JP7409077B2 - image forming device - Google Patents

Description

The present disclosure relates to an image forming apparatus.

Conventionally, an image forming apparatus includes a main body housing and a drum unit. The drum unit is removable from the main body housing. The drum unit includes a photosensitive drum, a first drum side plate, a second drum side plate, and a first shaft. A first shaft extends from the first drum side plate. The first shaft is guided by the first guide of the main body casing when the drum unit is attached to the main body casing. The first guide guides the first shaft toward the first contact surface of the main body housing. After the first shaft is guided by the first guide, the first shaft contacts the first contact surface with the drum unit attached to the main body case (see Patent Document 1 below).

Japanese Patent Application Publication No. 2010-197653

In the image forming apparatus as described in Patent Document 1 mentioned above, when the drum unit is transported with the drum unit installed inside the main body housing, impact is applied to the image forming apparatus during transport, resulting in contact with the first contact surface. The first shaft may be damaged due to contact.

Therefore, an object of the present disclosure is to form an image that can suppress damage to the first shaft due to contact with the first contact surface when an impact is applied to the image forming apparatus while the drum unit is attached to the main body housing. The goal is to provide equipment.

(1) The image forming apparatus of the present disclosure includes a main body housing, a drum unit, and a first cover. The main body case includes a first main body side plate and a second main body side plate. The second main body side plate is located apart from the first main body side plate in the first direction. The drum unit is removable from the main body housing. The drum unit includes a photosensitive drum, a first drum side plate, a second drum side plate, and a first shaft. The photosensitive drum is rotatable about the drum axis. The drum shaft extends in the first direction. The first drum side plate supports one end of the photosensitive drum in the first direction. When the drum unit is attached to the main body housing, the first drum side plate is closer to the first main body side plate than the second main body side plate in the first direction. The second drum side plate supports the other end of the photosensitive drum in the first direction. When the drum unit is attached to the main body housing, the second drum side plate is closer to the second main body side plate than the first main body side plate in the first direction. The first shaft extends in a first direction from the first drum side plate. The first shaft extends away from the second body side plate relative to the first body side plate. The first cover has a first hole. The first shaft is inserted into the first hole. The first cover is removably attached to the first shaft.

The first body side plate has a first contact surface and a first guide. When the drum unit is attached to the main body housing with the first cover not attached to the first shaft, the first contact surface comes into contact with the first shaft. When the drum unit is attached to the main body casing without the first cover attached to the first shaft, the first guide guides the first shaft toward the first contact surface.

When the drum unit is attached to the main body housing with the first cover attached to the first shaft, a part of the first cover comes into contact with the first guide, so that the first shaft is attached to the first contact surface. distance from.

According to such a configuration, when the drum unit is attached to the main body housing with the first cover attached to the first shaft, the first shaft can be kept separated from the first contact surface. .

Therefore, if an impact is applied to the image forming apparatus while the first cover is attached to the first shaft and the drum unit is attached to the main body housing, the first shaft may be damaged due to contact with the first contact surface. can be suppressed.

(2) The first cover may include a main body and a first protrusion. The main body has a first hole. The first protrusion is located away from the first hole. The first protrusion extends from the main body. When the drum unit is attached to the main body housing with the first cover attached to the first drum side plate, the first protrusion comes into contact with the first guide. When the drum unit is attached to the main body housing with the first cover attached to the first drum side plate, the first shaft is separated from the first contact surface by the first protrusion coming into contact with the first guide. do.

(3) The first drum side plate may have a second hole. The first cover may further include a second protrusion. The second protrusion is located apart from the first hole. The second protrusion extends from the main body. The second protrusion fits into the second hole.

(4) When the drum unit is attached to the main body casing with the first cover attached to the first shaft, the main body is located between the first main body side plate and the first drum side plate in the first direction, It may contact the first body side plate and the first drum side plate.

(5) The image forming apparatus may further include a developer cartridge and a first belt. The developer cartridge has a developer roller. The developing roller is rotatable about the developing shaft. The development axis extends in the first direction. The developer cartridge is removably attachable to the drum unit. With the developer cartridge attached to the drum unit, the developer cartridge is movable between a contact position and a separation position. With the developer cartridge located at the contact position, the developer roller contacts the photosensitive drum. With the developing cartridge located at the separated position, the developing roller separates from the photosensitive drum. The first belt is removably attached to the developer cartridge. When the drum unit is attached to the main body housing while the first belt is not attached to the developer cartridge, the developer cartridge is located at the contact position. When the drum unit is attached to the main body housing with the first belt attached to the developer cartridge, the developer cartridge is located at a separated position.

According to such a configuration, the first belt can separate the developing roller from the photosensitive drum in a state where the developing cartridge is attached to the drum unit and the drum unit is attached to the main body housing.

Therefore, deformation of a portion of the developing roller due to contact with the photosensitive drum can be prevented.

(6) The drum unit may further include a first beam and a second beam. The first beam is located between the first drum side plate and the second drum side plate in the first direction. The second beam is located on the opposite side of the first beam with respect to the photosensitive drum in the second direction. The second direction intersects the first direction. The second beam is located closer to the first shaft than the first beam in the second direction. The first belt may have a first end, a second end, and an attachment portion. The first end is attached to the first beam. The second end is located away from the first end in the second direction. The second end is attached to the second beam. The attachment portion extends in the second direction. The attachment portion is located between the first end and the second end in the second direction. The attachment portion is attached to one end of the developer cartridge in the first direction.

(7) The first cover may further include a third protrusion. The third protrusion is hooked on the second end of the first belt.

(8) The image forming apparatus may further include a second cover. The second cover is removable from the first drum side plate. With the developer cartridge attached to the drum unit, the second cover positions the developer cartridge at a separated position together with the first belt.

According to this configuration, when the developer cartridge is attached to the drum unit and the drum unit is attached to the main body housing, the first belt and the second cover more stably separate the developer roller from the photosensitive drum. be able to.

Therefore, deformation of a portion of the developing roller due to contact with the photosensitive drum can be further prevented.

(9) The developer cartridge further includes a toner housing, a developer coupling, and a gear cover. The toner housing can contain toner. The developer coupling is located at one end of the toner housing in the first direction. The gear cover partially covers the developer coupling. The gear cover has a cylindrical portion. The cylindrical portion supports the developer coupling. The first drum side plate has a first through hole. When the developer cartridge is attached to the drum unit, the first through hole exposes the developer coupling. The second cover may include a cover portion and a rib. The cover portion covers the first through hole. The rib protrudes from the cover portion into the first through hole. The ribs position the developer cartridge at the separated position by coming into contact with the cylindrical portion.

(10) The drum unit further includes a drum coupling. The first drum side plate has a second through hole. The second through hole exposes the drum coupling. The cover portion may cover the first through hole and the second through hole.

(11) The second cover may be removable from the first drum side plate together with the first cover.

(12) The second cover may further include a hook portion. The hook portion is hooked on the first cover.

(13) The image forming apparatus may further include a second belt. The second belt is removably attached to the developer cartridge. With the first belt and the second belt attached to the developer cartridge, the second belt is positioned away from the first belt in the first direction. When the drum unit is attached to the main body housing with the first belt and the second belt not attached to the developer cartridge, the developer cartridge is located at the contact position. When the drum unit is attached to the main body housing with the first belt and the second belt attached to the developer cartridge, the developer cartridge is located at a separated position.

According to this configuration, when the developer cartridge is attached to the drum unit and the drum unit is attached to the main body housing, the first belt and the second belt can more stably separate the developer roller from the photosensitive drum. be able to.

Therefore, deformation of a portion of the developing roller due to contact with the photosensitive drum can be further prevented.

(14) The main body case may further include a first metal plate. The first sheet metal has a first contact surface.

(15) The drum unit further includes a second shaft. The second shaft extends in the first direction from the second drum side plate. The second shaft extends away from the first body side plate relative to the second body side plate. The image forming apparatus may further include a third cover. The third cover has a third hole. The second shaft is inserted into the third hole. The third cover is removable from the second shaft. The second main body side plate has a second contact surface and a second guide. When the drum unit is attached to the main body casing without the third cover attached to the second shaft, the second contact surface comes into contact with the second shaft. When the drum unit is attached to the main body casing without the third cover attached to the second shaft, the second guide guides the second shaft toward the second contact surface. When the drum unit is attached to the main body housing with the third cover attached to the second shaft, a portion of the third cover comes into contact with the second guide, so that the second shaft is attached to the second contact surface. distance from.

According to such a configuration, when the drum unit is attached to the main body housing with the third cover attached to the second shaft, the second shaft can be kept separated from the second contact surface. .

Therefore, if an impact is applied to the image forming apparatus while the third cover is attached to the second shaft and the drum unit is attached to the main body housing, the second shaft may be damaged due to contact with the second contact surface. can be suppressed.

(16) The main body case may further include a second metal plate. The second sheet metal has a second contact surface.

According to the image forming apparatus of the present disclosure, when a shock is applied to the image forming apparatus while the drum unit is attached to the main body housing, damage to the first shaft due to contact with the first contact surface can be suppressed. .

FIG. 1 is a schematic configuration diagram of an image forming apparatus 1. As shown in FIG. FIG. 2 is an explanatory diagram for explaining the movement of the drum unit 4 shown in FIG. 1. FIG. 3 is an explanatory diagram for explaining the movement of developer cartridges 6Y, 6M, 6C, and 6K shown in FIG. 1. FIG. 4 is a perspective view of the drum unit 4 in which developer cartridges 6Y, 6M, 6C, and 6K are installed. FIG. 5 is a side view of the drum unit 4 in which developer cartridges 6Y, 6M, 6C, and 6K are installed. FIG. 6 is a perspective view of the drum unit 4 in which developer cartridges 6Y, 6M, 6C, and 6K are installed, and is a perspective view seen from a different angle from FIG. 4. FIG. 7 is an explanatory diagram for explaining a state in which the drum unit 4 shown in FIG. 4 is mounted between the main body side plate 21A and the main body side plate 21B. FIG. 8 is an explanatory diagram for explaining a state in which the drum unit 4 shown in FIG. 4 is attached to the main body casing 2 and the shaft 43A of the drum unit 4 is in contact with the contact surface S1 of the main body casing 2. FIG. 9 is a perspective view of the drum unit 4 in which developer cartridges 6Y, 6M, 6C, and 6K, covers 31A, 31B, belts 32A, 32B, and cover 33 are attached. FIG. 10 is an explanatory diagram for explaining a state in which the drum unit 4 shown in FIG. 9 is attached to the main body casing 2 and the shaft 43A of the drum unit 4 is separated from the contact surface S1 of the main body casing 2. FIG. 11 is a perspective view of the cover 31A. FIG. 12 is a perspective view of the cover 31A seen from a different angle from FIG. 11. FIG. 13 is an explanatory diagram for explaining a state in which the drum unit 4 shown in FIG. 9 is mounted between the main body side plate 21A and the main body side plate 21B. FIG. 14 is a perspective view of the cover 31B. FIG. 15 is a perspective view of the cover 31B seen from a different angle from FIG. 14. FIG. 16 is a perspective view of the belt 32A. FIG. 17 is a perspective view of the belt 32A seen from a different angle from FIG. 16. FIG. 18 is a perspective view of the cover 33.

1. Outline of Image Forming Apparatus 1 The outline of the image forming apparatus 1 will be described with reference to FIGS. 1 to 3. In addition, in the following description, the direction in which the drum shaft A1 extends is defined as a first direction. The drum axis A1 will be explained later.

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

1.1 Main body casing 2
The main body housing 2 houses a sheet cassette 3, a drum unit 4, an exposure device 5, developer cartridges 6Y, 6M, 6C, and 6K, a transfer device 7, and a fixing device 8.

As shown in FIGS. 1 and 2, the main body case 2 has an opening 2A. The main body case 2 includes a cover 2B.

The opening 2A is located at one end of the main body casing 2 in the second direction. The second direction intersects the first direction. Preferably, the second direction is perpendicular to the first direction.

The cover 2B is movable between a closed position (see FIG. 1) and an open position (see FIG. 2). When the cover 2B is located in the closed position, the cover 2B closes the opening 2A. When the cover 2B is located in the open position, the opening 2A is opened.

1.2 Sheet cassette 3
As shown in FIG. 1, the sheet cassette 3 can accommodate sheets S. As shown in FIG. The sheets S in the sheet cassette 3 are conveyed toward the photosensitive drum 9Y. The photosensitive drum 9Y will be explained later.

1.3 Drum unit 4
The drum unit 4 is removably attached to the main body casing 2. Specifically, as shown in FIG. 2, when the cover 2B is in the open position, the drum unit 4 moves between the inner position (see FIG. 1) and the outer position (see FIG. 2) through the opening 2A. , is movable in a second direction. As shown in FIG. 1, the entire drum unit 4 is located within the main body casing 2 with the drum unit 4 located at the inner position. As shown in FIG. 2, at least a portion of the drum unit 4 is located outside the main housing 2 with the drum unit 4 located at the outer position. The drum unit 4 is removable from the main body housing 2 in a state where the drum unit 4 is located at the outer position.

As shown in FIG. 1, the drum unit 4 includes four photosensitive drums 9Y, 9M, 9C, and 9K, and charging devices 10Y, 10M, 10C, and 10K.

The photosensitive drum 9Y extends in the first direction. The photosensitive drum 9Y has a cylindrical shape. The photosensitive drum 9Y is rotatable about the drum axis A1. The drum axis A1 extends in the first direction.

The charging device 10Y charges the circumferential surface of the photosensitive drum 9Y. In this embodiment, the charging device 10Y is a scorotron type charger. Note that the charging device 10Y may be a charging roller.

The photosensitive drums 9M, 9C, and 9K will be explained in the same way as the photosensitive drum 9Y, and the charging devices 10M, 10C, and 10K will be explained in the same way as the charging device 10Y. Therefore, a description of the photosensitive drums 9M, 9C, and 9K and a description of the charging devices 10M, 10C, and 10K will be omitted.

1.4 Exposure device 5
With the drum unit 4 located at the inner position, the exposure device 5 can expose the circumferential surfaces of the photosensitive drums 9Y, 9M, 9C, and 9K. In this embodiment, the exposure device 5 is a laser scanning unit.

1.5 Developer cartridge 6Y, 6M, 6C, 6K
As shown in FIG. 2, each of the developer cartridges 6Y, 6M, 6C, and 6K is removable from the drum unit 4 with the drum unit 4 located at the outer position.

As shown in FIG. 1, the developer cartridge 6Y includes a toner housing 61Y and a developer roller 62Y.

The toner housing 61Y can accommodate toner.

The developing roller 62Y extends in the first direction. The developing roller 62Y has a cylindrical shape. A portion of the developing roller 62Y is housed inside the toner housing 61Y. The developing roller 62Y contacts the circumferential surface of the photosensitive drum 9Y. The developing roller 62Y is rotatable about the developing axis A2. When the developer cartridge 6Y is attached to the drum unit 4 and the drum unit 4 is located in the inner position, the developer shaft A2 is located apart from the drum shaft A1. The development axis A2 extends in the first direction. The developing roller 62Y supplies the toner in the toner housing 61Y to the photosensitive drum 9Y exposed by the exposure device 5.

As shown in FIGS. 1 and 3, when the developer cartridge 6Y is attached to the drum unit 4 and the drum unit 4 is located in the inner position, the developer cartridge 6Y is in the contact position (see FIG. 1) and the separated position (see FIG. 3). ). As shown in FIG. 1, the developing roller 62Y contacts the photosensitive drum 9Y with the developing cartridge 6Y located at the contact position. As shown in FIG. 3, with the developing cartridge 6Y located at the separated position, the developing roller 62Y is separated from the photosensitive drum 9Y.

The developer cartridges 6M, 6C, and 6K will be explained in the same manner as the developer cartridge 6Y. Therefore, description of the developer cartridges 6M, 6C, and 6K will be omitted.

1.6 Transfer device 7
As shown in FIG. 1, the transfer device 7 includes a belt 71 and four transfer rollers 72Y, 72M, 72C, and 72K.

The belt 71 conveys the sheet S supplied from the sheet cassette 3 toward the fixing device 8 . The belt 71 extends between the photosensitive drum 9Y and the transfer roller 72Y, between the photosensitive drum 9M and the transfer roller 72M, between the photosensitive drum 9C and the transfer roller 72C, and between the photosensitive drum 9K and the transfer roller 72K. Pass. Belt 71 is an endless belt.

The transfer roller 72Y transfers the toner on the photosensitive drum 9Y onto the sheet S conveyed by the belt 71. The transfer roller 72M transfers the toner on the photosensitive drum 9M onto the sheet S conveyed by the belt 71. The transfer roller 72C transfers the toner on the photosensitive drum 9C to the sheet S conveyed by the belt 71. The transfer roller 72K transfers the toner on the photosensitive drum 9K onto the sheet S conveyed by the belt 71.

1.7 Fixing device 8
The fixing device 8 heats and presses the sheet S onto which the toner has been transferred, thereby fixing the toner onto the sheet S. The sheet S that has passed through the fixing device 8 is discharged to the outside of the main body housing 2 .

2. Details of Developer Cartridge 6Y Next, details of the developer cartridge 6Y will be described with reference to FIG. 4. Note that the developer cartridges 6M, 6C, and 6K will be explained in the same manner as the developer cartridge 6Y. Therefore, description of the developer cartridges 6M, 6C, and 6K will be omitted.

The developer cartridge 6Y includes a developer coupling 63Y and a gear cover 64Y in addition to the toner housing 61Y and the developer roller 62Y described above. The developer cartridge 6Y has grooves 651A and 651B and grooves 652A and 652B.

2.1 Development coupling 63Y
The developer coupling 63Y is located at one end of the toner housing 61Y in the first direction. The developer coupling 63Y is rotatable about the axis A3. Axis A3 is located apart from drum axis A1 and development axis A2. Axis A3 extends in the first direction. The development coupling 63Y has a cylindrical shape. The development coupling 63Y extends in the first direction. When the developer cartridge 6Y is attached to the drum unit 4, the drum unit 4 is in the inner position, the cover 2B is in the closed position, and the developer cartridge 6Y is in the contact position (see FIG. 1), the developer coupling 63Y is , are connected to a main body coupling (not shown) of the main body case 2. In a state where the developer coupling 63Y and the main body coupling are connected, the developer coupling 63Y is rotatable together with the main body coupling. The developer coupling 63Y is connected to the developer roller 62Y via a gear train (not shown). The power input from the main body coupling to the developing coupling 63Y is transmitted to the developing roller 62Y via a gear train.

2.2 Gear cover 64Y
The gear cover 64Y is located at one end of the toner housing 61Y in the first direction. The gear cover 64Y covers a part of the developing coupling 63Y. Gear cover 64Y has a cylindrical portion 641.

The cylindrical portion 641 extends in the first direction. The developer coupling 63Y fits into the cylindrical portion 641. The cylinder portion 641 supports the development coupling 63Y.

2.3 Grooves 651A, 651B
The groove 651A is located at one end of the developer cartridge 6Y in the first direction. Specifically, the groove 651A is located in the gear cover 64Y. The groove 651A is located at one end of the gear cover 64Y in the third direction. Specifically, the groove 651A is located at the upper end of the gear cover 64Y. The groove 651A extends in the second direction.

The groove 651B is located at the other end of the developer cartridge 6Y in the first direction. Specifically, the groove 651B is located at the other end of the toner housing 61Y in the first direction. The groove 651B is located at one end of the toner housing 61Y in the third direction. Specifically, the groove 651B is located at the upper end of the toner housing 61Y. The groove 651B extends in the second direction.

2.4 Grooves 652A, 652B
The groove 652A is located at one end of the developer cartridge 6Y in the first direction. Specifically, the groove 652A is located in the gear cover 64Y. The groove 652A is located at one end of the gear cover 64Y in the third direction. Specifically, the groove 652A is located at the upper end of the gear cover 64Y. Groove 652A extends in the first direction. Groove 652A intersects with groove 651A. Preferably, groove 652A is orthogonal to groove 651A.

The groove 652B is located at the other end of the developer cartridge 6Y in the first direction. Specifically, the groove 652B is located at the other end of the toner housing 61Y in the first direction. The groove 652B is located at one end of the toner housing 61Y in the third direction. Specifically, the groove 652B is located at the upper end of the toner housing 61Y. Groove 652B extends in the first direction. Groove 652B intersects with groove 651B. Preferably, groove 652B is orthogonal to groove 651B.

3. Details of Drum Unit 4 Next, details of the drum unit 4 will be described with reference to FIGS. 4 to 6.

As shown in FIG. 4, the drum unit 4 includes drum side plates 41A, 41B, beams 42A, 42B, in addition to the photosensitive drums 9Y, 9M, 9C, 9K and charging devices 10Y, 10M, 10C, 10K. , shafts 43A, 43B, and four drum couplings 44Y, 44M, 44C, 44K. The drum unit 4 has holes 45A, 45B and grooves 46A, 46B.

3.1 Drum side plate 41A
The drum side plate 41A includes one end of the photosensitive drum 9Y in the first direction, one end of the photosensitive drum 9M in the first direction, one end of the photosensitive drum 9C in the first direction, and one end of the photosensitive drum 9K in the first direction. support. The drum side plate 41A extends in the second direction and the third direction. The third direction intersects both the first direction and the second direction. Preferably, the third direction is perpendicular to both the first direction and the second direction.

As shown in FIG. 5, the drum side plate 41A has four through holes 411Y, 411M, 411C, and 411K, four through holes 412Y, 412M, 412C, and 412K, and a hole 413.

The through holes 411Y, 411M, 411C, and 411K are arranged in the second direction. When the developer cartridge 6Y is attached to the drum unit 4, the through hole 411Y exposes the developer coupling 63Y. The through hole 411Y extends in the direction in which the developer cartridge 6Y moves between the contact position and the separation position. In this embodiment, the through hole 411Y extends in the second direction. The through hole 411Y is a long hole.

The through holes 411M, 411C, and 411K will be explained in the same manner as the through hole 411Y. Therefore, a description of the through holes 411M, 411C, and 411K will be omitted.

The through holes 412Y, 412M, 412C, and 412K are arranged in the second direction. The through hole 412Y exposes the drum coupling 44Y. The through hole 412Y has a circular shape.

The through holes 412M, 412C, and 412K will be explained in the same manner as the through hole 411Y. Therefore, description of the through holes 412M, 412C, and 412K will be omitted.

The hole 413 is located at one end of the drum side plate 41A in the second direction. Hole 413 is located away from shaft 43A in the second direction. In this embodiment, the hole 413 is located on the opposite side of the through hole 411Y with respect to the shaft 43A.

3.2 Drum side plate 41B
As shown in FIG. 6, the drum side plate 41B is located apart from the drum side plate 41A in the first direction. The drum side plate 41B covers the other end of the photosensitive drum 9Y in the first direction, the other end of the photosensitive drum 9M in the first direction, the other end of the photosensitive drum 9C in the first direction, and the other end of the photosensitive drum 9K in the first direction. Support the other end. When the developer cartridge 6Y is attached to the drum unit 4, the drum side plate 41B is located on the opposite side of the drum side plate 41A with respect to the developer cartridge 6Y in the first direction. The drum side plate 41B extends in the second direction and the third direction. Unlike the drum side plate 41A (see FIG. 4), the drum side plate 41B does not have through holes 411Y, 411M, 411C, 411K and through holes 412Y, 412M, 412C, 412K.

3.3 Beams 42A, 42B
As shown in FIG. 4, the beam 42A is located at the other end of the drum unit 4 in the second direction. The beam 42A is located between the drum side plate 41A and the drum side plate 41B in the first direction. Beam 42A extends in the first direction and the third direction. Beam 42A has a plate shape.

Beam 42B is located at one end of drum unit 4 in the second direction. Beam 42B is located away from beam 42A in the second direction. Beam 42B is located on the opposite side of beam 42A with respect to photosensitive drum 9Y in the second direction. When the developer cartridge 6Y is attached to the drum unit 4, it is located on the opposite side of the beam 42A with respect to the developer cartridge 6Y. Beam 42B is located closer to shaft 43A than beam 42A in the second direction. Beam 42B extends in the first direction and the third direction. Beam 42B has a plate shape.

3.4 Shafts 43A, 43B
The shaft 43A is located at one end of the drum unit 4 in the second direction. The shaft 43A extends in the first direction from the drum side plate 41A. The shaft 43A extends in the first direction to the opposite side of the drum side plate 41B with respect to the drum side plate 41A. The shaft 43A has a cylindrical shape.

The shaft 43B is located at one end of the drum unit 4 in the second direction. The shaft 43B extends in the first direction from the drum side plate 41B. The shaft 43B extends in the first direction to the opposite side of the drum side plate 41A with respect to the drum side plate 41B. The shaft 43B has a cylindrical shape.

3.5 Drum coupling 44Y, 44M, 44C, 44K
The drum coupling 44Y is attached to one end of the photosensitive drum 9Y in the first direction. The drum coupling 44Y is rotatable together with the photosensitive drum 9Y.

Drum couplings 44M, 44C, 44K will be described similarly to drum coupling 44Y. Therefore, a description of the drum couplings 44M, 44C, and 44K will be omitted.

3.6 Holes 45A, 45B
Hole 45A is located at one end of beam 42A in the first direction. Hole 45A is located at one end of beam 42A in the third direction. In other words, hole 45A is located at the upper end of beam 42A.

Hole 45B is located at the other end of beam 42A in the first direction. Hole 45B is located away from hole 45A in the first direction. Hole 45B is located at one end of beam 42A in the third direction. In other words, hole 45B is located at the upper end of beam 42A.

3.7 Grooves 46A, 46B
Groove 46A is located at one end of beam 42B in the first direction. Groove 46A is located at one end of beam 42B in the third direction. In other words, groove 46A is located at the upper end of beam 42B.

Groove 46B is located at the other end of beam 42B in the first direction. Groove 46B is located away from groove 46A in the first direction. Groove 46B is located at one end of beam 42B in the third direction. In other words, groove 46B is located at the upper end of beam 42B.

4. Details of main body casing 2 Next, details of main body casing 2 will be described with reference to FIGS. 7 and 8.

As shown in FIG. 7, the main body case 2 includes main body side plates 21A and 21B.

4.1 Main body side plate 21A
With the drum unit 4 attached to the main body case 2, the main body side plate 21A faces the drum side plate 41A in the first direction. When the drum unit 4 is attached to the main body housing 2, the drum side plate 41A is closer to the main body side plate 21A than the main body side plate 21B in the first direction. In other words, when the drum unit 4 is attached to the main body housing 2, the drum side plate 41A is located between the main body side plate 21B and the main body side plate 21A in the first direction. When the drum unit 4 is attached to the main body housing 2, the drum side plate 41A is closer to the main body side plate 21A than the drum side plate 41B in the first direction. In other words, when the drum unit 4 is attached to the main body housing 2, the drum side plate 41A is located between the drum side plate 41B and the main body side plate 21A in the first direction. When the drum unit 4 is attached to the main body housing 2, the shaft 43A extends away from the main body side plate 21B with respect to the main body side plate 21A. In other words, when the drum unit 4 is attached to the main body housing 2, the shaft 43A extends in the first direction from the drum side plate 41A toward the main body side plate 21A. The main body side plate 21A extends in the second direction and the third direction.

As shown in FIGS. 7 and 8, the main body side plate 21A includes a metal plate 211A and a resin plate 212A. In other words, the main body case 2 includes the sheet metal 211A.

As shown in FIG. 8, the sheet metal 211A extends in the second direction and the third direction. The sheet metal 211A has a contact surface S1. In other words, the main body side plate 21A has a contact surface S1.

Contact surface S1 extends in the second direction. With the drum unit 4 attached to the main body casing 2, the contact surface S1 contacts the shaft 43A. Specifically, when the drum unit 4 is attached to the main body casing 2 without the cover 31A (see FIG. 9) attached to the shaft 43A, the contact surface S1 comes into contact with the shaft 43A. Cover 31A will be explained later.

As shown in FIG. 7, the resin plate 212A overlaps the metal plate 211A in the first direction. The resin plate 212A extends in the second direction and the third direction. As shown in FIG. 8, the resin plate 212A has a guide 213A. In other words, the main body side plate 21A has a guide 213A.

The guide 213A is located on one side of the contact surface S1 in the second direction. In other words, when the cover 2B (see FIG. 1) is in the closed position, the guide 213A is located between the contact surface S1 and the cover 2B in the second direction. Guide 213A extends in the second direction. When the drum unit 4 is attached to the main body case 2, the guide 213A guides the shaft 43A toward the contact surface S1. Specifically, when the drum unit 4 is attached to the main body casing 2 without the cover 31A attached to the shaft 43A, the guide 213A guides the shaft 43A toward the contact surface S1.

4.2 Main body side plate 21B
As shown in FIG. 7, the main body side plate 21B is located apart from the main body side plate 21A in the first direction. The main body side plate 21B will be explained in the same manner as the main body side plate 21A.

Specifically, when the drum unit 4 is attached to the main body housing 2, the main body side plate 21B faces the drum side plate 41B in the first direction. When the drum unit 4 is attached to the main body housing 2, the drum side plate 41B is closer to the main body side plate 21B than the main body side plate 21A in the first direction. In other words, when the drum unit 4 is attached to the main body housing 2, the drum side plate 41B is located between the main body side plate 21A and the main body side plate 21B in the first direction. When the drum unit 4 is attached to the main body housing 2, the drum side plate 41B is closer to the main body side plate 21B than the drum side plate 41A in the first direction. In other words, when the drum unit 4 is attached to the main body housing 2, the drum side plate 41B is located between the drum side plate 41A and the main body side plate 21B in the first direction. When the drum unit 4 is attached to the main body casing 2, the shaft 43B extends away from the main body side plate 21A with respect to the main body side plate 21B. In other words, when the drum unit 4 is attached to the main body housing 2, the shaft 43B extends in the first direction from the drum side plate 41B toward the main body side plate 21B. The main body side plate 21B extends in the second direction and the third direction.

The main body side plate 21B includes a metal plate 211B and a resin plate 212B. In other words, the main body case 2 includes the metal plate 211B.

The sheet metal 211B extends in the second direction and the third direction. The sheet metal 211B has a contact surface S2. In other words, the main body side plate 21B has a contact surface S2. Contact surface S2 is not shown. When the drum unit 4 is attached to the main body casing 2 without the cover 31B (see FIG. 9) attached to the shaft 43B, the contact surface S2 comes into contact with the shaft 43B.

The resin plate 212B overlaps the metal plate 211B. The resin plate 212B extends in the second direction and the third direction. The resin plate 212B has a guide 213B. In other words, the main body side plate 21B has the guide 213B. Guide 213B is not shown. When the drum unit 4 is attached to the main body casing 2 with the cover 31B not attached to the shaft 43B, the guide 213B guides the shaft 43B toward the contact surface S2.

5. Packaging of Image Forming Apparatus 1 Packing of image forming apparatus 1 will be described with reference to FIGS. 9 to 18.

The image forming apparatus 1 is packed in a predetermined box with the developer cartridges 6Y, 6M, 6C, and 6K mounted on the drum unit 4 and the drum unit 4 mounted on the main body housing 2 (see FIG. 1).

Here, when the image forming apparatus 1 is packed in a predetermined box, as shown in FIG. , cover 33 are attached. That is, the image forming apparatus 1 includes covers 31A and 31B, belts 32A and 32B, and cover 33.

5.1 Cover 31A
The cover 31A is removably attached to one end of the drum side plate 41A in the second direction. Specifically, the cover 31A is removable from the shaft 43A.

As shown in FIG. 10, when the drum unit 4 is attached to the main body casing 2 with the cover 31A attached to the shaft 43A, the cover 31A separates the shaft 43A from the contact surface S1 of the main body side plate 21A. .

Specifically, as shown in FIGS. 11 and 12, the cover 31A includes a main body 311A, a protrusion 312A, a protrusion 313A, and a protrusion 314A.

5.1.1 Main body part 311A
As shown in FIG. 13, when the drum unit 4 is attached to the main body casing 2 with the cover 31A attached to the shaft 43A, the main body 311A is attached to the main body side plate 21A and the drum side plate 41A in the first direction. located in between. The main body portion 311A has a plate shape. With the cover 31A attached to the shaft 43A, the main body 311A extends in the second direction and the third direction. The main body portion 311A has an outer surface S11 and an inner surface S12 in the first direction. With the cover 31A attached to the shaft 43A, the outer surface S11 is located away from the drum side plate 41A in the first direction. With the cover 31A attached to the shaft 43A, the inner surface S12 contacts the drum side plate 41B. In other words, the main body portion 311A contacts the drum side plate 41A with the cover 31A attached to the shaft 43A.

As shown in FIGS. 11 and 12, the main body portion 311A has a contact portion 315A, a hole 316A, and a hole 317. In other words, the cover 31A has the hole 316A.

The contact portion 315A is located at the other end of the main body portion 311A in the second direction. The contact portion 315A protrudes in the first direction from the outer surface S11 of the main body portion 311A. The contact portion 315A has a bent plate shape.

As shown in FIG. 13, when the drum unit 4 is attached to the main body casing 2 with the cover 31A attached to the shaft 43A, the contact portion 315A is formed between the main body side plate 21A and the drum side plate 41A in the first direction. located in between. When the drum unit 4 is attached to the main body casing 2 with the cover 31A attached to the shaft 43A, the contact portion 315A protrudes from the outer surface S11 of the main body 311A toward the main body side plate 21A in the first direction. . When the drum unit 4 is attached to the main body casing 2 with the cover 31A attached to the shaft 43A, the contact portion 315A comes into contact with the main body side plate 21A. In other words, when the drum unit 4 is attached to the main body casing 2 with the cover 31A attached to the shaft 43A, the main body portion 311A comes into contact with the main body side plate 21A. Thereby, when the drum unit 4 is attached to the main body casing 2 while the cover 31A is attached to the shaft 43A, it is possible to suppress the drum unit 4 from moving in the first direction with respect to the main body casing 2.

As shown in FIG. 11, the hole 316A is located between the protrusion 312A and the contact portion 315A in the second direction. In this embodiment, the hole 316A is a through hole. With the cover 31A attached to the shaft 43A (see FIG. 9), the shaft 43A is inserted into the hole 316A. Hole 316A has a circular shape.

Hole 317 is located away from hole 316A in the third direction. Hole 317 is located on the other side of hole 316A in the third direction. Hole 317 is located below hole 316A. Hole 317 has a rectangular shape.

5.1.2 Protrusion 312A
The protrusion 312A is located away from the hole 316A in the second direction. The protrusion 312A is located at one end of the main body portion 311A in the second direction. The protrusion 312A is located on the opposite side of the contact portion 315A with respect to the hole 316A in the second direction. The protrusion 312A extends from the outer surface S11 of the main body portion 311A. The protrusion 312A extends in the first direction. When the cover 31A is attached to the drum side plate 41A and the drum unit 4 is attached to the main body casing 2 (see FIG. 13), the protrusion 312A extends in the first direction from the outer surface S11 of the main body 311A toward the main body side plate 21A. It extends.

As shown in FIG. 10, when the drum unit 4 is attached to the main body casing 2 with the cover 31A attached to the drum side plate 41A, the protrusion 312A comes into contact with the guide 213A. When the drum unit 4 is attached to the main body casing 2 with the cover 31A attached to the drum side plate 41A, the shaft 43A is separated from the contact surface S1 by the protrusion 312A coming into contact with the guide 213A. In other words, when the drum unit 4 is attached to the main body casing 2 with the cover 31A attached to the shaft 43A, a portion of the cover 31A comes into contact with the guide 213A, so that the shaft 43A is moved away from the contact surface S1. Separate. As a result, if an impact is applied to the image forming apparatus 1 with the cover 31A attached to the shaft 43A and the drum unit 4 attached to the main body casing 2, the shaft 43A will not be damaged due to contact with the contact surface S1. can be suppressed.

5.1.3 Protrusion 313A
As shown in FIG. 12, the protrusion 313A is located away from the hole 316A in the second direction. The protrusion 313A extends from the inner surface S12 of the main body portion 311A. The protrusion 313A extends in the first direction. With the cover 31A attached to the shaft 43A, the protrusion 313A fits into the hole 413 (see FIG. 4) of the drum side plate 41A. By fitting the protrusion 313A into the hole 413, it is possible to prevent the cover 31A from rotating about the shaft 43A while the cover 31A is attached to the shaft 43A.

5.1.4 Protrusion 314A
The protrusion 314A is aligned with the protrusion 313A in the third direction. The protrusion 314A is located away from the protrusion 313A in the third direction. The protrusion 313A extends from the inner surface S12 of the main body portion 311A. The protrusion 313A extends in the first direction.

5.2 Cover 31B
As shown in FIG. 9, the cover 31B is removably attached to one end of the drum side plate 41B in the second direction. Specifically, the cover 31B is removable from the shaft 43B. Cover 31B will be described similarly to cover 31A.

Specifically, as shown in FIGS. 14 and 15, the cover 31B includes a main body 311B, a protrusion 312B, a protrusion 313B, and a protrusion 314B.

5.2.1 Main body part 311B
The main body portion 311B will be described in the same manner as the main body portion 311A.

That is, as shown in FIG. 14, the main body portion 311B has a contact portion 315B and a hole 316B. In other words, cover 31B has hole 316B.

As shown in FIG. 13, when the drum unit 4 is attached to the main body casing 2 with the cover 31B attached to the shaft 43B, the contact portion 315B comes into contact with the main body side plate 21B. In other words, when the drum unit 4 is attached to the main body casing 2 with the cover 31B attached to the shaft 43B, the main body portion 311B comes into contact with the main body side plate 21B. Thereby, when the drum unit 4 is attached to the main body casing 2 with the cover 31B attached to the shaft 43B, it is possible to suppress the drum unit 4 from moving in the first direction with respect to the main body casing 2.

With the cover 31B attached to the shaft 43B, the shaft 43B is inserted into the hole 316B.

5.2.2 Protrusion 312B
Protrusion 312B will be described similarly to protrusion 312A.

That is, the protrusion 312B is located away from the hole 316B in the second direction. The protrusion 312B extends from the outer surface S11 of the main body portion 311B. The protrusion 312B extends in the first direction. When the drum unit 4 is attached to the main body casing 2 with the cover 31B attached to the shaft 43B, the shaft 43B is separated from the contact surface S2 due to the protrusion 312B coming into contact with the guide 213B. In other words, when the drum unit 4 is attached to the main body casing 2 with the cover 31B attached to the shaft 43B, a portion of the cover 31B comes into contact with the guide 213B, so that the shaft 43B is moved away from the contact surface S2. Separate. As a result, if an impact is applied to the image forming apparatus 1 while the cover 31B is attached to the shaft 43B and the drum unit 4 is attached to the main body casing 2, the shaft 43B will not be damaged due to contact with the contact surface S2. can be suppressed.

5.2.3 Protrusion 313B
Protrusion 313B will be described similarly to protrusion 313A.

That is, as shown in FIG. 15, the protrusion 313B is located away from the hole 316B in the second direction. The protrusion 313B extends from the inner surface S12 of the main body portion 311B. The protrusion 313B extends in the first direction. With the cover 31B attached to the shaft 43B, the protrusion 313B fits into the hole 413 (see FIG. 6) of the drum side plate 41B. By fitting the protrusion 313B into the hole 413, it is possible to suppress rotation of the cover 31B about the shaft 43B while the cover 31B is attached to the shaft 43B.

5.2.4 Protrusion 314B
Protrusion 314B is described similarly to protrusion 314A.

That is, the protrusion 314B is aligned with the protrusion 313B in the third direction. The protrusion 314B is located away from the protrusion 313B in the third direction. The protrusion 313B extends from the inner surface S12 of the main body portion 311B. The protrusion 313B extends in the first direction.

5.3 Belt 32A
As shown in FIG. 9, the belt 32A is removably attached to the developer cartridges 6Y, 6M, 6C, 6K and the drum unit 4. Specifically, the belt 32A includes one end of the developer cartridge 6Y in the first direction, one end of the developer cartridge 6M in the first direction, one end of the developer cartridge 6C in the first direction, and one end of the developer cartridge 6K in the first direction. , and is removably attachable to one end of the drum unit 4 in the first direction. With the belt 32A attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, the belt 32A extends in the second direction. With the belt 32A attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, the belt 32A prevents the developer cartridges 6Y, 6M, 6C, and 6K from coming off the drum unit 4. Further, when the belt 32A is attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, the belt 32A positions each of the developer cartridges 6Y, 6M, 6C, and 6K at a separated position (see FIG. 3). let

Specifically, as shown in FIGS. 16 and 16, the belt 32A has an end E1 and an end E2 in the second direction. End E2 is located away from end E1 in the second direction. The belt 32A has four attachment parts 321Y, 321M, 321C, and 321K, a plate 322, and four bands 323Y, 323M, 323C, and 323K.

5.3.1 Mounting parts 321Y, 321M, 321C, 321K
The attachment portion 321Y is located between the end portion E1 and the end portion E2 in the second direction. When the belt 32A is attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4 (see FIG. 9), the attachment portion 321Y is located between the developer cartridges 6Y and 6M. With the belt 32A attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, the mounting portion 321Y positions the developer cartridge 6Y at the separated position. The attachment portion 321Y extends in the second direction.

The attachment portion 321Y has a claw 324Y and a surface 325Y.

The claw 324Y is located at one end of the attachment portion 321Y in the second direction. With the belt 32A attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, the claw 324Y fits into the groove 652A of the developer cartridge 6Y. As a result, the attachment portion 321Y is attached to one end of the developer cartridge 6Y in the first direction.

The surface 325Y is located at the other end of the attachment portion 321Y in the second direction. With the belt 32A attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, the surface 325Y contacts the gear cover 64M of the developer cartridge 6M.

The attachment portion 321M is located between the end portion E1 and the attachment portion 321Y in the second direction. With the belt 32A attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, the mounting portion 321M is located between the developer cartridges 6M and 6C. With the belt 32A attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, the mounting portion 321M positions the developer cartridge 6M at the separated position. The attachment portion 321M has the same shape as the attachment portion 321Y. Therefore, a description of the shape of the attachment portion 321M will be omitted.

The attachment portion 321C is located between the end portion E1 and the attachment portion 321M in the second direction. With the belt 32A attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, the attachment portion 321C is located between the developer cartridges 6C and 6K. With the belt 32A attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, the mounting portion 321C positions the developer cartridge 6C at the separated position. The attachment portion 321C has the same shape as the attachment portion 321Y. Therefore, a description of the shape of the attachment portion 321C will be omitted.

The attachment portion 321K is located between the end portion E1 and the attachment portion 321C in the second direction. With the belt 32A attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, the mounting portion 321K is located between the developer cartridge 6K and the beam 42A. With the belt 32A attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, the mounting portion 321K positions the developer cartridge 6K at the separated position. The attachment portion 321K extends in the second direction. The attachment portion 321K has a claw 324K and a protrusion 326.

The claw 324K is located at one end of the attachment portion 321K in the second direction. With the belt 32A attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, the claw 324K fits into the groove 652A of the developer cartridge 6K. As a result, the attachment portion 321M is attached to one end of the developer cartridge 6K in the first direction.

Protrusion 326 is located at end E1 of belt 32A. Specifically, the protrusion 326 is located at the other end of the attachment portion 321K in the second direction. With the belt 32A attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, the protrusion 326 fits into the hole 45A (see FIG. 4) of the beam 42A. Thereby, the end portion E1 of the belt 32A is attached to the beam 42A.

5.3.2 Plate 322
The plate 322 is located between the attachment portion 321Y and the end portion E2. With the belt 32A attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, the plate 322 extends in the third direction. With the belt 32A attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, the plate 322 is attached to the beam 42B. Thereby, the end E2 of the belt 32A is attached to the beam 42B. The plate 322 has a protrusion 327.

The protrusion 327 is located at the end E2 of the belt 32A. The protrusion 327 is located at the other end of the plate 322 in the third direction. A protrusion 327 extends from plate 322. The protrusion 327 extends in the second direction. When the belt 32B is attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, and the cover 31A is attached to the drum unit 4, the protrusion 327 is inserted between the protrusion 313A and the protrusion 314A of the cover 31A (see FIG. 12). ). As a result, when the belt 32A is attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, and the cover 31A is attached to the drum unit 4, the protrusion 314A of the cover 31A is connected to the protrusion 327 of the end E2 of the belt 32A. caught on.

5.3.3 Band 323Y, 323M, 323C, 323K
Band 323Y is located between plate 322 and attachment portion 321Y in the second direction. Band 323Y extends in the second direction. Band 323Y connects plate 322 and attachment portion 321Y. With the belt 32A attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, the band 323Y fits into the groove 46A of the beam 42B and the groove 651A of the gear cover 64Y.

Band 323M is located between attachment portion 321Y and attachment portion 321M in the second direction. Band 323M extends in the second direction. Band 323M connects attachment portion 321Y and attachment portion 321M. With the belt 32A attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, the band 323M fits into the groove 651A of the gear cover 64M.

Band 323C is located between attachment portion 321M and attachment portion 321C in the second direction. Band 323C extends in the second direction. Band 323C connects attachment portion 321M and attachment portion 321C. With the belt 32A attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, the band 323C fits into the groove 651A of the gear cover 64C.

Band 323K is located between attachment portion 321C and attachment portion 321K in the second direction. Band 323K extends in the second direction. Band 323K connects attachment portion 321C and attachment portion 321K. With the belt 32A attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, the band 323K fits into the groove 651A of the gear cover 64K.

5.4 Belt 32B
As shown in FIG. 9, the belt 32B is removably attached to the developer cartridges 6Y, 6M, 6C, 6K and the drum unit 4. Specifically, the belt 32B includes the other end of the developer cartridge 6Y in the first direction, the other end of the developer cartridge 6M in the first direction, the other end of the developer cartridge 6C in the first direction, and the other end of the developer cartridge 6K in the first direction. It is detachable from the other end and the other end of the drum unit 4 in the first direction. With the belt 32A and the belt 32B attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, the belt 32B is located away from the belt 32A in the first direction. Belt 32B will be described similarly to belt 32A. Therefore, a description of the belt 32B will be omitted.

If the drum unit 4 is attached to the main body casing 2 while the belt 32A and the belt 32B are not attached to the developer cartridges 6Y, 6M, 6C, 6K and the drum unit 4, each of the developer cartridges 6Y, 6M, 6C, 6K is located in the contact position (see Figure 1).

When the belt 32A and the belt 32B are attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, and the drum unit 4 is attached to the main body housing 2, each of the developer cartridges 6Y, 6M, 6C, and 6K is , located at a separate position (see FIG. 3).

5.5 Cover 33
As shown in FIG. 9, the cover 33 is removable from the drum side plate 41A. With the developer cartridges 6Y, 6M, 6C, and 6K attached to the drum unit 4, the belts 32A and 32B attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, and the cover 33 attached to the drum side plate 41A, The cover 33 positions the developer cartridges 6Y, 6M, 6C, and 6K at separate positions together with the belts 32A and 32B.

Specifically, as shown in FIG. 18, the cover 33 includes a cover portion 331, four ribs 332Y, 332M, 332C, and 332K, and a hook portion 333.

5.5.1 Cover part 331
With the cover 33 attached to the drum side plate 41A, the cover portion 331 extends in the second direction and the third direction. The cover portion 331 has a flat plate shape. The cover portion 331 covers the through holes 411Y, 411M, 411C, 411K and the through holes 412Y, 412M, 412C, 412K.

5.5.2 Rib 332Y, 332M, 332C, 332K
The ribs 332Y, 332M, 332C, and 332K are arranged in the second direction. Each of the ribs 332Y, 332M, 332C, and 332K protrudes from the cover portion 331. Each of the ribs 332Y, 332M, 332C, and 332K extends in the first direction.

With the cover 33 attached to the drum side plate 41A, the rib 332Y protrudes from the cover portion 331 into the through hole 411Y. With the cover 33 attached to the drum side plate 41A, the rib 332Y fits into the through hole 411Y (see FIG. 4). With the rib 332Y fitted into the through hole 411Y, the rib 332Y contacts the cylindrical portion 641 of the gear cover 64Y. The rib 332Y positions the developer cartridge 6Y at the separated position by coming into contact with the cylindrical portion 641 of the gear cover 64Y.

Ribs 332M, 332C, and 332K will be described similarly to rib 332Y. Therefore, a description of the ribs 332M, 332C, and 332K will be omitted.

5.5.3 Hook part 333
The hook portion 333 is located at one end of the cover 33 in the second direction. With the cover 31A attached to the shaft 43A and the cover 33 attached to the drum side plate 41A, the hook portion 333 protrudes toward the hole 317 of the cover 31A. With the cover 31A attached to the shaft 43A and the cover 33 attached to the drum side plate 41A, the hook portion 333 is caught on the edge of the hole 317 of the cover 31A. Thereby, the cover 33 is connected to the cover 31A with the cover 31A attached to the shaft 43A and the cover 33 attached to the drum side plate 41A. Thereby, the cover 33 can be removed from the drum side plate 41A together with the cover 31A.

6. Effects (1) According to the image forming apparatus 1, as shown in FIG. 10, when the drum unit 4 is attached to the main body casing 2 with the cover 31A attached to the shaft 43A, the protrusion 312A of the cover 31A When the shaft 43A comes into contact with the guide 213A, the shaft 43A separates from the contact surface S1.

Thereby, when the drum unit 4 is attached to the main body housing 2 with the cover 31A attached to the shaft 43A, the shaft 43A can be kept separated from the contact surface S1.

Therefore, if an impact is applied to the image forming apparatus 1 while the cover 31A is attached to the shaft 43A and the drum unit 4 is attached to the main body casing 2, the shaft 43A is prevented from being damaged due to contact with the contact surface S1. , can be suppressed.

(2) According to the image forming apparatus 1, as shown in FIG. 9, the belt 32A is attached to the developer cartridges 6Y, 6M, 6C, 6K and the drum unit 4, and the drum unit 4 is attached to the main body casing 2. In this case, developer cartridges 6Y, 6M, 6C, and 6K are located at separate positions (see FIG. 1).

Thereby, with the developing cartridge 6Y mounted on the drum unit 4 and the drum unit 4 mounted on the main body housing 2, the developing roller 62Y can be separated from the photosensitive drum 9Y by the belt 32A.

Therefore, deformation of a portion of the developing roller 62Y due to contact with the photosensitive drum 9Y can be prevented.

(3) According to the image forming apparatus 1, as shown in FIG. 9, when the belt 32A is attached to the developer cartridges 6Y, 6M, 6C, and 6K and the drum unit 4, and the cover 33 is attached to the drum side plate 41A, The cover 33 positions the developing cartridges 6Y, 6M, 6C, and 6K together with the belt 32A at separate positions (see FIG. 1).

This allows the belt 32A and the cover 33 to more stably separate the developing roller 62Y from the photosensitive drum 9Y when the developing cartridge 6Y is attached to the drum unit 4 and the drum unit 4 is attached to the main body housing 2. I can do it.

Therefore, deformation of a portion of the developing roller 62Y due to contact with the photosensitive drum 9Y can be further prevented.

(4) According to the image forming apparatus 1, when the drum unit 4 is attached to the main body casing 2 with the cover 31B (see FIG. 9) attached to the shaft 43B, the projection 312B of the cover 31B (see FIG. 14) ) comes into contact with a guide 213B (not shown) of the main body side plate 21B (see FIG. 13). Thereby, the shaft 43B separates from the contact surface S2 (not shown) of the main body side plate 21B.

Thereby, when the drum unit 4 is attached to the main body casing 2 with the cover 31B attached to the shaft 43B, the shaft 43B can be kept separated from the contact surface S2.

Therefore, if an impact is applied to the image forming apparatus 1 while the cover 31B is attached to the shaft 43B and the drum unit 4 is attached to the main body casing 2, the shaft 43B is prevented from being damaged due to contact with the contact surface S2. , can be suppressed.

(5) According to the image forming apparatus 1, as shown in FIG. 9, the belt 32A and the belt 32B are attached to the developer cartridges 6Y, 6M, 6C, 6K and the drum unit 4, and the drum unit 4 is attached to the main body housing 2. When the developer cartridges 6Y, 6M, 6C, and 6K are installed in the image forming apparatus, each of the developer cartridges 6Y, 6M, 6C, and 6K is located at a separated position (see FIG. 1).

As a result, with the developing cartridge 6Y mounted on the drum unit 4 and the drum unit 4 mounted on the main body housing 2, the developing roller 62Y can be more stably separated from the photosensitive drum 9Y by the belts 32A and 32B. I can do it.

Therefore, deformation of a portion of the developing roller 62Y due to contact with the photosensitive drum 9Y can be further prevented.

1 Image forming apparatus 2 Main body housing 4 Drum unit 6Y Developing cartridge 9Y Photosensitive drum 21A Main body side plate 21B Main body side plate 31A Cover 31B Cover 32A Belt 32B Belt 33 Cover 41A Drum side plate 41B Drum side plate 42A Beam 42B Beam 43A Shaft 43B Shaft 44Y Drum coupling 61Y Toner housing 62Y Developing roller 63Y Developing coupling 64Y Gear cover 211A Sheet metal 211B Sheet metal 213A Guide 213B Guide 311A Main body 312A Protrusion 313A Protrusion 314A Protrusion 316A Hole 321Y Mounting part 331 Cover part 332Y Rib 411Y Through hole 412Y Through hole 641 Cylinder part A1 Drum shaft A2 Developing shaft E1 End E2 End S1 Contact surface S2 Contact surface

Claims (16)

a main body casing comprising a first main body side plate and a second main body side plate located apart from the first main body side plate in a first direction;
A drum unit that is detachable from the main body housing,
a photosensitive drum rotatable about a drum shaft extending in the first direction;
a first drum side plate supporting one end of the photosensitive drum in the first direction, the first drum side plate supporting one end of the photosensitive drum in the first direction; 1 a first drum side plate close to the main body side plate;
a second drum side plate supporting the other end of the photosensitive drum in the first direction, the second drum side plate supporting the other end of the photosensitive drum in the first direction; a second drum side plate close to the second main body side plate;
a first shaft extending from the first drum side plate in the first direction, the first shaft extending away from the second main body side plate with respect to the first main body side plate;
a first cover having a first hole into which the first shaft is inserted, the first cover being detachable from the first shaft;
The first main body side plate is
When the drum unit is attached to the main body casing while the first cover is not attached to the first shaft, the first contact surface that contacts the first shaft and the first cover are attached to the first shaft. a first guide that guides the first shaft toward the first contact surface when the drum unit is attached to the main body casing without being attached to the first shaft;
When the drum unit is attached to the main body casing with the first cover attached to the first shaft, a part of the first cover comes into contact with the first guide, so that the first cover is attached to the first shaft. An image forming apparatus, wherein the shaft is spaced apart from the first contact surface. The first cover is
a main body portion having the first hole;
a first protrusion located away from the first hole and extending from the main body, the drum unit being attached to the main body housing with the first cover attached to the first drum side plate; a first protrusion that contacts the first guide;
has
When the drum unit is attached to the main body casing with the first cover attached to the first drum side plate, the first protrusion comes into contact with the first guide, so that the first shaft is The image forming apparatus according to claim 1, wherein the first contact surface is spaced apart from the first contact surface. the first drum side plate has a second hole;
The first cover is
The image forming apparatus according to claim 2, further comprising a second protrusion located apart from the first hole and extending from the main body, the second protrusion fitting into the second hole. Device. The main body portion is
When the drum unit is attached to the main body casing with the first cover attached to the first shaft, the first cover is located between the first main body side plate and the first drum side plate in the first direction, The image forming apparatus according to claim 2 or 3, wherein the image forming apparatus contacts the first main body side plate and the first drum side plate. Furthermore, the developing cartridge has a developing roller rotatable about a developing shaft extending in the first direction, the developing cartridge being removable from the drum unit, and in a state where the developing roller is attached to the drum unit, the developing roller is rotated by the photosensitive member. a developer cartridge that is movable between a contact position where it contacts the drum and a separation position where the developer roller is separated from the photosensitive drum;
a first belt removably attached to the developer cartridge;
When the drum unit is attached to the main body casing while the first belt is not attached to the developer cartridge, the developer cartridge is located at the contact position,
When the drum unit is attached to the main body casing with the first belt attached to the developer cartridge, the developer cartridge is located at the separated position. The image forming apparatus according to any one of Item 4. The drum unit is
a first beam located between the first drum side plate and the second drum side plate in the first direction;
a second beam located on the opposite side of the first beam with respect to the photosensitive drum in a second direction that intersects with the first direction; a second beam located near the
Furthermore,
The first belt is
a first end in the second direction, the first end being attached to the first beam;
a second end located away from the first end in the second direction and attached to the second beam;
an attachment portion extending in the second direction, the attachment portion being located between the first end portion and the second end portion in the second direction, and attached to the one end portion of the developer cartridge in the first direction; a mounting part,
The image forming apparatus according to claim 5, characterized in that it has: The image forming apparatus according to claim 6, wherein the first cover further includes a third protrusion that catches the second end of the first belt. Furthermore, a second cover is removably attached to the first drum side plate, and the second cover positions the developer cartridge at the separated position together with the first belt when the developer cartridge is attached to the drum unit. The image forming apparatus according to any one of claims 5 to 7, characterized in that the image forming apparatus comprises: The developer cartridge includes:
a toner housing capable of accommodating toner;
a developer coupling located at one end of the toner housing in the first direction;
Further comprising a gear cover that covers a part of the developer coupling, the gear cover having a cylindrical portion that supports the developer coupling,
The first drum side plate has a first through hole that exposes the developer coupling when the developer cartridge is attached to the drum unit,
The second cover is
a cover portion that covers the first through hole;
a rib that protrudes from the cover portion into the first through hole and that positions the developer cartridge at the separated position by contacting the cylindrical portion;
The image forming apparatus according to claim 8, characterized in that it has: The drum unit further includes a drum coupling,
The first drum side plate has a second through hole that exposes the drum coupling,
The image forming apparatus according to claim 9, wherein the cover portion covers the first through hole and the second through hole. 11. The image forming apparatus according to claim 8, wherein the second cover is removable from the first drum side plate together with the first cover. The image forming apparatus according to any one of claims 8 to 11, wherein the second cover further includes a hook portion that is hooked on the first cover. Further, a second belt is detachably attached to the developer cartridge, and the first belt and the second belt are positioned apart from the first belt in the first direction when the first belt and the second belt are attached to the developer cartridge. Equipped with a second belt that
When the drum unit is attached to the main body casing while the first belt and the second belt are not attached to the developer cartridge, the developer cartridge is located at the contact position,
When the drum unit is attached to the main body housing with the first belt and the second belt attached to the developer cartridge, the developer cartridge is located at the separated position. The image forming apparatus according to any one of claims 5 to 12. The image forming apparatus according to any one of claims 1 to 13, wherein the main body housing further includes a first metal plate having the first contact surface. The drum unit is
further comprising a second shaft extending in the first direction from the second drum side plate and extending away from the first body side plate with respect to the second body side plate;
The image forming apparatus further includes a third cover having a third hole into which the second shaft is inserted, the third cover being removable from the second shaft,
The second main body side plate is
When the drum unit is attached to the main body casing with the third cover not attached to the second shaft, the second contact surface that contacts the second shaft and the third cover are attached to the second shaft. a second guide that guides the second shaft toward the second contact surface when the drum unit is attached to the main body casing without being attached to the second shaft;
When the third cover is attached to the second shaft and the drum unit is attached to the main body housing, a part of the third cover comes into contact with the second guide, so that the third cover is attached to the second shaft. The image forming apparatus according to any one of claims 1 to 14, wherein the shaft is spaced apart from the second contact surface. The image forming apparatus according to claim 15, wherein the main body casing further includes a second metal plate having the second contact surface.

Images