Image forming device

Abstract

To provide an image forming apparatus that, in a configuration in which a transfer device is located above a photoconductor drum in a state where a drum unit is attached to a main body housing, allows replacement of a toner cartridge separate from the drum unit.SOLUTION: An image forming apparatus comprises a drum unit 4K, a toner cartridge 5K, and a transfer device. The drum unit 4K has a photoconductor drum 41K, a developing roller 43K, an agitator 45K, and a developing housing 46K. The developing housing 46K has an opening 4631. The opening 4631 communicates a first developing chamber 461 accommodating the agitator 45K and a second developing chamber 462 located above the first developing chamber 461 and accommodating the developing roller 43K with each other. The agitator 45K includes a shaft 451 and a blade 452. When the agitator 45K rotates, a second end 4522 of the blade 452 reaches the height of the opening 4631 in the vertical direction.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Conventionally, an image forming apparatus includes a main body housing, a process cartridge, and a transfer device. The process cartridge includes a photosensitive drum and a developing device. The transfer device is located above the photosensitive drum when the process cartridge is attached to the main body housing. The developing device includes a developing housing, a developing roller, and an agitator. The developing housing has a developing chamber in which the developing roller is disposed, and a toner storage chamber in which toner is stored. When the process cartridge is attached to the main body housing, the toner storage chamber is located below the developing chamber. The agitator is located within the toner storage chamber, and transports toner from the toner storage chamber to the developing chamber (see Patent Document 1 below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-170951 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the image forming apparatus described in Patent Document 1, when the amount of toner remaining in the toner chamber becomes low, the entire process cartridge including the photosensitive drum must be replaced even if there is no need to replace the photosensitive drum. In such an image forming apparatus, it is difficult to reduce the operating costs.

[0005] Therefore, an object of the present disclosure is to provide an image forming apparatus in which the toner cartridge can be replaced separately from the drum unit in a configuration in which the drum unit is attached to the main body housing and the transfer device is positioned above the photosensitive drum. [Means for solving the problem]

[0006] (1) The image forming apparatus of the present disclosure includes a main body housing, a drum unit, a toner cartridge, and a transfer device.

[0007] The drum unit is mountable to the main body housing. The drum unit has a photosensitive drum, a developing roller, a supply roller, an agitator, and a developing housing. The developing housing includes a wall. The wall has an opening. The opening communicates between the first developing chamber and the second developing chamber. The first developing chamber houses the agitator. The second developing chamber is located above the first developing chamber. The second developing chamber houses the developing roller and the supply roller.

[0008] The toner cartridge is attachable to the main body housing. The toner cartridge is capable of storing toner. The toner is supplied to a first developing chamber of the developing housing.

[0009] The transfer device is located above the photosensitive drum when the drum unit is attached to the main body housing, and transfers the toner on the photosensitive drum to a sheet.

[0010] The agitator includes a shaft and a blade. The shaft is rotatably supported in the developer housing. The blade is rotatable with the shaft. The blade has a first end and a second end. The first end of the blade is fixed to the shaft. The second end of the blade is located away from the first end. When the agitator rotates, the second end of the blade reaches the height of the opening in the vertical direction.

[0011] According to this configuration, the toner cartridge that contains the toner can be replaced separately from the drum unit that includes the photosensitive drum.

[0012] Furthermore, when the agitator housed in the first developing chamber rotates, the second end of the blade reaches the height of the opening in the vertical direction, so that even if the second developing chamber, which houses the developing roller and the supply roller, is located above the first developing chamber with the drum unit attached to the main body housing, the agitator can supply toner from the first developing chamber to the second developing chamber through the opening.

[0013] (2) The photosensitive drum may be rotatable about an axis. The axis extends in a first direction. The first developing chamber may have a first side wall, a second side wall, and a connecting wall. The first side wall is located on one side in the first direction. The second side wall is located on the other side in the first direction. The connecting wall connects the first side wall and the second side wall. The connecting wall may have an inlet. The inlet receives toner from a toner cartridge.

[0014] (3) The receiving opening may be located at the center of the connecting wall in the first direction.

[0015] (4) The toner cartridge may have a first portion and a second portion. The first portion of the toner cartridge is aligned in a second direction with respect to a first developing chamber of the developing housing when the toner cartridge is attached to the main housing. The second direction intersects with the first direction. The second portion of the toner cartridge is aligned in the first direction with respect to the drum unit when the toner cartridge is attached to the main housing.

[0016] According to this configuration, the image forming apparatus can be made smaller in size in the second direction, while the toner cartridge can have an increased capacity.

[0017] (5) The capacity of the second portion may be greater than the capacity of the first portion.

[0018] (6) The first portion may have a supply port that communicates with the receiving port when the toner cartridge is attached to the main body housing.

[0019] (7) The toner cartridge may further include a toner shutter. The toner shutter is movable between a toner closed position and a toner open position. When the toner shutter is located at the toner closed position, the toner shutter closes the supply port. When the toner shutter is located at the toner open position, the supply port is open.

[0020] According to this configuration, when the toner cartridge is removed from the main body housing with the toner shutter in the toner closing position, it is possible to prevent toner from leaking from the toner cartridge.

[0021] (8) The drum unit may further include a developer shutter. The developer shutter is movable between a developer closed position and a developer open position. When the developer shutter is located at the developer closed position, the developer shutter closes the receiving opening. When the developer shutter is located at the developer open position, the receiving opening is open.

[0022] According to this configuration, when the toner cartridge is removed from the main body housing with the development shutter in the development closed position, it is possible to prevent toner from leaking from the drum unit.

[0023] (9) When the toner cartridge is attached to the main body housing, the toner shutter may move in conjunction with the developer shutter. In this case, when the developer shutter is in the developer closed position, the toner shutter is in the toner closed position. When the developer shutter is in the developer open position, the toner shutter is in the toner open position.

[0024] (10) The toner cartridge may be mountable in a first direction relative to the main housing, and the second portion is located upstream of the first portion in the mounting direction of the toner cartridge.

[0025] (11) The toner cartridge may have an operating lever. The operating lever operates the developing shutter. The operating lever may be supported by the second portion.

[0026] With this configuration, the operability of the control lever can be improved.

[0027] (12) With the toner cartridge attached to the main body housing, the operating lever may be connected to the developing shutter, and the toner shutter may be connected to the developing shutter.

[0028] According to this configuration, the toner shutter and the developing shutter can be moved together by operating the operating lever.

[0029] (13) The toner cartridge may further include a screw auger disposed within the first portion. The screw auger feeds the toner in the first direction.

[0030] (14) The drum unit may further include a drum frame. The drum frame may support the developing housing so as to be movable relative to the photosensitive drum.

[0031] With this configuration, it is possible to suppress fluctuations in the contact state of the developing roller with respect to the photosensitive drum.

[0032] (15) The first portion may have a supply port. The supply port communicates with the receiving port when the toner cartridge is attached to the main body housing. The drum frame may include a receiving portion. The receiving portion receives the first portion when the toner cartridge is attached to the main body housing. The receiving portion has a communication port. The communication port communicates between the receiving port and the supply port.

[0033] According to this configuration, the toner can be supplied to the first developing chamber through the supply port, the communication port, and the receiving port.

[0034] (16) The drum unit may further include a cushion member that surrounds the receiving port. The cushion member may be located between the developing housing and the receiving portion and allows the developing housing to move relative to the photosensitive drum.

[0035] According to this configuration, it is possible to prevent toner from leaking between the developing housing and the receiving portion while allowing the developing housing to move relative to the photosensitive drum. Effect of the Invention

[0036] According to the image forming apparatus of the present disclosure, in a configuration in which the transfer device is located above the photosensitive drum with the drum unit attached to the main body housing, the toner cartridge can be replaced separately from the drum unit. [Brief description of the drawings]

[0037] [Figure 1] FIG. 1 is a schematic diagram of an image forming apparatus. [Diagram 2] FIG. 2 is an enlarged view of the drum unit shown in FIG. 1, showing a state in which the toner shutter is located at the toner open position. [Diagram 3] FIG. 3 is an enlarged view of the drum unit shown in FIG. 1, showing a state in which the development shutter is located at the development closing position and the toner shutter is located at the toner closing position. [Figure 4] FIG. 4 is a perspective view of the drum unit shown in FIG. 2, showing a state in which the developing casing has been removed. [Diagram 5] FIG. 5 is a perspective cross-sectional view of the drum unit shown in FIG. [Figure 6] FIG. 6 is a side view of the drum unit shown in FIG. 4, showing a state in which the developer shutter is located at the developer open position. [Figure 7] FIG. 7 is a side view of the drum unit shown in FIG. 4, showing a state in which the development shutter is located at the development closed position. [Figure 8] FIG. 8 is a front view of the developing housing shown in FIG. [Figure 9] FIG. 9 is a perspective view of the toner cartridge shown in FIG. [Figure 10] 10 is a cross-sectional view of the toner cartridge and the drum unit shown in FIG. [Figure 11]FIG. 11 is a side view of one side of the toner cartridge shown in FIG. [Figure 12] FIG. 12 is a side view of the other side of the toner cartridge shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] 1. Image forming device 1 The image forming apparatus 1 will be described with reference to FIGS.

[0039] As shown in FIG. 1, the image forming apparatus 1 includes a main body housing 2, a sheet cassette 3, four drum units 4Y, 4M, 4C, and 4K, four toner cartridges 5Y, 5M, 5C, and 5K, an exposure device 6, a transfer device 7, and a fixing device 8.

[0040] 1.1 Main unit 2 The main body housing 2 accommodates a sheet cassette 3, four drum units 4Y, 4M, 4C, and 4K, four toner cartridges 5Y, 5M, 5C, and 5K, an exposure device 6, a transfer device 7, and a fixing device 8.

[0041] 1.2 Sheet cassette 3 The sheet cassette 3 is capable of containing the sheet S. The sheet S in the sheet cassette 3 is transported toward the secondary transfer roller 73. The secondary transfer roller 73 will be described later.

[0042] 1.3 Four drum units 4Y, 4M, 4C, 4K The four drum units 4Y, 4M, 4C, and 4K can be attached to the main body housing 2. The four drum units 4Y, 4M, 4C, and 4K have the same configuration. Therefore, in the following, the drum unit 4K will be described in detail, and descriptions of the drum units 4Y, 4M, and 4C will be omitted.

[0043] 1.3.1 Drum unit 4K As shown in FIG. 2, the drum unit 4K includes a photosensitive drum 41K, a charging device 47K, a developing roller 43K, a supply roller 44K, and a layer thickness regulating blade 400K.

[0044] The photosensitive drum 41K extends in a first direction. The photosensitive drum 41K has a cylindrical shape. The photosensitive drum 41K is rotatable about a shaft 411. The shaft 411 extends in the first direction.

[0045] The charging device 47K charges the peripheral surface of the photosensitive drum 41K. Specifically, the charging device 47K is a charging roller. The charging device 47K may be a scorotron type charger.

[0046] The developing roller 43K is capable of supplying toner to the photosensitive drum 41K. The developing roller 43K extends in a first direction. The developing roller 43K is capable of rotating about a developing shaft 431. The developing shaft 431 extends in the first direction. In this embodiment, the developing roller 43K contacts the photosensitive drum 41K. The developing roller 43K may be separated from the photosensitive drum 41K at a predetermined interval.

[0047] The supply roller 44K supplies toner to the developing roller 43K. The supply roller 44K is located on the opposite side of the developing roller 43K to the photosensitive drum 41K. The supply roller 44K extends in a first direction. The supply roller 44K is rotatable about an axis. The axis of the supply roller 44K extends in the first direction.

[0048] The layer thickness regulating blade 400K regulates the toner layer thickness on the developing roller 43K by contacting the peripheral surface of the developing roller 43K. The layer thickness regulating blade 400K is located between the photosensitive drum 41K and the supply roller 44K, and is arranged so as to contact the developing roller 43K from below when the drum unit 4K is attached to the main body housing 2. The layer thickness regulating blade 400K extends in a first direction.

[0049] 1.3.2 Drum units 4Y, 4M, 4C 1, the drum unit 4Y includes a photosensitive drum 41Y, a charging device 47Y, a developing roller 43Y, a supply roller 44Y, and a layer thickness regulating blade 400Y. The drum unit 4M includes a photosensitive drum 41M, a charging device 47M, a developing roller 43M, a supply roller 44M, and a layer thickness regulating blade 400M. The drum unit 4C includes a photosensitive drum 41C, a charging device 47C, a developing roller 43C, a supply roller 44C, and a layer thickness regulating blade 400C.

[0050] 1.4 4 toner cartridges 5Y, 5M, 5C, 5K The four toner cartridges 5Y, 5M, 5C, and 5K can be attached to the main body housing 2. More specifically, the toner cartridge 5Y can be attached to the drum unit 4Y. The toner cartridge 5Y can accommodate toner to be supplied to the supply roller 44Y. The toner cartridge 5M can be attached to the drum unit 4M. The toner cartridge 5M can accommodate toner to be supplied to the supply roller 44M. The toner cartridge 5C can be attached to the drum unit 4C. The toner cartridge 5C can accommodate toner to be supplied to the supply roller 44C. The toner cartridge 5K can be attached to the drum unit 4K. The toner cartridge 5K can accommodate toner to be supplied to the supply roller 44K.

[0051] 1.5 Exposure Equipment 6 The exposure device 6 can expose the surfaces of the four photosensitive drums 41Y, 41M, 41C, and 41K. The exposure device 6 emits light that exposes the charged surfaces of the photosensitive drums 41Y, 41M, 41C, and 41K. As a result, electrostatic latent images are formed on the surfaces of the photosensitive drums 41Y, 41M, 41C, and 41K. Toner is supplied to the electrostatic latent images.

[0052] The exposure device 6 is located below the four drum units 4Y, 4M, 4C, and 4K. Note that below means below in the vertical direction when the image forming apparatus 1 is placed in a normal use state.

[0053] Specifically, the exposure device 6 is a laser scanning unit. The exposure device 6 may be an LED array.

[0054] 1.6 Transfer device 7 The transfer device 7 transfers the toner on the four photosensitive drums 41Y, 41M, 41C, and 41K to the sheet S. The transfer device 7 is located on the opposite side of the exposure device 6 with respect to the four drum units 4Y, 4M, 4C, and 4K. The transfer device 7 is located above the four photosensitive drums 41Y, 41M, 41C, and 41K in a state in which the four drum units 4Y, 4M, 4C, and 4K are attached to the main body housing 2. The transfer device 7 includes an intermediate transfer belt 71, four primary transfer rollers 72Y, 72M, 72C, and 72K, and a secondary transfer roller 73.

[0055] With the four drum units 4Y, 4M, 4C, and 4K attached to the main body housing 2, the four photosensitive drums 41Y, 41M, 41C, and 41K come into contact with the intermediate transfer belt 71. With the four drum units 4Y, 4M, 4C, and 4K attached to the main body housing 2, the intermediate transfer belt 71 passes between the photosensitive drum 41Y and the primary transfer roller 72Y, between the photosensitive drum 41M and the primary transfer roller 72M, between the photosensitive drum 41C and the primary transfer roller 72C, and between the photosensitive drum 41K and the primary transfer roller 72K.

[0056] The primary transfer roller 72Y transfers the toner on the photosensitive drum 41Y to the intermediate transfer belt 71. The primary transfer roller 72M transfers the toner on the photosensitive drum 41M to the intermediate transfer belt 71. The primary transfer roller 72C transfers the toner on the photosensitive drum 41C to the intermediate transfer belt 71. The primary transfer roller 72K transfers the toner on the photosensitive drum 41K to the intermediate transfer belt 71.

[0057] The secondary transfer roller 73 comes into contact with the intermediate transfer belt 71. The sheet S conveyed from the sheet cassette 3 passes between the intermediate transfer belt 71 and the secondary transfer roller 73. At this time, the secondary transfer roller 73 transfers the toner transferred onto the intermediate transfer belt 71 onto the sheet S.

[0058] 1.7 Fixing device 8 The fixing device 8 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 that has passed through the fixing device 8 is discharged onto the top surface of the main body housing 2.

[0059] 2. Details of Drum Unit 4K Next, the drum unit 4K will be described in detail with reference to FIGS.

[0060] As shown in FIG. 2, the drum unit 4K includes, in addition to the photosensitive drum 41K, the charging device 47K, the developing roller 43K, the supply roller 44K, and the layer thickness regulating blade 400K, a drum frame 42K, a first coupling 40K (see FIG. 5), a developing housing 46K, an agitator 45K, a developing shutter 48K, and a cushion member 49K.

[0061] 2.1 Drum Frame 42K The drum frame 42K supports the photosensitive drum 41K, the charging device 47K, and the developing housing 46K.

[0062] As shown in FIG. 4, the drum frame 42K includes a first side frame 421, a second side frame 422, and a receiving portion 423.

[0063] 2.1.1 First Side Frame 421 and Second Side Frame 422 The first side frame 421 supports one end of the photosensitive drum 41K in the first direction. The second side frame 422 is separated from the first side frame 421 in the first direction. The second side frame 422 supports the other end of the photosensitive drum 41K in the first direction.

[0064] The first side frame 421 extends in a second direction. The second direction intersects with the first direction. The first side frame 421 has a first oblong hole 4211, a second oblong hole 4212, and a hole 4213.

[0065] The first oblong hole 4211 extends in a direction in which the photosensitive drum 41K and the developing roller 43K face each other (see FIG. 2). The first protrusion 464A fits into the first oblong hole 4211 (see FIG. 6). The first protrusion 464A will be described later.

[0066] The second oblong hole 4212 is located on the opposite side of the photosensitive drum 41K with respect to the first oblong hole 4211 in the second direction. The extension direction of the second oblong hole 4212 is parallel to the extension direction of the first oblong hole 4211. The second protrusion 465A fits into the second oblong hole 4212. The second protrusion 465A will be described later.

[0067] The hole 4213 is located below the photosensitive drum 41K when the drum unit 4K is attached to the main body housing 2. When the toner cartridge 5K is attached to the main body housing 2, the first portion 511 of the toner cartridge 5K passes through the hole 4213 (see FIG. 2).

[0068] In addition, the first side frame 421 has a first boss 4214 .

[0069] The first boss 4214 rotatably supports the developing shutter 48K. The first boss 4214 is away from the hole 4213 in the second direction. When the drum unit 4K is attached to the main body housing 2, the first boss 4214 is located below the second elongated hole 4212. The first boss 4214 has a cylindrical shape. The first boss 4214 extends from a side surface of the first side frame 421 in the first direction.

[0070] The second side frame 422 will be described similarly to the first side frame 421, except that it has slits 4221 (see FIG. 6) instead of holes 4213. Therefore, a description of the second side frame 422 will be omitted. As shown in FIG. 6, the slits 4221 communicate with the internal space of the receiving portion 423. The slits 4221 extend in an arc shape.

[0071] 2.1.2 Reception Department 423 As shown in FIG. 2, when the toner cartridge 5K is attached to the main body housing 2, the receiving portion 423 receives the first portion 511 of the toner cartridge 5K.

[0072] The receiving portion 423 faces the first developing chamber 461 of the developing housing 46K in the second direction. When the drum unit 4K is attached to the main body housing 2, the receiving portion 423 is located below the second developing chamber 462 of the developing housing 46K. The first developing chamber 461 and the second developing chamber 462 will be described later.

[0073] The receiving portion 423 includes a first wall 4232. The first wall 4232 faces the connecting wall 4613 of the first developing chamber 461 in the second direction. The first wall 4232 has an arc shape that follows the outer circumferential surface of the connecting wall 4613. The connecting wall 4613 will be described later. The first wall 4232 has a communication opening 4231. In other words, the receiving portion 423 has the communication opening 4231. As shown in FIG. 5, the communication opening 4231 is located at the center of the first wall 4232 in the first direction.

[0074] The receiving portion 423 is located between the first side frame 421 and the second side frame 422 in the first direction. The receiving portion 423 extends in the first direction. One end of the receiving portion 423 in the first direction is connected to the first side frame 421. The internal space of the receiving portion 423 communicates with the hole 4213. The other end of the receiving portion 423 in the first direction is connected to the second side frame 422. The internal space of the receiving portion 423 communicates with the slit 4221 (see FIG. 6).

[0075] 2.2 First coupling 40K When the toner cartridge 5K is attached to the main body housing 2, the first coupling 40K inputs a driving force to the screw auger 54K. The screw auger 54K will be described later. When the toner cartridge 5K is attached to the main body housing 2, the first coupling 40K is connected to the second coupling 542 of the screw auger 54K. The first coupling 40K is provided on the second side frame 422. The first coupling 40K faces the internal space of the receiving portion 423.

[0076] 2.3 Developer box 46K As shown in FIG. 2, the developing housing 46K has a first developing chamber 461, a second developing chamber 462, a wall 463, two first protrusions 464A, 464B (see FIG. 8), and two second protrusions 465A, 465B (see FIG. 8).

[0077] 2.3.1 First developing chamber 461 The first developing chamber 461 houses the agitator 45K. The first developing chamber 461 faces the receiving portion 423 in the second direction.

[0078] As shown in FIG. 8, the first developing chamber 461 has a first side wall 4611, a second side wall 4612, and a connecting wall 4613.

[0079] The first side wall 4611 is located on one side in the first direction. The second side wall 4612 is located on the other side in the first direction. The second side wall 4612 is spaced apart from the first side wall 4611 in the first direction.

[0080] The connecting wall 4613 connects the first side wall 4611 and the second side wall 4612. The connecting wall 4613 is located between the first side wall 4611 and the second side wall 4612 in the first direction. The connecting wall 4613 extends in the first direction. The connecting wall 4613 has a cylindrical shape (see FIG. 2). The connecting wall 4613 faces the first wall 4232 of the receiving portion 423 in the second direction (see FIG. 2).

[0081] The connecting wall 4613 has a receiving opening 46131. ​​When the toner cartridge 5K is attached to the main housing 2, the receiving opening 46131 receives toner from the toner cartridge 5K. The receiving opening 46131 is located at the center of the connecting wall 4613 in the first direction. The receiving opening 46131 communicates with the communication opening 4231 (see FIG. 2).

[0082] 2.3.2 Second developing chamber 462 When the drum unit 4K is attached to the main body housing 2, the second developing chamber 462 is located above the first developing chamber 461 (see FIG. 2). The second developing chamber 462 houses the developing roller 43K, the supply roller 44K, and the layer thickness regulating blade 400K (see FIG. 2).

[0083] The second developing chamber 462 includes a third side wall 4621, a fourth side wall 4622, a bottom wall 4623 (see FIG. 2), and an upper wall 4624.

[0084] The third side wall 4621 is located on one side in the first direction. The third side wall 4621 is connected to the first side wall 4611. The third side wall 4621 rotatably supports one end of the developing roller 43K in the first direction and one end of the supply roller 44K in the first direction.

[0085] The fourth side wall 4622 is located on the other side in the first direction. The fourth side wall 4622 is connected to the second side wall 4612. The fourth side wall 4622 is separated from the third side wall 4621 in the first direction. The fourth side wall 4622 rotatably supports the other end of the developing roller 43K in the first direction and the other end of the supply roller 44K in the first direction.

[0086] 2, when the drum unit 4K is attached to the main body housing 2, the bottom wall 4623 is located between the developing roller 43K and the receiving portion 423. The bottom wall 4623 connects the third side wall 4621 and the fourth side wall 4622 in the first direction. The bottom wall 4623 supports the layer thickness regulating blade 400K.

[0087] The top wall 4624 is located on the opposite side of the bottom wall 4623 with respect to the developing roller 43K. The top wall 4624 connects the third side wall 4621 and the fourth side wall 4622 in the first direction.

[0088] 2.3.3 Wall 463 The wall 463 is located on the opposite side of the photosensitive drum 41K with respect to the second developing chamber 462. The wall 463 is located between the first developing chamber 461 and the second developing chamber 462. The wall 463 extends in the first direction. The wall 463 connects the third side wall 4621 and the fourth side wall 4622 in the first direction. When the drum unit 4K is attached to the main body housing 2, the upper end of the wall 463 is disposed so as to be spaced apart from the upper wall 4624 by a certain distance. When the drum unit 4K is attached to the main body housing 2, the lower end of the wall 463 is connected to the bottom wall 4623. The wall 463 forms an opening 4631 between the wall 463 and the upper wall 4624. The opening 4631 communicates between the first developing chamber 461 and the second developing chamber 462.

[0089] 2.3.4 Two first protrusions 464A, 464B 6 and 7, the first protrusion 464A is located on the opposite side of the third side wall 4621 from the fourth side wall 4622 in the first direction (see FIG. 8). The first protrusion 464A extends in the first direction. The first protrusion 464A has a cylindrical shape. The first protrusion 464A may be a shaft of the developing roller 43K.

[0090] The first protrusion 464A fits into the first long hole 4211 of the first side frame 421. In a state in which the first protrusion 464A fits into the first long hole 4211, the first long hole 4211 has play in the direction in which the first long hole 4211 extends.

[0091] The first protrusion 464B is located on the opposite side of the third side wall 4621 with respect to the fourth side wall 4622 in the first direction (see FIG. 8). Although not shown, the first protrusion 464B fits into the first long hole 4211 of the second side frame 422. The first protrusion 464B will be described in the same manner as the first protrusion 464A. Therefore, a description of the first protrusion 464B will be omitted.

[0092] 2.3.5 Second protrusion 465A, 465B The second protrusion 465A is located on the opposite side of the third side wall 4621 from the fourth side wall 4622 in the first direction (see FIG. 8). The second protrusion 465A extends in the first direction. The second protrusion 465A has a cylindrical shape.

[0093] The second protrusion 465A fits into the second long hole 4212 of the first side frame 421. The second protrusion 465A is located on the opposite side of the photosensitive drum 41K to the first protrusion 464A in the second direction. When the second protrusion 465A fits into the second long hole 4212, the second long hole 4212 has play in the extension direction of the second long hole 4212.

[0094] The second protrusion 465B is located on the opposite side of the third side wall 4621 with respect to the fourth side wall 4622 in the first direction (see FIG. 8). Although not shown, the second protrusion 465B fits into the second elongated hole 4212 of the second side frame 422. The second protrusion 465B will be described in the same manner as the second protrusion 465A. Therefore, a description of the second protrusion 465B will be omitted.

[0095] As a result, the developing housing 46K is supported by the first side frame 421 and the second side frame 422. The developing housing 46K is movable relative to the photosensitive drum 41K in a direction intersecting the first direction. More specifically, the developing housing 46K is movable relative to the photosensitive drum 41K in a direction in which the developing roller 43K and the photosensitive drum 41K face each other. In other words, the drum frame 42K supports the developing housing 46K movably relative to the photosensitive drum 41K.

[0096] Further, the first protrusion 464A is pressed toward the photosensitive drum 41K by a spring 466. The spring 466 is located on the opposite side of the photosensitive drum 41K from the first protrusion 464A. As a result, the developing roller 43K is pressed toward the photosensitive drum 41K.

[0097] Therefore, it is possible to suppress fluctuations in the contact state of the developing roller 43K with respect to the photosensitive drum 41K.

[0098] 2.4 Agitator 45K 2, the agitator 45K can transport the toner in the first developing chamber 461 toward the second developing chamber 462. The agitator 45K is rotatably supported in the first developing chamber 461. The agitator 45K includes a shaft 451 and a blade 452.

[0099] 2.4.1 Shaft 451 The shaft 451 is rotatably supported in the first developing chamber 461 of the developing housing 46K. The shaft 451 extends in a first direction. One end of the shaft 451 in the first direction is supported by a first side wall 4611. The other end of the shaft 451 in the first direction is supported by a second side wall 4612.

[0100] 2.4.2 Feather 452 The blade 452 is rotatable together with the shaft 451. The blade 452 is flexible. The blade 452 has a first end 4521 and a second end 4522. The first end 4521 of the blade 452 is fixed to the shaft 451. The second end 4522 of the blade 452 is located away from the first end 4521. When the agitator 45K rotates, the second end 4522 of the blade 452 reaches the height of the opening 4631 in the vertical direction. In other words, the second end 4522 of the blade 452 reaches above the upper end of the wall 463 that forms the opening. Therefore, even when the drum unit 4K is attached to the main housing 2 and the second developing chamber 462 housing the developing roller 43K and the supply roller 44K is located above the first developing chamber 461, the agitator 45K can stably supply toner from the first developing chamber 461 to the second developing chamber 462 through the opening 4631.

[0101] Furthermore, when the agitator 45K rotates, the second end 4522 of the blade 452 reaches above the bottom wall 4623 in the vertical direction. When the second end 4522 reaches the height of the opening 4631, the portion of the blade 452 between the first end 4521 and the second end 4522 passes through the opening 4631. Furthermore, when the second end 4522 reaches the height of the opening 4631, the blade 452 has a height that overlaps with the supply roller 44K in the vertical direction.

[0102] 2.5 Developing shutter 48K As shown in FIGS. 2 and 3, the development shutter 48K is movable between a development closed position (see FIG. 3) and a development open position (see FIG. 2).

[0103] When the development shutter 48K is located at the development closed position, the development shutter 48K closes the receiving port 46131 (see FIG. 3). More specifically, when the development shutter 48K is located at the development closed position, the development shutter 48K closes the communication port 4231 communicating with the receiving port 46131. ​​Therefore, when the development shutter 48K is located at the development closed position, by removing the toner cartridge 5K from the main body housing 2, it is possible to prevent toner from leaking from the drum unit 4K.

[0104] When the development shutter 48K is in the development open position, the receiving port 46131 is open (see FIG. 2). More specifically, when the development shutter 48K is in the development open position, the communication port 4231 communicating with the receiving port 46131 is open.

[0105] 5, the developing shutter 48K is rotatably supported by the drum frame 42K. The developing shutter 48K includes a developing shutter main body 481, a shutter coupling 482, a first arm 483, a second arm (not shown), a third arm 484, two ribs 485 and 486, and a protrusion 487.

[0106] 2.5.1 Developing shutter body 481 6 and 7, the developing shutter body 481 is located on the opposite side of the connecting wall 4613 with respect to the first wall 4232 of the receiving portion 423. The developing shutter body 481 is movable along the first wall 4232. The developing shutter body 481 has an arc shape that follows the first wall 4232.

[0107] 5, the developing shutter main body 481 extends in a first direction. One end of the developing shutter main body 481 in the first direction passes through a hole 4213 of the first side frame 421. The other end of the developing shutter main body 481 in the first direction passes through a slit 4221 of the second side frame 422 (see FIG. 6).

[0108] When the development shutter 48K is located at the development open position, the development shutter main body 481 is separated from the communication port 4231 (see FIG. 6). When the development shutter 48K is located at the development closed position, the development shutter main body 481 overlaps with the communication port 4231 in the second direction (see FIG. 7).

[0109] 2.5.2 Shutter Coupling 482 The shutter coupling 482 is connected to the lever coupling 533 of the operating lever 53K when the toner cartridge 5K is attached to the main housing 2. The operating lever 53K will be described later. The shutter coupling 482 is located on the opposite side of the second side frame 422 with respect to the first side frame 421 in the first direction. The shutter coupling 482 has a first annular portion 4821 and two bosses 4822, 4823.

[0110] The first annular portion 4821 has a circular ring shape. The first boss 4214 of the first side frame 421 fits into the first annular portion 4821.

[0111] The two bosses 4822, 4823 are located on the opposite side of the first side frame 421 with respect to the first annular portion 4821 in the first direction. Each of the two bosses 4822, 4823 extends from the first annular portion 4821 in the first direction. Each of the two bosses 4822, 4823 has a cylindrical shape. The two bosses 4822, 4823 are disposed at an interval in the circumferential direction of the first annular portion 4821.

[0112] Although not shown, the development shutter 48K further includes a second annular portion. The second annular portion is located on the opposite side of the second side frame 422 from the first side frame 421 in the first direction. The first boss of the second side frame 422 fits into the second annular portion.

[0113] 2.5.3 First Arm 483 and Second Arm The first arm 483 is located on the opposite side of the second side frame 422 with respect to the first side frame 421 in the first direction. The first arm 483 connects one end of the developing shutter main body 481 in the first direction to the first annular portion 4821. Although not shown, the second arm is located on the opposite side of the first side frame 421 with respect to the second side frame 422 in the first direction. The second arm connects the other end of the developing shutter main body 481 in the first direction to the second annular portion.

[0114] 2.5.4 Third Arm 484 The third arm 484 is located on the opposite side of the shutter coupling 482 from the first arm 483. The third arm 484 has a U-shape. One end of the third arm 484 is connected to the shutter coupling 482. Although not shown, the other end of the third arm 484 is connected to the second annular portion.

[0115] 2.5.5 Rib 485, 486 The two ribs 485, 486 are provided on the developing shutter main body 481. The two ribs 485, 486 are located between the communication port 4231 and the second side frame 422 in the first direction. Each of the two ribs 485, 486 protrudes from the developing shutter main body 481 in the second direction. The two ribs 485, 486 are located at an interval from each other in the moving direction of the developing shutter 48K. When the toner cartridge 5K is attached to the main body housing 2, the protrusion 522 of the toner shutter 52K fits between the two ribs 485, 486. The protrusion 522 will be described later.

[0116] 2.5.6 Protrusion 487 The protrusion 487 is provided on the first arm 483. The protrusion 487 is located on the opposite side of the first side frame 421 with respect to the first arm 483 in the first direction. The protrusion 487 protrudes in the first direction from the first arm 483. When the toner cartridge 5K is attached to the main housing 2, the protrusion 487 fits into the recessed portion 523 of the toner shutter 52K.

[0117] 2.6 Cushion member 49K 2, the cushion member 49K is located between the first developing chamber 461 of the developing casing 46K and the receiving portion 423 of the drum frame 42K. More specifically, the cushion member 49K is located between the connecting wall 4613 of the first developing chamber 461 and the first wall 4232 of the receiving portion 423. The cushion member 49K allows the developing casing 46K to move relative to the photosensitive drum 41K.

[0118] The cushion member 49K is made of a material having elasticity. In this embodiment, the cushion member 49K is made of sponge. The cushion member 49K is positioned between the connecting wall 4613 and the first wall 4232 in a slightly compressed state. The cushion member 49K may be attached to the connecting wall 4613 and / or the receiving portion 423 with double-sided tape or the like.

[0119] When the developing housing 46K moves relative to the photosensitive drum 41K, the cushion member 49K is elastically deformed. Specifically, when the developing housing 46K moves in a direction away from the photosensitive drum 41K, the connecting wall 4613 moves in a direction away from the receiving portion 423. Then, the cushion member 49K restores from the compressed state and fills the gap between the connecting wall 4613 and the first wall 4232.

[0120] Furthermore, when the developing housing 46K moves in a direction approaching the photosensitive drum 41K, the connecting wall 4613 moves in a direction approaching the receiving portion 423. Then, the cushion member 49K is compressed between the connecting wall 4613 and the first wall 4232.

[0121] The cushion member 49K surrounds the receiving port 46131. ​​The cushion member 49K surrounds the communication port 4231. The cushion member 49K has an opening 491. The opening 491 communicates between the receiving port 46131 and the communication port 4231. The cushion member 49K surrounding the receiving port 46131 comes into contact with the connecting wall 4613 and the first wall 4232, whereby the cushion member 49K seals between the connecting wall 4613 and the receiving portion 423. This makes it possible to prevent toner from leaking from between the connecting wall 4613 and the receiving portion 423 of the developing housing 46K.

[0122] 3. Toner Cartridge 5K Details 9, the toner cartridge 5K can be attached to the main body housing 2 along a first direction. More specifically, with the drum unit 4K attached to the main body housing 2, the toner cartridge 5K can be attached to the drum unit 4K along the first direction. Therefore, the toner cartridge 5K that contains toner can be replaced separately from the drum unit 4K.

[0123] The toner cartridge 5K can accommodate toner to be supplied to the first developing chamber 461 of the developing housing 46K. When the toner cartridge 5K is attached to the drum unit 4K, the toner cartridge 5K can supply toner to the first developing chamber 461 (see FIG. 2).

[0124] The toner cartridge 5K includes a cartridge housing 51K, a screw auger 54K (see FIG. 10), a toner shutter 52K, and an operating lever 53K.

[0125] 3.1 Cartridge housing 51K The cartridge housing 51K is capable of containing toner. The cartridge housing 51K has a first portion 511 and a second portion 512. In other words, the toner cartridge 5K has the first portion 511 and the second portion 512.

[0126] 3.1.1 Part 1511 2, the first portion 511 of the toner cartridge 5K is aligned with the first developing chamber 461 of the developing housing 46K in the second direction when the toner cartridge 5K is attached to the main housing 2. When the toner cartridge 5K is attached to the drum unit 4K, the first portion 511 fits into the receiving portion 423. When the toner cartridge 5K is attached to the drum unit 4K, the first portion 511 is located on the opposite side of the connecting wall 4613 with respect to the first wall 4232 of the receiving portion 423 in the second direction.

[0127] The first portion 511 extends in a first direction (see FIG. 9). The first portion 511 includes a second wall 5112. When the first portion 511 is fitted into the receiving portion 423, the second wall 5112 faces the first wall 4232 of the receiving portion 423 in the second direction. The second wall 5112 has an arc shape that follows the first wall 4232. The second wall 5112 has a supply port 5111. In other words, the first portion 511 has the supply port 5111. When the toner cartridge 5K is attached to the main body housing 2, the supply port 5111 communicates with the receiving port 46131 via the communication port 4231. In other words, the communication port 4231 communicates with the receiving port 46131 and the supply port 5111. As shown in FIG. 10, the supply port 5111 is located at the center of the second wall 5112 in the first direction.

[0128] 3.1.2 Second part 512 The second portion 512 of the toner cartridge 5K is aligned with the drum unit 4K in the first direction when the toner cartridge 5K is attached to the main housing 2. When the toner cartridge 5K is attached to the main housing 2, the second portion 512 is located on the opposite side of the second side frame 422 with respect to the first side frame 421 in the first direction, and is aligned with the photosensitive drum 41K. When the toner cartridge 5K is attached to the main housing 2, the second portion 512 overlaps with the photosensitive drum 41K when viewed from the first direction. In the attachment direction of the toner cartridge 5K, the second portion 512 is located upstream of the first portion 511.

[0129] The internal space of the second portion 512 communicates with the internal space of the first portion 511. The capacity of the second portion 512 is larger than the capacity of the first portion 511. The projected area of ​​the second portion 512 when projected in the first direction is larger than the projected area of ​​the first portion 511 when projected in the first direction. Therefore, the capacity of the toner cartridge 5K can be increased while the size of the image forming apparatus 1 in the second direction can be reduced.

[0130] 9, two lever support portions 513, 514 are provided on the outer surface of the second portion 512. The two lever support portions 513, 514 support the operating lever 53K. The two lever support portions 513, 514 are positioned at an interval from each other in the first direction. The lever support portion 514 is positioned on the opposite side of the lever support portion 513 to the first portion 511 in the first direction. In the mounting direction of the toner cartridge 5K, the lever support portion 514 is positioned upstream of the lever support portion 513.

[0131] 3.2 Screw Auger 54K 10, the screw auger 54K sends toner in a first direction inside the cartridge housing 51K. At least a portion of the screw auger 54K is disposed inside the first portion 511. In this embodiment, the screw auger 54K is disposed across the first portion 511 and the second portion 512. The screw auger 54K has an auger main body 541 and a second coupling 542.

[0132] The auger body 541 extends in a first direction. One end 5411 of the auger body 541 in the first direction is supported by a side wall of the first portion 511. The other end 5412 of the auger body 541 in the first direction is located away from the one end 5411 in the first direction and is supported by a side wall of the second portion 512. A portion of the auger body 541 between the other end 5412 and the supply port 5111 sends toner from the other end 5412 toward the supply port 5111. A portion of the auger body 541 between the supply port 5111 and the one end 5411 sends toner from the one end 5411 toward the supply port 5111.

[0133] The second coupling 542 is provided at one end 5411 of the auger body 541. With the first portion 511 fitted in the receiving portion 423, the second coupling 542 is connected to the first coupling 40K. As a result, with the first portion 511 fitted in the receiving portion 423, a driving force is input from the first coupling 40K to the screw auger 54K.

[0134] 3.3 Toner Shutter 52K 2 and 3, the toner shutter 52K is movable between a toner closed position (see FIG. 3) and a toner open position (see FIG. 2). When the toner shutter 52K is located at the toner closed position, the toner shutter 52K closes the supply port 5111 (see FIG. 3). Therefore, by removing the toner cartridge 5K from the main body housing 2 with the toner shutter 52K located at the toner closed position, it is possible to prevent toner from leaking from the toner cartridge 5K.

[0135] When the toner shutter 52K is in the toner open position, the supply port 5111 is open (see FIG. 2).

[0136] Further, when the toner cartridge 5K is mounted on the main body housing 2, the toner shutter 52K moves in conjunction with the developing shutter 48K. Therefore, when the developing shutter 48K is positioned at the developing closed position, the toner shutter 52K is positioned at the toner closed position. When the developing shutter 48K is positioned at the developing open position, the toner shutter 52K is positioned at the toner open position. When the toner cartridge 5K is mounted on the main body housing 2, the developing shutter 48K is positioned at the developing open position, and the toner shutter 52K is positioned at the toner open position, the supply port 5111, the communication port 4231, and the receiving port 46131 communicate with each other. Therefore, the toner can be supplied from the first part 511 of the toner cartridge 5K to the first developing chamber 461 of the developing housing 46K through the supply port 5111, the communication port 4231, and the receiving port 46131.

[0137] As shown in FIG. 9, the toner shutter 52K includes a toner shutter main body 521, a protrusion 522, and a recessed portion 523.

[0138] 3.3.1 Toner shutter body 521 The toner shutter body 521 is movable along the second wall 5112. The toner shutter body 521 has an arc shape that fits along the second wall 5112.

[0139] The toner shutter body 521 extends in the first direction. When the toner shutter 52K is in the toner open position, the toner shutter body 521 is separated from the supply port 5111 (see FIG. 2). When the toner shutter 52K is in the toner closed position, the toner shutter 52K overlaps with the supply port 5111 in the second direction (see FIG. 3).

[0140] 3.3.2 Protrusion 522 The protrusion 522 is provided at one end of the toner shutter main body 521 in the first direction. The protrusion 522 protrudes in the first direction from the toner shutter main body 521. When the toner cartridge 5K is attached to the main housing 2, the protrusion 522 fits between the two ribs 485, 486 of the development shutter 48K (see FIG. 5).

[0141] 3.2.3 Concave portion 523 The recessed portion 523 is provided at the other end of the toner shutter main body 521 in the first direction. The recessed portion 523 is located on the opposite side of the toner shutter main body 521 from the second wall 5112 in the second direction. The recessed portion 523 protrudes from the toner shutter main body 521 in the second direction. When the toner cartridge 5K is attached to the main body housing 2, the recessed portion 523 receives the protrusion 487 of the development shutter 48K. As a result, when the toner cartridge 5K is attached to the main body housing 2, the toner shutter 52K is connected to the development shutter 48K.

[0142] 3.3 Operating lever 53K The operating lever 53K operates the developing shutter 48K. The operating lever 53K is supported by the second portion 512. More specifically, the operating lever 53K is supported by two lever support portions 513, 514 provided on the second portion 512. Therefore, compared to the case where the operating lever 53K is supported by the first portion 511, it is possible to improve the operability of the operating lever 53K.

[0143] As shown in FIGS. 11 and 12, the operating lever 53K includes a shaft 532, a handle 531, and a lever coupling 533.

[0144] The shaft 532 extends in a first direction and is rotatably supported by two lever support portions 513 and 514.

[0145] The handle 531 is operated by a user. The handle 531 is located on the opposite side of the lever support portion 513 with respect to the lever support portion 514 in the first direction. The handle 531 is fixed to the shaft 532.

[0146] The lever coupling 533 is connected to the shutter coupling 482 when the toner cartridge 5K is attached to the main body housing 2. The lever coupling 533 is located on the opposite side of the lever support part 513 from the lever support part 514 in the first direction. The lever coupling 533 is fixed to the shaft 532. The lever coupling 533 has a disk shape. The lever coupling 533 has two grooves 5331, 5332. The two grooves 5331, 5332 are located at an interval from each other in the circumferential direction of the lever coupling 533.

[0147] When the toner cartridge 5K is attached to the main body housing 2, a boss 4822 of the developing shutter 48K fits into the groove 5331, and a boss 4823 of the developing shutter 48K fits into the groove 5332.

[0148] As a result, the operating lever 53K is connected to the developing shutter 48K when the toner cartridge 5K is attached to the main body housing 2. Also, as described above, the toner shutter 52K is connected to the developing shutter 48K when the toner cartridge 5K is attached to the main body housing 2. Therefore, the user can move the toner shutter 52K and the developing shutter 48K together by holding the handle 531 and operating the operating lever 53K.

[0149] 4. Effects (1) As shown in Fig. 10, in the image forming apparatus 1, the toner cartridge 5K that contains toner can be removed separately from the drum unit 4K that includes the photosensitive drum 41K from the main body housing 2. Therefore, the toner cartridge 5K can be replaced separately from the drum unit 4K.

[0150] 2, when the agitator 45K housed in the first developing chamber 461 rotates, the second end 4522 of the blade 452 reaches the height of the opening 4631 in the vertical direction. Therefore, even if the second developing chamber 462 housing the developing roller 43K and the supply roller 44K is located above the first developing chamber 461 with the drum unit 4K attached to the main body housing 2, the agitator 45K can stably supply toner from the first developing chamber 461 to the second developing chamber 462 through the opening 4631. [Explanation of symbols]

[0151] 1. Image forming device 2 Main unit 4 Drum Unit 41 Photosensitive drum 42 Drum Frame 423 Acceptance Department 4231 Connecting port 43 Developing roller 44 Supply roller 45 Agitator 451 Shaft 452 Feather 4521 1st end 4522 2nd end 46 Developing unit 461 First Development Chamber 4611 First side wall 4612 Second side wall 4613 Connecting wall 46131 Inlet 462 Second Development Chamber 463 Wall 4631 Aperture 48 Developing shutter 49 Cushioning material 5 Toner Cartridge 511 Part 1 5111 Supply port 512 Part 2 52 Toner Shutter 53 Operating lever 54 Screw Auger 7. Transcription device

Claims

1. A main body housing; A drum unit that can be attached to the main body housing, a photosensitive drum rotatable about an axis extending in a first direction; A developing roller; A supply roller; An agitator; a developing housing including a wall having an opening communicating a first developing chamber accommodating the agitator and a second developing chamber located above the first developing chamber and accommodating the developing roller and the supply roller; A drum unit having a toner cartridge capable of accommodating toner to be supplied to the first developing chamber of the developing housing, the toner cartridge being attachable to the main body housing; a transfer device that is positioned above the photosensitive drum when the drum unit is attached to the main body housing and transfers the toner on the photosensitive drum to a sheet; Equipped with The first developing chamber is a first side wall located on one side in the first direction; a second side wall located on the other side in the first direction; a connecting wall that connects the first side wall and the second side wall, the connecting wall having an inlet that receives toner from the toner cartridge, The agitator is a shaft rotatably supported by the developing housing; a blade rotatable with the shaft, the blade having a first end fixed to the shaft and a second end spaced apart from the first end; When the agitator rotates, the second end of the blade reaches the height of the opening in the vertical direction.

2. The image forming apparatus according to claim 1 , wherein the receiving opening is located at a center of the connecting wall in the first direction.

3. The toner cartridge includes: a first portion aligned with the first developing chamber of the developing housing in a second direction intersecting the first direction when the toner cartridge is attached to the main housing; The image forming apparatus according to claim 2 , further comprising: a second portion that is aligned with the drum unit in the first direction when the toner cartridge is attached to the main body housing.

4. The image forming apparatus according to claim 3 , wherein the capacity of the second portion is greater than the capacity of the first portion.

5. 5. The image forming apparatus according to claim 3, wherein the first portion has a supply port that communicates with the receiving port when the toner cartridge is attached to the main body housing.

6. 6. The image forming apparatus according to claim 5, wherein said toner cartridge further comprises a toner shutter movable between a toner closed position where said supply port is closed and a toner open position where said supply port is opened.

7. 7. The image forming apparatus according to claim 6, wherein the drum unit further comprises a developer shutter movable between a developer closed position where the receiving opening is closed and a developer open position where the receiving opening is opened.

8. When the toner cartridge is attached to the main body housing, the toner shutter moves in conjunction with the developing shutter; When the developing shutter is positioned at the developing closing position, the toner shutter is positioned at the toner closing position, 8. The image forming apparatus according to claim 7, wherein said toner shutter is located at said toner open position when said developer shutter is located at said developer open position.

9. the toner cartridge is mountable to the main body along the first direction, In the mounting direction of the toner cartridge, the second portion is The image forming apparatus according to claim 8 , which is located on the upstream side.

10. 10. The image forming apparatus according to claim 9, wherein the toner cartridge has an operating lever for operating the developing shutter, the operating lever being supported by the second portion.

11. 11. The image forming apparatus according to claim 10, wherein, in a state in which the toner cartridge is mounted in the main body housing, the operating lever is connected to the developing shutter, and the toner shutter is connected to the developing shutter.

12. The image forming apparatus according to claim 3 , wherein the toner cartridge further comprises a screw auger disposed within the first portion, the screw auger feeding toner in the first direction.

13. The image forming apparatus according to claim 3 , wherein the drum unit further comprises a drum frame that supports the developing casing so as to be movable relative to the photosensitive drum.

14. the first portion has a supply port that communicates with the receiving port when the toner cartridge is attached to the main body housing, 14. The image forming apparatus according to claim 13, wherein the drum frame includes a receiving portion that receives the first portion when the toner cartridge is attached to the main body housing, the receiving portion having a communication opening that connects the receiving opening and the supply opening.

15. 15. The image forming apparatus according to claim 14, wherein the drum unit further includes a cushion member surrounding the receiving port, the cushion member being located between the developing housing and the receiving portion and allowing the developing housing to move relative to the photosensitive drum.

Images