (see FIG. 4) comes out of the locking guide 431.

[0145] 3.6.3 Through Hole 433 6, the through hole 433 is located in the center of the lock member 43Y. The through hole 433 is located inside the lock guide 431. The through hole 433 has a circular shape.

[0146] 4, when the drum cartridge 5Y is attached to the drawer 4, the coupling 111Y of the photosensitive drum 11Y is exposed from the through hole 433. When the drum cartridge 5Y is attached to the drawer 4 and the drawer 4 is located at the inner position, the main body coupling (not shown) passes through the through hole 433 and fits into the coupling 111Y.

[0147] 3.6.4 Pressing member 434 As shown in FIG. 4 and FIG. 6, the pressing member 434 is attached to the locking portion 432. When the drum cartridge 5Y is attached to the drawer 4 and the locking member 43Y is in the locked position, the pressing member 434 is located between one end of the photosensitive drum 11Y and the drawer guide 411Y. When the drum cartridge 5Y is attached to the drawer 4 and the locking member 43Y is in the locked position, the pressing member 434 is located on the opposite side of the positioning plate 42A with respect to one end of the photosensitive drum 11Y. When the drum cartridge 5Y is attached to the drawer 4 and the locking member 43Y is in the locked position, the pressing member 434 presses the cylindrical portion 512A of the drum cartridge 5Y toward the positioning plate 42A. As a result, when the drum cartridge 5Y is attached to the drawer 4 and the locking member 43Y is in the locked position, the pressing member 434 presses one end of the photosensitive drum 11Y toward the positioning plate 42A. Specifically, when the drum cartridge 5Y is attached to the drawer 4 and the locking member 43Y is in the locked position, the pressing member 434 presses one end of the photosensitive drum 11Y toward the recessed portion 421Y (see FIG. 6) of the positioning plate 42A.

[0148] 8, when the drum cartridge 5Y is attached to the drawer 4 and the locking member 43Y is in the unlocked position, the pressing member 434 retreats from between one end of the photosensitive drum 11Y and the drawer guide 411Y. As a result, when the drum cartridge 5Y is attached to the drawer 4 and the locking member 43Y is in the unlocked position, the pressing of the pressing member 434 against the one end of the photosensitive drum 11Y toward the positioning plate 42A is released.

[0149] 3.6.5 Spring 435 4 and 6, the spring 435 presses the pressing member 434. When the drum cartridge 5Y is attached to the drawer 4, the spring 435 presses the pressing member 434 toward one end of the photosensitive drum 11Y.

[0150] When the drum cartridge 5Y is attached to the drawer 4 and the locking member 43Y is in the locked position, the spring 435 presses the pressing member 434 toward the positioning plate 42A.

[0151] 3.7 Levers 44Y, 44M, 44C, 44K The explanation for each of the levers 44M, 44C, and 44K is the same as the explanation for the lever 44Y, so in the following explanation, the explanation for the levers 44M, 44C, and 44K will be omitted.

[0152] As shown in FIG. 4 and FIG. 5, the lever 44Y is attached to an outer surface S41 of the locking member 43Y. This allows the lever 44Y to move together with the locking member 43Y. The lever 44Y is located outside the outer surface S21 of the side plate 41A in the axial direction. In other words, the lever 44Y is located on the opposite side of the side plate 41B with respect to the side plate 41A in the axial direction. The lever 44Y is grasped by an operator when the operator moves the locking member 43Y. In detail, the lever 44Y is operated by the operator to move the locking member 43Y between a locked position (see FIG. 6) and an unlocked position (see FIG. 8).

[0153] Here, the lever 44Y has a function of locking the locking member 43Y in the locking position. More specifically, as shown in Fig. 4, when the locking member 43Y is in the locking position, the lever 44Y is movable between a first position and a second position. The lever 44Y in the first position is shown by a solid line in Fig. 4. The lever 44Y in the second position is shown by a virtual line in Fig. 4.

[0154] When the lock member 43Y is in the locked position and the lever 44Y is in the first position, the lever 44Y is locked to the side plate 41A. This causes the lever 44Y to lock the lock member 43Y in the locked position. When the lever 44Y is in the first position, the lever 44Y extends along the outer surface S21 of the side plate 41A.

[0155] On the other hand, when the locking member 43Y is in the locked position and the lever 44Y is in the second position, the lock of the lever 44Y to the side plate 41A is released. This causes the lever 44Y to release the lock of the locking member 43Y in the locked position. When the lever 44Y is in the second position, the locking member 43Y is movable between the locked position and the unlocked position. When the lever 44Y is in the second position, the lever 44Y protrudes from the outer surface S21 of the side plate 41A.

[0156] In addition, when the lever 44Y is located at the second position and the lock member 43Y has moved from the lock position, the lever 44Y cannot move from the second position to the first position. Therefore, when the drawer 4 is located at the outer position (see FIG. 2) and the lever 44Y is located at the second position, if the drawer 4 moves from the outer position to the inner position (see FIG. 1), the lever 44Y abuts against the abutment portion of the main body housing 2. This makes it possible to prevent the drawer 4 from being located at the inner position when the lock member 43Y is not located at the lock position. Therefore, it is possible to prompt the operator to place the lock member 43Y at the lock position. In this embodiment, the abutment portion is the edge of the opening 21 of the main body housing 2. That is, the main body housing 2 has the abutment portion.

[0157] 4 and 9, when the drum cartridge 5Y is attached to the drawer 4 and the lever 44Y is in the second position, the lever 44Y covers at least a part of the coupling 111Y in the axial direction. This prevents the main body coupling (not shown) from fitting into the coupling 111Y even if the drawer 4 is in the inner position when the locking member 43Y is not in the locked position. This prevents image formation from starting when the photosensitive drum 11Y is not locked to the drawer 4.

[0158] As shown in FIG. 9, the lever 44Y has a lever body 441 and two protrusions 442A and 442B.

[0159] 3.7.1 Lever body 441 When the drum cartridge 5Y is attached to the drawer 4 and the lever 44Y is located at the second position, the lever body 441 extends in the radial direction of the photosensitive drum 11Y. In other words, when the drum cartridge 5Y is attached to the drawer 4 and the lever 44Y is located at the second position, the lever 44Y extends in the radial direction of the photosensitive drum 11Y. The lever body 441 has a first end 441A, a second end 441B, and a circular arc portion 441C.

[0160] The first end 441A is one end of the lever body 441 in the direction in which the lever 44Y extends. The second end 441B is the other end of the lever body 441 in the direction in which the lever 44Y extends. In other words, the lever 44Y has a first end 441A and a second end 441B in the direction in which the lever 44Y extends. The second end 441B is located on the opposite side of the through hole 433 of the locking member 43Y to the first end 441A.

[0161] 5, when the lever 44Y is located at the first position, the arc portion 441C fits along the edge of the through hole 433 of the locking member 43Y. As a result, when the lever 44Y is located at the first position, the lever 44Y does not cover the through hole 433 of the locking member 43Y.

[0162] 3.7.2 Protrusions 442A, 442B 9, the protrusion 442A extends from a first end 441A of the lever body 441. The protrusion 442A may be attached to the first end 441A of the lever body 441.

[0163] The protrusion 442B extends from the second end 441B of the lever body 441. The protrusion 442B may be attached to the second end 441B of the lever body 441.

[0164] 4, when the locking member 43Y is in the locked position and the lever 44Y is in the first position, the protrusion 442A of the lever 44Y fits into one of the two holes 414Y in the side plate 41A, and the protrusion 442B of the lever 44Y fits into the other of the two holes 414Y in the side plate 41A. This locks the lever 44Y to the side plate 41A.

[0165] When the locking member 43Y is in the locked position and the lever 44Y is in the second position, the projection 442A of the lever 44Y comes out of one of the two holes 414Y in the side plate 41A, and the projection 442B of the lever 44Y comes out of the other of the two holes 414Y in the side plate 41A. This releases the lock of the lever 44Y from the side plate 41A.

[0166] 3.8 Locking members 45Y, 45M, 45C, 45K 4 and 7, the locking member 45Y is located in a through hole 416Y of the side plate 41B. The description of the locking member 45Y is similar to the description of the locking member 43Y. Therefore, the description of the locking member 45Y will be omitted.

[0167] Further, the description of each of the locking members 45M, 45C, and 45K is similar to the description of the locking member 43Y, and therefore the description of each of the locking members 45M, 45C, and 45K will also be omitted.

[0168] 3.9 Levers 46Y, 46M, 46C, 46K 4, the lever 46Y is attached to the outer surface of the lock member 45Y. The description of the lever 46Y is similar to the description of the lever 44Y. Therefore, the description of the lever 46Y will be omitted.

[0169] Further, the description of each of the levers 46M, 46C, and 46K is similar to the description of the lever 44Y, and therefore the description of each of the levers 46M, 46C, and 46K will also be omitted.

[0170] 3.10 Developing pressing members 47Y, 47M, 47C, 47K As shown in FIG. 6, the developer pressing member 47Y is attached to the side plate 41A. The developer pressing member 47Y is located between the drawer guide 411Y and the drawer guide 411M in the first direction. The developer pressing member 48Y is located on the opposite side of the drawer guide 411Y with respect to the developer guide 413Y in the first direction. With the drum cartridge 5Y and the developer cartridge 6Y attached to the drawer 4, the developer pressing member 47Y is located on the opposite side of the photosensitive drum 11Y with respect to the developing roller 62Y in the direction connecting the drum axis A1 (see FIG. 1) and the developer axis A2 (see FIG. 1). With the drum cartridge 5Y and the developer cartridge 6Y attached to the drawer 4, the developer pressing member 47Y presses the developer cartridge 6Y toward the photosensitive drum 11Y. More specifically, when the developer cartridge 6Y is attached to the drawer 4, the developer pressing member 47Y presses a protrusion 64A (see FIG. 10) of the developer cartridge 6Y toward the photosensitive drum 11Y. The protrusion 64A will be described later.

[0171] The developer pressing member 47M is attached to the side plate 41A. The developer pressing member 47M is located between the drawer guide 411M and the drawer guide 411C in the first direction. When the drum cartridge 5M and the developer cartridge 6M are attached to the drawer 4, the developer pressing member 47M presses the developer cartridge 6M toward the photosensitive drum 11M.

[0172] The developer pressing member 47C is attached to the side plate 41A. The developer pressing member 47C is located between the drawer guide 411C and the drawer guide 411K in the first direction. When the drum cartridge 5C and the developer cartridge 6C are attached to the drawer 4, the developer pressing member 47C presses the developer cartridge 6C toward the photosensitive drum 11C.

[0173] The developer pressing member 47K is attached to the side plate 41A. The developer pressing member 47K is located on the opposite side of the drawer guide 411K from the drawer guide 411C in the first direction. When the drum cartridge 5K and the developer cartridge 6K are attached to the drawer 4, the developer pressing member 47K presses the developer cartridge 6K toward the photosensitive drum 11K.

[0174] The description of each of the developing device pressing members 47M, 47C, and 47K is the same as the description of the developing device pressing member 47Y, and therefore, the description of each of the developing device pressing members 47M, 47C, and 47K will be omitted.

[0175] 3.11 Developing pressing members 48Y, 48M, 48C, 48K As shown in FIG. 7, each of the developing device pressing members 48Y, 48M, 48C, and 48K is attached to the side plate 41B.

[0176] The description of each of the developing device pressing members 48Y, 48M, 48C, and 48K is the same as the description of the developing device pressing member 47Y (see FIG. 6). Therefore, the description of each of the developing device pressing members 48Y, 48M, 48C, and 48K will be omitted.

[0177] 3.12 Developing pressure springs 49Y, 49M, 49C, 49K 6, the developer pressing spring 49Y presses the developer pressing member 47Y. When the developer cartridge 6Y is attached to the drawer 4, the developer pressing spring 49Y presses the developer pressing member 47Y toward the protrusion 64A (see FIG. 10) of the developer cartridge 6Y. The developer pressing spring 49Y is, for example, a torsion spring.

[0178] The description of the developer pressing springs 49M, 49C, and 49K is the same as the description of the developer pressing spring 49Y, and therefore the description of the developer pressing springs 49M, 49C, and 49K will be omitted.

[0179] 3.13 Developing pressure springs 50Y, 50M, 50C, 50K 7, the developer pressing spring 50Y presses the developer pressing member 48Y. When the developer cartridge 6Y is attached to the drawer 4, the developer pressing spring 50Y presses the developer pressing member 48Y toward the protrusion 64B (see FIG. 10) of the developer cartridge 6Y. The developer pressing spring 50Y is, for example, a torsion spring.

[0180] The description of the developer pressing springs 50M, 50C, and 50K is the same as the description of the developer pressing spring 50Y, so the description of the developer pressing springs 50M, 50C, and 50K will be omitted.

[0181] 4. Details of the 6Y Developing Cartridge The developing cartridge 6Y will be described in detail with reference to FIG.

[0182] The description of each of the developing cartridges 6M, 6C, and 6K is the same as the description of the developing cartridge 6Y, and therefore the description of the developing cartridges 6M, 6C, and 6K will be omitted.

[0183] In addition, in the following description of the developing cartridge 6Y, the "axial direction" refers to the "axial direction" in a state in which the developing cartridge 6Y is attached to the drum cartridge 5Y.

[0184] The developing cartridge 6Y has a plurality of protrusions 63A and 63B, a plurality of protrusions 64A and 64B, and a second handle 65, in addition to the developing casing 61 and the developing roller 62Y described above.

[0185] 4.1 Protrusions 63A, 63B The protrusion 63A extends from one side surface S51 of the developing housing 61Y in the axial direction. The protrusion 63A may be attached to one side surface S51 of the developing housing 61Y in the axial direction. The protrusion 63A extends in the axial direction. The protrusion 63A has a cylindrical shape. The protrusion 63A receives one end of the shaft of the developing roller 62Y.

[0186] The protrusion 63B extends from the other side surface S52 of the developing housing 61Y in the axial direction. The protrusion 63B is located on the opposite side of the protrusion 63A with respect to the developing housing 61Y in the axial direction. The protrusion 63B may be attached to the other side surface S52 of the developing housing 61Y in the axial direction. The protrusion 63B extends in the axial direction. The protrusion 63B has a cylindrical shape. The protrusion 63B receives the other end of the shaft of the developing roller 62Y.

[0187] 4.2 Protrusions 64A, 64B The protrusion 64A extends from one side surface S51 of the developing housing 61Y in the axial direction. The protrusion 64A may be attached to one side surface S51 of the developing housing 61Y in the axial direction. The protrusion 64A is located away from the protrusion 63A. When the drum cartridge 5Y and the developing cartridge 6Y are attached to the drawer 4, the protrusion 64A is located on the opposite side of the photosensitive drum 11Y to the protrusion 63A in the direction connecting the drum axis A1 and the developing axis A2. When the developing cartridge 6Y is attached to the drawer 4, the protrusion 64A is pressed toward the photosensitive drum 11Y by the developing pressing member 47Y (see FIG. 6). The protrusion 64A extends in the axial direction. The protrusion 64A has a cylindrical shape.

[0188] The protrusion 64B extends from the other side surface S52 of the developing housing 61Y in the axial direction. The protrusion 64B may be attached to the other side surface S52 of the developing housing 61Y in the axial direction. The protrusion 64B is located away from the protrusion 63B. When the drum cartridge 5Y and the developing cartridge 6Y are attached to the drawer 4, the protrusion 64B is located on the opposite side of the photosensitive drum 11Y to the protrusion 63B in the direction connecting the drum axis A1 and the developing axis A2. When the developing cartridge 6Y is attached to the drawer 4, the protrusion 64B is pressed toward the photosensitive drum 11Y by the developing pressing member 48Y (see FIG. 7). The protrusion 64B extends in the axial direction. The protrusion 64B has a cylindrical shape.

[0189] 4.3 Second Handle 65 2 and 10, when the developing cartridge 6Y is attached to the drawer 4, the second handle 65 is located at the upper end of the developing housing 61. The second handle 65 may be attached to the developing housing 61.

[0190] 2, when the developer cartridge 6Y is attached to the drawer 4, the second handle 65 protrudes outside the drawer 4. In other words, when the developer cartridge 6Y is attached to the drawer 4, the second handle 65 is located above the upper end of the drawer 4. In further other words, when the drum cartridge 5Y and the developer cartridge 6Y are attached to the drawer 4, the second handle 65 is located above the first handle 52 of the drum cartridge 5Y. When the developer cartridge 6Y is attached to the drawer 4 and an operator removes the developer cartridge 6Y from the drawer 4, the second handle 65 is grasped by the operator.

[0191] 5. Replacing the 6Y developing cartridge Next, the replacement operation of the developing cartridge 6Y will be described with reference to FIGS.

[0192] As shown in FIGS. 1 and 2, to replace the developing cartridge 6Y, an operator first moves the drawer 4 from the inner position (see FIG. 1) to the outer position (see FIG. 2).

[0193] When the drawer 4 is in the outer position, the locking member 43Y is in the locked position and the lever 44Y is in the first position as shown in Figures 5 and 6. Also, the locking member 45Y is in the locked position and the lever 46Y is in the first position as shown in Figures 4 and 7.

[0194] When the lever 44Y is in the first position, the locking member 43Y is locked in the locked position, and when the lever 46Y is in the first position, the locking member 45Y is locked in the locked position.

[0195] The photosensitive drum 11Y is locked to the drawer 4 by the locking member 43Y being in the locking position and the locking member 45Y being in the locking position.

[0196] 2, the operator grasps the second handle 65 and pulls the developing cartridge 6Y out of the drawer 4 in the second direction.

[0197] At this time, since the photosensitive drum 11Y is locked to the drawer 4, the photosensitive drum 11Y can be prevented from moving relative to the drawer 4.

[0198] Next, when the drawer 4 is in the outer position and the drum cartridge 5Y is attached to the drawer 4, to attach the developing cartridge 6Y to the drum cartridge 5Y, the operator first fits the protrusion 63A (see Figure 10) into the developing guide 413Y (see Figure 6) and fits the protrusion 63B (see Figure 10) into the developing guide 417Y (see Figure 7).

[0199] As a result, the developing cartridge 6Y is attached to the drawer 4 while being guided by the developing guide 413Y and the developing guide 417Y.

[0200] 1 and 2, the operator moves the drawer 4 from the outer position (see FIG. 2) to the inner position (see FIG. 1). This completes the replacement operation of the developing cartridge 6Y.

[0201] 6. Replacing the drum cartridge 5Y Next, the replacement operation of the drum cartridge 5Y will be described with reference to FIGS.

[0202] The drum cartridge 5Y may be replaced with the developing cartridge 6Y attached to the drawer 4, or may be replaced with the developing cartridge 6Y detached from the drawer 4 and attached.

[0203] As shown in FIGS. 1 and 2, to replace the drum cartridge 5Y, an operator first moves the drawer 4 from the inner position (see FIG. 1) to the outer position (see FIG. 2).

[0204] When the drawer 4 is in the outer position, the locking member 43Y is in the locked position and the lever 44Y is in the first position as shown in Figures 5 and 6. Also, the locking member 45Y is in the locked position and the lever 46Y is in the first position as shown in Figures 4 and 7.

[0205] When the lever 44Y is in the first position, the locking member 43Y is locked in the locked position, and when the lever 46Y is in the first position, the locking member 45Y is locked in the locked position.

[0206] The photosensitive drum 11Y is locked to the drawer 4 by the locking member 43Y being in the locking position and the locking member 45Y being in the locking position.

[0207] Next, the worker moves the lever 44Y from the first position to the second position. Then, with the lever 44Y in the second position, the locking member 43Y is unlocked. Also, the worker moves the lever 46Y from the first position to the second position. Then, with the lever 46Y in the second position, the locking member 45Y is unlocked.

[0208] 6 and 8, the worker rotates the locking member 43Y from the locking position to the unlocking position. The worker also rotates the locking member 45Y (see FIG. 7) from the locking position to the unlocking position. Then, the locking of the photosensitive drum 11Y with respect to the drawer 4 is released in a state in which the locking member 43Y is located at the unlocking position and the locking member 45Y (see FIG. 7) is located at the unlocking position.

[0209] 2, the operator grasps the first handle 52 and pulls out the drum cartridge 5Y from the drawer 4. Then, the cylindrical portion 512A (see FIG. 4) of the drum cartridge 5Y comes off the lock guide 431 (see FIG. 4) of the locking member 43Y, and the cylindrical portion 512B (see FIG. 4) of the drum cartridge 5Y comes off the lock guide 451 (see FIG. 4) of the locking member 45Y, and the drum cartridge 5Y is removed from the drawer 4.

[0210] Next, to install the drum cartridge 5Y in the drawer 4 with the drawer 4 in the outer position, the operator first fits the cylindrical portion 512A into the drawer guide 411Y of the drawer 4 and fits the cylindrical portion 512B into the drawer guide 415Y of the drawer 4, as shown in Fig. 4. As a result, the drum cartridge 5Y is guided by the drawer guide 411Y and the drawer guide 415Y and installed in the drawer 4.

[0211] When the drum cartridge 5Y is attached to the drawer 4, the cylindrical portion 512A of the drum cartridge 5Y fits into the lock guide 431 of the locking member 43Y, and the cylindrical portion 512B of the drum cartridge 5Y fits into the lock guide 451 of the locking member 45Y.

[0212] 5 and 9, the worker grasps the lever 44Y located at the second position and rotates the locking member 43Y from the unlocked position to the locked position. The worker also grasps the lever 46Y (see FIG. 4) located at the second position and rotates the locking member 45Y (see FIG. 4) from the unlocked position to the locked position.

[0213] Then, as shown in FIGS. 6 and 7, the photosensitive drum 11Y is locked to the drawer 4 with the locking member 43Y located at the locking position and the locking member 45Y located at the locking position.

[0214] 4, the worker moves the lever 44Y from the second position to the first position, and the worker moves the lever 46Y from the second position to the first position.

[0215] 1 and 2, the worker moves the drawer 4 from the outer position (see FIG. 2) to the inner position (see FIG. 1). This completes the replacement operation of the drum cartridge 5Y.

[0216] 7. Effects (1) According to the image forming device 1, when the developing cartridge 6Y is replaced while the drum cartridge 5Y is attached to the drawer 4 as shown in FIG. 2, the developing cartridge 6Y can be replaced with respect to the drawer 4 while the photosensitive drum 11Y is locked to the drawer 4 by the locking member 43Y as shown in FIG. 4.

[0217] Therefore, the photosensitive drum 11Y can be prevented from moving relative to the drawer 4 during the replacement work of the developing cartridge 6Y.

[0218] As a result, the positioning accuracy of the photosensitive drum 11Y in the main body housing 2 can be prevented from decreasing.

[0219] (2) According to the image forming apparatus 1, as shown in FIGS. 6 and 8, the locking member 43Y is rotatable about a first shaft A11 extending in the axial direction between a locked position (see FIG. 6) and an unlocked position (see FIG. 8).

[0220] Therefore, when the locking member 43Y is moved between the locked position and the unlocked position, it is not necessary to move the locking member 43Y in the axial direction.

[0221] As a result, it is possible to save space in the axial direction.

[0222] (3) According to the image forming apparatus 1, as shown in FIGS. 6 and 8, the locking member 43Y is rotatable about the drum shaft A1 between a locked position (see FIG. 6) and an unlocked position (see FIG. 8).

[0223] Therefore, the movement range of the lock member 43Y relative to the photosensitive drum 11Y can be made small.

[0224] As a result, the drawer 4 can be prevented from becoming large due to the provision of the locking member 43Y.

[0225] (4) According to image forming apparatus 1, as shown in FIG. 6, when lock member 43Y is in the unlocked position, lock guide 431 extends in the same direction as drawer guide 411Y and is connected to drawer guide 411Y.

[0226] Therefore, when the drum cartridge 5Y is attached to the drawer 4 with the locking member 43Y positioned in the unlocked position, one end of the photosensitive drum 11Y in the axial direction can be guided by the drawer guide 411Y and the locking guide 431, allowing it to be smoothly fitted into the locking member 43Y.

[0227] Furthermore, as shown in FIG. 8, when the lock member 43Y is in the locked position, the lock guide 431 extends in a direction intersecting with the direction in which the drawer guide 411Y extends.

[0228] Therefore, when the drum cartridge 5Y is attached to the drawer 4 and the locking member 43Y is in the locked position, one end of the photosensitive drum 11Y in the axial direction can be locked to the drawer 4 by the locking guide 431.

[0229] (5) According to the image forming apparatus 1, as shown in FIG. 6, when the drum cartridge 5Y is attached to the drawer 4 and the locking member 43Y is in the locked position, the locking portion 432 is positioned between one end of the photosensitive drum 11Y and the drawer guide 411Y.

[0230] With this, when the drum cartridge 5Y is attached to the drawer 4 and the locking member 43Y is in the locked position, one end of the photosensitive drum 11Y in the axial direction can be locked to the drawer 4 by the locking portion 432.

[0231] (6) According to the image forming apparatus 1, as shown in Fig. 6, the locking member 43Y has a pressing member 434. When the drum cartridge 5Y is attached to the drawer 4, the pressing member 434 presses one end of the photosensitive drum 11Y toward the positioning plate 42A.

[0232] This makes it possible to press one end of the photosensitive drum 11Y toward the positioning plate 42A by utilizing the locking member 43Y.

[0233] (7) According to the image forming apparatus 1, as shown in FIG. 4, the lever 44Y is located outside the outer surface S21 of the side plate 41A.

[0234] Therefore, an operator can operate the lock member 43Y from the outside of the side plate 41A.

[0235] As a result, the operator can smoothly move the lock member 43Y.

[0236] (8) According to the image forming apparatus 1, as shown in FIGS. 4 and 5, when the locking member 43Y is in the locked position and the lever 44Y is in the first position, the lever 44Y is locked with respect to the side plate 41A.

[0237] Therefore, the lever 44Y can be used to lock the locking member 43Y in the locked position.

[0238] (9) According to the image forming device 1, as shown by the phantom lines in FIG. 4, when the drawer 4 is positioned at the outer position and the lever 44Y is positioned at the second position, when the drawer 4 moves from the outer position to the inner position, the lever 44Y abuts against the abutment portion of the main housing 2.

[0239] This makes it possible to prevent the drawer 4 from being positioned at the inner position when the lever 44Y is positioned at the second position.

[0240] Therefore, when the worker moves the drawer 4 from the outer position to the inner position, the worker can be prompted to place the lock member 43Y in the lock position and the lever 44Y in the first position.

[0241] (10) According to the image forming device 1, as shown in FIG. 9, when the drum cartridge 5Y is attached to the drawer 4 and the lever 44Y is in the second position, the lever 44Y covers at least a portion of the coupling 111Y in the axial direction of the photosensitive drum 11Y.

[0242] Therefore, if the drawer 4 is located at the inner position while the lever 44Y is located at the second position, the main body coupling can be prevented from fitting into the coupling 111Y by the lever 44Y.

[0243] As a result, it is possible to prevent image formation from being started in a state in which the photosensitive drum 11Y is not locked in the drawer 4.

[0244] (11) According to the image forming apparatus 1, as shown in FIG. 6, when the locking member 43Y is positioned in the locked position, in the direction in which the locking guide 431 extends, the first end E11 of the locking guide 431 is positioned between the second end E12 of the locking guide 431 and the developing device pressing member 47Y.

[0245] Therefore, when the drum cartridge 5Y and the developing cartridge 6Y are attached to the drawer 4, the force transmitted from the developing pressing member 47Y to the drum cartridge 5Y via the developing cartridge 6Y is applied in a direction from the first end E11 of the lock guide 431 toward the second end E12 of the lock guide 431.

[0246] Therefore, it is possible to prevent one end of the photosensitive drum 11Y from coming off the lock guide 431 due to the force from the developing device pressing member 47Y.

[0247] (12) According to the image forming apparatus 1, as shown in Fig. 2, when the drum cartridge 5Y is attached to the drawer 4, the first handle 52 of the drum cartridge 5Y is housed within the drawer 4. On the other hand, when the developer cartridge 6Y is attached to the drawer 4, the second handle 65 of the developer cartridge 6Y protrudes outside the drawer 4.

[0248] Therefore, when an operator attempts to replace the developing cartridge 6Y while the drum cartridge 5Y and the developing cartridge 6Y are attached to the drawer 4, the operator can easily notice the second handle 65 of the developing cartridge 6Y compared to the first handle 52 of the drum cartridge 5Y.

[0249] As a result, when an operator attempts to replace the developing cartridge 6Y while the drum cartridge 5Y and the developing cartridge 6Y are attached to the drawer 4, the operator is prevented from accidentally removing the drum cartridge 5Y.

[0250] 8. Variations (1) The image forming apparatus 1 does not have to include the drum cartridges 5Y, 5M, and 5C. The image forming apparatus 1 may be dedicated to printing monochrome images.

[0251] (2) The locking member 43Y may be movable linearly. [Explanation of symbols]

[0252] 1. Image forming device 4 Drawer 5Y drum cartridge 6Y developing cartridge 11Y Photosensitive drum 23 Positioning member 41A side plate 42A Positioning plate 43Y Locking member 44Y Lever 47Y Developing pressing member 49Y Developing pressure spring 52 First Handle 65 Second Handle 111Y Coupling 411Y Drawer Guide 412Y through hole 413Y Development Guide 414Y Hole 421Y Recess 422 Positioned part 431 Lock Guide 432 Rock Department 433 Through Hole 434 Pressing member 435 Spring 441A 1st end 441B 2nd end 442A Protrusion A1 Drum shaft A11 1st axis E11 1st end E12 2nd end S21 Exterior S22 Inside

Claims

1. A main body housing; a drum cartridge having a photosensitive drum rotatable about a drum shaft extending in an axial direction; a developing cartridge having a developing roller; a drawer movable between an inner position located within the main body housing and an outer position located outside the main body housing, the drum cartridge and the developing cartridge being each detachable, and including a locking member rotatable about a first axis extending in the axial direction between a locking position that locks the photosensitive drum to the drawer and an unlocking position that unlocks the photosensitive drum from the drawer when the drum cartridge is attached to the drawer; An image forming apparatus comprising:

2. A main body housing, a drum cartridge having a photosensitive drum rotatable about a drum shaft extending in an axial direction; a developing cartridge having a developing roller; a drawer movable between an inner position located within the main body housing and an outer position located outside the main body housing, the drum cartridge and the developing cartridge being each detachable, and including a locking member rotatable about the drum shaft between a locking position that locks the photosensitive drum to the drawer and an unlocking position that unlocks the photosensitive drum from the drawer when the drum cartridge is attached to the drawer; An image forming apparatus comprising:

3. A main body housing, a drum cartridge having a photosensitive drum; a developing cartridge having a developing roller; a drawer movable between an inner position located within the main body housing and an outer position located outside the main body housing, the drum cartridge and the developing cartridge are each detachable, and the drawer includes a locking member movable between a locking position that locks the photosensitive drum to the drawer and an unlocking position that unlocks the photosensitive drum from the drawer when the drum cartridge is attached to the drawer; Equipped with The drawer includes: a positioning plate that contacts one end of the photosensitive drum when the drum cartridge is attached to the drawer to determine a position of the photosensitive drum; The locking member is an image forming apparatus including a pressing member that presses the one end of the photosensitive drum toward the positioning plate when the drum cartridge is attached to the drawer;

4. 4. The image forming apparatus according to claim 3, wherein the locking member has a spring that presses the pressing member toward the one end of the photosensitive drum when the drum cartridge is attached to the drawer.

5. The positioning plate is a recess into which the one end of the photosensitive drum fits when the drum cartridge is attached to the drawer, 5. The image forming apparatus according to claim 3, wherein the pressing member presses the one end of the photosensitive drum toward the recess of the positioning plate in a state in which the drum cartridge is attached to the drawer.

6. The main body housing includes: a positioning member for positioning the positioning plate to the main body housing when the drawer is located at the inner position; The positioning plate is The image forming apparatus according to claim 3 , further comprising a positioned portion that comes into contact with the positioning member when the drawer is located at the inner position.

7. The positioning member has a cylindrical shape, The image forming apparatus according to claim 6 , wherein the positioned portion is a notch into which the positioning member fits when the drawer is located at the inner position.

8. A main body housing, a drum cartridge having a photosensitive drum; a developing cartridge having a developing roller; a drawer movable between an inner position located within the main body housing and an outer position located outside the main body housing, the drum cartridge and the developing cartridge are each detachable, and the drawer includes a locking member movable between a locking position that locks the photosensitive drum to the drawer and an unlocking position that unlocks the photosensitive drum from the drawer when the drum cartridge is attached to the drawer; Equipped with The image forming apparatus, wherein the drawer further includes a lever for moving the locking member between the locked position and the unlocked position, the lever being movable together with the locking member.

9. The drawer includes: a side plate having an inner surface facing the drum cartridge when the drum cartridge is attached to the drawer, an outer surface positioned on the opposite side of the drum cartridge from the inner surface when the drum cartridge is attached to the drawer, and a through hole penetrating from the inner surface to the outer surface, the locking member is positioned within the through hole of the side plate, The image forming apparatus according to claim 8 , wherein the lever is positioned outside the outer surface of the side plate.

10. the lever is movable between a first position extending along the outer surface of the side plate and a second position protruding from the outer surface of the side plate when the locking member is in the locked position; When the locking member is in the locking position and the lever is in the first position, the lever is locked with respect to the side plate; 10. The image forming apparatus according to claim 9, wherein the lever is unlocked from the side plate when the locking member is in the lock position and the lever is in the second position.

11. The lever has a protrusion, The side plate has a hole. when the locking member is located at the lock position and the lever is located at the first position, the projection of the lever fits into the hole of the side plate, thereby locking the lever with respect to the side plate; 11. The image forming apparatus according to claim 10, wherein when the locking member is located at the locking position and the lever is located at the second position, the protrusion of the lever comes out of the hole of the side plate, thereby releasing the lock of the lever to the side plate.

12. The main body housing includes:

12. The image forming apparatus according to claim 10, further comprising an abutment portion against which the lever abuts when the drawer is moved from the outer position to the inner position with the drawer positioned at the outer position and the lever positioned at the second position.

13. The photosensitive drum is a coupling located at one end of the photosensitive drum; The locking member is a through hole through which the coupling is exposed when the drum cartridge is attached to the drawer; 13. The image forming apparatus according to claim 10, wherein when the drum cartridge is attached to the drawer and the lever is positioned at the second position, the lever covers at least a portion of the coupling in the axial direction of the photosensitive drum.

14. When the drum cartridge is attached to the drawer and the lever is located at the second position, the lever extends in a radial direction of the photosensitive drum, The image forming apparatus according to claim 13 , wherein the lever has a first end and a second end located on an opposite side of the through hole from the first end in a direction in which the lever extends.

15. A main body housing, a drum cartridge having a photosensitive drum; a developing cartridge having a developing roller; a drawer movable between an inner position located within the main body housing and an outer position located outside the main body housing, the drum cartridge and the developing cartridge are each detachable, and the drawer includes a locking member movable between a locking position that locks the photosensitive drum to the drawer and an unlocking position that unlocks the photosensitive drum from the drawer when the drum cartridge is attached to the drawer; Equipped with The drawer includes: an image forming apparatus having a developer guide for guiding the developer cartridge when the developer cartridge is attached to the drawer;

16. A main body housing, a drum cartridge having a photosensitive drum; a developing cartridge having a developing roller; a drawer movable between an inner position located within the main body housing and an outer position located outside the main body housing, the drum cartridge and the developing cartridge are each detachable, and the drawer includes a locking member movable between a locking position that locks the photosensitive drum to the drawer and an unlocking position that unlocks the photosensitive drum from the drawer when the drum cartridge is attached to the drawer; Equipped with The drawer includes: an image forming apparatus having a developer pressing member that presses the developer cartridge toward the photosensitive drum when the drum cartridge and the developer cartridge are attached to the drawer;

17. The drawer includes:

17. The image forming apparatus according to claim 16, further comprising a developer pressing spring that presses the developer pressing member toward the developer cartridge when the developer cartridge is attached to the drawer.

18. The drawer includes: a drawer guide that guides one end of the photosensitive drum in an axial direction of the photosensitive drum when the drum cartridge is attached to the drawer; The locking member is a lock guide into which the one end of the photosensitive drum is fitted when the drum cartridge is attached to the drawer; The lock guide is a first end portion connected to the drawer guide when the locking member is in the unlocked position; a second end located away from the first end in a direction in which the lock guide extends, 18. The image forming apparatus according to claim 16, wherein, in a direction in which the lock guide extends, when the lock member is located at the lock position, the first end is located between the second end and the developing device pressing member.

19. A main body housing, a drum cartridge having a photosensitive drum; a developing cartridge having a developing roller; a drawer movable between an inner position located within the main body housing and an outer position located outside the main body housing, the drum cartridge and the developing cartridge are each detachable, and the drawer includes a locking member movable between a locking position that locks the photosensitive drum to the drawer and an unlocking position that unlocks the photosensitive drum from the drawer when the drum cartridge is attached to the drawer; Equipped with the drum cartridge has a first handle that is accommodated in the drawer when the drum cartridge is attached to the drawer; The developing cartridge has a second handle that protrudes outside the drawer when the developing cartridge is attached to the drawer.

20. The locking member has a disk shape, A lock guide extending in a radial direction of the lock member; The image forming apparatus according to claim 1 , further comprising: a circular through hole located at a center of the locking member, the through hole being located within the locking guide.

21. The drawer includes: a drawer guide that guides one end of the photosensitive drum in an axial direction of the photosensitive drum when the drum cartridge is attached to the drawer; The locking member is a lock guide into which the one end of the photosensitive drum is fitted when the drum cartridge is attached to the drawer; When the locking member is in the locking position, the locking guide extends in a direction intersecting with a direction in which the drawer guide extends, The image forming apparatus according to claim 1 , wherein, when the locking member is in the unlocked position, the locking guide extends in a direction in which the drawer guide extends and is connected to the drawer guide.

22. The drawer includes: a drawer guide that guides one end of the photosensitive drum in an axial direction of the photosensitive drum when the drum cartridge is attached to the drawer; The locking member is 22. The image forming apparatus of claim 1, further comprising a locking section that locks the photosensitive drum to the drawer when the locking member is positioned at the locked position, the locking section being positioned between one end of the photosensitive drum and the drawer guide when the drum cartridge is attached to the drawer and the locking member is positioned at the locked position, and retracting from between the one end of the photosensitive drum and the drawer guide when the drum cartridge is attached to the drawer and the locking member is positioned at the unlocked position.

Images