阅读说明：本技术 显影盒 (Developing box ) 是由 桥本淳一 王裕雯 于 2020-02-13 设计创作，主要内容包括：一种显影盒,包括壳体(10)、显影辊(30)和第一倾斜表面(61a)。第一倾斜表面(61a)定位在壳体(10)在第二方向上的一端部的外表面处。第一倾斜表面(61a)固定到壳体(10)并相对于第一方向倾斜。在显影盒(1)附接到鼓盒(2)的状态下,第一倾斜表面(61a)可与壳体(10)和显影辊(30)一起在第一方向上相对于感光鼓(21)在第一位置和第二位置之间移动。在第一倾斜表面(61a)处于第一位置的状态下,显影辊(30)与感光鼓(21)接触。在第一倾斜表面(61a)处于第二位置的状态下,显影辊(30)与感光鼓分离。(A developing cartridge includes a casing (10), a developing roller (30), and a first inclined surface (61 a). The first inclined surface (61a) is positioned at an outer surface of one end portion of the housing (10) in the second direction. The first inclined surface (61a) is fixed to the housing (10) and inclined with respect to the first direction. The first inclined surface (61a) is movable in a first direction together with the casing (10) and the developing roller (30) relative to the photosensitive drum (21) between a first position and a second position in a state where the developing cartridge (1) is attached to the drum cartridge (2). The developing roller (30) is in contact with the photosensitive drum (21) in a state where the first inclined surface (61a) is in the first position. In a state where the first inclined surface (61a) is at the second position, the developing roller (30) is separated from the photosensitive drum.)

1. A developing cartridge attachable to a drum cartridge including a photosensitive drum, characterized by comprising:

a housing configured to accommodate a developer therein;

a developing roller rotatable about a developing roller axis extending in a first direction, the developing roller contactable with the photosensitive drum, the developing roller having a circumferential surface having one side portion exposed to an outside of the casing and another side portion positioned inside the casing in a second direction intersecting the first direction; and

a first inclined surface positioned at an outer surface of one end portion of the casing in the second direction, the first inclined surface being fixed to the casing, the first inclined surface being inclined with respect to the first direction, the first inclined surface being movable together with the casing and the developing roller in the first direction between a first position and a second position with respect to the photosensitive drum in a state in which the developing cartridge is attached to the drum cartridge,

wherein the developing roller is in contact with the photosensitive drum in a state where the first inclined surface is at the first position, and

wherein the developing roller is separated from the photosensitive drum in a state where the first inclined surface is at the second position.

2. A developing cartridge according to claim 1, wherein said first inclined surface has one end edge and the other end edge in said first direction, and

wherein a first distance between the one end edge of the first inclined surface and the outer surface in the second direction is smaller than a second distance between the other end edge of the first inclined surface and the outer surface in the second direction.

3. A developing cartridge according to claim 1 or 2, further comprising a second inclined surface positioned at said outer surface, said second inclined surface being fixed to said casing, said second inclined surface being inclined with respect to said first direction, said second inclined surface being positioned away from said first inclined surface in said first direction, said second inclined surface being movable together with said first inclined surface in said first direction between a third position and a fourth position with respect to said photosensitive drum in said state in which said developing cartridge is attached to said drum cartridge,

wherein in the state in which the first inclined surface is in the first position, the second inclined surface is in the third position and the developing roller is in contact with the photosensitive drum, and

wherein in a state where the first inclined surface is in the second position, the second inclined surface is in the fourth position and the developing roller is separated from the photosensitive drum.

4. A developing cartridge according to claim 3, wherein said second inclined surface has one end edge and the other end edge in said first direction,

wherein a third distance between the one end edge of the second inclined surface and the outer surface in the second direction is smaller than a fourth distance between the other end edge of the second inclined surface and the outer surface in the second direction.

5. A developing cartridge according to any one of claims 1 to 4, wherein said casing has one end portion and another end portion in the first direction, the another end portion of said casing in the first direction having an outer surface,

the developing cartridge further includes a pressure receiving surface positioned at the outer surface of the other end portion of the casing in the first direction, the pressure receiving surface being configured to receive a pressing force in a direction from the other end portion of the casing in the first direction toward the one end portion of the casing in the first direction.

6. A developing cartridge according to claim 5, wherein when said pressure receiving surface receives said pressing force, said first inclined surface moves from said first position to said second position.

7. A developing cartridge according to claim 6, wherein said drum cartridge is attachable to a main body of an image forming apparatus, said main body includes a drive shaft extending in said first direction, said drive shaft is configured to advance and retract in said first direction by receiving a driving force from said main body, said drive shaft is configured to press said pressure receiving surface in said direction from said other end portion of said casing in said first direction toward said one end portion of said casing in said first direction, and

wherein the first inclined surface moves from the first position to the second position when the drive shaft presses the pressure receiving surface.

8. A developing cartridge according to claim 7, wherein said developing roller includes:

a roller body extending in the first direction; and

a developing roller shaft rotatable together with the roller body, the developing roller shaft having one end portion and the other end portion in the first direction,

the developing cartridge further includes:

a collar positioned at the one end portion of the developing roller shaft in the first direction, the collar rotatably supporting the developing roller shaft; and

an elastic member positioned between the roller body and the collar in the first direction.

9. A developing cartridge according to claim 8, wherein said elastic member is a spring.

10. A developing cartridge according to claim 9, wherein said spring is a coil spring.

11. A developing cartridge according to any one of claims 8 to 10, wherein when said drum cartridge is attached to said main body in the state in which said developing cartridge is attached to said drum cartridge, said elastic member urges one of said developing roller and said casing in a direction from said one end of said casing in said first direction toward said other end of said casing in said first direction.

12. A developing cartridge according to any one of claims 8 to 11, wherein said collar is electrically connected to said developing roller.

13. A developing cartridge according to any one of claims 8 to 12, wherein when said drum cartridge is attached to said main body in the state in which said developing cartridge is attached to said drum cartridge, a direction in which said elastic member urges one of said developing roller and said casing is opposite to a direction in which said drive shaft presses said pressure receiving surface.

14. A developing cartridge according to any one of claims 8 to 13, wherein when supply of the driving force from the main body to the driving shaft is stopped in a state in which the drum cartridge is attached to the main body and the developing cartridge is attached to the drum cartridge, the first inclined surface is moved from the second position to the first position by an urging force of the elastic member.

15. A developing cartridge according to any one of claims 1 to 14, wherein said drum cartridge has a contact surface contactable with said first inclined surface.

16. A developing cartridge according to any one of claims 5 to 14, wherein said pressure receiving surface is a flat surface perpendicular to said first direction.

17. A developing cartridge according to any one of claims 7 to 14, wherein in a state in which said drum cartridge is attached to said main body and said developing cartridge is attached to said drum cartridge, when said first inclined surface is in said first position and when said first inclined surface is in said second position, said pressure receiving surface overlaps with said drive shaft in said first direction.

18. A developing cartridge according to any one of claims 7 to 14, wherein in a state in which said drum cartridge is attached to said main body and said developing cartridge is attached to said drum cartridge,

the first inclined surface is in the second position in a state where the pressing force is applied from the driving shaft to the pressure receiving surface, and

the first inclined surface is in the first position in a state where the pressing force is not applied from the driving shaft to the pressure receiving surface.

19. A developing cartridge according to claim 15, wherein the contact surface is an outer circumferential surface of a cylindrical member, a center of the cylindrical member being a rotational axis extending in a third direction intersecting both the first direction and the second direction.

20. A developing cartridge according to claim 19, wherein said cylindrical member is rotatable about said rotation axis.

21. A developing cartridge according to any one of claims 1 to 20, wherein said first inclined surface has one end edge and another end edge in said first direction, and said first inclined surface is inclined away from said outer surface of said one end portion of said casing in said second direction as extending from said one end edge of said first inclined surface to said another end edge of said inclined surface.

22. A developing cartridge according to claim 3 or 4, wherein said casing has one end portion and another end portion in the first direction,

wherein the drum cartridge is attachable to a main body of an image forming apparatus,

wherein the main body includes a drive shaft extending in the first direction, the drive shaft being configured to advance and retract in the first direction by receiving a driving force from the main body, the drive shaft being configured to press the second inclined surface in a direction from the other end portion of the housing in the first direction toward the one end portion of the housing in the first direction, and

wherein the second inclined surface moves from the third position to the fourth position when the drive shaft presses the second inclined surface.

23. A developing cartridge according to claim 22, further comprising a recess positioned at said outer surface of said one end portion of said casing in said second direction, and

wherein the recess has the second inclined surface.

24. A developing cartridge according to claim 23, wherein in a state in which said drum cartridge is attached to said main body and said developing cartridge is attached to said drum cartridge,

the first inclined surface is in the second position and the second inclined surface is in the fourth position in a state where a pressing force is applied from the driving shaft to the second inclined surface, and

the first inclined surface is in the first position and the second inclined surface is in the third position in a state where the pressing force is not applied from the driving shaft to the second inclined surface.

Technical Field

The present disclosure relates to a developing cartridge.

Background

Conventionally, electrophotographic type image forming apparatuses such as laser printers, LED printers, are known. Such a conventional image forming apparatus includes a developing cartridge. The developing cartridge includes a developing roller for supplying a developer. A conventional image forming apparatus is described in patent document 1. The image forming apparatus described in patent document 1 includes a drum cartridge. The drum cartridge includes a photosensitive drum. The developing cartridge is attached to the drum cartridge. When the developing cartridge is attached to the drum cartridge, the photosensitive drum and the developing roller contact each other.

[ list of references ]

[ patent document ]

[PTL 1]

Japanese patent application laid-open No. 2011-

Disclosure of Invention

[ problem ] to

The image forming apparatus according to patent document 1 is switchable between a state in which the developing roller and the photosensitive drum are in contact with each other and a state in which the developing roller and the photosensitive drum are separated from each other. In the image forming apparatus described in patent document 1, a member for moving the developing cartridge to separate the developing roller from the photosensitive drum is provided on each side of the drum unit. Therefore, the components on each side need to receive driving force from the main body of the image forming apparatus.

In view of the above, an object of the present disclosure is to provide a developing cartridge capable of separating a developing roller from a photosensitive drum by applying a driving force to only one side without applying a driving force to each side.

[ solution of problem ]

According to a first aspect of the present disclosure, there is provided a developing cartridge including a casing, a developing roller, and a first inclined surface. The developing cartridge is attachable to a drum cartridge including a photosensitive drum. The housing is configured to accommodate developer therein. The developing roller is rotatable about a developing roller axis extending in a first direction. The developing roller can be in contact with the photosensitive drum. The developing roller has a circumferential surface having one side portion and the other side portion in a second direction intersecting the first direction. One side is exposed to the outside of the housing and the other side is positioned inside the housing. The first inclined surface is positioned at an outer surface of one end portion of the housing in the second direction. The first inclined surface is fixed to the housing and inclined with respect to the first direction. The first inclined surface is movable in a first direction together with the casing and the developing roller relative to the photosensitive drum between a first position and a second position in a state where the developing cartridge is attached to the drum cartridge. In a state where the first inclined surface is at the first position, the developing roller is in contact with the photosensitive drum. In a state where the first inclined surface is at the second position, the developing roller is separated from the photosensitive drum.

According to a second aspect of the present disclosure, in the developing cartridge of the first aspect, the first inclined surface has one end edge and the other end edge in the first direction, and a first distance between the one end edge of the first inclined surface and the outer surface in the second direction is smaller than a second distance between the other end edge of the first inclined surface and the outer surface in the second direction.

According to a third aspect of the present disclosure, in the developing cartridge of one of the first and second aspects, the developing cartridge further includes a second inclined surface positioned at the outer surface. The second inclined surface is fixed to the housing and inclined with respect to the first direction. The second inclined surface is positioned to be spaced apart from the first inclined surface in the first direction. The second inclined surface is movable together with the first inclined surface in the first direction between a third position and a fourth position with respect to the photosensitive drum in a state where the developing cartridge is attached to the drum cartridge. In a state where the first inclined surface is at the first position, the second inclined surface is at the third position and the developing roller is in contact with the photosensitive drum. In a state where the first inclined surface is at the second position, the second inclined surface is at the fourth position and the developing roller is separated from the photosensitive drum.

According to a fourth aspect of the present disclosure, in the developing cartridge of the third aspect, the second inclined surface has one end edge and the other end edge in the first direction, and a third distance between the one end edge of the second inclined surface and the outer surface in the second direction is smaller than a fourth distance between the other end edge of the second inclined surface and the outer surface in the second direction.

According to a fifth aspect of the present disclosure, in the developing cartridge of any one of the first to fourth aspects, the casing has one end portion and the other end portion in the first direction. The other end portion of the housing in the first direction has an outer surface. The developing cartridge further includes a pressure receiving surface positioned at an outer surface of the other end portion of the casing in the first direction. The pressure receiving surface is configured to receive a pressing force in a direction from the other end portion of the housing in the first direction toward the one end portion of the housing in the first direction.

According to a sixth aspect of the present disclosure, in the developing cartridge of the fifth aspect, when the pressure receiving surface receives the pressing force, the first inclined surface moves from the first position to the second position.

According to a seventh aspect of the present disclosure, in the developing cartridge of the sixth aspect, the drum cartridge is attachable to a main body of the image forming apparatus. The body includes a drive shaft extending in a first direction. The drive shaft is configured to advance and retract in a first direction by receiving a driving force from the main body. The drive shaft is configured to press the pressure receiving surface in a direction from the other end portion of the housing in the first direction toward the one end portion of the housing in the first direction. When the drive shaft presses the pressure receiving surface, the first inclined surface moves from the first position to the second position.

According to an eighth aspect of the present disclosure, in the developing cartridge of the seventh aspect, the developing roller includes a roller body and a developing roller shaft. The roller body extends in a first direction. The developing roller shaft is rotatable together with the roller body. The developing roller shaft has one end portion and the other end portion in the first direction. The developing cartridge further includes a collar and an elastic member. The collar is positioned at an end portion of the developing roller shaft in the first direction. The collar rotatably supports the developing roller shaft. The elastic member is positioned between the roller body and the collar in the first direction.

According to a ninth aspect of the present disclosure, in the developing cartridge of the eighth aspect, the elastic member is a spring.

According to a tenth aspect of the present disclosure, in the developing cartridge of the ninth aspect, the spring is a coil spring.

According to an eleventh aspect of the present disclosure, in the developing cartridge of any one of the eighth to tenth aspects, when the drum cartridge is attached to the main body in a state in which the developing cartridge is attached to the drum cartridge, the elastic member urges one of the developing roller and the casing in a direction from one end of the casing in the first direction toward the other end of the casing in the first direction.

According to a twelfth aspect of the present disclosure, in the developing cartridge of any one of the eighth to eleventh aspects, the collar is electrically connected to the developing roller.

According to a thirteenth aspect of the present disclosure, in the developing cartridge of any one of the eighth to twelfth aspects, when the drum cartridge is attached to the main body in a state in which the developing cartridge is attached to the drum cartridge, a direction in which the elastic member urges one of the developing roller and the casing is opposite to a direction in which the driving shaft presses the pressure receiving surface.

According to a fourteenth aspect of the present disclosure, in the developing cartridge of any one of the eighth to thirteenth aspects, when the supply of the driving force from the main body to the driving shaft is stopped in a state where the drum cartridge is attached to the main body and the developing cartridge is attached to the drum cartridge, the first inclined surface is moved from the second position to the first position by the urging force of the elastic member.

According to a fifteenth aspect of the present disclosure, in the developing cartridge of any one of the first to fourteenth aspects, the drum cartridge has a contact surface contactable with the first inclined surface.

According to a sixteenth aspect of the present disclosure, in the developing cartridge of any one of the fifth to fourteenth aspects, the pressure receiving surface is a flat surface perpendicular to the first direction.

According to a seventeenth aspect of the present disclosure, in the developing cartridge of any one of the seventh to fourteenth aspects, in a state in which the drum cartridge is attached to the main body and the developing cartridge is attached to the drum cartridge, the pressure receiving surface overlaps the driving shaft in the first direction when the first inclined surface is in the first position and when the first inclined surface is in the second position.

According to an eighteenth aspect of the present disclosure, in the developing cartridge of any one of the seventh to fourteenth aspects, in a state in which the drum cartridge is attached to the main body and the developing cartridge is attached to the drum cartridge; the first inclined surface is in the second position in a state where the pressing force is applied from the driving shaft to the pressure receiving surface; and the first inclined surface is in the first position in a state where the pressing force is not applied from the driving shaft to the pressure receiving surface.

According to a nineteenth aspect of the present disclosure, in the developing cartridge of the fifteenth aspect, the contact surface is an outer circumferential surface of a cylindrical member, and a center of the cylindrical member is a rotational axis extending in a third direction intersecting both the first direction and the second direction.

According to a twentieth aspect of the present disclosure, in the developing cartridge of the nineteenth aspect, the cylindrical member is rotatable about the rotation axis.

According to a twenty-first aspect of the present disclosure, in the developing cartridge of any one of the first to twentieth aspects, the first inclined surface has one end edge and the other end edge in the first direction. The first inclined surface is inclined away from an outer surface of an end portion of the housing in the second direction as extending from one end edge of the first inclined surface to the other end edge of the inclined surface.

According to a twenty-second aspect of the present disclosure, in the developing cartridge of one of the third and fourth aspects, the casing has one end portion and the other end portion in the first direction. The drum cartridge is attachable to a main body of the image forming apparatus. The body includes a drive shaft extending in a first direction. The drive shaft is configured to advance and retract in a first direction by receiving a driving force from the main body. The drive shaft is configured to press the second inclined surface in a direction from the other end portion of the housing in the first direction toward the one end portion of the housing in the first direction. When the drive shaft presses the second inclined surface, the second inclined surface moves from the third position to the fourth position.

According to a twenty-third aspect of the present disclosure, in the developing cartridge of the twenty-second aspect, the developing cartridge further includes a recessed portion positioned at an outer surface of one end portion of the casing in the second direction. The recess has a second inclined surface.

According to a twenty-fourth aspect of the present disclosure, in the developing cartridge of the twenty-third aspect, in a state where the drum cartridge is attached to the main body and the developing cartridge is attached to the drum cartridge; in a state where a pressing force is applied from the driving shaft to the second inclined surface, the first inclined surface is in the second position and the second inclined surface is in the fourth position; and the first inclined surface is in the first position and the second inclined surface is in the third position in a state where no pressing force is applied from the driving shaft to the second inclined surface.

[ advantageous effects of the invention ]

According to the first to twenty-fourth aspects of the present disclosure, it is possible to provide a developing cartridge which can be moved in the second direction by a driving force applied to only one side, thereby separating the developing roller from the photosensitive drum.

According to the first aspect of the present disclosure, in the process in which the first inclined surface moves from the first position to the second position, the first inclined surface is pressed by the contact surface of the drum cartridge, and thus the developing roller can be separated from the photosensitive drum.

According to the second aspect of the present disclosure, in the process of the first inclined surface moving from the first position to the second position, the first inclined surface is gradually pushed from one side toward the other side in the second direction, and thus the developing roller can be separated from the photosensitive drum.

According to the third aspect of the present disclosure, in the process in which the first inclined surface moves from the first position to the second position and the second inclined surface moves from the third position to the fourth position, the first inclined surface and the second inclined surface are pressed by the contact surface of the drum cartridge, and thus the developing roller can be separated from the photosensitive drum. Further, since the first inclined surface and the second inclined surface are positioned away from each other in the first direction, both sides of the housing in the first direction can be pressed by the contact surface of the drum cartridge.

According to the fourth aspect of the present disclosure, during the movement of the second inclined surface from the third position to the fourth position, the second inclined surface is gradually pushed from one side toward the other side in the second direction, and thus the developing roller can be separated from the photosensitive drum.

According to the fifth aspect of the present disclosure, the first inclined surface may be moved together with the casing and the developing roller by applying a pressing force to the pressure receiving surface.

According to the sixth aspect of the present disclosure, the pressing force from the other side toward the one side in the first direction is converted into the force in the second direction by the contact between the first inclined surface and the contact surface. As a result, the developing roller can be separated from the photosensitive drum.

According to the seventh aspect of the present disclosure, the developing roller can be separated from the photosensitive drum by the driving force applied from the main body of the image forming apparatus.

According to an eleventh aspect of the present disclosure, the first inclined surface may be moved from the second position to the first position by an urging force of the elastic member. As a result, the developing roller can be easily moved from a state in which the developing roller is separated from the photosensitive drum to a state in which the developing roller is in contact with the photosensitive drum.

According to the twelfth aspect of the present disclosure, the collar also serves as an electrode of the developing roller, thereby reducing the number of components.

According to the thirteenth aspect of the present disclosure, the first inclined surface is movable between the first position and the second position with high accuracy.

According to the fourteenth aspect of the present disclosure, by stopping the supply of the driving force from the main body to the driving shaft, the developing roller can be easily shifted from the state in which the developing roller is separated from the photosensitive drum to the state in which the developing roller is in contact with the photosensitive drum.

According to a fifteenth aspect of the present disclosure, the first inclined surface moves in the first direction while contacting the contact surface of the drum cartridge, thereby causing the contact surface to press the first inclined surface. Therefore, the developing roller can be moved from a state in which the developing roller is in contact with the photosensitive drum to a state in which the developing roller is separated from the photosensitive drum.

According to the sixteenth aspect of the present disclosure, it is possible to easily slidingly move the pressure receiving surface in the second direction with respect to a member (such as the drive shaft) that applies the pressing force to the pressure receiving surface. As a result, the developing roller can smoothly transit from a state in which the developing roller is in contact with the photosensitive drum to a state in which the developing roller is separated from the photosensitive drum.

According to the seventeenth aspect of the present disclosure, by slidably moving the pressure receiving surface with respect to the drive shaft, the state of the developing roller can be continuously changed between the state in which the developing roller is in contact with the photosensitive drum and the state in which the developing roller is separated from the photosensitive drum.

According to the twentieth aspect of the present disclosure, when the first inclined surface moves in the first direction while contacting the contact surface (the outer circumferential surface of the cylindrical member), a frictional force generated between the first inclined surface and the contact surface may be reduced.

According to the twenty-first aspect of the present disclosure, the posture of the developing roller can be smoothly changed between the state in which the developing roller is in contact with the photosensitive drum and the state in which the developing roller is separated from the photosensitive drum.

According to the twenty-second aspect of the present disclosure, the pressing force from the other side toward the one side in the first direction is converted into the force in the second direction by the contact between the second inclined surface and the drive shaft. As a result, the developing roller can be separated from the photosensitive drum.

According to a twenty-third aspect of the present disclosure, the drive shaft is inserted into the recess and pushes the second inclined surface. Therefore, the developing roller can be separated from the photosensitive drum.

Drawings

Fig. 1 is a schematic diagram of an image forming apparatus.

Fig. 2 is a perspective view of the developing cartridge according to the first embodiment.

Fig. 3 is a schematic view showing one end portion of the developing roller in the first direction.

Fig. 4 is a view of the drum cartridge as viewed from the other side toward one side in the third direction, and illustrates a state in which the developing cartridge according to the first embodiment is attached to the drum cartridge.

Fig. 5 is an enlarged perspective view of a contact surface (i.e., an outer circumferential surface of the first guide roller).

Fig. 6 is an enlarged perspective view of the contact surface (i.e., the outer circumferential surface of the second guide roller).

Fig. 7 is a view of the developing cartridge and the photosensitive drum in a contact state when viewed from the other side toward one side in the third direction in the first embodiment.

Fig. 8 is a view of the developing cartridge and the photosensitive drum in a contact state when viewed from the other side toward one side in the first direction in the first embodiment.

Fig. 9 is a perspective view of the developing cartridge and the photosensitive drum in a contact state in the first embodiment.

Fig. 10 is a view of the developing cartridge and the photosensitive drum in a separated state as viewed from the other side toward one side in the third direction in the first embodiment.

Fig. 11 is a view of the developing cartridge and the photosensitive drum in a separated state as viewed from the other side toward one side in the first direction in the first embodiment.

Fig. 12 is a perspective view of the developing cartridge and the photosensitive drum in a separated state in the first embodiment.

Fig. 13 is a perspective view of the developing cartridge according to the second embodiment.

Fig. 14 is a cross-sectional view of the developing cartridge according to the second embodiment in a contact state taken along a plane perpendicular to the third direction.

Fig. 15 is a view of the developing cartridge according to the second embodiment in a contact state when viewed from the other side to the one side in the first direction.

Fig. 16 is a perspective view of the developing cartridge according to the second embodiment in a contact state.

Fig. 17 is a cross-sectional view of the developing cartridge according to the second embodiment in a separated state taken along a plane perpendicular to the third direction.

Fig. 18 is a view of the developing cartridge according to the second embodiment in a separated state as viewed from the other side to the one side in the first direction.

Fig. 19 is a perspective view of the developing cartridge according to the second embodiment in a separated state.

Detailed Description

Embodiments of the present disclosure will be described while referring to the drawings.

In the following description, a direction in which the rotational axis of the developing roller (developing roller axis) extends will be referred to as a "first direction". Here, the outer circumferential surface of the developing roller has a portion exposed to the outside of the casing and another portion accommodated inside the casing. The arrangement direction of the exposed portion and the receiving portion of the circumferential surface will be referred to as "second direction". The first direction and the second direction cross each other. Preferably, the first direction and the second direction are orthogonal to each other. Further, a direction intersecting with (preferably orthogonal to) both the first direction and the second direction will be referred to as a "third direction".

< first embodiment >

<1. structural overview of image Forming apparatus >

Fig. 1 is a schematic diagram of an image forming apparatus 100. The image forming apparatus 100 is an electrophotographic type printer. Examples of the image forming apparatus 100 include a laser printer and an LED printer. As shown in fig. 1, the image forming apparatus 100 includes four developing cartridges 1, a drum cartridge 2, and a main body 9.

<1-1. structural overview of subject >

The structure of the main body 9 of the image forming apparatus 100 will be outlined. As shown in fig. 1, the main body 9 includes a main body frame 101, a transfer belt (not shown), and a controller 102.

The main body frame 101 has a substantially rectangular parallelepiped shape. The main body frame 101 has an inner space. In a state where the developing cartridge 1 is attached to the drum cartridge 2, the drum cartridge 2 is attached in the inner space of the main body frame 101. Further, four chargers (not shown), four light sources (not shown), a transfer belt, and a controller 102 are attached in the main body frame 101.

The transfer belt is an endless belt for conveying a print sheet. In a state where the drum cartridge 2 is attached in the inner space of the main body frame 101 and the developing cartridge 1 is attached to the drum cartridge 2, the transfer belt is positioned on the opposite side of the developing roller 30 with respect to the photosensitive drum 21. The outer peripheral surface of the transfer belt may be in contact with the outer peripheral surface of the photosensitive drum 21.

The controller 102 includes a processor such as a CPU and a main body memory. The main body memory is a readable and writable storage medium such as a flash ROM, an EEPROM, or the like. The main body memory stores therein a computer program for controlling the operation of the image forming apparatus 100. The processor is configured to execute various processes according to a computer program stored in the main body memory. That is, the processor is configured to execute the printing process performed by the image forming apparatus 100 and various processes accompanying the same.

<1-2. structural overview of developing Cartridge >

The structure of the developing cartridge 1 will be summarized with reference to fig. 1 to 3. Fig. 2 is a perspective view of the developing cartridge 1. Fig. 3 is a schematic view showing one end portion of the developing roller 30 in the first direction.

As shown in fig. 1, the developing cartridge 1 is attachable to and detachable from a drum frame 200 of the drum cartridge 2. As shown in fig. 2, the developing cartridge 1 includes a casing 10 configured to accommodate developer therein.

The housing 10 includes a container 10A and a lid 10B. The container 10A has an inner space. The cover 10B is in the shape of a flat plate. The cover 10B is positioned at one end of the housing 10 in the second direction. The cover 10B has a third outer surface 13 described later. The cover 10B covers an opening portion formed at one end portion of the container 10A in the second direction. The container 10A has an opening 10C formed at one end of the container 10A in the third direction. The developing roller 30 is positioned at the opening 10C.

The housing 10 has one end portion and the other end portion in the first direction. The other end portion of the housing 10 in the first direction has a first outer surface 11, and one end portion of the housing 10 in the first direction has a second outer surface 12. Further, the housing 10 has a third outer surface 13 and a fourth outer surface 14 (fig. 7) spaced apart from each other in the second direction. The third outer surface 13 is positioned at one end of the housing 10 in the second direction. The fourth outer surface 14 is positioned at the other end portion of the housing 10 in the second direction.

The four developing cartridges 1 contain therein developers of different colors (for example, cyan, magenta, yellow, and black). However, the four developing cartridges 1 may contain the same color developer therein. For example, the developer is a toner.

The developing cartridge 1 further includes a developing roller 30. The developing roller 30 is a member having a cylindrical shape. The developing roller 30 is rotatable about a developing roller axis, which is a rotational axis extending in the first direction. The developing roller 30 is supported by the casing 10 so as to be rotatable about a developing roller axis.

The developing roller 30 includes a roller body 31 and a developing roller shaft 32. The roller body 31 is a cylindrical member extending in the first direction. The roller body 31 is made of an elastic material such as rubber. The developing roller shaft 32 is a solid cylindrical member that penetrates the roller body 31 in the first direction. The developing roller shaft 32 is made of metal or conductive resin. The roller body 31 is fixed to the developing roller shaft 32 so as not to rotate relative to the developing roller shaft 32. That is, the roller body 31 is rotatable about the developing roller axis together with the developing roller shaft 32. The circumferential surface of the roller body 31 has one side and the other side in the second direction. One side portion of the circumferential surface of the roller body 31 in the second direction is exposed to the outside of the housing 10 through the opening 10C. The other side of the circumferential surface of the roller body 31 in the second direction is positioned inside the housing 10.

The developing roller shaft 32 has one end portion and the other end portion in the first direction. A developing roller gear (not shown) is attached to the other end portion of the developing roller shaft 32 in the first direction. The developing roller gear is positioned at the first outer surface 11. The developing roller shaft 32 is fixed to the developing roller gear so as not to rotate relative to the developing roller gear. Therefore, when the developing roller gear rotates, the developing roller shaft 32 and the roller body 31 rotate together with the developing roller gear.

As shown in fig. 3, a collar 33 having a cylindrical shape is positioned at one end portion of the developing roller shaft 32 in the first direction. One end portion of the developing roller shaft 32 in the first direction is positioned in the collar 33. The collar 33 is electrically connected to the developing roller 30. The collar 33 has one end face and the other end face in the first direction. The collar 33 has an elastic member accommodating portion 33 a. The elastic member accommodating portion 33a has a cylindrical shape and is recessed from the other end surface toward one side from the other side in the first direction. The elastic member accommodating portion 33a has a bottom portion 33 b.

The developing roller shaft 32 has a retaining ring 34. One end portion of the developing roller shaft 32 in the first direction is fitted with a retaining ring 34. The retaining ring 34 is positioned further in the first direction from one side towards the other than the collar 33.

The developing roller shaft 32 includes an elastic member 35. The elastic member 35 is a coil spring formed by spirally winding a metal wire. One end of the elastic member 35 is connected to the bottom portion 33b of the elastic member accommodating portion 33 a. The other end of the elastic member 35 is connected to the retaining ring 34.

The developing roller shaft 32 may not penetrate the roller body 31 in the first direction. For example, the developing roller shaft 32 may extend in the first direction from each end of the roller body 31 in the first direction.

As shown in fig. 2, the developing cartridge 1 includes a gear portion 40. The gear portion 40 is positioned at the first outer surface 11 of the housing 10. The gear portion 40 includes a coupling 41, a developing roller gear, and a gear cover 43.

The coupling 41 is a rotating body configured to receive the driving force supplied from the image forming apparatus 100. The coupling 41 is rotatable about a rotational axis extending in a first direction. The coupler 41 has a fixing hole 411 recessed in the first direction. When the drum cartridge 2 in a state in which the developing cartridge 1 is attached in the main body 9 of the image forming apparatus 100, a transmission shaft (not shown) of the main body 9 is inserted into the fixing hole 411. Thus, the propeller shaft and the coupler 41 are coupled together so as not to rotate relative to each other. Thus, when the drive shaft rotates, the coupling 41 rotates. When the coupling 41 rotates, the developing roller gear rotates. The developing roller 30 also rotates together with the developing roller gear. Further, when the coupling 41 rotates, the supply roller (not shown) and the agitator (not shown) also rotate.

The housing 10 includes a handle 38 for grasping by a user. The handle 38 is positioned at the outer surface at the other end portion of the housing 10 in the third direction.

<1-3. structural overview of drum Cartridge >

The structure of the drum cartridge 2 will be summarized with reference to fig. 1 and 4. Fig. 4 is a view of the drum cartridge 2 as viewed from the other side toward one side in the third direction, and shows a state in which the developing cartridge 1 is attached to the drum cartridge 2. The drum cartridge 2 includes four photosensitive drums 21 and a drum frame 200.

Each of the four photosensitive drums 21 shown in fig. 1 has an outer circumferential surface having a cylindrical shape whose center is a drum axis which is a rotation axis extending in the first direction. The outer circumferential surface of the photosensitive drum 21 is coated with a photosensitive material. Each of the four photosensitive drums 21 is rotatable about a drum axis.

The drum frame 200 is a frame that holds the four photosensitive drums 21. The drum frame 200 holds the photosensitive drum 21 in a state where the photosensitive drums 21 are spaced apart from each other in the second direction. The drum frame 200 includes a pair of side frames 201, 202 facing each other in a first direction. The side frame 202 is positioned farther from the other side toward one side than the side frame 201 in the first direction. Each photosensitive drum 21 is rotatably supported by the side frames 201 and 202.

In a state where the developing cartridge 1 is attached to the drum frame 200, one end portion of the developing roller shaft 32 in the first direction faces the side frame 202. Specifically, as shown in fig. 3, the collar 33 positioned at one end portion of the developing roller shaft 32 in the first direction contacts the inner surface of the side frame 202. The collar 33 is pressed in a direction from one side toward the other side by contact between the side frame 202 and one end portion of the collar 33 in the first direction. Therefore, the collar 33 moves on the developing roller shaft 32 from one side toward the other side in the first direction. Thus, the distance between the bottom 33b and the retaining ring 34 is reduced, so that the elastic member 35 is in a compressed state in which its length is less than its natural length. Therefore, the elastic member 35 urges the developing roller shaft 32 from one side toward the other side in the first direction by the retaining ring 34. Therefore, the first outer surface 11 of the developing cartridge 1 is positioned near the inner surface of the side frame 201. Thus, the position of the developing cartridge 1 in the first direction with respect to the drum cartridge 2 is fixed.

To perform a printing process in the image forming apparatus 100, the controller 102 drives a motor (not shown). By the driving of the motor, the photosensitive drum 21 and the developing roller 30 are rotated by the transmission shaft and the coupling 41. The controller 102 also supplies power to a charger (not shown) to charge the outer circumferential surface of the photosensitive drum 21. Further, the controller 102 turns on a light source (not shown) to irradiate the outer circumferential surface of the photosensitive drum 21 with light of the light source. Accordingly, an electrostatic latent image corresponding to an image to be printed is formed on the outer circumferential surface of the photosensitive drum 21. The developer accommodated in the developing cartridge 1 is supplied to the electrostatic latent image formed on the photosensitive drum 21 by the developing roller 30. Therefore, the electrostatic latent image becomes a visible developer image on the outer circumferential surface of the photosensitive drum 21. Then, the print sheet is conveyed to a portion between the photosensitive drum 21 and the transfer belt. Thus, the developer image is transferred from the outer circumferential surface of the photosensitive drum 21 onto the print sheet. In a state where the developer image is transferred to the print sheet, the print sheet is conveyed to a fixing unit (not illustrated) provided in the image forming apparatus 100. Thus, the developer image transferred to the print sheet is thermally fixed to the print sheet. As a result, an image is printed on the print sheet.

In the image forming apparatus 100, preferably, each of the developing rollers 30 is separated from a corresponding one of the photosensitive drums 21 during switching of a print color or during standby in a print process. For this reason, the image forming apparatus 100 in the present embodiment has a contact state and a separation state.

The contact state is a state in which each of the developing rollers 30 is in contact with a corresponding one of the photosensitive drums 21 in a state in which the four developing cartridges 1 are attached to the drum cartridge 2. The separated state is a state in which each of the developing rollers 30 is separated from a corresponding one of the photosensitive drums 21 in a state in which the four developing cartridges 1 are attached to the drum cartridge 2.

For this reason, each developing cartridge 1 further includes, as members for contact and separation, a first cam 61 and a second cam 62. The first cam 61 has a first inclined surface 61 a. The second cam 62 has a second inclined surface 62a and a pressure receiving surface 62 b. Further, as a member for contact and separation, the drum cartridge 2 includes a first guide roller 24 and a second guide roller 25 for each of the four developing cartridges 1. Further, as a member for contact and separation, the main body 9 of the image forming apparatus 100 includes a drive shaft 103 for each of the four developing cartridges 1.

<2. parts in drum cartridge for contact and separation >

The components included in the drum cartridge 2 for making contact and separation will be described with reference to fig. 4 to 6.

In a state where the developing cartridge 1 is attached to the drum cartridge 2, the first outer surface 11 of the developing cartridge 1 faces the inner surface of the first side frame 201 in the first direction. In a state where the developing cartridge 1 is attached to the drum cartridge 2, the second outer surface 12 of the developing cartridge 1 faces the inner surface of the second side frame 202 in the first direction.

As shown by a dotted line in an enlarged view of a lower portion of fig. 4, the first side frame 201 includes a first guide roller 24. That is, the first guide roller 24 is positioned at the other end portion of the drum frame 200 in the first direction.

Fig. 5 is an exploded perspective view showing the first guide roller 24 and a bearing portion 26 supporting the first guide roller 24. As shown in fig. 5, the first guide roller 24 has an outer circumferential surface (contact surface) 240, and the outer circumferential surface (contact surface) 240 has a cylindrical shape extending in the third direction. Each end portion of the first guide roller 24 in the third direction is rotatably supported by a bearing portion 26. Therefore, the first guide roller 24 is rotatable about its center axis extending in the third direction.

As shown by a dotted line in an upper enlarged view of fig. 4, the second side frame 202 includes a second guide roller 25. That is, the second guide roller 25 is positioned at one end portion of the drum frame 200 in the first direction.

Fig. 6 is an exploded perspective view showing the second guide roller 25 and the bearing portion 27 supporting the second guide roller 25. As shown in fig. 6, the second guide roller 25 has an outer circumferential surface (contact surface) 250, and the outer circumferential surface (contact surface) 250 has a cylindrical shape extending in the third direction. Each end portion of the second guide roller 25 in the third direction is rotatably supported by a bearing portion 27. Therefore, the second guide roller 25 is rotatable about its central axis extending in the third direction.

The first guide roller 24 and the second guide roller 25 are positioned to function as a roller pair in the first direction. As described later, the second inclined surface 62a of the second cam 62 may contact the outer circumferential surface 240 of the first guide roller 24, and the first inclined surface 61a of the first cam 61 may contact the outer circumferential surface 250 of the second guide roller 25.

<3. parts in body for contacting and separating >

The components included in the main body 9 of the image forming apparatus 100 for making contact and separation will be described with reference to fig. 7 and 8. The main body 9 of the image forming apparatus 100 includes a drive shaft 103 for each of the four developing cartridges 1. The drive shaft 103 is a solid cylinder or a solid prism extending in a first direction. The drive shaft 103 advances and retracts in the first direction by receiving a driving force from the main body 9.

<4. Components in developing Cartridge for contact and separation >

The components included in the developing cartridge 1 for making contact and separation will be described with reference to fig. 2 and 7 to 9. Fig. 7 is a view of the developing cartridge 1 and the photosensitive drum 21 in a contact state when viewed from the other side toward one side in the third direction in the present embodiment. Fig. 8 is a view of the developing cartridge 1 and the photosensitive drum 21 in a contact state when viewed from the other side toward one side in the first direction in the present embodiment. Fig. 9 is a perspective view of the developing cartridge 1 and the photosensitive drum 21 in a contact state in the present embodiment.

The first cam 61 shown in fig. 7 and 9 has a right triangular prism shape. The first cam 61 has a first inclined surface 61 a. The first inclined surface 61a is positioned at the third outer surface 13 of one end portion of the housing 10 in the second direction. The first inclined surface 61a is fixed to the housing 10. The first inclined surface 61a is inclined with respect to the first direction.

Specifically, the first inclined surface 61a has one end edge 61b and the other end edge 61c in the first direction. A distance in the second direction between one end edge 61B of the first inclined surface 61a and the third outer surface 13 (specifically, the outer surface of the cover 10B) of one end portion of the housing 10 in the second direction is defined as a first distance L1. A distance in the second direction between the other end edge 61c of the first inclined surface 61a and the third outer surface 13 (specifically, the outer surface of the cover 10B) of one end portion of the housing 10 in the second direction is defined as a second distance L2. The first distance L1 is less than the second distance L2(L1 < L2). That is, the first inclined surface 61a is inclined so as to be away from the third outer surface 13 (specifically, the outer surface of the cover 10B) of one end portion of the housing 10 in the second direction as extending from one end edge 61B of the first inclined surface 61a to the other end edge 61c of the first inclined surface 61 a.

In a state where the developing cartridge 1 is attached to the drum cartridge 2, the first inclined surface 61a is movable together with the casing 10 and the developing roller 30 in the first direction between the first position and the second position with respect to the photosensitive drum 21.

The second cam 62 shown in fig. 7 and 9 has a half-truncated conical shape. The second cam 62 has a second inclined surface 62 a. The second inclined surface 62a is positioned at the third outer surface 13 of one end portion of the housing 10 in the second direction. The second inclined surface 62a is fixed to the housing 10. The second inclined surface 62a is inclined with respect to the first direction.

Specifically, the second inclined surface 62a has one end edge 62c and the other end edge 62d in the first direction. A distance in the second direction between one end edge 62c of the second inclined surface 62a and the third outer surface 13 (specifically, the outer surface of the cover 10B) of one end portion of the housing 10 in the second direction is defined as a third distance L3. A distance in the second direction between the other end edge 62d of the second inclined surface 62a and the third outer surface 13 (specifically, the outer surface of the cover 10B) of one end portion of the housing 10 in the second direction is defined as a fourth distance L4. The third distance L3 is less than the fourth distance L4(L3 < L4). That is, the second inclined surface 62a is inclined so as to be away from the third outer surface 13 (specifically, the outer surface of the cover 10B) of one end portion of the housing 10 in the second direction as extending from one end edge 62c of the second inclined surface 62a to the other end edge 62d of the second inclined surface 62 a.

In a state where the developing cartridge 1 is attached to the drum cartridge 2, the second inclined surface 62a is movable together with the casing 10 and the developing roller 30 in the first direction relative to the photosensitive drum 21 between the third position and the fourth position.

The second cam 62 has a pressure receiving surface 62 b. The pressure receiving surface 62b is positioned at the first outer surface 11 of the housing 10. The pressure receiving surface 62b is fixed to the gear cover 43. The pressure receiving surface 62b is a flat surface perpendicular to the first direction.

The second inclined surface 62a and the pressure receiving surface 62b are surfaces different from each other in the outer surface of the second cam 62.

<5. movement of each component at the time of switching between the contact state and the separation state >

The movement of each member for contact and separation when switching the state of the image forming apparatus 100 between the contact state and the separation state will be described with reference to fig. 7 to 12. Fig. 10 is a view of the developing cartridge 1 and the photosensitive drum 21 in a separated state as viewed from the other side toward one side in the third direction in the present embodiment. Fig. 11 is a view of the developing cartridge 1 and the photosensitive drum 21 in a separated state as viewed from the other side toward one side in the first direction in the present embodiment. Fig. 12 is a perspective view of the developing cartridge 1 and the photosensitive drum 21 in a separated state in the present embodiment.

In the image forming apparatus 100, when the drive shaft 103 is driven to advance in a direction from the other end portion of the housing 10 in the first direction toward the one end portion of the housing 10 in the first direction, the pressure receiving surface 62b of the second cam 62 is pressed by the drive shaft 103. Therefore, the pressure receiving surface 62b receives a pressing force directed from the other end portion of the housing 10 in the first direction to the one end portion of the housing 10 in the first direction. Here, the pressure receiving surface 62b, the first inclined surface 61a, and the second inclined surface 62a are fixed to the housing 10. Therefore, when the pressure receiving surface 62b receives the pressing force, the first inclined surface 61a moves in the first direction from the first position shown in fig. 7 and 9 to the second position shown in fig. 10 and 12. Further, when the pressure receiving surface 62b receives the pressing force, the second inclined surface 62a moves in the first direction from the third position shown in fig. 7 and 9 to the fourth position shown in fig. 10 and 12.

In the process of the first inclined surface 61a moving from the first position to the second position, the first inclined surface 61a comes into contact with the outer circumferential surface 250 of the second guide roller 25 of the drum cartridge 2. In accordance with the movement of the first inclined surface 61a from the first position to the second position, the contact position of the first inclined surface 61a with the second guide roller 25 is gradually shifted on the first inclined surface 61a from a position near the one end edge 61b to a position near the other end edge 61 c. Therefore, the distance in the second direction between the outer surface of the cover 10B and the contact position where the first inclined surface 61a and the second guide roller 25 contact each other gradually increases as the first inclined surface 61a approaches the second position from the first position. As a result, since the first inclined surface 61a is pressed by the second guide roller 25, the casing 10 and the developing roller 30 are gradually moved from side to side in the second direction with respect to the photosensitive drum 21 together with the first cam 61.

In the process of the second inclined surface 62a moving from the third position to the fourth position, the second inclined surface 62a comes into contact with the outer circumferential surface 240 of the first guide roller 24 of the drum cartridge 2. In accordance with the movement of the second inclined surface 62a from the third position to the fourth position, the contact position between the second inclined surface 62a and the first guide roller 24 is gradually shifted on the second inclined surface 62a from a position near the one end edge 62c to a position near the other end edge 62 d. Therefore, the distance in the second direction between the outer surface of the cover 10B and the contact position where the second inclined surface 62a and the first guide roller 24 contact each other gradually increases as the second inclined surface 62a approaches the fourth position from the third position. As a result, since the second inclined surface 62a is pressed by the first guide roller 24, the casing 10 and the developing roller 30 are gradually moved from side to side in the second direction with respect to the photosensitive drum 21 together with the second cam 62.

As described above, since the first inclined surface 61a is pressed by the second guide roller 25, the one end portions of the casing 10 and the developing roller 30 in the first direction are pushed out from side to side in the second direction with respect to the photosensitive drum 21. Further, since the second inclined surface 62a is pressed by the first guide roller 24, the other end portions of the casing 10 and the developing roller 30 in the first direction are pushed out from side to side in the second direction with respect to the photosensitive drum 21. As a result, the developing roller 30 can be separated from the photosensitive drum 21 while the developing cartridge 1 can be prevented from being inclined with respect to the first direction.

That is, when the first inclined surface 61a is in the first position and the second inclined surface 62a is in the third position, the developing roller 30 is in contact with the photosensitive drum 21. When the first inclined surface 61a is in the second position and the second inclined surface 62a is in the fourth position, the developing roller 30 is separated from the photosensitive drum 21. Here, as shown in fig. 8 and 11, with the first inclined surface 61a in the first position and the second position, the pressure receiving surface 62b overlaps the drive shaft 103 in the first direction. In other words, when the first inclined surface 61a is in the first position and when the first inclined surface 61a is in the second position, the pressure receiving surface 62b overlaps the drive shaft 103 as viewed in the first direction. Further, the pressure receiving surface 62b is a flat surface perpendicular to the first direction. Therefore, the pressure receiving surface 62b can be slidingly moved relative to the drive shaft 103. As a result, the transition from the contact state to the separation state can be continuously and smoothly performed in the image forming apparatus 100.

In the image forming apparatus 100, when the drive shaft 103 is retracted in a direction from one end portion of the casing 10 in the first direction toward the other end portion of the casing 10 in the first direction, the first outer surface 11 of the developing cartridge 1 is pressed against the inner surface of the side frame 201 by the urging force of the elastic member 35 shown in fig. 3. Accordingly, the first inclined surface 61a moves from the second position to the first position in the first direction, and the second inclined surface 62a moves from the fourth position to the third position in the first direction.

Here, the drum frame 200 of the drum cartridge 2 includes a pressing mechanism (not shown) for pressing the casing 10 of the developing cartridge 1 in a direction toward the photosensitive drum 21. The developing cartridge 1 is pushed from the other side toward one side in the second direction by the pressing mechanism, thereby restoring the contact state in which the developing roller 30 and the photosensitive drum 21 contact each other. In this way, the state of the image forming apparatus 100 is switched between the contact state (fig. 6 to 8) and the separation state (fig. 9 to 11).

<6. overview of the first embodiment >

As described above, the developing cartridge 1 according to the first embodiment includes the casing 10, the developing roller 30, and the first inclined surface 61 a. As shown in fig. 7 to 9, in the developing cartridge 1 according to the present embodiment, the developing roller 30 is in contact with the photosensitive drum 21 in a state where the first inclined surface 61a is in the first position. As shown in fig. 10 to 12, in the developing cartridge 1 according to the present embodiment, the developing roller 30 is separated from the photosensitive drum 21 in a state where the first inclined surface 61a is in the second position. Therefore, during the movement of the first inclined surface 61a from the first position to the second position, the first inclined surface 61a is pressed by the outer circumferential surface (contact surface) 250 of the second guide roller 25 of the drum cartridge 2, so that the developing roller 30 can be separated from the photosensitive drum 21.

In this way, in the developing cartridge 1 according to the present embodiment, the developing roller 30 and the photosensitive drum 21 can be separated from each other by applying the driving force to only one side in the first direction of the developing cartridge 1 without applying the driving force to each side of the developing cartridge 1.

Further, in the developing cartridge 1 according to the present embodiment, the first distance L1 is smaller than the second distance L2(L1 < L2). Therefore, during the movement of the first inclined surface 61a from the first position to the second position, the first inclined surface 61a is gradually pressed from one side toward the other side in the second direction, so that the developing roller 30 can be separated from the photosensitive drum 21.

The developing cartridge 1 according to the present embodiment further includes a second inclined surface 62 a. As shown in fig. 7 to 9, in the developing cartridge 1 according to the present embodiment, in a state where the first inclined surface 61a is in the first position, the second inclined surface 62a is in the third position and the developing roller 30 is in contact with the photosensitive drum 21. As shown in fig. 10 to 12, in the developing cartridge 1 according to the present embodiment, in the state where the first inclined surface 61a is in the second position, the second inclined surface 62a is in the fourth position and the developing roller 30 is separated from the photosensitive drum 21. Therefore, in the process in which the first inclined surface 61a moves from the first position to the second position and the second inclined surface 62a moves from the third position to the fourth position, the first inclined surface 61a and the second inclined surface 62a are pressed by the outer circumferential surface 250 (contact surface) of the second guide roller 25 and the outer circumferential surface 240 (contact surface) of the first guide roller 24, respectively. As a result, the developing roller 30 can be separated from the photosensitive drum 21. Since the first and second inclined surfaces 61a and 62a are positioned away from each other in the first direction, the ends of the housing 10 in the first direction may be pressed by the outer circumferential surfaces 240 and 250 of the guide rollers 24 and 25.

Further, in the developing cartridge 1 according to the present embodiment, the third distance L3 is smaller than the fourth distance L4(L3 < L4). Therefore, in the process of the second inclined surface 62a moving from the third position to the fourth position, the second inclined surface 62a is gradually pressed from one side toward the other side in the second direction, so that the developing roller 30 can be separated from the photosensitive drum 21.

The developing cartridge 1 according to the present embodiment further includes a pressure receiving surface 62 b. Therefore, the first inclined surface 61a can move together with the casing 10 and the developing roller 30 by the pressing force applied through the pressure receiving surface 62 b.

Further, in the developing cartridge 1 according to the present embodiment, when the pressure receiving surface 62b receives a pressing force directed from the other end portion of the casing 10 in the first direction to the one end portion of the casing 10 in the first direction, the first inclined surface 61a moves from the first position to the second position. Here, the pressing force directed from the other end portion of the housing 10 in the first direction to the one end portion is converted into a force directed in the second direction by the contact between the first inclined surface 61a and the outer circumferential surface 250 of the second guide roller 25. As a result, the developing roller 30 can be separated from the photosensitive drum 21.

Further, in the present embodiment, the main body 9 includes a drive shaft 103. When the drive shaft 103 presses the pressure receiving surface 62b, the first inclined surface 61a moves from the first position to the second position. Therefore, the developing roller 30 can be separated from the photosensitive drum 21 by the driving force applied from the main body 9.

Further, in the developing cartridge 1 according to the present embodiment, the developing roller 30 includes a roller body 31 and a developing roller shaft 32. The developing cartridge 1 according to the present embodiment includes a collar 33 and an elastic member 35. In a state where the drum cartridge 2 is attached to the main body 9 and the developing cartridge 1 is attached to the drum cartridge 2, the elastic member 35 urges the developing roller 30 in a direction from one end of the casing 10 in the first direction toward the other end of the casing 10 in the first direction. Therefore, the first inclined surface 61a can be moved from the second position to the first position by the urging force of the elastic member 35. As a result, the developing roller 30 can be moved from a state in which the developing roller 30 is separated from the photosensitive drum 21 to a state in which the developing roller 30 is in contact with the photosensitive drum 21.

Further, in the developing cartridge 1 according to the present embodiment, the collar 33 is electrically connected to the developing roller 30. Therefore, the collar 33 also serves as an electrode of the developing roller 30, thereby reducing the number of components.

Further, in the developing cartridge 1 according to the present embodiment, the direction in which the elastic member 35 urges the developing roller 30 is opposite to the direction in which the drive shaft 103 presses the pressure receiving surface 62 b. Therefore, the first inclined surface 61a can move between the first position and the second position with high accuracy.

Further, in the developing cartridge 1 according to the present embodiment, when the supply of the driving force from the main body 9 to the driving shaft 103 is stopped, the first inclined surface 61a is moved from the second position to the first position by the urging force of the elastic member 35. Therefore, by stopping the supply of the driving force from the main body 9 to the driving shaft 103, the developing roller 30 can be easily shifted from the state in which the developing roller 30 is separated from the photosensitive drum 21 to the state in which the developing roller 30 is in contact with the photosensitive drum 21.

Further, in the present embodiment, the drum cartridge 2 includes the second guide roller 25 having the outer circumferential surface 250 contactable with the first inclined surface 61 a. Accordingly, the first inclined surface 61a moves in the first direction while maintaining contact with the outer circumferential surface 250 of the second guide roller 25, so that the first inclined surface 61a is pressed by the outer circumferential surface 250. As a result, the developing roller 30 can move from a state in which the developing roller 30 is in contact with the photosensitive drum 21 to a state in which the developing roller 30 is separated from the photosensitive drum 21.

Further, in the present embodiment, the pressure receiving surface 62b is a flat surface perpendicular to the first direction. Therefore, the pressure receiving surface 62b can be easily slidably moved in the second direction with respect to the drive shaft 103. As a result, the developing roller 30 can smoothly transit from a state in which the developing roller 30 is in contact with the photosensitive drum 21 to a state in which the developing roller 30 is separated from the photosensitive drum 21.

In addition, in the present embodiment, the pressure receiving surface 62b overlaps the drive shaft 103 in the first direction when the first inclined surface 61a is in the first position and when the first inclined surface 61a is in the second position. In other words, the pressure receiving surface 62b overlaps the drive shaft 103 in both cases when viewed in the first direction. Therefore, by slidably moving the pressure receiving surface 62b relative to the drive shaft 103, the state of the developing roller 30 can be continuously changed between the state in which the developing roller 30 is in contact with the photosensitive drum 21 and the state in which the developing roller 30 is separated from the photosensitive drum 21.

Further, in the present embodiment, the second guide roller 25 is rotatable about a rotation axis extending in the third direction. This configuration can reduce the frictional force generated between the first inclined surface 61a and the outer circumferential surface 250 of the second guide roller 25 when the first inclined surface 61a moves in the first direction while contacting the outer circumferential surface 250 of the second guide roller 25.

< second embodiment >

Next, a developing cartridge 4 according to a second embodiment of the present disclosure will be described with reference to fig. 13 to 19. Fig. 13 is a perspective view of the developing cartridge 4 according to the present embodiment.

The second embodiment differs from the first embodiment mainly in that the developing cartridge 4 has the recess 262 instead of the second cam 62, and the drum cartridge 2 does not include the first guide roller 24. In the following description of the second embodiment, the same parts and components are denoted by the same reference numerals as those shown in the first embodiment to avoid repetitive description.

<7 > detailed structure of the second embodiment

The gear cover 43 of the developing cartridge 4 has a recess 262. The recessed portion 262 is recessed in a direction from the other end portion of the gear cover 43 in the first direction toward one end portion of the gear cover 43 in the first direction. The concave portion 262 has a semicircular shape when viewed from the other side toward the one side in the first direction. The recess 262 is open toward one end of the housing 10 in the second direction. That is, the concave portion 262 is positioned at the third outer surface 13 of one end portion of the housing 10 in the second direction.

The recess 262 has a second inclined surface 262c on the opposite side of the opening side. That is, the second inclined surface 262c is positioned at the inner wall surface of the recess 262. The second inclined surface 262c is fixed to the housing 10. The second inclined surface 262c is inclined with respect to the first direction. The second inclined surface 262c is inclined away from the third outer surface 13 (specifically, the outer surface of the cover 10B) of one end portion of the housing 10 in the second direction from one side toward the other side in the second direction as extending from one side to the other side in the first direction.

In a state where the developing cartridge 1 is attached to the drum cartridge 2, the second inclined surface 262c is movable together with the casing 10 and the developing roller 30 in the first direction and the second direction between the third position and the fourth position with respect to the photosensitive drum 21.

<8. movement of each component in the second embodiment when switching between the contact state and the separation state >

The movement of each member for contact and separation when the state of the image forming apparatus 100 according to the second embodiment is switched between the contact state and the separation state will be described with reference to fig. 14 to 19. Fig. 14 is a cross-sectional view of the developing cartridge 4 according to the second embodiment in a contact state taken along a plane perpendicular to the third direction. Fig. 15 is a view of the developing cartridge 4 according to the second embodiment in a contact state when viewed from the other side toward the one side in the first direction. Fig. 16 is a perspective view of the developing cartridge 4 according to the second embodiment in a contact state. Fig. 17 is a cross-sectional view of the developing cartridge 4 according to the second embodiment in a separated state taken along a plane perpendicular to the third direction. Fig. 18 is a view of the developing cartridge 4 according to the second embodiment in a separated state as viewed from the other side to the one side in the first direction. Fig. 19 is a perspective view of the developing cartridge 4 according to the second embodiment in a separated state.

In the image forming apparatus 100, when the drive shaft 103 is driven to start advancing in a direction from the other end portion of the housing 10 in the first direction toward the one end portion of the housing 10 in the first direction, the head end portion of the drive shaft 103 enters the recessed portion 262 and contacts the second inclined surface 262c at a position closer to the other end of the second inclined surface 262c in the first direction.

When the drive shaft 103 further advances toward one end portion of the housing 10 in the first direction, the second inclined surface 262c is pressed from the other side toward one side in the first direction due to the contact of the second inclined surface 262c with the drive shaft 103. Therefore, the contact position between the second inclined surface 262c and the drive shaft 103 is gradually shifted on the second inclined surface 262c from a position closer to the other end of the second inclined surface 262c in the first direction to a position closer to one end of the second inclined surface 262c in the first direction. Accordingly, due to the contact of the second inclined surface 262c with the drive shaft 103, the second inclined surface 262c is pressed from one side toward the other side in the second direction. Thus, the second inclined surface 262c is pressed by the driving shaft 103, thereby moving in the second direction while moving in the first direction. Accordingly, the second inclined surface 262c moves from the third position shown in fig. 14 to 16 to the fourth position shown in fig. 17 to 19.

Here, in the process of the second inclined surface 262c moving from the third position to the fourth position, the casing 10 and the developing roller 30 move in the first direction and the second direction together with the second inclined surface 262 c. Accordingly, the first inclined surface 61a contacts the outer circumferential surface 250 of the second guide roller 25. The second guide roller 25 gradually pushes out the first inclined surface 61a (the housing 10) from one side toward the other side in the second direction in accordance with the movement of the first inclined surface 61a from the other side toward the position of one side in the first direction. In this way, the first inclined surface 61a moves in the second direction by being pushed by the second guide roller 25, while moving in the first direction by being pressed by the drive shaft 103. Accordingly, the first inclined surface 61a moves from the first position shown in fig. 14 to 16 to the second position shown in fig. 17 to 19.

<9. overview of the second embodiment >

As described above, in the second embodiment, the drive shaft 103 presses the second inclined surface 262c in the direction from the other end portion of the housing 10 in the first direction toward the one end portion of the housing 10 in the first direction. When the drive shaft 103 presses the second inclined surface 262c, the second inclined surface 262c moves from the third position (fig. 14 to 16) to the fourth position (fig. 17 to 20). Here, the pressing force directed to one side from the other side in the first direction is converted into a force directed to the second direction by the contact between the driving shaft 103 and the second inclined surface 262 c. As a result, the developing roller 30 can be separated from the photosensitive drum 21.

Further, the developing cartridge 4 according to the second embodiment has a recessed portion 262, and the recessed portion 262 is positioned at the third outer surface 13 of one end portion of the casing 10 in the second direction. The recess 262 has a second inclined surface 262 c. Accordingly, the drive shaft 103 is inserted into the recessed portion 262 and pushes the second inclined surface 262c, so that the developing roller 30 can be separated from the photosensitive drum 21.

<10. modification >

The present disclosure is not limited to the above-described embodiments, but various changes may be made and various modifications may be conceived.

In the above-described embodiment, the elastic member 35 urges the developing roller 30 in the direction from one end portion of the casing 10 in the first direction toward the other end portion of the casing 10 in the first direction. However, the elastic member may push the housing 10 in a direction from one end of the housing 10 in the first direction toward the other end of the housing 10 in the first direction.

In the above embodiment, the elastic member 35 is a coil spring. Alternatively, a plate spring and a sponge may be used as the elastic member.

The drum cartridge 2 does not necessarily include the first guide roller 24 and the second guide roller 25. The first inclined surface may contact the drum frame of the drum cartridge when the first inclined surface moves from the first position to the second position. Further, the second inclined surface may contact the drum frame of the drum cartridge when the second inclined surface moves from the third position to the fourth position.

The shapes of the first cam 61 and the second cam 62 are not limited to the above. For example, the first cam may have a frustoconical shape similar to the second cam.

Further, the detailed configuration of the developing cartridge may be different from that described above and shown in the drawings, and the components in the above-described embodiments and modifications may be appropriately combined together as long as no technical conflict is caused.

[ list of reference marks ]

1: developing box

2: drum box

4: developing box

9: main body

10: shell body

10A: container with a lid

10B: cover

10C: opening of the container

11: first outer surface

12: second outer surface

13: third outer surface

14: a fourth outer surface

21: photosensitive drum

24: first guide roller

25: second guide roller

26: bearing part

27: bearing part

30: developing roller

31: roller body

32: developing roller shaft

33: collar

33 a: elastic member housing

33 b: bottom part

34: retaining ring

35: elastic member

38: handle bar

40: gear part

41: coupling device

43: gear cover

61: first cam

61 a: first inclined surface

61 b: one end edge

61 c: the other end edge

62: second cam

62 a: second inclined surface

62 b: pressure receiving surface

62c, the ratio of: one end edge

62 d: the other end edge

100: image forming apparatus

101: main body frame

102: controller

103: drive shaft

200: frame structure

201: first side frame

202: second side frame

240: outer peripheral surface (contact surface)

250: outer peripheral surface (contact surface)

262: concave part

262 c: second inclined surface

411: fixing hole

L1: first distance

L2: second distance

L3: third distance

L4: a fourth distance