Image forming device

Abstract

To prevent interference between a development cartridge and a drum cartridge.SOLUTION: An image forming apparatus 1 includes a drum cartridge 40, a development cartridge 50, a body housing 2, a cover 2A, a first inside surface 21A, and a second inside surface 22A. The body housing 2 allows the drum cartridge 40 and the development cartridge 50 to be attached / detached in an axial direction. The second inside surface 22A is farther from the cover 2A than the first inside surface 21A. A development housing 52 includes: a first contact surface 53B which comes into contact with the first inside surface 21A when the development cartridge 50 is mounted with the drum cartridge 40 mounted thereon; and a second contact surface 54B which comes into contact with the second inside surface 22A when the development cartridge 50 is mounted on the slot 20 with the drum cartridge 40 mounted on the slot 20. A first contact position between the first inside surface 21A and the first contact surface 53B is farther from a developing roller 51 than a second contact position between the second inside surface 22A and the second contact surface 54B.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to an image forming apparatus including a detachable drum cartridge and a developing cartridge. [Background technology]

[0002] Conventionally, there is known an image forming apparatus in which a drum cartridge and a developing cartridge are detachable from a main body casing in the axial direction of a photosensitive drum (see Patent Document 1). In this technology, the drum cartridge and the developing cartridge are each detachable from the main body casing separately. In this image forming apparatus, after the drum cartridge and the developing cartridge are installed, the developing roller is pressed against the photosensitive drum. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-173805 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional technology, for example, when a developer cartridge is installed while a drum cartridge is already installed in the main housing, there is a possibility that the developer cartridge and the drum cartridge may interfere with each other during the process of installing the developer cartridge into the main housing.

[0005] Therefore, the present disclosure aims to prevent interference between the developing cartridge and the drum cartridge when the developing cartridge is attached axially in an image forming device that has a drum cartridge and a developing cartridge that are individually detachable in the axial direction while the drum cartridge is attached to the main body housing of the image forming device. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the image forming apparatus of the present invention includes a drum cartridge, a developer cartridge, a main housing, a cover, a first inner surface, and a second inner surface. The drum cartridge has a photosensitive drum that is rotatable about a first axis extending in the axial direction. The developer cartridge has a developer roller that is rotatable about a second axis extending in the axial direction, and a developer housing that can store toner. The main housing has a slot that extends in the axial direction, and the slot allows the drum cartridge to be attached and detached in the axial direction, and also allows the developer cartridge to be attached and detached in the axial direction. The cover has a closed state that closes the slot and an open state that opens the slot. The first inner surface is located inside the slot. The second inner surface is located inside the slot and is located farther from the cover in the axial direction than the first inner surface. The developing housing further includes a first contact surface that comes into contact with the first inner surface when the developing cartridge is installed in the slot with the drum cartridge installed in the slot, and a second contact surface that comes into contact with the second inner surface when the developing cartridge is installed in the slot with the drum cartridge installed in the slot. A first contact position between the first inner surface and the first contact surface is farther from the developing roller than a second contact position between the second inner surface and the second contact surface. The image forming apparatus further includes a pressing member that presses the developing roller against the photosensitive drum with the first inner surface in contact with the first contact surface and the second inner surface in contact with the second contact surface.

[0007] According to this configuration, in an image forming apparatus having a detachable drum cartridge and a detachable developing cartridge, the developing roller can be pressed against the photosensitive drum with a simple configuration.

[0008] In the above-described configuration, the image forming device may further include an intermediate transfer belt that is positioned above the drum cartridge and the developing cartridge when the drum cartridge and the developing cartridge are attached to the main body housing, and that comes into contact with the surface of the photosensitive drum when the drum cartridge and the developing cartridge are attached to the main body housing.

[0009] In the above-described configuration, the image forming apparatus may further include a discharge section located above the intermediate transfer belt and into which the recording sheet is discharged.

[0010] In the above-described configuration, when the drum cartridge is attached to the main body casing, the first inner surface may be positioned farther from the photosensitive drum than the second inner surface.

[0011] In the above-described configuration, the first contact surface may be positioned farther from the developing roller than the second contact surface.

[0012] In the above-described configuration, when the developing cartridge is installed in the slot with the drum cartridge installed in the main body casing, the second contact surface may not come into contact with the first inner surface.

[0013] This makes it easy to insert the developing cartridge into the slot.

[0014] In the above-described configuration, the first inner surface may be located at the tip of a first protruding portion that protrudes from the slot, and the second inner surface may be located at the tip of a second protruding portion that protrudes from the slot.

[0015] In the above-described configuration, the pressing member may include a first pressing member and a second pressing member, and the first contact surface may be located at the tip of the first pressing member, and the second contact surface may be located at the tip of the second pressing member.

[0016] In the above-described configuration, the pressing member may include a first pressing member and a second pressing member, and the first inner surface may be located at the tip of the first pressing member, and the second inner surface may be located at the tip of the second pressing member.

[0017] In the above-described configuration, the first contact surface may be located at the tip of a first protruding portion that protrudes from the developing housing, and the second contact surface may be located at the tip of a second protruding portion that protrudes from the developing housing.

[0018] In the above-described configuration, the main body housing may have a first inclined surface located on one axial side of the first inner surface, and the first inclined surface may extend away from the developing roller as it approaches the cover from the first inner surface when the drum cartridge and the developing cartridge are attached to the main body housing.

[0019] According to this, the first inclined surface guides the first contact surface to the first inner surface, making it easier to mount the developer cartridge.

[0020] In the above-described configuration, the main housing may have a second inclined surface located on one axial side of the second inner surface, and the second inclined surface may extend away from the developing roller as it approaches the cover from the second contact surface when the drum cartridge and the developing cartridge are attached to the main housing.

[0021] According to this, the second inclined surface guides the second contact surface to the second inner surface, making it easier to mount the developer cartridge.

[0022] In the above-described configuration, the slot may have a guide portion that guides the developer cartridge when the developer cartridge is installed, and the guide portion may be configured to prevent the developer roller from contacting the photosensitive drum when the developer cartridge is installed or removed, and to allow contact between the developer roller and the photosensitive drum when the developer cartridge is installed in the slot. [Effects of the Invention]

[0023] According to the present disclosure, when a developer cartridge is mounted axially while the drum cartridge is mounted in the main body housing of an image forming apparatus, interference between the developer cartridge and the drum cartridge can be suppressed. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a diagram illustrating a schematic configuration of an image forming apparatus according to a first embodiment of the present disclosure. [Figure 2] FIG. 10 is a diagram showing the drum cartridge and the developing cartridge being inserted into the slots. [Figure 3] FIG. 2 is a perspective view of the slot, the drum cartridge, and the developing cartridge as viewed from above. [Figure 4] 3A and 3B are diagrams illustrating a mechanism for pressing a developing roller against a photosensitive drum. [Figure 5] FIG. 2 is a perspective view of the slot, the drum cartridge, and the developing cartridge as seen from below. [Figure 6] 10A to 10D are diagrams illustrating the action when the developing cartridge is attached to the slot. [Figure 7] FIG. 10 is a perspective view of a slot, a drum cartridge, and a developing cartridge according to a second embodiment. [Figure 8] FIG. 11 is a perspective view of a slot, a drum cartridge, and a developing cartridge according to a third embodiment. [Figure 9] FIG. 10 is a perspective view of a slot, a drum cartridge, and a developing cartridge according to a fourth embodiment. [Figure 10] FIG. 10 is a diagram showing a first inclined surface and a second inclined surface according to a first modified example. [Figure 11] The slot, drum cartridge, and developing cartridge according to the second modified example (a) and the third modified example (b). [Figure 12] The slot, drum cartridge, and developing cartridge according to the fourth modified example (c) and the fifth modified example (d). DETAILED DESCRIPTION OF THE INVENTION

[0025] Next, the first embodiment of the present disclosure will be described in detail with reference to the drawings as appropriate. As shown in Fig. 1, the image forming apparatus 1 is a color printer. The image forming apparatus 1 includes a main body housing 2, a supply unit 3, an image forming unit 4, and discharge rollers 9. The supply unit 3 supplies a recording sheet S to the image forming unit 4. The image forming unit 4 forms an image on the recording sheet S. The discharge rollers 9 discharge the recording sheet S.

[0026] The main body housing 2 has a discharge section 2E at its top. The recording sheet S is discharged to the discharge section 2E. The discharge section 2E is located above an intermediate transfer belt 63, which will be described later.

[0027] The supply unit 3 is located at the bottom inside the main body housing 2. The supply unit 3 includes a supply tray 31 and a supply mechanism 32. The supply tray 31 is detachable from the main body housing 2. The supply mechanism 32 transports the recording sheet S from the supply tray 31 to the image forming unit 4.

[0028] The image forming unit 4 includes a drum cartridge 40, a developing cartridge 50, an exposure device SU, a transfer unit 60, and a fixing unit 70. A plurality of drum cartridges 40 and developing cartridges 50 are arranged corresponding to the number of toner colors. In this embodiment, four drum cartridges 40 and four developing cartridges 50 are arranged side by side.

[0029] Each drum cartridge 40 has a photosensitive drum 41, a frame 42, and a charger (not shown). The photosensitive drum 41 is rotatable about a first axis X1 extending in the axial direction. The four photosensitive drums 41 are aligned in an orthogonal direction (hereinafter simply referred to as the "orthogonal direction") that is perpendicular to the axial direction and the up-down direction. The frame 42 supports the photosensitive drums 41 so that they can rotate. Each drum cartridge 40 is independently attachable to and detachable from the main body casing 2 in the axial direction.

[0030] When the drum cartridge 40 and the developer cartridge 50 are attached to the main body casing 2, the drum cartridge 40 is aligned with the developer cartridge 50 in the orthogonal direction. In this embodiment, the drum cartridge 40 is located on one side of the developer cartridge 50 in the orthogonal direction (the right side in FIG. 1). The developer cartridge 50 is located on the other side of the drum cartridge 40 in the orthogonal direction (the left side in FIG. 1).

[0031] Each developer cartridge 50 contains a different color toner. Each developer cartridge 50 has a developer roller 51 and a developer housing 52. The developer roller 51 is rotatable about a second axis X2 extending in the axial direction. The developer housing 52 is capable of containing toner. The four developer rollers 51 are arranged in an orthogonal direction. The developer cartridges 50 are each independently attachable to and detachable from the main body housing 2 in the axial direction.

[0032] The exposure unit SU is located below each drum cartridge 40. The exposure unit SU emits a laser beam (not shown) onto each photosensitive drum 41.

[0033] The transfer unit 60 is located between the four photosensitive drums 41 and the discharge unit 2E. 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.

[0034] The intermediate transfer belt 63 is an endless belt. When the drum cartridge 40 and the developer cartridge 50 are attached to the main body housing 2, the intermediate transfer belt 63 is located above 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 surface of the photosensitive drum 41 comes into contact with the intermediate transfer belt 63. The intermediate transfer belt 63 is stretched between a drive roller 61 and a driven roller 62.

[0035] 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 therebetween.

[0036] 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 therebetween.

[0037] 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. The pressure roller 72 is pressed against the heating roller 71.

[0038] In the image forming unit 4, first, the surface of the photosensitive drum 41 is charged by a charger. Then, the exposure device SU exposes the surface of the photosensitive drum 41 to light. As a result, an electrostatic latent image is formed on the photosensitive drum 41.

[0039] Next, the developing roller 51 supplies toner to the electrostatic latent image on the photosensitive drum 41. As a result, a toner image is formed on the photosensitive drum 41. Then, the toner image on the photosensitive drum 41 is transferred onto the intermediate transfer belt 63.

[0040] When the recording sheet S passes between the intermediate transfer belt 63 and the secondary transfer roller 65, the toner image on the intermediate transfer belt 63 is transferred onto the recording sheet S. Thereafter, the toner image on the recording sheet S is fixed by a fixing unit 70. Next, the recording sheet S is discharged to a discharge section 2E by a discharge roller 9.

[0041] As shown in FIG. 2, the main body housing 2 has a cover 2A and a slot 20.

[0042] The cover 2A is provided at one axial end of the main body housing 2. The cover 2A can be opened and closed. The cover 2A has a closed state in which the slot 20 is closed, and an open state in which the slot 20 is open.

[0043] A slot 20 is provided corresponding to each drum cartridge 40 and each developer cartridge 50. Each slot 20 extends in the axial direction. One axial side of each slot 20 is open. Each slot 20 allows the drum cartridge 40 to be attached and detached in the axial direction, and also allows the developer cartridge 50 to be attached and detached in the axial direction. One drum cartridge 40 and one developer cartridge 50 can be attached to each slot 20.

[0044] As shown in FIG. 3, each slot 20 has a first wall 20A, a second wall 20B, and a third wall 20C. The first wall 20A extends in the axial direction and the vertical direction. The second wall 20B faces the first wall 20A and is positioned a predetermined distance perpendicular to the first wall 20A. The second wall 20B also extends in the axial direction and the vertical direction. The third wall 20C connects one end of the first wall 20A to one end of the second wall 20B.

[0045] The second wall 20B has a first protrusion 21 and a second protrusion 22. The first protrusion 21 and the second protrusion 22 are located inside the slot 20. The first protrusion 21 protrudes from the second wall 20B. The second protrusion 22 protrudes from the second wall 20B. The first protrusion 21 is located at an end on one side in the axial direction. The second protrusion 22 is located at an end on the other side in the axial direction. In other words, the second protrusion 22 is located farther from the cover 2A in the axial direction than the first protrusion 21 (see FIG. 2).

[0046] 4, the first protrusion 21 has a first inner surface 21A and a first inclined surface 21B. The first inner surface 21A and the first inclined surface 21B are located inside the slot 20. The first inner surface 21A protrudes from the inner surface of the slot 20. The first inner surface 21A is located at the tip of the first protruding portion 21. The first inclined surface 21B is located on one axial side of the first inner surface 21A. When the drum cartridge 40 and the developer cartridge 50 are attached to the main body housing 2, the first inclined surface 21B extends from the first inner surface 21A so as to move away from the developing roller 51 as it approaches the cover 2A.

[0047] The second protruding portion 22 has a second inner surface 22A and a second inclined surface 22B. The second inner surface 22A and the second inclined surface 22B are located inside the slot 20. The second inner surface 22A protrudes from the inner surface of the slot 20. The second inner surface 22A is located at the tip of the second protruding portion 22. The second inner surface 22A is located farther from the cover 2A in the axial direction than the first inner surface 21A (see FIG. 2). The second inclined surface 22B is located on one side of the second inner surface 22A in the axial direction. When the drum cartridge 40 and the developer cartridge 50 are attached to the main housing 2, the second inclined surface 22B extends from the second inner surface 22A toward the cover 2A and away from the developing roller 51.

[0048] In this embodiment, the first inclined surface 21B and the second inclined surface 22B have the same inclination angle.

[0049] 4, when the drum cartridge 40 is attached to the main body housing 2, the distance L3 from the first inner surface 21A to the photosensitive drum 41 is greater than the distance L4 from the second inner surface 22A to the photosensitive drum 41. In other words, when the drum cartridge 40 is attached to the main body housing 2, the first inner surface 21A is located farther from the photosensitive drum 41 than the second inner surface 22A.

[0050] As shown in FIG. 5, the third wall 20C has a first guide portion 80, a second guide portion 90, and a slit SL.

[0051] The first guide portion 80 has a first rail 81 and a second rail 82. The first rail 81 and the second rail 82 are located inside the slot 20. The first rail 81 and the second rail 82 protrude from the third wall 20C. The first rail 81 and the second rail 82 extend from one axial end of the slot 20 to the other axial end. When the drum cartridge 40 is installed or removed, the first rail 81 and the second rail 82 guide the drum cartridge 40 in the axial direction and restrict the drum cartridge 40 from moving in the perpendicular direction. Furthermore, when the drum cartridge 40 is installed, the first rail 81 and the second rail 82 restrict the drum cartridge 40 from moving in the perpendicular direction.

[0052] The second guide portion 90 is an example of a guide portion that guides the developer cartridge when the developer cartridge is installed. The second guide portion 90 prevents the developer roller 51 from contacting the photosensitive drum 41 when the developer cartridge 50 is installed or removed, and allows the developer roller 51 and the photosensitive drum 41 to contact each other when the developer cartridge 50 is installed in the slot 20.

[0053] The second guide portion 90 has a third rail 91 and a fourth rail 92. The third rail 91 and the fourth rail 92 are located inside the slot 20. The third rail 91 and the fourth rail 92 protrude from the third wall 20C. The third rail 91 and the fourth rail 92 extend from one end of the slot 20 in the axial direction to the other end. The first rail 81, the second rail 82, the third rail 91, and the fourth rail 92 are arranged in parallel in this order from one end in the perpendicular direction.

[0054] The third rail 91 includes a first rail portion 91X, a second rail portion 91Y, and a third rail portion 91Z. A first opening 91A is located between the first rail portion 91X and the second rail portion 91Y in the axial direction. A second opening 91B is located between the second rail portion 91Y and the third rail portion 91Z in the axial direction. The first opening 91A is located at one axial end of the slot 20. The second opening 91B is located at the other axial end of the slot 20. The axial dimension K1 of the first opening 91A is smaller than the axial dimension K2 of the second opening 91B (see FIG. 3).

[0055] The fourth rail 92 protrudes from the third wall 20C. Specifically, the fourth rail 92 has a first portion 92A and a second portion 92B. The first portion 92A protrudes upward from the third wall 20C. The second portion 92B extends from the upper end of the first portion 92A toward one side in the perpendicular direction.

[0056] The third rail 91 and the fourth rail 92 guide the developer cartridge 50 in the axial direction and restrict it from moving in the perpendicular direction when the developer cartridge 50 is installed or removed. Furthermore, when the developer cartridge 50 is installed or removed, the fourth rail 92 engages with a first engagement portion 55 and a second engagement portion 56 (described later) to restrict the developer cartridge 50 from moving in the up and down direction.

[0057] The slit SL extends in the axial direction and allows the laser light emitted from the exposure device SU to pass through.

[0058] As shown in FIG. 5, the developer cartridge 50 has a first pressing member 53, a second pressing member 54, a first engagement portion 55, a second engagement portion 56, and a pivotal support portion 57.

[0059] As shown in Fig. 4, the developing housing 52 has a first hole 52A and a second hole 52B. The first hole 52A and the second hole 52B are open to the other side in the perpendicular direction. The first hole 52A is located at one end of the developing housing 52 in the axial direction. The second hole 52B is located at the other end of the developing housing 52 in the axial direction. A flange 52C is provided on the edge of the first hole 52A to prevent the first pressing member 53 from coming off. A flange 52D is provided on the edge of the second hole 52B to prevent the second pressing member 54 from coming off.

[0060] The first pressing member 53 engages with the first hole 52A and is held slidably in the orthogonal direction. A flange 53A provided at the base end of the first pressing member 53 comes into contact with a flange 52C of the first hole 52A, preventing the first pressing member 53 from slipping out of the first hole 52A. A first contact surface 53B located at the tip of the first pressing member 53 protrudes from the developing housing 52. The first contact surface 53B is rounded when viewed from above. A spring 53S is provided between the base end surface of the first pressing member 53 and the bottom of the first hole 52A. The spring 53S constantly biases the first pressing member 53 toward the other side in the orthogonal direction.

[0061] When the developer cartridge 50 is installed in the slot 20, the tip of the first pressing member 53 comes into contact with the first inner surface 21A of the slot 20 at a first contact surface 53B. The first contact surface 53B is the surface that comes into contact with the first inner surface 21A when the developer cartridge 50 is installed in the slot 20 with the drum cartridge 40 installed in the slot 20.

[0062] The second pressing member 54 engages with the second hole 52B and is held slidably in the orthogonal direction. A flange 54A provided at the base end of the second pressing member 54 comes into contact with a flange 52D of the second hole 52B, preventing the second pressing member 54 from slipping out of the second hole 52B. A second contact surface 54B located at the tip of the second pressing member 54 protrudes from the developing housing 52. The second contact surface 54B is rounded when viewed from above. A spring 54S is provided between the base end surface of the second pressing member 54 and the bottom of the second hole 52B. The spring 54S constantly biases the second pressing member 54 toward the other side in the orthogonal direction.

[0063] When the developer cartridge 50 is installed in the slot 20, the tip of the second pressing member 54 comes into contact with the second inner surface 22A of the slot 20 at the second contact surface 54B. The second contact surface 54B is the surface that comes into contact with the second inner surface 22A when the developer cartridge 50 is installed in the slot 20 with the drum cartridge 40 installed in the slot 20.

[0064] When the developer cartridge 50 is not installed in the slot 20, the distance L1 from the first contact surface 53B to the developer roller 51 is greater than the distance L2 from the second contact surface 54B to the developer roller 51. In other words, when the developer cartridge 50 is not installed in the slot 20, the first contact surface 53B is located farther from the developer roller 51 than the second contact surface 54B.

[0065] The distance L3 from the first inner surface 21A to the developing roller 51 is greater than the distance L4 from the second inner surface 22A to the developing roller 51.

[0066] When the drum cartridge 40 and the developer cartridge 50 are installed in the slot 20, the distance L3 from the first contact surface 53B to the developer roller 51 is greater than the distance L4 from the second contact surface 54B to the developer roller 51. In other words, when the drum cartridge 40 and the developer cartridge 50 are installed in the slot 20, the first contact surface 53B is located farther from the developer roller 51 than the second contact surface 54B.

[0067] When the drum cartridge 40 and the developer cartridge 50 are installed in the slot 20, a distance L3 from a first contact position between the first inner surface 21A and the first contact surface 53B to the developer roller 51 is greater than a distance L4 from a second contact position between the second inner surface 22A and the second contact surface 54B to the developer roller 51. In other words, the first contact position between the first inner surface 21A and the first contact surface 53B is farther from the developer roller 51 than the second contact position between the second inner surface 22A and the second contact surface 54B.

[0068] When the developing cartridge 50 is inserted into the slot 20 with the drum cartridge 40 attached to the main body housing 2, the distance L2 from the tip of the second pressing member 54 (shown by the two-dot chain line in FIG. 4) to the developing roller 51 is smaller than the distance L3 from the first inner surface 21A to the developing roller 51. Therefore, when the developing cartridge 50 is inserted into the slot 20 with the drum cartridge 40 attached to the main body housing 2, the second contact surface 54B does not come into contact with the first inner surface 21A (see FIG. 6(a)).

[0069] The first pressing member 53 and the second pressing member 54 are an example of a pressing member. In the present embodiment, the pressing member includes the first pressing member 53 and the second pressing member 54. The first pressing member 53 and the second pressing member 54 press the developing roller 51 against the photosensitive drum 41 in a state in which the first inner surface 21A contacts the first contact surface 53B and the second inner surface 22A contacts the second contact surface 54B.

[0070] 5, the first engagement portion 55 is located on the lower surface of the developing housing 52. The first engagement portion 55 has a first main body portion 55A and a first extension portion 55B. The first main body portion 55A protrudes downward from the lower surface of the developing housing 52. The first extension portion 55B extends from the lower end of the first main body portion 55A to the other end side in the perpendicular direction.

[0071] The first main body portion 55A has a first surface 55C and a second surface 55D. The first surface 55C extends along the axial direction. The first surface 55C is the surface that comes into contact with the third rail 91 during the process of installing or removing the developer cartridge 50. The second surface 55D extends at an angle from the first surface 55C. Specifically, the second surface 55D extends at an angle relative to the axial direction so as to extend from the end of the first surface 55C toward one side in the axial direction and then toward the other side in the perpendicular direction. The second surface 55D is the surface that comes into contact with the first rail portion 91X of the third rail 91 when the developer cartridge 50 is pulled out of the slot 20.

[0072] First main body portion 55A is a portion that is restricted by third rail 91 so as not to move to one side in the orthogonal direction. First extension portion 55B is restricted by first portion 92A of fourth rail 92 so as not to move to the other side in the orthogonal direction, and is restricted by second portion 92B of fourth rail 92 so as not to move upward.

[0073] The axial dimension K3 of the first engagement portion 55 is smaller than the axial dimension K4 of the second engagement portion 56. The axial dimension K3 of the first engagement portion 55 is smaller than the axial dimension K1 of the first opening 91A. The axial dimension K3 of the first engagement portion 55 is smaller than the axial dimension K2 of the second opening 91B.

[0074] The second engagement portion 56 is located on the lower surface of the developing housing 52. The second engagement portion 56 has a second main body portion 56A and a second extension portion 56B. The second main body portion 56A protrudes downward from the lower surface of the developing housing 52. The second extension portion 56B extends from the lower end of the second main body portion 56A to the other end side in the perpendicular direction.

[0075] The second main body portion 56A has a third surface 56C and a fourth surface 56D. The third surface 56C extends along the axial direction. The third surface 56C is the surface that comes into contact with the third rail 91 during the process of installing or removing the developer cartridge 50. The fourth surface 56D extends at an angle from the third surface 56C. Specifically, the fourth surface 56D extends at an angle relative to the axial direction so that the fourth surface 56D extends from the end of the third surface 56C toward one side in the axial direction and then toward the other side in the perpendicular direction. The fourth surface 56D is the surface that comes into contact with the second rail portion 91Y of the third rail 91 when the developer cartridge 50 is pulled out of the slot 20.

[0076] Second main body portion 56A is a portion that is restricted by third rail 91 so as not to move to one side in the orthogonal direction. Second extension portion 56B is restricted by first portion 92A of fourth rail 92 so as not to move to the other side in the orthogonal direction, and is restricted by second portion 92B of fourth rail 92 so as not to move upward.

[0077] The axial dimension K4 of the second engagement portion 56 is larger than the axial dimension K1 of the first opening 91A, and smaller than the axial dimension K2 of the second opening 91B.

[0078] The shaft support portion 57 extends from one axial end face of the developing housing 52 to one orthogonal side. The shaft support portion 57 has an elongated hole 57A. The elongated hole 57A is adapted to engage with a boss 43 provided on one axial end face of the drum cartridge 40.

[0079] Next, the operation of the drum cartridge 40 and the developing cartridge 50 when they are mounted will be described. As shown in FIG. 6(a), first, the drum cartridge 40 is installed in the slot 20. Then, the second engagement portion 56 of the developer cartridge 50 is engaged with the third rail 91 and the fourth rail 92. At this time, the developer roller 51 is not in contact with the photosensitive drum 41. In addition, the second contact surface 54B of the developer cartridge 50 is not in contact with the first inner surface 21A of the slot 20. At this time, the axial dimension K4 of the second engagement portion 56 is larger than the axial dimension K1 of the first opening 91A, so the second engagement portion 56 passes through the first opening 91A without entering it.

[0080] When the developer cartridge 50 is pushed toward the back of the slot 20 from the state shown in Figure 6(a), the first pressing member 53 contacts the first inclined surface 21B of the first protrusion 21, and the second pressing member 54 contacts the second inclined surface 22B of the second protrusion 22, as shown in Figure 6(b).

[0081] When the developer cartridge 50 is pushed toward the back of the slot 20 from the state shown in FIG. 6(b), as shown in FIG. 6(c), the first pressing member 53 is pushed by the first inclined surface 21B and slides toward the developing roller 51, and the second pressing member 54 is pushed by the second inclined surface 22B and slides toward the developing roller 51. At this time, the first engagement portion 55 and the second engagement portion 56 are in contact with the third rail 91. Therefore, the developer cartridge 50 cannot move to one side in the orthogonal direction. As a result, the developing roller 51 is not in contact with the photosensitive drum 41.

[0082] When the developer cartridge 50 is pushed toward the back of the slot 20 from the state shown in FIG. 6(c), as shown in FIG. 6(d), the first pressing member 53 comes into contact with the first inner surface 21A. Similarly, the second pressing member 54 comes into contact with the second inner surface 22A. In this way, the first contact surface 53B of the first pressing member 53 comes into contact with the first inner surface 21A. Furthermore, the second contact surface 54B of the second pressing member 54 comes into contact with the second inner surface 22A. At this time, a portion of the first engagement portion 55 enters the first opening 91A, and a portion of the second engagement portion 56 enters the second opening 91B.

[0083] Next, the operation when removing the developing cartridge 50 will be described. When removing the developer cartridge 50 from the slot 20, the developer cartridge 50 is pulled out to one side in the axial direction from the state shown in Figure 6(d). As a result, the second surface 55D of the first engagement portion 55 comes into contact with the first rail portion 91X of the third rail 91, and the fourth surface 56D of the second engagement portion 56 comes into contact with the second rail portion 91Y of the third rail 91.

[0084] When the developer cartridge 50 is further pulled out from this state, as shown in FIG. 6(c), the second surface 55D of the first engagement portion 55 is pressed against the first rail portion 91X, causing the first engagement portion 55 to move to the other side in the orthogonal direction. This causes the first surface 55C of the first engagement portion 55 to come into contact with the third rail 91. Similarly, the fourth surface 56D of the second engagement portion 56 is pressed against the second rail portion 91Y, causing the second engagement portion 56 to move to the other side in the orthogonal direction. This causes the third surface 56C of the second engagement portion 56 to come into contact with the third rail 91. Therefore, when the developer cartridge 50 is pulled out to one side in the axial direction, the developer cartridge 50 is pressed against the other side in the orthogonal direction, causing the contact between the developing roller 51 and the photosensitive drum 41 to be released.

[0085] Thereafter, the developing cartridge 50 is guided by the third rail 91, and movement to one side in the orthogonal direction is restricted, and the developing roller 51 is pulled out in the axial direction without contacting the photosensitive drum 41.

[0086] According to the image forming apparatus 1 described above, when the drum cartridge 40 is inserted in the slot 20, inserting the developer cartridge 50 into the slot 20 allows the developer roller 51 to press the photosensitive drum 41. Furthermore, when the developer cartridge 50 is mounted axially relative to the main body housing 2 with the drum cartridge 40 mounted in the main body housing 2 of the image forming apparatus 1, interference between the developer cartridge and the drum cartridge can be suppressed.

[0087] Furthermore, when the developing cartridge 50 is inserted into the slot 20 while the drum cartridge 40 is attached to the main body casing 2, the second contact surface 54B does not come into contact with the first inner surface 21A. This makes it easy to insert the developing cartridge 50 into the slot 20.

[0088] Furthermore, when the developer cartridge 50 is installed in the slot 20, the first inclined surface 21B guides the first contact surface 53B to the first inner surface 21A, and the second inclined surface 22B guides the second contact surface 54B to the second inner surface 22A. This makes it easy to install the developer cartridge 50.

[0089] Furthermore, when the developer cartridge 50 is attached or detached, the second guide portion 90 prevents the developer roller 51 from coming into contact with the photosensitive drum 41. Therefore, when the developer cartridge 50 is attached axially to the main body housing 2 with the drum cartridge 40 already attached to the main body housing 2 of the image forming apparatus 1, interference between the developer cartridge and the drum cartridge can be suppressed.

[0090] Next, a second embodiment of the present disclosure will be described. In the following description, members having substantially the same structures as those in the first embodiment will be given the same reference numerals, and descriptions thereof will be omitted.

[0091] In the first embodiment, the first and second inner surfaces are located on the protruding portion of the slot, and the first and second contact surfaces are located on the tip of the pressing member. However, the first and second inner surfaces may be located on the tip of the pressing member, and the first and second contact surfaces may be located on the protruding portion of the developing housing.

[0092] For example, in the second embodiment shown in FIG. 7, the first inner surface 121A is located at the tip of the first pressing member 121. A spring 121S is provided between the base end surface of the first pressing member 121 and the slot 120. The spring 121S constantly urges the first pressing member 121 toward one side in the orthogonal direction. The second inner surface 122A is located at the tip of the second pressing member 122. A spring 122S is provided between the base end surface of the second pressing member 122 and the slot 120. The spring 122S constantly urges the second pressing member 122 toward one side in the orthogonal direction.

[0093] The first contact surface 153B is located at the tip of the first protruding portion 153 protruding from the developing housing 152. The second contact surface 154B is located at the tip of the second protruding portion 154 protruding from the developing housing 152.

[0094] 7, when the developer cartridge 150 is inserted into the slot 120, the first inner surface 121A comes into contact with the first contact surface 153B. Similarly, the second inner surface 122A comes into contact with the second contact surface 154B.

[0095] When the developing cartridge 150 is attached to the main body housing 2, the distance M1 from the first inner surface 121A to the photosensitive drum 41 becomes the same as the distance M3 from the first contact surface 153B to the photosensitive drum 41. Similarly, when the developing cartridge 150 is attached to the main body housing 2, the distance M2 from the second inner surface 122A to the photosensitive drum 41 becomes the same as the distance M4 from the second contact surface 154B to the photosensitive drum 41.

[0096] When the drum cartridge 40 and the developing cartridge 150 are attached to the main body housing 2, the distance M3 from the first inner surface 121A to the photosensitive drum 41 is greater than the distance M4 from the second inner surface 122A to the photosensitive drum 41. In other words, when the drum cartridge 40 and the developing cartridge 150 are attached to the main body housing 2, the first inner surface 121A is located farther from the photosensitive drum 41 than the second inner surface 122A.

[0097] Furthermore, when the developing cartridge 150 is inserted into the slot 120 with the drum cartridge 40 attached to the main body casing 2, the second contact surface 154B does not come into contact with the first inner surface 121A.

[0098] According to the second embodiment described above, when the drum cartridge 40 is inserted in the slot 120, if the developer cartridge 150 is inserted into the slot 120, the developer roller 51 can press the photosensitive drum 41. Furthermore, when the developer cartridge 150 is attached to the main body housing 2 of the image forming apparatus 1 in the axial direction, interference between the developer cartridge and the drum cartridge can be suppressed.

[0099] Next, a third embodiment of the present disclosure will be described. In the following description, members having substantially the same structures as those in the first embodiment will be given the same reference numerals, and descriptions thereof will be omitted.

[0100] In the first embodiment, the first inner surface and the second inner surface are provided in a part of the main body housing, but the first inner surface and the second inner surface may be provided in another member.

[0101] 8, the slot 220 in the third embodiment allows insertion of four drum cartridges 240 and four developer cartridges 50. In the third embodiment, a first protrusion 221 having a first inner surface 221A is provided on the frame 242 of the adjacent drum cartridge 140. Similarly, a second protrusion 222 having a second inner surface 222A is provided on the frame 242 of the adjacent drum cartridge 240.

[0102] According to the third embodiment, similarly to the first embodiment, when the developer cartridge 50 is inserted into the slot 220, the developer roller 51 can be pressed against the photosensitive drum 41. Furthermore, when the developer cartridge 50 is mounted axially relative to the main body housing 2 with the drum cartridge 40 already mounted in the main body housing 2 of the image forming apparatus 1, interference between the developer cartridge and the drum cartridge can be suppressed. Furthermore, in the third embodiment, there is no wall between each drum cartridge 240 and each developer cartridge 50, so the size can be made compact in the orthogonal direction.

[0103] Next, a fourth embodiment of the present disclosure will be described. In the following description, members having substantially the same structures as those in the second embodiment will be given the same reference numerals, and descriptions thereof will be omitted.

[0104] As shown in FIG. 9, in the fourth embodiment, a first pressing member 121 having a first inner surface 121A and a second pressing member 122 having a second inner surface 122A are provided on a frame 342 of an adjacent drum cartridge 340.

[0105] In the fourth embodiment, similarly to the second embodiment, when the developer cartridge 150 is inserted into the slot 320, the developer roller 51 can press the photosensitive drum 41. Furthermore, when the developer cartridge 150 is attached axially to the main body housing 2 while the drum cartridge 340 is attached to the main body housing 2 of the image forming apparatus 1, interference between the developer cartridge and the drum cartridge can be suppressed. Furthermore, in the fourth embodiment, since there is no wall between each drum cartridge 340 and each developer cartridge 150, the size can be made compact in the orthogonal direction.

[0106] In the above-described embodiments, the first inclined surface of the first inner surface and the second inclined surface of the second inner surface have the same inclination angle, but they may have different inclination angles.

[0107] 10, for example, the inclinations of first inclined surface 421B of first protrusion 421 and second inclined surface 422B of second protrusion 422 are different. Specifically, inclination angle θ1 of first inclined surface 421B with respect to the axial direction is smaller than inclination angle θ2 of second inclined surface 422B with respect to the axial direction.

[0108] As in the first modified example, by making the inclination angle θ1 of the first inclined surface 421B and the inclination angle θ2 of the second inclined surface 422B different, it is possible to adjust the increasing tendency of the pressing forces of the first pressing member 453 and the second pressing member 454.

[0109] Furthermore, in the first embodiment described above, multiple protrusions protruding from the inner surface of the slot 20 are provided, but the number of protrusions may be one. For example, in the second modified example shown in FIG. 11(a), the first inner surface 521A and the second inner surface 522A are connected by the third inclined surface 523A, and there is one protrusion. This modification also provides the same effects as the first embodiment.

[0110] In the second embodiment described above, multiple protrusions protrude from the developing housing, but only one protrusion may be provided. For example, in a third modified example shown in Fig. 11(b), the first inner surface 621A and the second inner surface 622A are connected by a third inclined surface 623A, and only one protrusion protrudes from the developing housing 652. This modification also provides the same effects as the second embodiment.

[0111] Furthermore, in the first embodiment described above, the first pressing member and the second pressing member are biased by springs, but the springs themselves may be the pressing members.

[0112] For example, in a fourth modified example shown in FIG. 12(a), a developer cartridge 750 has a first leaf spring 753 and a second leaf spring 754 in a developer housing 752. The first leaf spring 753 and the second leaf spring 754 are fixed to the developer housing 752. A first contact surface 753B is located at the tip of the first leaf spring 753. A second contact surface 754B is located at the tip of the second leaf spring 754.

[0113] In this fourth modified example, similarly to the above-described embodiments, when the developer cartridge 750 is inserted into the slot 20, the developer roller 51 can press the photosensitive drum 41. The spring is not limited to a leaf spring, and may be a torsion spring or the like. According to this fourth modified example, the number of parts can be reduced.

[0114] In the second embodiment described above, the first inner surface 121A is provided at the tip of the first pressing member 121, but the first inner surface may be provided at the tip of the biasing member. Similarly, the second inner surface 122A is provided at the tip of the second pressing member 122, but the second inner surface may be provided at the tip of the biasing member.

[0115] 12(b), a first leaf spring 821 and a second leaf spring 822 are provided on the inner surface of a slot 820. A first inner surface 821A is located at the tip of the first leaf spring 821. A first inner surface 822A is located at the tip of the second leaf spring 822.

[0116] In this fifth modified example, similar to the second embodiment, when the developer cartridge 150 is inserted into the slot 820, the developer roller 51 can press the photosensitive drum 41. The spring is not limited to a plate spring, and may be a torsion spring or the like. According to this fifth modified example, the number of parts can be reduced.

[0117] In each of the above-described embodiments, the image forming device 1 is a color printer, but the present invention is not limited to this and may be applied to other image forming devices, such as monochrome printers, copiers, and multifunction devices.

[0118] The elements described in the above-described embodiment and modifications may be implemented in any combination. [Explanation of symbols]

[0119] 1. Image forming device 2 Main unit housing 2A Cover 2E Ejection section 20 slots 21 1st protrusion 21A 1st internal surface 21B 1st slope 22 Second protrusion 22A 2nd internal surface 22B 2nd slope 40 drum cartridges 41 Photosensitive drum 42 frames 50 Developer cartridge 51 Developing roller 52 Developing cabinet 53 First pressing member 53B 1st contact surface 54 Second pressing member 54B 2nd contact surface 63 Intermediate transfer belt X1 1st axis X2 2nd axis

Claims

1. a drum cartridge having a photosensitive drum rotatable about a first axis extending in the axial direction; a developing cartridge including a developing roller rotatable about a second axis extending in the axial direction and a developing housing capable of accommodating toner; a main body housing having a slot extending in the axial direction, the slot allowing the drum cartridge to be attached and detached in the axial direction, and allowing the developing cartridge to be attached and detached in the axial direction; a first interior surface located within the slot; a second inner surface located within the slot and spaced apart from the first inner surface in the axial direction; An image forming apparatus comprising: The developing housing further includes: a first contact surface that comes into contact with the first inner surface when the developing cartridge is installed in the slot in a state in which the drum cartridge is installed in the slot; a second contact surface that comes into contact with the second inner surface when the developing cartridge is installed in the slot in a state in which the drum cartridge is installed in the slot; Equipped with With the first inner surface in contact with the first contact surface and the second inner surface in contact with the second contact surface, the first inner surface and the second inner surface press the developing housing so that the developing roller moves toward the photosensitive drum; When the drum cartridge is installed in the slot and the developer cartridge is removed from the slot, the first inner surface is disposed farther from the photosensitive drum than the second inner surface, When the developer cartridge is removed from the slot, the first contact surface is disposed farther from the developer roller than the second contact surface, The developing cartridge is characterized in that it has an elongated hole located at one end of the axial direction of the developing housing, which allows the developing cartridge to be moved by the first inner surface and the second inner surface of the image forming apparatus.

2. The image forming apparatus according to claim 1, further comprising an intermediate transfer belt positioned above the drum cartridge and the developing cartridge when the drum cartridge and the developing cartridge are mounted in the main housing, the intermediate transfer belt coming into contact with the surface of the photosensitive drum when the drum cartridge and the developing cartridge are mounted in the main housing.

3. 3. The image forming apparatus according to claim 2, further comprising a discharge unit located above the intermediate transfer belt and for discharging the recording sheet.

4. the main body housing has a first pressing member held movably relative to the main body housing and a second pressing member held movably relative to the main body housing, the first inner surface is located at a tip of the first pressing member, 4. The image forming apparatus according to claim 1, wherein the second inner surface is located at a tip of the second pressing member.

5. 5. The image forming apparatus according to claim 4, wherein the first pressing member and the second pressing member are movable by the biasing force of a spring.

6. the first contact surface is located at a tip of a first protruding portion that protrudes from the developing housing, 6. The image forming apparatus according to claim 4, wherein the second contact surface is located at a tip of a second protruding portion that protrudes from the developing housing.

7. a cover having a closed state that closes the slot and an open state that opens the slot; 7. The image forming apparatus according to claim 1, wherein the second contact surface is farther from the cover than the first contact surface.

8. the main body housing has a first inclined surface located on one side of the first inner surface in the axial direction, 8. The image forming apparatus according to claim 7, wherein the first inclined surface extends away from the developing roller as it approaches the cover from the first inner surface when the drum cartridge and the developing cartridge are attached to the main housing.

9. the main body housing has a second inclined surface located on one side of the second inner surface in the axial direction, The image forming apparatus according to claim 7, characterized in that, when the drum cartridge and the developer cartridge are attached to the main housing, the second inclined surface extends away from the developing roller as it approaches the cover from the second contact surface.

10. The developing cartridges are arranged in a direction perpendicular to the axial direction, 10. The image forming apparatus according to claim 1, wherein the first inner surface and the second inner surface are provided corresponding to each of the plurality of developing cartridges.

11. 11. The image forming apparatus according to claim 1, wherein the first contact surface and the second contact surface are disposed on a surface of the developing housing facing a direction perpendicular to the axial direction.

12. 12. The image forming apparatus according to claim 1, wherein, when the first inner surface is in contact with the first contact surface and the second inner surface is in contact with the second contact surface, the first inner surface and the second inner surface press the developing housing so that the developing roller contacts the photosensitive drum.

Images