JP2023139300A - Image forming apparatus - Google Patents

Abstract

To provide an image forming apparatus that, with one operation, can bring photoconductor drums into contact with an intermediate transfer belt and subsequently move developing rollers toward the photoconductor drums.SOLUTION: An image forming apparatus comprises: a body housing; a cover; drum units (drum cartridges 40); developing units (developing cartridges 50); and an intermediate transfer belt 63. In conjunction with the movement of the cover from an open position to a closed position, photoconductor drums, the intermediate transfer belt 63, and developing rollers take a first state where the photoconductor drums are separated from the intermediate transfer belt 63 and the developing rollers are separated from the photoconductor drums, a second state where the photoconductor drums are in contact with the intermediate transfer belt 63 and the developing rollers are separated from the photoconductor drums, and a third state where the photoconductor drums are in contact with the intermediate transfer belt 63 and the developing rollers are closer to the photoconductor drums than the first state.SELECTED DRAWING: Figure 6

Description

The present disclosure relates to an image forming apparatus that includes a drum cartridge and a developer cartridge that are removably attached to a main body housing.

2. Description of the Related Art Conventionally, an image forming apparatus is known in which a drum cartridge and a developer cartridge can be individually attached to and detached from a main body housing (see Patent Document 1). In this technique, the drum cartridge and the developer cartridge are removable in the axial direction of the photosensitive drum.

Japanese Patent Application Publication No. 2018-77459

In the configuration disclosed in Patent Document 1, when the drum cartridge is attached to the main body casing of the image forming apparatus, the photosensitive drum comes into contact with the intermediate transfer belt, resulting in damage to the photosensitive drum and the intermediate transfer belt. In order to suppress this, the photosensitive drum is separated from the intermediate transfer belt when the drum cartridge is installed in the main body housing. When the cover is moved from the open position to the closed position with the drum cartridge attached to the main body housing, the drum cartridge moves relative to the intermediate transfer belt, and the photosensitive drum comes into contact with the intermediate transfer belt.
In addition, in order to prevent the developing roller from coming into contact with the photosensitive drum and damaging the developing roller and photosensitive drum when the developing cartridge is installed into the main body housing, the developing cartridge is installed into the main body housing. At this time, the developing roller is separated from the photosensitive drum. After the user moves the cover from the open position to the closed position with the drum cartridge and developer cartridge installed in the main body housing, the motor and cam inside the main body housing move the developer cartridge relative to the drum cartridge. Then, the developing roller comes into contact with the photosensitive drum.

Therefore, before the image forming apparatus starts image forming operation, the user moves the cover from the open position to the closed position, moves the drum cartridge relative to the intermediate transfer belt, and brings the photosensitive drum into contact with the intermediate transfer belt. Two operations were required: a first operation and a second operation in which the motor and cam move the developer cartridge relative to the photosensitive drum after the user moves the cover from the open position to the closed position.

The present disclosure allows the user to move the drum cartridge relative to the intermediate transfer belt and bring the photosensitive drum into contact with the intermediate transfer belt by one action of the user positioning the cover from the open position to the closed position without using a motor. Another object of the present invention is to provide an image forming apparatus in which a developing cartridge can be moved relative to a drum cartridge.

In order to solve the above problem, an image forming apparatus according to the present disclosure includes a main body housing having an opening, a cover movable between an open position where the opening is opened and a closed position where the opening is closed, and a drum cartridge. , a developer cartridge, an intermediate transfer belt, and a moving cam.
The drum cartridge has a photosensitive drum rotatable about a first axis extending in a first direction, and is removable from the main body housing in the first direction.
The developing cartridge has a developing roller rotatable about a second shaft extending in the first direction, and is removable from the main body housing in the first direction.
The intermediate transfer belt is located above the drum cartridge and the developer cartridge when the drum cartridge and the developer cartridge are attached to the main body housing.
The moving cam is located below the drum cartridge and the developer cartridge when the drum cartridge and the developer cartridge are attached to the main body housing. The cover is located in a first position when the cover is located in the open position, and is located in a second position while the cover moves from the open position to the closed position, and the cover is located in the closed position. When it is located in the third position.
When the moving cam is located at the first position, the photosensitive drum is separated from the intermediate transfer belt, and the developing roller is separated from the photosensitive drum.
When the moving cam is located at the second position, the photosensitive drum is in contact with the intermediate transfer belt, and the developing roller is separated from the photosensitive drum.
When the moving cam is located at the third position, the photosensitive drum contacts the intermediate transfer belt, and the developing roller contacts the photosensitive drum.

According to this configuration, the contact between the intermediate transfer belt and the photosensitive drum due to the movement of the drum cartridge relative to the intermediate transfer belt, and the contact between the photosensitive drum and the developing roller due to the movement of the developer cartridge relative to the drum cartridge can be achieved without using a motor. , can be accomplished by a single action by the user of positioning the cover from the open position to the closed position.

In the image forming apparatus described above, the drum cartridge is configured to be aligned with the developer cartridge in a second direction intersecting the first direction when the drum cartridge and the developer cartridge are installed in the main body housing. You may.
Further, in the image forming apparatus described above, the movable cam may be configured to be movable in the first direction as the cover moves from the open position to the closed position.

In the image forming apparatus described above, the main body casing includes a first lift and a second lift, and the first lift engages with the moving cam to move the drum cartridge upward, and the first lift engages with the moving cam to move the drum cartridge upward, and The lift may be configured to engage the moving cam and move the developer cartridge upwardly.

In the image forming apparatus described above, the first lift may be configured to include a first drum contact portion that contacts the moving cam.
The moving cam may include a first drum separation surface extending in the first direction, a first drum inclined surface, and a first drum contact surface.
The first drum inclined surface extends from the first drum separation surface toward the intermediate transfer belt and is inclined with respect to the first direction.
The first drum contact surface extends in the first direction from the first drum inclined surface and is closer to the intermediate transfer belt than the first drum separation surface in the vertical direction.
The first drum inclined surface is located between the first drum separation surface and the first drum contact surface in the first direction.
When the moving cam is located at the first position, the first drum contact portion contacts the first drum separation surface.
Further, while the moving cam moves from the first position to the second position, the first drum contact portion contacts the first drum inclined surface.
Further, when the movable cam is located at the second position and the third position, the first drum contact portion contacts the first drum contact surface.

According to this, when the movable cam moves in conjunction with opening and closing of the cover, the first drum contact portion of the first lift comes into contact with the first drum separation surface, the first drum slope surface, or the first drum contact surface. , the height position of the first lift changes, and the drum cartridge can be positioned at a predetermined position.

In the image forming apparatus described above, the second lift may be configured to include a first developer contact portion that contacts the moving cam.
The movable cam may include a first developer separation surface extending in the first direction, a first developer inclined surface, and a first developer contact surface.
The first developing inclined surface extends from the first developing separation surface toward the intermediate transfer belt and is inclined with respect to the first direction.
The first developer contact surface extends from the first developer inclined surface in the first direction and is closer to the intermediate transfer belt than the first developer spacing surface in the vertical direction.
The first developing inclined surface is located between the first developing separation surface and the first developing contact surface in the first direction.
When the movable cam is located at the first position, the first developer contact portion contacts the first developer separating surface.
Further, while the movable cam moves from the first position to the third position, the first developer contact portion contacts the first developer inclined surface.
Furthermore, when the movable cam is located at the third position, the first developer contact portion contacts the first developer contact surface.

According to this, when the movable cam moves in conjunction with opening and closing of the cover, the first developer contact portion of the second lift comes into contact with the first developer separating surface, the first developer inclined surface, or the first developer contact surface. The height position of the second lift changes, and the developer cartridge can be positioned at a predetermined position.

In the image forming apparatus described above, in the moving direction in which the movable cam moves from the first position toward the third position, the downstream end of the first drum contact surface is lower than the downstream end of the first developer contact surface. It may also be configured such that it is also located on the downstream side.

In the image forming apparatus described above, the moving cam may be configured to have a second drum separation surface, a second drum slope surface, and a second drum contact surface.
The second drum separation surface is located apart from the first drum separation surface in the first direction.
The second drum inclined surface extends from the second drum separation surface toward the intermediate transfer belt. Further, the second drum inclined surface is inclined with respect to the first direction and is located apart from the first drum inclined surface in the first direction.
A second drum contact surface extends in the first direction from the second drum slope. Further, the second drum contact surface is located closer to the intermediate transfer belt than the second drum separation surface in the up-down direction, and is located away from the first drum contact surface in the first direction.
The second drum inclined surface is located between the second drum separation surface and the second drum contact surface in the first direction.
The first lift may include a second drum contact portion that contacts the moving cam. The second drum contact portion is located apart from the first drum contact portion in the first direction.
When the movable cam is located at the first position, the second drum contact portion contacts the second drum separation surface.
Further, while the moving cam moves from the first position to the second position, the second drum contact portion contacts the second drum inclined surface.
Further, when the movable cam is located at the second position and the third position, the second drum contact portion contacts the second drum contact surface.

In the image forming apparatus described above, the movable cam may be configured to have a second developing separating surface, a second developing inclined surface, and a second developing inclined surface.
The second development separation surface is located apart from the first development separation surface in the first direction.
The second developing inclined surface extends from the second developing separating surface toward the intermediate transfer belt. Further, the second developing inclined surface is inclined with respect to the first direction and is located apart from the first developing inclined surface in the first direction.
A second developer contact surface extends from the second developer inclined surface in the first direction. Further, the second developer contact surface is located closer to the intermediate transfer belt than the second developer separation surface in the vertical direction, and is located farther from the first developer contact surface in the first direction.
The second developing inclined surface is located between the second developing separation surface and the second developing contact surface in the first direction.
The second lift may include a second developer contact portion that contacts the moving cam. The second developer contact portion is located apart from the first developer contact portion in the first direction.
When the movable cam is located at the first position, the second developer contact portion contacts the second developer separation surface.
Further, while the movable cam moves from the first position to the third position, the second developer contact portion contacts the second developer inclined surface.
Further, when the movable cam is located at the third position, the second developer contact portion contacts the second developer contact surface.

According to these configurations, the first lift is provided with two drum contact parts, the second lift is provided with two developer contact parts, and the moving cam presses the two drum contact parts and the two developer contact parts. Therefore, the drum cartridge and the developer cartridge can be stably positioned.

Furthermore, in the image forming apparatus described above, in the moving direction in which the moving cam moves from the first position to the third position, the downstream end of the second drum contact surface is located downstream of the second developer contact surface. It may be configured to be located downstream from the end.

In the image forming apparatus described above, the first lift may include a drum guide protrusion and a developing guide protrusion.
The drum guide protrusion extends in the first direction and is for guiding the drum cartridge.
The developer guide protrusion extends in the first direction and is for guiding the developer cartridge.
The drum cartridge may be configured to have a drum groove guided by the drum guide protrusion.
Further, the developer cartridge may be configured to have a developer groove guided by the developer guide protrusion.

In the image forming apparatus described above, the development guide protrusion may have a guide hole, and the second lift may be configured to be movable within the guide hole.

According to this, after the drum cartridge and the developer cartridge are moved relative to the intermediate transfer belt by the first lift and the positioning of the photosensitive drum relative to the intermediate transfer belt is completed, the developer cartridge is moved relative to the drum cartridge by the second lift. By moving the developing roller, the developing roller can be positioned with respect to the photosensitive drum.

The above-described image forming apparatus may be configured to include a paper ejection section for ejecting the paper and located above the intermediate transfer belt.

Further, the above-described image forming apparatus may be configured to include a paper feeding section for feeding paper, which is located below the movable cam.

According to the present disclosure, contact between the intermediate transfer belt and the photosensitive drum due to the movement of the drum cartridge relative to the intermediate transfer belt, and contact between the photosensitive drum and the developing roller due to the movement of the developer cartridge relative to the drum cartridge, can be achieved without using a motor. , can be accomplished by a single action by the user of positioning the cover from the open position to the closed position.

1 is a cross-sectional view showing a schematic configuration of a color printer according to an embodiment of the present disclosure. It is a perspective view explaining a cover, a moving cam, and a 1st lift. They are a perspective view (a) of a moving cam and a sectional view (b) of the moving cam. They are a perspective view (a) of a first lift and a second lift, and a cross-sectional view (b) of the first lift. FIG. 6 is an explanatory diagram when the movable cam is in the first position, and includes a cross-sectional view (a) taken along a plane perpendicular to the second direction, and an enlarged view (b) taken along a plane perpendicular to the first direction. FIG. 7 is an explanatory diagram when the movable cam is in the second position, and includes a cross-sectional view (a) taken along a plane perpendicular to the second direction and an enlarged view (b) taken along a plane perpendicular to the first direction. FIG. 7 is an explanatory diagram when the movable cam is in the third position, and includes a cross-sectional view (a) taken along a plane perpendicular to the second direction and an enlarged view (b) taken along a plane perpendicular to the first direction.

Next, one embodiment of the present disclosure will be described in detail with reference to the drawings as appropriate. In the following description, first, the overall configuration of a color printer 1 as an example of an image forming apparatus will be described.

As shown in FIG. 1, the color printer 1 includes a main body housing 2, a paper feed section 3, an image forming section 4, and a paper discharge section 5. The paper feed section 3 supplies paper P to the image forming section 4 . The image forming section 4 forms an image on the paper P. The paper discharge section 5 discharges the paper P.

The paper feed section 3 is located at the bottom inside the main body casing 2. The paper feed section 3 includes a paper feed tray 31 and a paper feed mechanism 32. The paper feed tray 31 is removably attachable to the main body housing 2 . The paper feed mechanism 32 transports the paper P from the paper feed tray 31 to the image forming section 4 .
The paper feed section 3 is located below a moving cam 110, which will be described later.

The image forming section 4 includes four drum cartridges 40, four developer cartridges 50, an exposure device SU, a transfer unit 60, and a fixing unit 70.

Each drum cartridge 40 includes a photosensitive drum 41, a charger (not shown), and a drum frame F1. The photosensitive drum 41 is rotatable about a first axis X1 extending in a first direction. The four drum cartridges 40 are mounted on the main body casing 2 and lined up in a second direction intersecting the first direction.
Note that the first direction is a direction perpendicular to the vertical direction, and the second direction is a direction perpendicular to the first direction and the vertical direction. The vertical direction refers to the vertical direction.

Each developing cartridge 50 includes a developing roller 51 and a developing frame F2. The developing frame F2 accommodates developer. The developing roller 51 is rotatable about a second axis X2 extending in the first direction.

The drum cartridge 40 and the developer cartridge 50 are lined up in the second direction in a state where the drum cartridge 40 and the developer cartridge 50 are attached to the main body housing 2 . As shown in FIG. 2, the drum cartridge 40 is removable from the main body housing 2 in the first direction. Similarly, the developer cartridge 50 is removable from the main body housing 2 in the first direction. Each drum cartridge 40 has the same structure. Each developer cartridge 50 has the same structure.

The exposure device SU is located below each drum cartridge 40. The exposure device SU emits laser light to each photosensitive drum 41.

The transfer unit 60 is located between the four photosensitive drums 41 and a paper discharge tray 21, which will be described later. The transfer unit 60 includes a drive roller 61 , a driven roller 62 , an intermediate transfer belt 63 , four primary transfer rollers 64 , and a secondary transfer roller 65 .

The intermediate transfer belt 63 is an endless belt. Intermediate transfer belt 63 is located above drum cartridge 40 and developer cartridge 50 when drum cartridge 40 and developer cartridge 50 are attached to main body housing 2 .

The primary transfer roller 64 is located inside the intermediate transfer belt 63. The primary transfer roller 64 and the photosensitive drum 41 sandwich the intermediate transfer belt 63.

The secondary transfer roller 65 is located outside the intermediate transfer belt 63. The secondary transfer roller 65 and the drive roller 61 sandwich the intermediate transfer belt 63.

The fixing unit 70 is located above the intermediate transfer belt 63. The fixing unit 70 includes a heating roller 71 and a pressure roller 72. Pressure roller 72 is pressed by heating roller 71 .

The paper discharge section 5 is located at the upper part of the main body housing 2. The paper discharge section 5 is located above the intermediate transfer belt 63. The paper discharge section 5 includes a discharge roller 9 and a paper discharge tray 21. The discharge roller 9 conveys the paper P toward the paper discharge tray 21 .

In the color printer 1, the charger first charges the surface of the photosensitive drum 41. After that, the exposure device SU exposes the surface of the photosensitive drum 41. As a result, an electrostatic latent image is formed on the photosensitive drum 41.

Next, the developing roller 51 supplies developer to the electrostatic latent image on the photosensitive drum 41. As a result, a developer image is formed on the photosensitive drum 41. The developer image on the photosensitive drum 41 is then transferred onto the intermediate transfer belt 63.

When paper P passes between intermediate transfer belt 63 and secondary transfer roller 65, the developer image on intermediate transfer belt 63 is transferred onto paper P. Thereafter, the developer image on the paper P is fixed by the fixing unit 70. Next, the paper P is discharged onto the paper discharge tray 21 by the discharge roller 9.

The main body case 2 has an opening 22A. The opening 22A allows each drum cartridge 40 and each developer cartridge 50 to pass through when the drum cartridge 40 and each developer cartridge 50 are attached and detached in the first direction.

As shown in FIG. 2, the color printer 1 has a cover C. As shown in FIG. The cover C is a member for opening and closing the opening 22A. The cover C rotates around rotational axes C1 on both sides of the lower end of the cover C. The rotation shaft C1 is inserted into a bearing (not shown) of the main body casing 2. The cover C is movable between an open position (the position shown in FIG. 2) in which the opening 22A is opened and a closed position (not shown) in which the opening 22A is closed.
The cover C has an arm holding portion C2 on one side. The arm holding portion C2 has an elongated hole C3 into which a cylindrical projection 156 of an arm 152, which will be described later, is inserted.

In the drum cartridge 40, a photosensitive drum 41 is rotatably supported by a drum frame F1. Further, the drum cartridge 40 has a drum groove 42 extending in the first direction at the bottom of the drum frame F1. The drum groove 42 is guided by a drum guide protrusion 133, which will be described later.

In the developer cartridge 50, a developer roller 51 is rotatably supported by a developer frame F2. Further, the developer cartridge 50 has a developer groove 52 extending in the first direction at the bottom of the developer frame F2. The developing groove 52 is guided by a developing guide protrusion 134, which will be described later.
Note that the size of the developer cartridge 50 in the vertical direction is smaller than the size of the drum cartridge 40 in the vertical direction. More specifically, when the drum cartridge 40 and the developer cartridge 50 are attached to the main body housing 2, the developer cartridge 50 has a size such that the developer roller 51 is located at a lower position than the photosensitive drum 41. ing.

The main body housing 2 includes a moving cam 110, a first lift 130, and a second lift 140 (see FIG. 4).
The moving cam 110 is located below the drum cartridge 40 and the developer cartridge 50 when the drum cartridge 40 and the developer cartridge 50 are attached to the main body housing 2 .
The moving cam 110 is a plate-shaped member. The moving cam 110 is movable in the first direction as the cover C moves from the open position to the closed position. Specifically, the movable cam 110 is movable in the first direction via the arm 152 in conjunction with opening and closing of the cover C.
As shown in FIG. 3, the moving cam 110 has an upper surface 111 and a cylindrical projection 112 located on the side surface of the moving cam 110. The moving cam 110 slides on the upper surface of the guide portion 22B (see FIG. 5) of the main body housing 2.

As shown in FIG. 2, the arm 152 has one end 152A and the other end 152B.
One end portion 152A of the arm 152 has a through hole 154 that rotatably supports the cylindrical projection 112 of the moving cam 110. The other end 152B of the arm 152 has a cylindrical projection 156. The cylindrical projection 156 is inserted into the long hole C3 of the arm holding portion C2.

As shown in FIG. 3, the moving cam 110 includes a set of drum spacing surfaces 114, a set of drum slope surfaces 116, and a set of drum contact surfaces 118 spaced apart in a first direction. A set of drum spacing surfaces 114 , a set of drum inclined surfaces 116 , and a set of drum contact surfaces 118 are located on the upper surface 111 of the moving cam 110 .
The set of drum spacing surfaces 114 includes a first drum spacing surface 114A that is closer to the opening 22A, and a second drum spacing surface 114B that is located farther from the opening 22A than the first drum spacing surface 114A. The first drum separation surface 114A and the second drum separation surface 114B extend in the first direction. The second drum separation surface 114B is located apart from the first drum separation surface 114A in the first direction.
The set of drum ramps 116 includes a first drum ramp 116A that is closer to the opening 22A and a second drum ramp 116B that is located farther from the opening 22A than the first drum ramp 116A. The first drum inclined surface 116A extends toward the intermediate transfer belt 63 from the first drum separation surface 114A. The first drum inclined surface 116A is inclined with respect to the first direction. The second drum inclined surface 116B is located apart from the first drum inclined surface 116A in the first direction. The second drum inclined surface 116B extends toward the intermediate transfer belt 63 from the second drum separation surface 114B. Further, the second drum inclined surface 116B is inclined with respect to the first direction.
The first drum inclined surface 116A is located between the first drum separation surface 114A and the first drum contact surface 118A, which will be described later, in the first direction. Similarly, the second drum inclined surface 116B is located between the second drum separation surface 114B and a second drum contact surface 118B, which will be described later, in the first direction.
Note that a connecting portion 115A between the first drum separating surface 114A and the first drum inclined surface 116A is formed into a curved surface, and a first drum contacting portion 135A, which will be described later, is between the first drum separating surface 114A and the first drum inclined surface 116A. can be moved smoothly. Similarly, a connecting portion 115B between the second drum separating surface 114B and the second drum inclined surface 116B is formed into a curved surface, and a second drum contacting portion 135B, which will be described later, is formed between the second drum separating surface 114B and the second drum inclined surface 116B. This allows for smooth movement between the two.
The set of drum contact surfaces 118 includes a first drum contact surface 118A that is closer to the aperture 22A and a second drum contact surface 118B that is located further from the aperture 22A than the first drum contact surface 118A. The first drum contact surface 118A extends in the first direction from the first drum inclined surface 116A. The first drum contact surface 118A is closer to the intermediate transfer belt 63 than the first drum separation surface 114A in the vertical direction. The second drum contact surface 118B is located apart from the first drum contact surface 118A in the first direction. The second drum contact surface 118B extends in the first direction from the second drum inclined surface 116B. Further, the second drum contact surface 118B is closer to the intermediate transfer belt 63 than the second drum separation surface 114B in the vertical direction.
Note that a connecting portion 117A between the first drum inclined surface 116A and the first drum contact surface 118A is formed into a curved surface, and a first drum contact portion 135A, which will be described later, is located between the first drum inclined surface 116A and the first drum contact surface 118A. can be moved smoothly. Similarly, a connecting portion 117B between the second drum inclined surface 116B and the second drum contact surface 118B is formed into a curved surface, and a second drum contact portion 135B, which will be described later, connects the second drum inclined surface 116B and the second drum contact surface 118B. This allows for smooth movement between the two.

Furthermore, the moving cam 110 includes a set of developer separation surfaces 124, a set of developer slope surfaces 126, and a set of developer contact surfaces 128 that are spaced apart in the first direction. A set of developer separation surfaces 124 , a set of developer inclined surfaces 126 , and a set of developer contact surfaces 128 are located on the upper surface 111 of the movable cam 110 .
One set of development separation surfaces 124 corresponds to one set of drum separation surfaces 114. The set of developing separation surfaces 124 is formed at a lower position than the set of drum separation surfaces 114.
One set of developer slopes 126 corresponds to one set of drum slopes 116. The set of developing slopes 126 is formed at a lower position than the set of drum slopes 116.
The set of developer contact surfaces 128 corresponds to the set of drum contact surfaces 118.
There are four sets of development separation surfaces 124, one set of development slope surfaces 126, and one set of development contact surfaces 128, each spaced apart in the second direction.

The set of development separation surfaces 124 includes a first development separation surface 124A that is closer to the opening 22A, and a second development separation surface 124B that is located farther from the opening 22A than the first development separation surface 124A. The first development separation surface 124A and the second development separation surface 124B extend in the first direction. The second development separation surface 124B is located apart from the first development separation surface 124A in the first direction.
The set of developing inclined surfaces 126 includes a first developing inclined surface 126A that is closer to the opening 22A, and a second developing inclined surface 126B that is located farther from the opening 22A than the first developing inclined surface 126A. The first developing inclined surface 126A extends toward the intermediate transfer belt 63 from the first developing separating surface 124A. The first developing inclined surface 126A is inclined with respect to the first direction. The second developing inclined surface 126B is located apart from the first developing inclined surface 126A in the first direction. The second developing inclined surface 126B extends from the second developing separating surface 124B toward the intermediate transfer belt 63. Further, the second developing inclined surface 126B is inclined with respect to the first direction.
The first developer inclined surface 126A is located between the first developer separation surface 124A and the first developer contact surface 128A, which will be described later, in the first direction. Similarly, the second developer inclined surface 126B is located between the second developer separation surface 124B and a second developer contact surface 128B, which will be described later, in the first direction.
The set of developer contact surfaces 128 includes a first developer contact surface 128A that is closer to the aperture 22A and a second developer contact surface 128B that is located further from the aperture 22A than the first developer contact surface 128A. The first developer contact surface 128A extends in the first direction from the first developer inclined surface 126A. The first developer contact surface 128A is closer to the intermediate transfer belt 63 than the first developer separation surface 124A in the vertical direction. The second developer contact surface 128B is located apart from the first developer contact surface 128A in the first direction. The second developer contact surface 128B extends in the first direction from the second developer inclined surface 126B. Further, the second developer contact surface 128B is closer to the intermediate transfer belt 63 than the second developer separation surface 124B in the vertical direction.
The first developer contact surface 128A is the same surface as the first drum contact surface 118A, and the second developer contact surface 128B is the same surface as the second drum contact surface 118B.
Note that the connecting portion between the developing separating surface 124 and the developing inclined surface 126 and the connecting portion between the developing inclined surface 126 and the developing contact surface 128 may be formed into curved surfaces.

As shown in FIG. 4, the first lift 130 is a member that engages with the moving cam 110 to move the drum cartridge 40 upward. The first lift 130 has an upper surface 131 and a lower surface 132. The four drum guide projections 133 and the four development guide projections 134 are located on the upper surface 131 of the first lift 130. The first lift 130 also includes a first drum contact portion 135A and a second drum contact portion 135B that contact the upper surface 111 of the moving cam 110. The second drum contact portion 135B is located apart from the first drum contact portion 135A in the first direction. More specifically, the distance between the first drum contact portion 135A and the second drum contact portion 135B in the first direction is, for example, the distance between the first drum slope surface 116A and the second drum slope surface 116B in the first direction. It is the same as distance.
Each drum guide protrusion 133 extends in the first direction and is for guiding the drum cartridge 40.
Each developing guide protrusion 134 extends in the first direction and is for guiding the developing cartridge 50. The vertical height of each developing guide projection 134 is lower than the vertical height of each drum guide projection 133.
Further, each development guide protrusion 134 has a guide hole 136. The guide hole 136 extends in the first direction and is a through hole into which the second lift 140 is inserted. As shown in FIG. 4(b), the guide hole 136 includes a first portion 136A and a second portion 136B. The first portion 136A is an opening that vertically passes through the development guide protrusion 134. The second portion 136B is an opening that communicates with the first portion 136A and vertically passes through the first drum contact portion 135A and the second drum contact portion 135B. Note that the first lift 130 has a support surface 137 inside the guide hole 136. The support surface 137 functions as a retainer for the second lift 140 inserted into the guide hole 136.
In addition, as shown in FIG.5(b), the 1st lift 130, the moving cam 110, and the guide part 22B have an opening through which the laser beam from exposure apparatus SU passes.

The second lift 140 is a member that engages with the moving cam 110 and moves the developer cartridge 50 upward. The second lift 140 is inserted into the guide hole 136. The second lift 140 includes a main body part 141 extending in the first direction, and a first developer contact part 142 and a second developer contact part 144 extending downward from the main body part 141. The main body portion 141 is supported by the support surface 137 during assembly. The first developer contact portion 142 and the second developer contact portion 144 come into contact with the upper surface 111 of the moving cam 110 through the second portion 136B of the guide hole 136. The second developer contact portion 144 is located apart from the first developer contact portion 142 in the first direction. The second lift 140 is movable up and down within the guide hole 136.
In the second lift 140, the lower ends of the first developer contact part 142 and the second developer contact part 144 protrude downward from the lower ends of the first drum contact part 135A and the second drum contact part 135B (see FIG. 5). .

With reference to FIGS. 2 and 5 to 7, a method for mounting the drum cartridge 40 and the developer cartridge 50 and positioning the developer roller 51 and the photosensitive drum 41 will be described.
As shown in FIG. 2, the drum cartridge 40 and the developer cartridge 50 are installed in the main body casing 2 with the cover C in the open position and the opening 22A exposed. The drum cartridge 40 is inserted in the first direction along the upper surface 131 of the first lift 130 with the drum groove 42 fitted into the drum guide protrusion 133 of the first lift 130 . Similarly, the developer cartridge 50 is inserted in the first direction along the upper surface 131 of the first lift 130 with the developer groove 52 fitted into the developer guide protrusion 134 of the first lift 130 .

As shown in FIG. 5, when the cover C is in the open position, the moving cam 110 is in the first position.
More specifically, when the moving cam 110 is located at the first position, the first drum contact portion 135A contacts the first drum separation surface 114A, and the second drum contact portion 135B contacts the second drum separation surface 114B. Contact. At this time, the first lift 130 is in the lowered position, and the photosensitive drum 41 of the drum cartridge 40 is separated from the intermediate transfer belt 63. Further, when the movable cam 110 is located at the first position, the first developer contact portion 142 contacts the first developer separation surface 124A, and the second developer contact portion 144 contacts the second developer separation surface 124B. At this time, since the second lift 140 does not protrude from the upper surface of the first lift 130, the developing roller 51 of the developer cartridge 50 is spaced apart from the photosensitive drum 41.
That is, when the cover C is in the open position, the moving cam 110 is in the first position, the photosensitive drum 41 is separated from the intermediate transfer belt 63, and the developing roller 51 is separated from the photosensitive drum 41.

As shown in FIG. 6, while the cover C moves from the open position to the closed position, the moving cam 110 is located at the second position.
More specifically, when the cover C is moved from the open position to the closed position, the arm 152 moves the moving cam 110 away from the opening 22A along the first direction. While the moving cam 110 moves from the first position to the second position, the first drum contact part 135A contacts the first drum inclined surface 116A, and the second drum contact part 135B contacts the second drum inclined surface. 116B. As a result, the first lift 130 ascends toward the intermediate transfer belt 63. Further, while the movable cam 110 moves from the first position to the second position, the first developer contact portion 142 contacts the first developer inclined surface 126A, and the second developer contact portion 144 contacts the second developer inclined surface 126B. come into contact with. As a result, the second lift 140 moves up toward the intermediate transfer belt 63 together with the first lift 130.

When the cover C further moves toward the closed position, the moving cam 110 further moves in the first direction and is located at the second position.
When the moving cam 110 is in the second position, the first drum contact portion 135A contacts the first drum contact surface 118A, and the second drum contact portion 135B contacts the second drum contact surface 118B. At this time, the first lift 130 is in the raised position, and the photosensitive drum 41 of the drum cartridge 40 supported by the first lift 130 contacts the intermediate transfer belt 63 .
Further, when the movable cam 110 is located at the second position, the first developer contact portion 142 remains in contact with the first developer inclined surface 126A, and the second developer contact portion 144 remains in contact with the second developer inclined surface 126B. It remains as it is. In other words, while the movable cam 110 moves from the first position to the third position, the first developer contact portion 142 contacts the first developer inclined surface 126A, and the second developer contact portion 144 contacts the second developer inclined surface 126A. Contact surface 126B. At this time, since the second lift 140 does not protrude from the upper surface of the first lift 130, the developing roller 51 of the developing cartridge 50 remains separated from the photosensitive drum 41.
That is, when the moving cam 110 is located at the second position, the photosensitive drum 41 is in contact with the intermediate transfer belt 63, and the developing roller 51 is separated from the photosensitive drum 41.

As shown in FIG. 7, when the cover C is in the closed position, the moving cam 110 is in the third position.
More specifically, when the moving cam 110 is located at the third position, the first drum contact portion 135A contacts the first drum contact surface 118A, and the second drum contact portion 135B contacts the second drum contact surface 118B. Contact. At this time, the first lift 130 is in the raised position, and the photosensitive drum 41 of the drum cartridge 40 supported by the first lift 130 remains in contact with the intermediate transfer belt 63. Further, when the movable cam 110 is located at the third position, the first developer contact portion 142 contacts the first developer contact surface 128A, and the second developer contact portion 144 contacts the second developer contact surface 128B. At this time, the second lift 140 protrudes upward from the guide hole 136, and the developer cartridge 50 is pressed by the second lift 140 and rises with respect to the drum cartridge 40. Then, the developing roller 51 comes into contact with the photosensitive drum 41.
That is, when the moving cam 110 is located at the third position, the photosensitive drum 41 contacts the intermediate transfer belt 63 and the developing roller 51 contacts the photosensitive drum 41.

Note that, as shown in FIG. 3B, in the moving direction in which the moving cam 110 moves from the first position to the third position, the downstream end of the first drum contact surface 118A is aligned with the first developer contact surface 128A. Located downstream from the downstream end. Similarly, in the moving direction in which the moving cam 110 moves from the first position to the third position, the downstream end of the second drum contact surface 118B is located downstream of the downstream end of the second developer contact surface 128B. .

According to such a configuration, the first drum contact portion 135A and the second drum contact portion 135B first ride on the first drum contact surface 118A and the second drum contact surface 118B, and then the first developer contact portion 142 and the second drum contact portion 135B ride on the first drum contact surface 118A and the second drum contact surface 118B. Since the developer contact portion 144 rides on the first developer contact surface 128A and the second developer contact surface 128B, the developer roller 51 does not come into contact with the photosensitive drum 41 after the photosensitive drum 41 contacts the intermediate transfer belt 63. become.
Note that the distance between the downstream end of the first drum contact surface 118A and the downstream end of the first developer contact surface 128A, and the distance between the downstream end of the second drum contact surface 118B and the downstream end of the second developer contact surface 128B are changed. By doing so, it is possible to change the timing at which the developing roller 51 and the photosensitive drum 41 contact after the photosensitive drum 41 and the intermediate transfer belt 63 contact.

According to the above, the following effects can be obtained in this embodiment.
The contact between the intermediate transfer belt 63 and the photosensitive drum 41 due to the movement of the drum cartridge 40 relative to the intermediate transfer belt 63, and the contact between the photosensitive drum 41 and the developing roller 51 due to the movement of the developer cartridge 50 relative to the drum cartridge 40 are achieved using a motor. This can be achieved by a single action of the user moving the cover C from the open position to the closed position.

When the moving cam 110 moves in conjunction with the opening and closing of the cover C, the first drum contact portion 135A of the first lift 130 comes into contact with the first drum separation surface 114A, the first drum inclined surface 116A, or the first drum contact surface 118A. By doing so, the height position of the first lift 130 changes, and the drum cartridge 40 can be positioned at a predetermined position.

When the moving cam 110 moves in conjunction with the opening and closing of the cover C, the first developer contact portion 142 of the second lift 140 comes into contact with the first developer separating surface 124A, the first developer inclined surface 126A, or the first developer contact surface 128A. By doing so, the height position of the second lift 140 changes, and the developer cartridge 50 can be positioned at a predetermined position.

The first lift 130 has two drum contact parts 135A, 135B, the second lift has two developer contact parts 142, 144, and the moving cam 110 has two drum contact parts 135A, 135B and two developer contact parts 142. , 144, the drum cartridge and developer cartridge can be stably positioned.

Since the developer guide protrusion 134 has a guide hole 136 and the second lift 140 is movable within the guide hole 136, the drum cartridge 40 and the developer cartridge 50 are moved relative to the intermediate transfer belt 63 by the first lift 130. After the positioning of the photosensitive drum 41 with respect to the intermediate transfer belt 63 is completed, the developing cartridge 50 is moved with respect to the drum cartridge 40 by the second lift 140, and the positioning of the developing roller 51 with respect to the photosensitive drum 41 can be performed. .

Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the embodiments described above. The specific configuration can be modified as appropriate without departing from the spirit of the present disclosure.

In the embodiment described above, in conjunction with the closing operation of the cover, the first lift 130 raises the drum cartridge 40 and the developer cartridge 50 toward the intermediate transfer belt 63, and the second lift 140 further raises the developer cartridge 50. However, the present disclosure is not limited to such a configuration.
For example, a drum lift that engages with the top surface 111 of the movable cam 110 to move the drum cartridge 40 upward and a developer lift that engages with the top surface 111 of the movable cam 110 to move the developer cartridge 50 upward are independent. It may also be configured so that they can be moved separately.
In such a configuration, the drum guide protrusion may be located on the upper surface of the drum lift, and the developing guide protrusion may be located on the upper surface of the developer lift.

In the embodiment described above, the first lift 130 had the drum guide protrusion 133 and the developer guide protrusion 134, the drum cartridge 40 had the drum groove 42, and the developer cartridge 50 had the developer groove 52. The disclosure is not limited to such configurations. For example, a drum guide groove may be used instead of the drum guide protrusion 133, and a drum protrusion may be used instead of the drum groove 42. Similarly, a development guide groove may be used instead of the development guide protrusion 134, and a development protrusion may be used instead of the development groove 52. Moreover, you may combine these arbitrarily.

In the embodiment described above, the movable cam 110 includes one set (two) of each of the drum separation surface 114, the drum slope surface 116, the drum contact surface 118, the developer separation surface 124, the developer slope surface 126, and the developer contact surface 128. The first lift 130 includes a first drum contact portion 135A and a second drum contact portion 135B, and the second lift 140 includes a first developer contact portion 142 and a second developer contact portion 144. The present disclosure is not limited to such a configuration, and any number may be used.
For example, the moving cam 110 has a drum separation surface 114, a drum slope surface 116, a drum contact surface 118, a developer separation surface 124, a developer slope surface 126, and a developer contact surface 128, and the first lift 130 , the second lift 140 may be configured to include only one drum contact portion, and the second lift 140 may include only one developer contact portion.
Further, the movable cam 110 can also be configured without a developing separation surface.

In the embodiments described above, the present disclosure is applied to the color printer 1, but the present disclosure is not limited thereto, and the present disclosure may be applied to other image forming apparatuses, such as monochrome printers, copiers, multifunction devices, etc. Good too.

The elements described in the above-described embodiments and modifications may be implemented in any combination.

1 Color printer 2 Main body housing 22A Opening C Cover 40 Drum cartridge 41 Photosensitive drum 50 Developing cartridge 51 Developing roller 63 Intermediate transfer belt 110 Moving cam

Claims (8)

a main body casing having an opening;
a cover movable between an open position where the opening is opened and a closed position where the opening is closed;
a drum unit having a photosensitive drum rotatable about a first axis extending in a first direction;
a developing unit having a developing roller rotatable about a second axis extending in the first direction;
an intermediate transfer belt located above the drum unit and the developing unit,
In conjunction with the movement of the cover from the open position to the closed position, the photosensitive drum, the intermediate transfer belt, and the developing roller
a first state in which the photosensitive drum is separated from the intermediate transfer belt and the developing roller is separated from the photosensitive drum;
a second state in which the photosensitive drum is in contact with the intermediate transfer belt and the developing roller is separated from the photosensitive drum;
An image forming apparatus characterized in that the photosensitive drum is in contact with the intermediate transfer belt, and the developing roller is in a third state closer to the photosensitive drum than in the first state. a first position when the cover is in the open position; a second position while the cover moves from the open position to the closed position; and a second position when the cover is in the closed position. comprising a moving member located in three positions,
Image forming according to claim 1, wherein the photosensitive drum, the intermediate transfer belt, and the developing roller take the first state, the second state, and the third state by the movement of the moving member. Device. The image forming apparatus according to claim 2, wherein the moving member moves the drum unit and the developing unit independently and separately. The image forming apparatus according to claim 1, wherein the drum unit is removable from the main body housing in the first direction through the opening. The image forming apparatus according to claim 1, wherein the developing unit is removable from the main body housing through the opening in the first direction. The image forming apparatus according to claim 1, further comprising a paper ejection section for ejecting paper, the paper ejection section being located above the intermediate transfer belt. The image forming apparatus according to claim 2, further comprising a paper feeding section for feeding paper, the paper feeding section being located below the moving member. The image according to claim 1, wherein the drum unit is aligned with the developing unit in a second direction intersecting the first direction when the drum unit and the developing unit are attached to the main body housing. Forming device.

Images