JP2020052356A - Image forming apparatus - Google Patents

Abstract

To provide an image forming apparatus with which operations to attach/detach cartridges can be easily performed.SOLUTION: An image forming apparatus comprises: a body housing; developing cartridges 50 that each has a developing roller 51 rotatable about a first axis extending in a first direction and a developing frame F2, the developing cartridges 50 each being removably attached to a drum cartridge 40; the drum cartridges 40 that each has a photoconductor drum 41 and a drum frame F1, the drum cartridges 40 each being removably attached to the body housing in the first direction together with the developing cartridge 50 while the developing cartridge 50 is attached to the drum cartridge 40; and an intermediate transfer belt that is located above the drum cartridges 40 and developing cartridges 50 while the drum cartridges 40 and developing cartridges 50 are attached to the body housing.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an image forming apparatus including a drum cartridge and a developing cartridge.

  2. Description of the Related Art Conventionally, an image forming apparatus in which an intermediate transfer belt is located above a drum cartridge and a developing cartridge in a state where the drum cartridge and the developing cartridge are mounted on a main body housing has been known (Japanese Patent Application Laid-Open No. H10-163873). In this technique, the drum cartridge and the developing cartridge are detachable from the main housing in a first direction along the rotation axis of the photosensitive drum. Further, the drum cartridge and the developing cartridge are each detachable from the main body housing.

JP-A-2017-173805

  In the related art, the user needs to attach and detach the drum cartridge and the developing cartridge to and from the main body housing.

  Accordingly, it is an object of the present invention to provide an image forming apparatus capable of easily performing a cartridge attaching / detaching operation.

  In order to solve the above-mentioned problem, an image forming apparatus according to the present invention includes a developing cartridge including a main body housing, a developing roller rotatable about a first shaft extending in a first direction, and a developing frame that stores a developer. A drum cartridge having a developing cartridge detachable from the drum cartridge, a photosensitive drum rotatable about a second axis extending in the first direction, and a drum frame, wherein the developing cartridge is the drum cartridge. A drum cartridge in which the drum cartridge is detachably attached to the main body housing in the first direction together with the developing cartridge, and a state in which the drum cartridge and the developing cartridge are mounted in the main body housing. In the above, than the drum cartridge and the developing cartridge An intermediate transfer belt that is in contact with a surface of the photosensitive drum when the drum cartridge is mounted on the main body housing in the first direction together with the developing cartridge. .

  According to this configuration, since the developing cartridge can be attached to and detached from the main body housing together with the drum cartridge in the first direction, the cartridge attaching / detaching operation can be easily performed.

  Further, the image forming apparatus may include a paper discharge unit located above the intermediate transfer belt.

  Further, the developing cartridge has a protrusion located at one end of the developing roller in the first direction, and the drum cartridge is a guide groove located at one end of the drum frame in the first direction. In the state where the developing cartridge is mounted on the drum cartridge, the developing cartridge may have a guide groove in which the projection fits.

  Further, the drum cartridge has a drum bearing positioned at one end of the photosensitive drum in the first direction, the drum bearing rotatably supporting the photosensitive drum, and the drum bearing includes the guide groove. May be provided.

  According to this, the positioning accuracy of the developing roller and the photosensitive drum can be improved by providing the guide groove in the drum bearing.

  The drum cartridge is a drum coupling located at the one end of the photosensitive drum in the first direction, the drum cartridge having a drum coupling rotatable with the photosensitive drum, and wherein the drum bearing is The coupling may have an opening through which the coupling is exposed.

  The drum cartridge may have a drum handle, and the drum bearing may be located between the photosensitive drum and the drum handle in the first direction.

  The drum handle may have a recess that allows a user's finger to be hooked when the user takes out the drum cartridge from the main body housing.

  The drum cartridge may further include a lock position for locking the developer cartridge to the drum cartridge in a state where the developer cartridge is mounted on the drum cartridge, and a release position for releasing the lock of the developer cartridge to the drum cartridge. And a lock lever rotatable about a third axis extending in the first direction, the lock lever being located at one end of the drum frame in the first direction.

  The main body housing includes a motor, and the developing cartridge is a developing coupling located at one end of the developing frame in the first direction, and is a developing coupling rotatable with the developing roller. And a developing coupling for receiving a driving force from the motor.

  Further, in a state where the developing cartridge is mounted on the drum cartridge, the developing cartridge is moved between a contact position where the developing roller contacts the photosensitive drum and a separating position where the developing roller separates from the photosensitive drum. May be rotatable with respect to the developing coupling.

  The lock lever contacts the developing coupling when the lock lever is located at the lock position, locks the developer cartridge to the drum cartridge, and the lock lever is located at the release position. Alternatively, the developing cartridge may be configured to be separated from the developing coupling and to unlock the developing cartridge from the drum cartridge.

  Further, the developing cartridge may include a developing handle located at the other end of the developing frame in the first direction.

  The developing handle may have a recess that allows a user's finger to be hooked when the user takes out the drum cartridge from the main body housing.

  Further, the drum cartridge may include a pressing member for pressing the developing roller toward the photosensitive drum.

  According to the present invention, the cartridge attaching / detaching operation can be easily performed.

FIG. 1 is a diagram illustrating a schematic configuration of a color printer according to an embodiment of the present invention. FIG. 9 is a perspective view illustrating a state where the developing cartridge is drawn out of a main body housing together with a drum cartridge. FIG. 3A is a perspective view illustrating a developing cartridge, and FIG. 3B is a perspective view illustrating a drum cartridge. FIG. 4 is a perspective view illustrating a state where a developing cartridge is mounted on a drum cartridge. FIG. 4 is a perspective view illustrating a state where a developing cartridge is mounted on a drum cartridge. FIG. 9 is a side view illustrating a state before a developing cartridge is mounted on a drum cartridge. It is a figure (a)-(c) which shows each state of the lock lever which rotates from a lock state to a release state. FIG. 6A is a diagram illustrating a state in which the developing cartridge is located at a contact position, and FIG. It is an exploded perspective view showing a modification of a drum bearing. It is a perspective view showing the state where a drum bearing was assembled to a drum frame.

  Next, an embodiment of the present invention 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 feeding unit 3, an image forming unit 4, and a paper discharging unit 21. The paper supply unit 3 supplies the paper P to the image forming unit 4. The image forming unit 4 forms an image on the sheet P. The paper discharge unit 21 discharges the paper P.

  The paper discharge unit 21 is located above the main body housing 2. The paper discharge unit 21 is located above an intermediate transfer belt 63 described later. The paper discharge unit 21 includes the discharge roller 9 and a paper discharge surface. The discharge roller 9 conveys the paper P toward the discharge surface. The main housing 2 includes a motor M.

  The paper feed unit 3 is located at a lower part in the main body housing 2. The paper feed unit 3 includes a paper feed tray 31 and a paper feed mechanism 32. The paper feed tray 31 is detachable from the main body housing 2. The paper feed mechanism 32 conveys the paper P from the paper feed tray 31 to the image forming unit 4.

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

  The drum cartridge 40 has a photosensitive drum 41, a drum frame F1, and a charger (not shown). The photosensitive drum 41 is rotatable about a second axis X2 extending in the first direction. The four drum cartridges 40 are arranged in a second direction orthogonal to the first direction and the vertical direction.

  The developing cartridge 50 has a developing roller 51 and a developing frame F2. The developing frame F2 contains a developer. The developing roller 51 is rotatable about a first axis X1 extending in the first direction. The four developing cartridges 50 are arranged in the second direction.

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

  The transfer unit 60 is located between the four drum cartridges 40 and the paper discharge unit 21 in a state where the drum cartridges 40 are mounted on the main body housing 2. 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. The intermediate transfer belt 63 is located above the drum cartridge 40 and the developing cartridge 50 when the drum cartridge 40 and the developing cartridge 50 are mounted on the main body housing 2. The driving roller 61 and the driven roller 62 are located inside the intermediate transfer belt 63. The intermediate transfer belt 63 is supported by a driving roller 61 and a driven roller 62 in a state where tension is applied.

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

  First, the charger charges the surface of the photosensitive drum 41. After that, the exposure device SU exposes the surface of the photosensitive drum 41 to light. Thus, an electrostatic latent image is formed on the photosensitive drum 41.

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

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

  As shown in FIG. 2, the drum cartridge 40 is detachable from the main housing 2 together with the developing cartridge 50 in the first direction in a state where the developing cartridge 50 is mounted on the drum cartridge 40. The developing cartridge 50 is detachable from the drum cartridge 40. When the drum cartridge 40 is mounted on the main housing 2 in the first direction together with the developing cartridge 50, the surface of the photosensitive drum 41 comes into contact with the intermediate transfer belt 63 (see FIG. 1).

  As shown in FIG. 3A, the developing cartridge 50 has two projections 52 and 53 and a developing coupling 54. One protrusion 52 is located at one end of the developing roller 51 in the first direction. The other protrusion 53 is located at the other end of the developing roller 51 in the first direction. Each of the projections 52 and 53 is a collar that rotatably supports each end of the shaft of the developing roller 51. The one projection 52 projects from the first outer development surface of the development frame F2. The other protrusion 53 projects from the second outer development surface of the development frame F2.

  The developing coupling 54 is a coupling that receives a driving force from the motor M (see FIG. 1). The developing coupling 54 is rotatable together with the developing roller 51. The developing coupling 54 is located at one end of the developing frame F2 in the first direction.

  As shown in FIG. 3B, the drum cartridge 40 includes two drum bearings 42 and 43, a drum coupling 44, a lock lever 45, two pressing members 46 and 47, and two springs S1 and S2. And Each of the drum bearings 42 and 43 constitutes each side wall of the drum frame F1 in the first direction.

  One drum bearing 42 is located at one end of the photosensitive drum 41 in the first direction. The other drum bearing 43 is located at the other end of the photosensitive drum 41 in the first direction. Each of the drum bearings 42 and 43 rotatably supports the photosensitive drum 41. One drum bearing 42 has an opening 42A from which the drum coupling 44 is exposed.

  Each drum bearing 42, 43 has guide grooves G1, G2. As shown in FIGS. 4 and 5, the guide grooves G1 and G2 are grooves into which the projections 52 and 53 fit when the developing cartridge 50 is mounted on the drum cartridge 40. Each guide groove G1, G2 has the same shape. In the following description, the structure of the guide groove G1 will be described in detail, and description of the guide groove G2 will be omitted.

  The guide groove G1 has a first groove G11 and a second groove G12. The first groove G11 extends linearly. Specifically, the first groove G11 extends along the second direction. The second direction is a direction in which the photosensitive drum 41 and the developing roller 51 are arranged in a state where the drum cartridge 40 and the developing cartridge 50 are mounted on the apparatus main body 1. The first groove G11 has one end and the other end farther from the drum coupling 44 than the one end. The second groove G12 extends obliquely from the other end of the first groove G11 in a direction away from the drum coupling 44 and downward.

  As shown in FIG. 6, when the developing cartridge 50 is mounted on the drum cartridge 40, the projection 52 of the developing cartridge 50 is guided by the guide groove G1. Thus, the developing cartridge 50 is mounted on the drum cartridge 40.

  As shown in FIG. 4, the drum coupling 44 is a coupling that receives a driving force from the motor M (see FIG. 1). The drum coupling 44 is rotatable together with the photosensitive drum 41. The drum coupling 44 is located at one end of the photosensitive drum 41 in the first direction.

  As shown in FIGS. 7A to 7C, the lock lever 45 is rotatable about a third axis X3 extending in the first direction. The lock lever 45 is rotatable between a lock position shown in FIG. 7A and a release position shown in FIG. 7C. The lock position is a position where the developing cartridge 50 is locked to the drum cartridge 40 when the developing cartridge 50 is mounted on the drum cartridge 40. The release position is a position where the lock of the developing cartridge 50 to the drum cartridge 40 is released when the developing cartridge 50 is mounted on the drum cartridge 40.

  The lock lever 45 is located at one end of the drum frame F1 in the first direction (see FIG. 3). When the lock lever 45 is located at the lock position, the lock lever 45 contacts the developing coupling 54 and locks the developing cartridge 50 to the drum cartridge 40. When the lock lever 45 is located at the release position, the lock lever 45 separates from the developing coupling 54 and releases the lock of the developing cartridge 50 to the drum cartridge 40.

  Specifically, the lock lever 45 has a concave portion 45A. When the lock lever 45 is located at the lock position, the developing coupling 54 enters the recess 45A. Thus, in a state where the lock lever 45 is located at the lock position, the concave portion 45A rotatably supports the developing coupling 54. The concave portion 45A separates from the developing coupling 54 when the lock lever 45 is located at the release position.

  If there is a cover that covers the outer surface of the developing coupling 54, the lock lever 45 may lock the cover.

  As shown in FIG. 3B, the pressing members 46 and 47 are members for pressing the developing roller 51 toward the photosensitive drum 41. One pressing member 46 is located at one end of the drum frame F1 in the first direction. The other pressing member 47 is located at the other end of the drum frame F1 in the first direction. The spring S1 is located between the pressing member 46 and the drum frame F1. The spring S2 is located between the pressing member 47 and the drum frame F1. The spring S1 presses the pressing member 46 toward the developing cartridge 50. The spring S2 presses the pressing member 47 toward the developing cartridge 50. The spring S1 biases the pressing member 46 in a direction along the first groove G11 of the guide groove G1. The spring S2 biases the pressing member 47 in a direction along the first groove G11 of the guide groove G1.

  As shown in FIG. 7A, in a state where the drum cartridge 40 and the developing cartridge 50 are mounted on the main body housing 2 and the lock lever 45 is in the lock position, the pressing members 46 and 47 are , Is located below the developing coupling 54. In a state where the drum cartridge 40 and the developing cartridge 50 are mounted on the main body housing 2 and the lock lever 45 is located at the locked position, the developing roller 51 is positioned above the developing coupling 54. I do.

  In a state in which the drum cartridge 40 and the developing cartridge 50 are mounted on the main body housing 2 and the lock lever 45 is in the locked position, the pressing members 46 and 47 are moved to the lower part of the developing frame F2 of the developing cartridge 50. Is pressed in one of the second directions. As a result, the developing cartridge 50 rotates about the developing coupling 54, and the developing roller 51 is pressed against the photosensitive drum 41.

  With the developing cartridge 50 attached to the drum cartridge 40, the developing cartridge 50 rotates the developing coupling 54 between a contact position shown in FIG. 8A and a separated position shown in FIG. It is possible to move. The contact position is a position where the developing roller 51 and the photosensitive drum 41 are in contact. The separation position is a position where the developing roller 51 and the photosensitive drum 41 are separated.

  The developing cartridge 50 is rotated from the separated position to the contact position by the pressing members 46 and 47. Further, the developing cartridge 50 is rotated from the contact position to the separated position by a separating mechanism of the main body housing 2 (not shown). Note that, for example, a mechanism that presses the projections 52 and 53 of the developing cartridge 50 in a direction away from the photosensitive drum 41 can be adopted as the separating mechanism.

  As shown in FIG. 5, the developing cartridge 50 has a developing handle 55. The developing handle 55 is located at the other end of the developing frame F2 in the first direction. The developing handle 55 has a recess 55A. The recess 55 </ b> A allows the user's finger to be hooked when the user takes out the drum cartridge 40 from the main body housing 2.

  As shown in FIG. 2, the drum cartridge 40 has a drum handle 48. The drum handle 48 has a recess 48A. The recess 48 </ b> A allows a user's finger to be hooked when the user takes out the drum cartridge 40 from the main body housing 2. The drum bearing 43 is located between the photosensitive drum 41 and the drum handle 48 in the first direction.

Next, a method of replacing the drum cartridge 40 and the developing cartridge 50 will be described.
For example, when the developer in the developing cartridge 50 becomes empty, as shown in FIG. 2, the user removes the developing cartridge 50 together with the drum cartridge 40 from the main housing 2 in the first direction. Next, the user removes the developing cartridge 50 from the drum cartridge 40 after rotating the lock lever 45 from the lock position to the release position (see FIG. 7).

  Thereafter, a new developing cartridge 50 is mounted on the drum cartridge 40. Then, the developing cartridge 50 is mounted on the main housing 2 in the first direction together with the drum cartridge 40. In order to replace the drum cartridge 40 with a new one, the developing cartridge 50 in use may be attached to the new drum cartridge 40 in the above-described method, and the drum cartridge 40 may be mounted on the main body housing 2.

According to the above, the following effects can be obtained in the present embodiment.
Since the developing cartridge 50 and the drum cartridge 40 can be taken out from the main housing 2 in the first direction, the attaching / detaching operation of the cartridge can be easily performed. Further, since the developing cartridge 50 can be removed from the drum cartridge 40, the developing cartridge 50 and the drum cartridge 40 can be individually exchanged.

  Since the drum bearings 42 and 43 have the guide grooves G1 and G2, the positioning accuracy between the developing roller 51 and the photosensitive drum 41 can be improved.

  Note that the present invention is not limited to the above embodiment, but can be used in various forms as exemplified below. In the following description, members having the same structure as in the above embodiment are denoted by the same reference numerals, and description thereof will be omitted.

  In the above embodiment, each side wall in the first direction of the drum frame F1 is configured by each of the drum bearings 42 and 43, but the present invention is not limited to this. For example, as shown in FIGS. 9 and 10, each of the drum bearings BR1, BR2 may be configured separately from each of the side walls F11, F12 in the first direction of the drum frame F1. Here, illustration of the photosensitive drum 41 is omitted in FIGS. 9 and 10.

  Hereinafter, each of the drum bearings BR1 and BR2 will be described in detail. Since the drum bearings BR1 and BR2 have the same structure, in the following description, the structure of the drum bearing BR1 will be described in detail, and the description of the drum bearing BR2 will be omitted.

  The drum bearing BR1 is located at one end of the photosensitive drum 41 in the first direction. The drum bearing BR1 has an opening BR11, a guide groove BR12, and two bosses BR13, BR14. The opening BR11 is an opening from which the drum coupling 44 is exposed. The opening BR11 is circular.

  The guide groove BR12 extends linearly. The guide groove BR12 extends along the second direction. The guide groove BR12 has one end and the other end farther from the opening BR11 than the one end.

  The drum bearing BR1 is located inside the side wall F11 of the drum frame F1 in the first direction. Each boss BR13, BR14 protrudes toward the side wall F11 of the drum frame F1.

  The side wall F12 has the same guide groove G1 and opening 42A as in the above embodiment, and two holes H1 and H2. The boss BR13 fits into the hole H1. The boss BR14 fits into the hole H2.

  As described above, also in this embodiment, since the drum bearing BR1 has the guide groove BR12, the positioning accuracy between the developing roller 51 and the photosensitive drum 41 can be improved.

  In the above-described embodiment, the projections 52 and 53 are formed as collars that fit into the respective ends of the shaft of the developing roller 51, but the present invention is not limited to this. For example, the protrusion may be the shaft of the developing roller itself. When the pressing member is a spring or rubber, the springs S1 and S2 may not be provided.

  In the above embodiment, the pressing members 46 and 47 are rectangular members urged by the springs S1 and S2, but the present invention is not limited to this. For example, the pressing member may be a spring or rubber.

  In the above-described embodiment, the present invention is applied to the color printer 1, but the present invention is not limited to this, and the present invention may be applied to other image forming apparatuses, for example, a monochrome printer, a copier, a multifunction peripheral, and the like. Good.

  The components described in the embodiment and the modified examples described above may be implemented in any combination.

DESCRIPTION OF SYMBOLS 1 Color printer 2 Main body housing 40 Drum cartridge 41 Photosensitive drum 50 Developing cartridge 51 Developing roller 63 Intermediate transfer belt F1 Drum frame F2 Developing frame X1 First axis X2 Second axis

Claims (14)

A main body housing,
A developing cartridge having a developing roller rotatable about a first axis extending in a first direction, and a developing frame for storing a developer, wherein the developing cartridge is detachable from a drum cartridge;
A drum cartridge comprising: a photosensitive drum rotatable about a second axis extending in the first direction; and a drum frame, wherein the developing cartridge is mounted on the drum cartridge, and the drum cartridge is mounted together with the developing cartridge. A drum cartridge that is detachably attached to the main body housing in the first direction;
An intermediate transfer belt positioned above the drum cartridge and the developing cartridge when the drum cartridge and the developing cartridge are mounted on the main body housing, wherein the drum cartridge and the developing cartridge are the first transfer belt; And an intermediate transfer belt that is in contact with the surface of the photosensitive drum when mounted on the main body housing in a direction.   The image forming apparatus according to claim 1, further comprising a paper discharge unit located above the intermediate transfer belt. The developing cartridge has a protrusion located at one end of the developing roller in the first direction,
The drum cartridge has a guide groove located at one end of the drum frame in the first direction, and the guide groove fits with the protrusion when the developing cartridge is mounted on the drum cartridge. The image forming apparatus according to claim 1 or 2, wherein The drum cartridge is a drum bearing located at one end of the photosensitive drum in the first direction, and has a drum bearing rotatably supporting the photosensitive drum,
The image forming apparatus according to claim 3, wherein the drum bearing has the guide groove. The drum cartridge is a drum coupling located at the one end of the photosensitive drum in the first direction, and has a drum coupling rotatable with the photosensitive drum,
The image forming apparatus according to claim 4, wherein the drum bearing has an opening through which the drum coupling is exposed. The drum cartridge has a drum handle,
The image forming apparatus according to claim 4, wherein the drum bearing is located between the photosensitive drum and the drum handle in the first direction.   The image forming apparatus according to claim 6, wherein the drum handle has a recess that allows a user's finger to be hooked when the user takes out the drum cartridge from the main body housing.   The drum cartridge is between a lock position for locking the developer cartridge to the drum cartridge and a release position for releasing the lock of the developer cartridge to the drum cartridge in a state where the developer cartridge is mounted on the drum cartridge. A lock lever rotatable about a third axis extending in the first direction, the lock lever being located at one end of the drum frame in the first direction. Item 8. The image forming apparatus according to any one of items 7. The main body housing includes a motor,
The developing cartridge is a developing coupling located at one end of the developing frame in the first direction, the developing coupling being rotatable with the developing roller, and receiving a driving force from the motor. The image forming apparatus according to claim 8, further comprising:   In a state where the developing cartridge is mounted on the drum cartridge, the developing cartridge moves between a contact position where the developing roller and the photosensitive drum are in contact with each other, and a separating position where the developing roller and the photosensitive drum are separated from each other. The image forming apparatus according to claim 9, wherein the image forming apparatus is rotatable about the developing coupling. The lock lever is
When the lock lever is at the lock position, the lock lever comes into contact with the developing coupling to lock the developing cartridge to the drum cartridge;
11. The image according to claim 9, wherein when the lock lever is located at the release position, the lock lever is separated from the developing coupling to release the lock of the developing cartridge to the drum cartridge. Forming equipment.   The image forming apparatus according to claim 9, wherein the developing cartridge has a developing handle located at the other end of the developing frame in the first direction.   13. The image forming apparatus according to claim 12, wherein the developing handle has a recess that allows a user's finger to be hooked when the user takes out the drum cartridge from the main body housing.   The image forming apparatus according to any one of claims 1 to 13, wherein the drum cartridge includes a pressing member that presses the developing roller toward the photosensitive drum.

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