WO2019064643A1

WO2019064643A1 - Developer cartridge

Info

Publication number: WO2019064643A1
Application number: PCT/JP2018/011011
Authority: WO
Inventors: 板橋　奈緒
Original assignee: ブラザー工業株式会社
Priority date: 2017-09-29
Filing date: 2018-03-20
Publication date: 2019-04-04
Also published as: JP7417876B2; JP2019066576A; JP2022092049A

Abstract

A developer cartridge structure is provided which allows positioning a developer roller without using the shaft of the developer roller. This developer cartridge has a housing that can house a developer. The housing has a first end and a second end in a first direction. Further, the housing has a rotation shaft part 53. The housing can rotate about the rotation shaft part 53. The developer cartridge has a first curved surface 631. In the first direction, the first curved surface 631 is positioned further away from an agitator shaft than a developer roller 30. The first curved surface 631 can rotate together with the housing. By means of this structure, it is possible to position the developer roller using not the shaft of the developer roller 30, but the first curved surface 631 and the rotation shaft part 53, which are separate from the developer roller 30.

Description

Developer cartridge

The present disclosure relates to a developing cartridge.

2. Description of the Related Art Conventionally, electrophotographic image forming apparatuses such as laser printers and LED printers are known. A developing cartridge is used in the image forming apparatus. The developing cartridge has a developing roller. A conventional developing cartridge is described in, for example, Patent Document 1. The developing cartridge of Patent Document 1 is mounted on a drum unit (process frame). The drum unit has a photosensitive drum. When the developing cartridge is inserted into the drum unit, the photosensitive drum and the developing roller face each other. Then, the drum unit on which the developing cartridge is mounted is accommodated inside the image forming apparatus.

JP 2011-59510 A

When the developing cartridge is mounted on the drum unit, the developing cartridge is positioned on the frame of the drum unit by the shaft of the developing roller. Thereby, the developing roller is positioned with respect to the photosensitive drum.

An object of the present invention is to provide a structure in which the developing roller can be positioned in the developing cartridge without using the shaft of the developing roller.

In order to solve the above-mentioned subject, the 1st invention of this application is a case which can store a developer, and is a case which has one end and the other end in the 1st direction, and is extended in the 2nd direction. A housing having a moving shaft and rotatable in a rotating direction about the rotating shaft, and an agitator capable of stirring the developer, the agitator having an agitator shaft extending in the second direction And a developing roller positioned closer to the one end than the agitator shaft in the first direction, the developing roller being rotatable about a rotation axis extending in the second direction and rotatable with the housing A first curved surface that curves in the rotation direction, and is further away from the agitator shaft than the developing roller in the first direction, and can be rotated in the rotation direction with the housing First Characterized in that it comprises a curved surface, the.

A second invention of the present application is the developing cartridge of the first invention, wherein a distance between the developing roller and the first curved surface in the first direction is a fixed distance.

A third invention of the present application is the developing cartridge of the first invention or the second invention, wherein the diameter of the first curved surface is smaller than the diameter of the outer peripheral surface of the developing roller.

A fourth invention of the present application is the developing cartridge according to any one of the first invention to the third invention, wherein the case includes the first curved surface.

A fifth invention of the present application is the developing cartridge according to any one of the first invention to the fourth invention, wherein the developing cartridge is rotatable about a rotation shaft extending in the second direction, and is more than the developing roller in the first direction. It is characterized by further comprising: a first roller located apart from the agitator shaft, the first roller being rotatable in the rotation direction together with the casing and having the first curved surface.

A sixth invention of the present application is the developing cartridge of the fifth invention, wherein an interval between the developing roller and the first roller in the first direction is a fixed distance.

A seventh invention of the present application is the developing cartridge of the fifth invention or the sixth invention, wherein the diameter of the outer peripheral surface of the first roller is smaller than the diameter of the outer peripheral surface of the developing roller.

An eighth invention of the present application is the developing cartridge according to any one of the fifth invention to the seventh invention, wherein the case includes an axis of the first roller.

A ninth invention of the present application is the developing cartridge according to any one of the first invention to the eighth invention, wherein the developing cartridge is mounted on a drum unit having a photosensitive drum rotatable about a rotating shaft extending in the second direction. In the state where the developing cartridge is mounted on the drum unit, the first peripheral surface of the developing roller is in contact with the outer peripheral surface of the photosensitive drum, and in the state where the developing cartridge is mounted on the drum unit, The curved surface is in contact with the outer peripheral surface of the photosensitive drum.

A tenth invention of the present application is the developing cartridge of the ninth invention, wherein the housing, the developing roller, and the first curved surface with respect to the drum unit in a state where the developing cartridge is mounted to the drum unit. After rotating in the rotation direction, the outer circumferential surface of the developing roller contacts the outer circumferential surface of the photosensitive drum, and the first curved surface contacts the outer circumferential surface of the photosensitive drum.

The eleventh invention of the present application is the developing cartridge of the tenth invention, wherein the outer peripheral surface of the developing roller contacts the outer peripheral surface of the photosensitive drum after the first curved surface contacts the outer peripheral surface of the photosensitive drum. It is characterized by

A twelfth invention of the present application is the developing cartridge of the first invention, wherein the second curved surface is curved in the rotation direction, and is further away from the agitator shaft than the developing roller in the first direction. It is a second curved surface that is located and can be rotated in the rotation direction together with the housing, and further includes a second curved surface located away from the first curved surface in the second direction. .

A thirteenth invention of the present application is the developing cartridge of the twelfth invention, wherein a distance between the developing roller and the first curved surface in the first direction is a fixed distance, and the developing roller and the developing roller in the first direction are the same. The distance between the second curved surface and the second curved surface is a constant distance.

A fourteenth invention of the present application is the developing cartridge according to the twelfth invention or the thirteenth invention, wherein the diameter of the first curved surface is smaller than the diameter of the outer peripheral surface of the developing roller, and the diameter of the second curved surface is And a diameter smaller than the diameter of the outer peripheral surface of the developing roller.

A fifteenth invention of the present application is the developing cartridge according to any one of the twelfth invention to the fourteenth invention, wherein the casing includes the first curved surface and the second curved surface. .

A sixteenth invention of the present application is the developing cartridge according to any one of the twelfth invention to the fifteenth invention, wherein the developing cartridge is rotatable about a rotation shaft extending in the second direction, and is more than the developing roller in the first direction. A first roller located apart from the agitator shaft, the first roller having a first curved surface and being rotatable in the pivoting direction together with the housing; and a rotation shaft extending in the second direction A second roller, which is rotatable in the first direction and is farther from the agitator shaft than the developing roller in the first direction, and is rotatable in the pivoting direction together with the housing; And a second roller having a surface.

A seventeenth invention of the present application is the developing cartridge according to the sixteenth invention, wherein a distance between the developing roller and the first roller in the first direction is a fixed distance, and the developing roller and the first roller in the first direction The distance between the two rollers is characterized by a fixed distance.

The eighteenth invention of the present application is the developing cartridge according to the sixteenth invention or the seventeenth invention, wherein the diameter of the outer peripheral surface of the first roller is smaller than the diameter of the outer peripheral surface of the developing roller, and the outer periphery of the first roller The diameter of the surface is smaller than the diameter of the outer peripheral surface of the developing roller.

A nineteenth invention of the present application is the developing cartridge according to any one of the sixteenth invention to the eighteenth invention, wherein the housing includes an axis of the first roller and an axis of the second roller. I assume.

The twentieth invention of the present application is the developing cartridge according to any one of the twelfth to nineteenth inventions, wherein the developing cartridge is mounted on a drum unit having a photosensitive drum rotatable about a rotating shaft extending in the second direction. In the state where the developing cartridge is mounted on the drum unit, the first peripheral surface of the developing roller is in contact with the outer peripheral surface of the photosensitive drum, and in the state where the developing cartridge is mounted on the drum unit, The curved surface and the second curved surface are in contact with the outer peripheral surface of the photosensitive drum.

A twenty-first invention of the present application is the developing cartridge according to the twentieth invention, wherein the housing, the developing roller, and the first curved surface with respect to the drum unit in a state where the developing cartridge is mounted to the drum unit. After the second curved surface is rotated in the rotation direction, the outer peripheral surface of the developing roller contacts the outer peripheral surface of the photosensitive drum, and the first curved surface and the second curved surface are photosensitive. Contacting the outer peripheral surface of the drum.

A twenty-second invention of the present application is the developing cartridge according to the twenty-first invention, wherein the outer peripheral surface of the developing roller is the above-mentioned outer surface after the first curved surface and the second curved surface contact the outer peripheral surface of the photosensitive drum. It contacts the outer peripheral surface of the photosensitive drum.

A twenty-third invention of the present application is the developing cartridge according to any one of the first invention to the twenty-second invention, wherein the pivot shaft portion extends in the second direction from the outer surface of the housing. It is characterized by

A twenty-fourth invention of the present application is the developing cartridge according to any one of the first invention to the twenty-third invention, wherein the pressing receiving surface is positioned closer to the other end than the pivot shaft in the first direction. And further comprising a pressing receiving surface for receiving the pressing force.

A twenty-fifth invention of the present application is the developing cartridge according to the twenty-fourth invention, wherein the pressing receiving surface receives the pressing force along the rotation direction.

The 26th invention of the present application is the developing cartridge according to any one of the 9th to 11th inventions or the 20th to 22nd inventions, wherein the developing roller is provided along the rotation axis. The developing roller shaft extends in the second direction, and the developing roller shaft and the drum unit are not in contact with each other.

A twenty-seventh invention of the present application is the developing cartridge according to any one of the first invention to the twenty-sixth invention, wherein the casing is rotated in the rotational direction about the rotational shaft according to an external force. It is characterized by being movable.

According to the first to twenty-seventh aspects of the present invention, it is possible to position the developing roller not by the shaft of the developing roller but by using the pivot shaft portion and the first curved surface different from the developing roller.

Further, according to the twelfth invention, the developing roller can be positioned using the first curved surface and the second curved surface separated in the second direction from the first curved surface. Thereby, the developing roller can be positioned more accurately.

1st Embodiment: It is a perspective view of a developing cartridge and a drum unit. First embodiment: a partial exploded perspective view of a developing cartridge. 1st Embodiment: It is the figure which showed a mode when mounting | wearing with a developing cartridge. 1st Embodiment: It is the figure which showed a mode when mounting | wearing with a developing cartridge. 1st Embodiment: It is the figure which showed a mode when mounting | wearing with a developing cartridge. Second embodiment: an exploded perspective view of a developing cartridge.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

Hereinafter, the direction in which the agitator and the developing roller are arranged will be referred to as a "first direction". Further, the direction in which the rotation shaft of the developing roller extends is referred to as a "second direction". The first direction and the second direction intersect (preferably are orthogonal to) each other. The structure of the drum unit will also be described using the “first direction” and the “second direction” in the state where the developing cartridge is mounted on the drum unit.

<1. First embodiment>
<1-1. Structure of developing cartridge and drum unit>
FIG. 1 is a perspective view of the developing cartridge 1 and the drum unit 9 according to the first embodiment. The developing cartridge 1 and the drum unit 9 are used in an electrophotographic image forming apparatus. Examples of the image forming apparatus include a laser printer and an LED printer. The drum unit 9 is removable from the image forming apparatus. That is, the drum unit 9 is a replaceable cartridge. As shown in FIG. 1, the frame 90 of the drum unit 9 has four cartridge holding portions 91. The drum unit 9 also has a photosensitive drum 92 for each of the cartridge holding portions 91. Each photosensitive drum 92 is rotatable about a rotational axis extending in the second direction. Each photosensitive drum 92 has a cylindrical outer peripheral surface centered on the rotation axis.

The developing cartridge 1 is attachable to and detachable from the cartridge holding unit 91. In the present embodiment, four developing cartridges 1 are attached to one drum unit 9. The four developing cartridges 1 contain developers of different colors (for example, cyan, magenta, yellow, and black). An example of the developer is toner. However, the number of developing cartridges 1 mounted to the drum unit 9 may be one to three, or five or more.

FIG. 2 is a partially exploded perspective view of the developing cartridge 1. As shown in FIGS. 1 and 2, the developing cartridge 1 has a casing 10, an agitator 20, a developing roller 30, a gear portion 40, a gear cover 50, and a bearing plate 60.

The casing 10 is a housing capable of containing a developer. The casing 10 has a first outer surface 11 and a second outer surface 12. The first outer surface 11 is located at one end of the casing 10 in the second direction. The second outer surface 12 is located at the other end of the casing 10 in the second direction. The casing 10 extends in a second direction between the first outer surface 11 and the second outer surface 12. The gear portion 40, the gear cover 50, and the bearing plate 60 are located on the first outer surface 11. Further, inside the casing 10, a storage chamber 13 is provided. The developer is stored in the storage chamber 13.

The casing 10 also has one end 15 and the other end 16 in the first direction. An opening 14 is provided in the vicinity of one end 15 of the casing 10. The storage chamber 13 and the outside communicate with each other through the opening 14.

The agitator 20 has an agitator shaft 21 and an agitation blade 22. The agitator shaft 21 is rotatable about a rotational axis extending in the second direction. The stirring blade 22 spreads radially outward from the agitator shaft 21. At least a part of the agitator shaft 21 and the stirring blade 22 are located in the storage chamber 13. One end of the agitator shaft 21 in the second direction is non-rotatably fixed to the agitator gear 42 included in the gear portion 40. Therefore, the agitator shaft 21 and the stirring blade 22 rotate with the agitator gear 42. When the stirring blade 22 rotates, the developer in the storage chamber 13 is stirred.

The developing roller 30 is a roller that is rotatable about a rotation axis extending in the second direction. The developing roller 30 is located at the opening 14 of the casing 10. That is, the developing roller 30 is positioned closer to the one end 15 than the agitator shaft 21 in the first direction. When the developing cartridge 1 is attached to the cartridge holding portion 91 of the drum unit 9, the outer peripheral surface of the developing roller 30 contacts the outer peripheral surface of the photosensitive drum 92.

The developing roller 30 of the present embodiment has a developing roller main body 31 and a developing roller shaft 32. The developing roller main body 31 is a cylindrical member extending in the second direction. As a material of the developing roller main body 31, for example, rubber having elasticity is used. The developing roller shaft 32 is a cylindrical member penetrating the developing roller main body 31 in the second direction. For the material of the developing roller shaft 32, metal or resin having conductivity is used. The developing roller main body 31 is fixed to the developing roller shaft 32 so as not to be relatively rotatable.

The developing roller gear 43 included in the gear portion 40 is attached to one end of the developing roller shaft 32 in the second direction. More specifically, one end of the developing roller shaft 32 in the second direction is non-rotatably fixed to the developing roller gear 43. Therefore, when the developing roller gear 43 rotates, the developing roller shaft 32 also rotates, and the developing roller main body 31 also rotates with the developing roller shaft 32.

The developing roller shaft 32 may not penetrate through the developing roller main body 31 in the second direction. For example, the pair of developing roller shafts 32 may extend in the first direction from both ends of the developing roller main body 31 in the second direction. Specifically, the developing roller shaft 32 may be bonded or welded as separate parts to both ends of the developing roller main body 31 in the second direction.

Further, the developing cartridge 1 has a supply roller whose illustration is omitted. The supply roller is located between the developing roller 30 and the agitator 20. Also, the supply roller is rotatable about a rotation axis extending in the second direction. When the developing cartridge 1 receives the driving force, the developer is supplied from the storage chamber 13 in the casing 10 to the outer peripheral surface of the developing roller 30 through the supply roller. At this time, the developer is frictionally charged between the supply roller and the developing roller 30. On the other hand, a bias voltage is applied to the developing roller shaft 32 of the developing roller 30. For this reason, the developer is attracted to the outer peripheral surface of the developing roller main body 31 by the electrostatic force between the developing roller shaft 32 and the developer.

Further, the developing cartridge 1 has a layer thickness regulating blade whose illustration is omitted. The layer thickness regulating blade shapes the developer supplied to the outer peripheral surface of the developing roller main body 31 into a constant thickness. Thereafter, the developer on the outer peripheral surface of the developing roller main body 31 is supplied to the photosensitive drum 92 of the drum unit 9. At this time, the developer moves from the developing roller main body 31 to the photosensitive drum 92 in accordance with the electrostatic latent image formed on the outer peripheral surface of the photosensitive drum 92. Thereby, the electrostatic latent image is visualized on the outer peripheral surface of the photosensitive drum 92.

The gear portion 40 is located on the first outer surface 11 of the casing 10. The gear portion 40 has a plurality of gears including the agitator gear 42 and the developing roller gear 43 described above, and a coupling 41. The coupling 41 has a fastening hole 411. When the drum unit 9 to which the developing cartridge 1 is mounted is stored in the image forming apparatus, the drive shaft of the image forming apparatus is inserted into the fastening hole 411 of the coupling 41. Then, the rotation of the drive shaft is transmitted to the plurality of gears including the agitator gear 42 and the developing roller gear 43 through the coupling 41.

In FIG. 2, illustration of the teeth of each gear included in the gear portion 40 is omitted. The plurality of gears included in the gear portion 40 may transmit rotational force by meshing of teeth, or may transmit rotational force by friction. For example, the plurality of gears may have an outer circumferential surface made of rubber instead of the teeth.

The gear cover 50 is fixed to the first outer surface 11 of the casing 10, for example, by screwing. The gear cover 50, together with the casing 10 and the bearing plate 60, constitutes a part of the housing of the developing cartridge 1. At least a portion of the plurality of gears of the gear unit 40 is covered by a gear cover 50. The outer surface of the gear cover 50 has an extending portion 51 extending in the second direction. A circular hole 52 is provided at the tip of the extension 51. The coupling 41 fits in the circular hole 52. Therefore, the fastening hole 411 of the coupling 41 is exposed to the outside from the gear cover 50.

Further, the extension portion 51 of the gear cover 50 has a first rotation shaft portion 53. The first pivot shaft portion 53 protrudes from the surface of the extending portion 51 in a third direction crossing (preferably orthogonal to) the first direction and the second direction, and extends in the second direction. In addition, the casing 10 has a second rotation shaft 17 at the other end in the second direction. The second pivot shaft portion 17 protrudes in the third direction from the surface of the casing 10 and extends in the second direction. When viewed in the second direction, at least a portion of the first pivoting shaft portion 53 and at least a portion of the second pivoting shaft portion 17 are in an overlapping position.

When the developing cartridge 1 is attached to the cartridge holding portion 91 of the drum unit 9, the first pivoting shaft portion 53 and the second pivoting shaft portion 17 contact the frame 90 of the drum unit 9. Then, the casing 10, the agitator 20, the developing roller 30, the gear portion 40, the gear cover 50, and the bearing plate 60 perform the first rotation in accordance with the external force received from the first pressing portion 95 and the second pressing portion 96 described later. It pivots around the shaft 53 and the second pivot shaft 17.

The bearing plate 60 is located between the casing 10 and the gear cover 50 in the second direction. The bearing plate 60 constitutes a part of the housing of the developing cartridge 1 together with the casing 10 and the gear cover 50. The coupling 41 and the developing roller gear 43 described above are located between the bearing plate 60 and the gear cover 50. The agitator gear 42 described above is located between the casing 10 and the bearing plate 60. The bearing plate 60 has a flat portion 61 and a bearing protrusion 62. The flat portion 61 spreads perpendicularly to the second direction. The bearing projection 62 projects in the second direction from the flat plate portion 61 toward the gear cover 50. The coupling 41 rotates while being supported by the bearing projection 62.

The flat portion 61 of the bearing plate 60 has a first curved surface 63. The first curved surface 63 is located at one end of the bearing plate 60 in the first direction. Further, the first curved surface 63 is positioned farther from the agitator shaft 21 than the developing roller 30 in the first direction. The first curved surface 63, together with the other portions of the bearing plate 60, is pivotable about the first pivot shaft portion 53 and the second pivot shaft portion 17 described above. The first curved surface 63 protrudes in a pivoting direction about the first pivoting shaft portion 53 and the second pivoting shaft portion 17. In addition, the first curved surface 63 is curved in an arc shape around an axis extending in the second direction.

The casing 10 also has a second curved surface 18 at the other end in the second direction. The second curved surface 18 is located at one end of the second outer surface 12 of the casing 10 in the first direction. Further, the second curved surface 18 is positioned farther from the agitator shaft 21 than the developing roller 30 in the first direction. The second curved surface 18, together with the other parts of the casing 10, is pivotable about the first pivot shaft 53 and the second pivot shaft 17 described above. The second curved surface 18 protrudes in a pivoting direction about the first pivoting shaft 53 and the second pivoting shaft 17. In addition, the second curved surface 18 curves in an arc shape around an axis extending in the second direction.

The first curved surface 63 and the second curved surface 18 are spaced apart in the second direction. However, at least a portion of the first curved surface 63 and at least a portion of the second curved surface 18 are in an overlapping position when viewed in the second direction. Moreover, the 1st curved surface 63 and the 2nd curved surface 18 have the same diameter. The diameters of the first curved surface 63 and the second curved surface 18 are smaller than the diameter of the outer peripheral surface of the developing roller 30. Further, the distance between the developing roller 30 and the first curved surface 63 in the first direction is a fixed distance. Further, the distance between the developing roller 30 and the second curved surface 18 in the first direction is also a fixed distance.

<1-2. Mounting operation of developing cartridge to drum unit>
Subsequently, an operation when the developing cartridge 1 is attached to the cartridge holding portion 91 of the drum unit 9 will be described.

As shown in FIG. 1, the frame 90 of the drum unit 9 has a first contact surface 93 and a second contact surface 94 for each cartridge holding portion 91. The first contact surface 93 is located at one end of the cartridge holding portion 91 in the second direction. The first contact surface 93 is a surface that intersects (preferably is orthogonal to) the third direction and extends in the second direction. The second contacted surface 94 is located at the other end of the cartridge holding portion 91 in the second direction. The second contact surface 94 is a surface that intersects (preferably is orthogonal to) the third direction and extends in the first direction.

As shown in FIG. 1, the frame 90 of the drum unit 9 has a first pressing portion 95 and a second pressing portion 96 for each cartridge holding portion 91. The first pressing portion 95 is located at one end of the cartridge holding portion 91 in the second direction. The first contact surface 93 and the first pressing portion 95 face each other in the third direction. The second pressing portion 96 is located at the other end of the cartridge holding portion 91 in the second direction. The second contact surface 94 and the second pressing portion 96 face each other in the third direction.

FIGS. 3 to 5 are views showing how the developing cartridge 1 is attached to the cartridge holding portion 91. FIG. As shown in FIGS. 3 to 5, the first pressing portion 95 has a coil spring 951 and a pressing member 952. The coil spring 951 is an elastic member that can expand and contract in the third direction. One end of the coil spring 951 in the third direction is connected to the pressing member 952. The other end of the coil spring 951 in the third direction is connected to the frame 90 of the drum unit 9. The coil spring 951 is compressed in the third direction than the natural length. In addition, the coil spring 95 expands and contracts in the third direction between the first length and the second length shorter than the first length. When the coil spring 951 has the first length, the pressing member 952 is disposed at the first position. When the coil spring 951 has a second length, the pressing member 952 is disposed at a second position farther from the first contacted surface 93 than the first position. The pressing member 952 has a pressing surface 953 that protrudes in the third direction toward the first contact surface 93.

Similarly to the first pressing portion 95, the second pressing portion 96 also has a coil spring and a pressing member.

When the developing cartridge 1 is inserted into the cartridge holding portion 91, first, the first pivot shaft portion 53 of the gear cover 50 contacts the first contact surface 93 of the frame 90 as shown in FIG. Similarly, the second pivot shaft 17 of the casing 10 contacts the second contact surface 94 of the frame 90.

Subsequently, of the outer surface of the extending portion 51 of the gear cover 50, the surface (hereinafter referred to as the “first pressing receiving surface”) 54 opposite to the first pivot shaft portion 53 in the third direction 1 Contact the pressing portion 95. Specifically, the first pressing receiving surface 54 contacts the pressing surface 953. Thereby, the length of the coil spring 951 contracts from the first length to the second length. The first pressure receiving surface 54 receives a pressing force in the third direction from the first pressing portion 95. Further, also at the other end of the casing 10 in the second direction, the surface (hereinafter referred to as the “second pressure receiving surface”) 19 opposite to the second rotation shaft 17 in the third direction is the second Contact the pressing portion 96. Thereby, the second pressure receiving surface 19 receives the pressing force in the third direction from the second pressing portion 96.

The first pressing receiving surface 54 is located closer to the other end 16 than the first pivot shaft 53 in the first direction. That is, the first pressing receiving surface 54 is at a position farther from the developing roller 30 than the first rotation shaft 53 in the first direction. Further, the second pressing receiving surface 19 is positioned closer to the other end than the second pivot shaft 17 in the first direction. That is, the second pressing receiving surface 19 is located at a position farther from the developing roller 30 than the second rotating shaft portion 17 in the first direction.

The pressing force received by the first pressing receiving surface 54 and the second pressing receiving surface 19 has a component of force along the rotation direction about the first rotation shaft 53 and the second rotation shaft 17. . Therefore, the developing cartridge 1 receives the pressing force received by the first pressing receiving surface 54 and the second pressing receiving surface 19 around the first pivot shaft portion 53 and the second pivot shaft portion 17 in FIG. Rotate in the direction of the dashed arrow. Accordingly, the developing roller 30, the first curved surface 63, and the second curved surface 18 also pivot about the first pivot shaft portion 53 and the second pivot shaft portion. As a result, the developing roller 30, the first curved surface 63, and the second curved surface 18 approach the photosensitive drum 92. Then, first, as shown in FIG. 4, the first curved surface 63 and the second curved surface 18 contact the outer peripheral surface of the photosensitive drum 92. Thereafter, as shown in FIG. 5, the outer circumferential surface of the developing roller 30 contacts the outer circumferential surface of the photosensitive drum 92. As a result, the position and attitude of the developing cartridge 1 with respect to the photosensitive drum 92 are fixed. Then, the outer peripheral surface of the photosensitive drum 92 and the outer peripheral surface of the developing roller 30 are maintained in contact with each other.

As described above, the developing cartridge 1 according to the present embodiment is not positioned on the frame 90 of the drum unit 9 using the developing roller shaft 32, but the first rotation shaft 53 and the second rotating shaft different from the developing roller shaft 32. The developing roller 30 is positioned using the pivot shaft portion 17, the first curved surface 63, and the second curved surface 18. The developing roller shaft 32 and the frame 90 of the drum unit 9 are not in contact with each other. That is, the developing roller shaft 32 and the frame 90 of the drum unit 9 are not in direct contact with each other nor in indirect contact with other members. Therefore, the developing roller 30 can be positioned independently of the dimensional accuracy of the developing roller shaft 32.

Conventionally, positioning of the developing roller with respect to the photosensitive drum involved many parts. Specifically, the outer peripheral surface of the photosensitive drum, the bearing of the photosensitive drum provided on the frame of the drum unit, and the guide groove for the developing roller shaft provided on the frame concerned with the positioning of the developing roller with respect to the photosensitive drum . Further, the developing roller shaft, and in some cases, a collar attached to the developing roller shaft, a bearing of the developing roller, and an outer peripheral surface of the developing roller are also involved in the positioning of the developing roller with respect to the photosensitive drum. On the other hand, in the structure of the present embodiment, the developing roller relative to the photosensitive drum 92 is constituted by the surface of the photosensitive drum 92, the first curved surface 63 and the second curved surface 18 of the bearing plate 60, and the outer peripheral surface of the developing roller 30. 30 positioning can be performed. This reduces the number of parts involved in positioning. As a result, it is possible to suppress the positioning error caused by the tolerance of each part.

Also, conventionally, the guide grooves of the frame are provided along the direction in which the photosensitive drums are arranged. Therefore, in the conventional structure, it is necessary to widen the interval between the adjacent photosensitive drums. On the other hand, in the structure of the present embodiment, it is not necessary to provide the frame 90 with the guide groove. Therefore, the distance between the adjacent photosensitive drums 92 can be made narrower than in the prior art.

As described above, in the first embodiment, after the first curved surface 63 and the second curved surface 18 contact the outer peripheral surface of the photosensitive drum 92, the outer peripheral surface of the developing roller 30 is formed on the outer peripheral surface of the photosensitive drum 92. Contact. In this case, the contact pressure of the first curved surface 63 and the second curved surface 18 with respect to the outer peripheral surface of the photosensitive drum 92 when the developing cartridge 1 is mounted to the cartridge holding portion 91 is increased.

However, after the outer peripheral surface of the developing roller 30 contacts the outer peripheral surface of the photosensitive drum 92, the first curved surface 63 and the second curved surface 18 may contact the outer peripheral surface of the photosensitive drum 92. In this case, the contact pressure of the outer peripheral surface of the developing roller 30 with the outer peripheral surface of the photosensitive drum 92 becomes large when the developing cartridge 1 is mounted in the cartridge holding portion 91. When the developing cartridge 1 is removed from the cartridge holding portion 91, the contact pressure of the first curved surface 63 and the second curved surface 18 with respect to the outer peripheral surface of the photosensitive drum 92 may be temporarily increased.

Further, immediately after the developing cartridge 1 is inserted into the cartridge holding portion 91 of the drum unit 9, all of the developing roller 30, the first curved surface 63, and the second curved surface 18 necessarily contact the outer peripheral surface of the photosensitive drum 92. You do not have to. After the drum unit is inserted into the image forming apparatus, the photosensitive drum 92 and the developing roller 30 start rotating by the driving force from the image forming apparatus, whereby the developing roller 30, the first curved surface 63, and the second curved surface It is sufficient that all the components 18 contact the outer peripheral surface of the photosensitive drum 92.

For example, after the developing cartridge 1 is inserted into the cartridge holding portion 91 of the drum unit 9, the first curved surface 63 and the second curved surface 18 are in contact with the outer peripheral surface of the photosensitive drum 92. When the photosensitive drum 92 is not in contact with the outer circumferential surface of the photosensitive drum 92, the frictional force between the photosensitive drum 92 and the first curved surface 63 caused by the rotation of the photosensitive drum 92 and the photosensitive drum 92 and the second curved surface 18. The first curved surface 63 and the second curved surface 18 move in the rotational direction of the photosensitive drum 92 by the frictional force. Thereby, the outer peripheral surface of the developing roller 30 may be in contact with the outer peripheral surface of the photosensitive drum 92.

In addition, for example, after the developing cartridge 1 is inserted into the cartridge holding portion 91 of the drum unit 9, the outer peripheral surface of the developing roller 30 is in contact with the outer peripheral surface of the photosensitive drum 92. When the surface 18 is not in contact with the outer peripheral surface of the photosensitive drum 92, the developing roller 30 moves on the outer peripheral surface of the photosensitive drum 92 because the rotational speed of the developing roller 30 is faster than the rotational speed of the photosensitive drum 92. . Thereby, the first curved surface 63 and the second curved surface 18 may be in contact with the outer peripheral surface of the photosensitive drum 92.

In the present embodiment, the first curved surface 63 is included in the bearing plate 60 that constitutes a part of the housing of the developing cartridge 1. Therefore, it is not necessary to provide a member having the first curved surface 63 separately from the bearing plate 60. Thereby, the number of parts of the developing cartridge 1 can be suppressed. Further, in the present embodiment, the second curved surface 18 is included in the casing 10 that constitutes a part of the housing of the developing cartridge 1. Therefore, it is not necessary to provide a member having the second curved surface 18 separately from the casing 10. Thereby, the number of parts of the developing cartridge 1 can be suppressed. However, the first curved surface 63 and the second curved surface 18 may be provided on a member different from the housing of the developing cartridge 1.

Further, in the present embodiment, the diameter of the first curved surface 63 is smaller than the diameter of the outer peripheral surface of the developing roller 30. Further, the diameter of the second curved surface 18 is smaller than the diameter of the outer peripheral surface of the developing roller 30. Thereby, the mounting of the developing cartridge 1 to the cartridge holding portion 91 is facilitated. Further, even when the drum unit is miniaturized, the diameter of the first curved surface 63 is smaller than the diameter of the outer peripheral surface of the developing roller 30, and the diameter of the second curved surface 18 is the diameter of the outer peripheral surface of the developing roller 30. Since the size is smaller than this, mounting of the developing cartridge 1 to the cartridge holding portion 91 is facilitated.

<2. Second embodiment>
Subsequently, the developing cartridge 1 of the second embodiment will be described.

The developing cartridge 1 according to the second embodiment is different from that according to the first embodiment in that the first roller 71 and the second roller 72 are provided. In the following, differences from the first embodiment will be mainly described, and parts equivalent to the first embodiment will be assigned the same reference numerals as in the first embodiment and redundant description will be omitted.

FIG. 6 is an exploded perspective view of the developing cartridge 1 of the second embodiment. The illustration of the gear cover 50 is omitted in FIG. As shown in FIG. 6, in the second embodiment, the casing 10 has a first roller shaft 711 and a second roller shaft 721. The first roller shaft 711 is located at one end of the first outer surface 11 of the casing 10 in the first direction. That is, the first roller shaft 711 is positioned farther from the agitator shaft 21 than the developing roller 30 in the first direction. The first roller shaft 711 is cylindrical and extends in the second direction. The second roller shaft 721 is located at one end of the second outer surface 12 of the casing 10 in the first direction. That is, the second roller shaft 721 is positioned farther from the agitator shaft 21 than the developing roller 30 in the first direction. The second roller shaft 721 is cylindrical and extends in the second direction.

The first roller 71 is a roller having a cylindrical outer peripheral surface (first curved surface). The second roller 72 is a roller having a cylindrical outer peripheral surface (second curved surface). The diameters of the outer peripheral surfaces of the first roller 71 and the second roller 72 are smaller than the diameter of the outer peripheral surface of the developing roller 30. The first roller 71 is supported by the first roller shaft 711 and is rotatable about a rotation axis extending in the second direction. The second roller 72 is rotatable about a rotational axis extending in the second direction while being supported by the second roller shaft 721. The first roller 71 and the second roller 72 are positioned farther from the agitator shaft 21 than the developing roller 30 in the first direction. When the casing 10 pivots about the first pivot shaft portion 53 and the second pivot shaft portion 17, the first roller 71 and the second roller 72 also cooperate with the casing 10 with the first pivot shaft portion 53 and the first pivot shaft portion 53. 2 Pivot about the pivot shaft portion 17.

The first roller 71 and the second roller 72 are separated in the second direction. However, at least a portion of the first roller 71 and at least a portion of the second roller 72 are in an overlapping position when viewed in the second direction. The outer peripheral surface of the first roller 71 and the outer peripheral surface of the second roller 72 have the same diameter. The diameters of the outer peripheral surfaces of the first roller 71 and the second roller 72 are smaller than the diameter of the outer peripheral surface of the developing roller 30. Further, the distance between the developing roller 30 and the first roller 71 in the first direction is a fixed distance. The distance between the developing roller 30 and the second roller 72 in the first direction is also a fixed distance.

When the developing cartridge 1 of the second embodiment is attached to the cartridge holding portion 91 of the drum unit 9, as in the first embodiment, developing is performed by the pressing force from the first pressing portion 95 and the second pressing portion 96. The cartridge 1 pivots about the first pivot shaft portion 53 and the second pivot shaft portion 17. At this time, together with the casing 10, the developing roller 30, the first roller 71, and the second roller 72 rotate around the first rotation shaft 53 and the second rotation shaft 17. As a result, the developing roller 30, the first roller 71, and the second roller 72 contact the photosensitive drum 92. As a result, the position and attitude of the developing cartridge 1 with respect to the photosensitive drum 92 are fixed. Then, the outer peripheral surface of the photosensitive drum 92 and the outer peripheral surface of the developing roller 30 are maintained in contact with each other.

The developing cartridge 1 further includes a third roller 73 and a fourth roller 74. The third roller 73 is located at one end of the developing roller main body 31 in the second direction. The third roller 73 is rotatably supported at one end of the developing roller shaft 32 in the second direction. The fourth roller 74 is located at the other end of the developing roller main body 31 in the second direction. The fourth roller 74 is rotatably supported by the other end of the developing roller shaft 32 in the second direction. As a result, even when the outer peripheral surface of the developing roller main body 31 is excessively pressed against the outer peripheral surface of the photosensitive drum 92, the third roller 73 and the fourth roller 74 contact the surface of the photosensitive drum 92. Therefore, the pressing force of the developing roller main body 31 against the outer peripheral surface of the photosensitive drum 92 can be appropriately adjusted.

As described above, also in the second embodiment, instead of positioning using the developing roller shaft 32 to the frame 90 of the drum unit 9, the first pivoting shaft 53 and the second pivot different from the developing roller shaft 32. The developing roller 30 is positioned using the shaft portion 17, the first roller 71, and the second roller 72. The developing roller shaft 32 and the frame 90 of the drum unit 9 are not in contact with each other. That is, the developing roller shaft 32 and the frame 90 of the drum unit 9 are not in direct contact with each other nor in indirect contact with other members. Therefore, the developing roller 30 can be positioned independently of the dimensional accuracy of the developing roller shaft 32.

Also in the second embodiment, the positioning of the developing roller 30 with respect to the photosensitive drum 92 can be performed with a smaller number of parts than in the prior art. For this reason, the positioning error resulting from the tolerance of each part can be suppressed.

In particular, in the present embodiment, the outer peripheral surface of the first roller 71 which is the first curved surface is rotatable around the first roller shaft 711. Further, the outer peripheral surface of the second roller 72 which is a second curved surface is rotatable around the second roller shaft 721. Therefore, when the first roller 71 and the second roller 72 contact the photosensitive drum 92, the space between the outer circumferential surface of the first roller 71 or the outer circumferential surface of the second roller 72 and the outer circumferential surface of the photosensitive drum 92 , Less likely to rub. In addition, it is possible to suppress the abrasion of the surface of the photosensitive drum 92. Further, the rotational torque of the photosensitive drum 92 can be reduced.

Further, in the present embodiment, the first roller shaft 711 is included in the casing 10 that constitutes a part of the housing of the developing cartridge 1. Therefore, it is not necessary to provide a member having the first roller shaft 711 separately from the casing 10. Thereby, the number of parts of the developing cartridge 1 can be suppressed. Further, in the present embodiment, the second roller shaft 721 is included in the casing 10 that constitutes a part of the housing of the developing cartridge 1. Therefore, there is no need to provide a member having the second roller shaft 721 separately from the casing 10. Thereby, the number of parts of the developing cartridge 1 can be suppressed. However, the first roller shaft 711 and the second roller shaft 721 may be provided on a member different from the housing of the developing cartridge 1.

When the developing cartridge 1 of the second embodiment is attached to the cartridge holding portion 91 of the drum unit 9, for example, the outer peripheral surface of the first roller 71 and the outer peripheral surface of the second roller 72 make contact with the outer peripheral surface of the photosensitive drum 92. Thereafter, the outer peripheral surface of the developing roller 30 contacts the outer peripheral surface of the photosensitive drum 92. In this case, the contact pressure between the outer peripheral surface of the first roller 71 and the outer peripheral surface of the second roller 72 with respect to the outer peripheral surface of the photosensitive drum 92 when the developing cartridge 1 is mounted in the cartridge holding portion 91 is increased.

However, the outer peripheral surface of the first roller 71 and the outer peripheral surface of the second roller 72 may be in contact with the outer peripheral surface of the photosensitive drum 92 after the outer peripheral surface of the developing roller 30 contacts the outer peripheral surface of the photosensitive drum 92 . In this case, the contact pressure of the outer peripheral surface of the developing roller 30 with the outer peripheral surface of the photosensitive drum 92 becomes large when the developing cartridge 1 is mounted in the cartridge holding portion 91. When the developing cartridge 1 is removed from the cartridge holding portion 91, the contact pressure between the outer peripheral surface of the first roller 71 and the outer peripheral surface of the second roller 72 against the outer peripheral surface of the photosensitive drum 92 temporarily increases. Good.

Immediately after the developing cartridge 1 is inserted into the cartridge holding portion 91 of the drum unit 9, all of the developing roller 30, the first roller 71, and the second roller 72 are in contact with the outer peripheral surface of the photosensitive drum 92. It does not have to be. After the drum unit is inserted into the image forming apparatus, the photosensitive drum 92 and the developing roller 30 start rotating by the driving force from the image forming apparatus, whereby the outer peripheral surface of the developing roller 30, the outer peripheral surface of the first roller 71, The entire outer peripheral surface of the second roller 72 may be in contact with the outer peripheral surface of the photosensitive drum 92.

Further, in the present embodiment, the diameter of the outer peripheral surface of the first roller 71 is smaller than the diameter of the outer peripheral surface of the developing roller 30. Further, the diameter of the outer peripheral surface of the second roller 72 is smaller than the diameter of the outer peripheral surface of the developing roller 30. Thereby, the mounting of the developing cartridge 1 to the cartridge holding portion 91 is facilitated. Further, even when the drum unit is miniaturized, the diameter of the outer peripheral surface of the first roller 71 is smaller than the diameter of the outer peripheral surface of the developing roller 30, and the diameter of the outer peripheral surface of the second roller 72 is smaller than that of the developing roller 30. Since the diameter is smaller than the diameter of the outer peripheral surface, mounting of the developing cartridge 1 to the cartridge holding portion 91 is facilitated.

Instead of the casing 10 having the first roller shaft 711, the first roller 71 may have the first roller shaft. In this case, the casing 10 may have an opening through which the first roller shaft can be inserted. Also, instead of the casing 10 having the second roller shaft, the second roller may have the second roller shaft. In this case, the casing 10 may have an opening through which the second roller shaft can be inserted.

<3. Modified example>
As mentioned above, although 1st Embodiment and 2nd Embodiment were described, this invention is not limited to said embodiment.

In the above embodiment, the developing cartridge has the first pivot shaft portion and the second pivot shaft portion. However, the number of rotation shaft portions of the developing cartridge may be one, or three or more. For example, the developing cartridge may have one rotation shaft extending from one end to the other end in the second direction. Also, in the above embodiment, the developing cartridge has the first curved surface and the second curved surface. However, the number of curved surfaces of the developing cartridge may be one, or three or more. For example, the developer cartridge may have one curved surface extending from one end to the other end in the second direction.

Moreover, in said embodiment, the shape of the curved surface was circular arc shape. However, the curved surface may be a convex curved surface, and may not necessarily be arc-shaped. The shape of the curved surface may be, for example, spherical.

In the above embodiment, the frame 90 of the drum unit 9 has the first pressing portion 95 and the second pressing portion 96 for each cartridge holding portion 91. However, instead of the frame 90 having the first pressing portion 95 and the second pressing portion 96, the developing cartridge 1 may have the first pressing portion and the second pressing portion. In this case, the first pressing portion 95 and the second pressing portion 96 are in contact with the frame 90, and the developing cartridge 1 rotates with respect to the frame 90 according to the pressing force.

Further, the shape of each part of the developing cartridge may be different from the shape shown in each drawing of the present application. In addition, the elements appearing in the first embodiment, the second embodiment, and the modification may be combined appropriately as long as no contradiction occurs.

DESCRIPTION OF SYMBOLS 1 developing cartridge 9 drum unit 10 casing 11 1st outer surface 12 2nd outer surface 13 accommodation chamber 14 opening part 15 one end part 16 other end part 17 2nd rotation axial part 18 2nd curved surface 19 2nd press receiving surface 20 agitator Reference Signs List 21 agitator shaft 22 stirring blade 30 developing roller 31 developing roller main body 32 developing roller shaft 40 gear portion 41 coupling 42 agitator gear 43 developing roller gear 50 gear cover 51 extending portion 52 circular hole 53 first rotation shaft portion 54 first pressure Receiving surface 60 Bearing plate 61 Flat portion 62 Bearing protrusion 63 First curved surface 71 First roller 72 Second roller 73 Third roller 74 Fourth roller 90 Frame 91 Cartridge holder 92 Photosensitive drum 93 First contact surface 94 Second Contact surface 95 first pressing portion 96 second pressing portion 11 fastening hole 711 second roller shaft 951 coil spring 952 pressing member 953 pressing surface first roller shaft 721

Claims

A housing capable of containing a developer, the housing having one end and the other end in the first direction, and having a pivot shaft extending in the second direction, the center of the pivot shaft As a pivotable housing in the rotational direction,
An agitator capable of agitating the developer, the agitator having an agitator shaft extending in the second direction;
A developing roller positioned closer to the one end than the agitator shaft in the first direction, the developing roller being rotatable about a rotation axis extending in the second direction, and rotatable with the housing;
A first curved surface that curves in the rotation direction, and is located farther from the agitator shaft than the developing roller in the first direction, and can be rotated in the rotation direction with the housing. With 1 curved surface,
A developer cartridge comprising:
The developing cartridge according to claim 1, wherein
A developing cartridge characterized in that a distance between the developing roller and the first curved surface in the first direction is a fixed distance.
The developing cartridge according to claim 1 or 2, wherein
The diameter of the first curved surface is smaller than the diameter of the outer peripheral surface of the developing roller.
The developing cartridge according to any one of claims 1 to 3, wherein
The developer cartridge, wherein the housing includes the first curved surface.
The developing cartridge according to any one of claims 1 to 4, wherein
A first roller which is rotatable about a rotation axis extending in the second direction and which is located farther from the agitator shaft than the developing roller in the first direction, and rotates in the rotation direction together with the housing A developer cartridge, further comprising: a first roller having the first curved surface;
The developing cartridge according to claim 5, wherein
A developing cartridge characterized in that an interval between the developing roller and the first roller in the first direction is a fixed distance.
The developing cartridge according to claim 5 or 6, wherein
The diameter of the outer peripheral surface of the first roller is smaller than the diameter of the outer peripheral surface of the developing roller.
The developing cartridge according to any one of claims 5 to 7, wherein
A developer cartridge including the shaft of the first roller;
The developing cartridge according to any one of claims 1 to 8, wherein
The developing cartridge can be mounted on a drum unit having a photosensitive drum rotatable about a rotating shaft extending in the second direction,
When the developing cartridge is mounted on the drum unit, the outer peripheral surface of the developing roller contacts the outer peripheral surface of the photosensitive drum,
The developing cartridge according to claim 1, wherein the first curved surface is in contact with an outer peripheral surface of the photosensitive drum when the developing cartridge is mounted on the drum unit.
The developing cartridge according to claim 9, wherein
In a state where the developing cartridge is mounted on the drum unit, the outer peripheral surface of the developing roller after the housing, the developing roller, and the first curved surface rotate in the rotation direction with respect to the drum unit Is in contact with the outer peripheral surface of the photosensitive drum, and the first curved surface is in contact with the outer peripheral surface of the photosensitive drum.
11. The developing cartridge according to claim 10, wherein
The developing cartridge according to claim 1, wherein the outer circumferential surface of the developing roller contacts the outer circumferential surface of the photosensitive drum after the first curved surface contacts the outer circumferential surface of the photosensitive drum.
The developing cartridge according to claim 1, wherein
A second curved surface that curves in the rotation direction, and is further away from the agitator shaft than the developing roller in the first direction, and can be rotated in the rotation direction with the housing. 2. A developing cartridge according to claim 1, further comprising: a second curved surface which is a two-curved surface and is separated from said first curved surface in said second direction.
The developing cartridge according to claim 12, wherein
The distance between the developing roller and the first curved surface in the first direction is a constant distance,
A developing cartridge characterized in that a distance between the developing roller and the second curved surface in the first direction is a fixed distance.
The developing cartridge according to claim 12 or 13, wherein
The diameter of the first curved surface is smaller than the diameter of the outer peripheral surface of the developing roller,
The diameter of the second curved surface is smaller than the diameter of the outer peripheral surface of the developing roller.
The developing cartridge according to any one of claims 12 to 14, wherein
The developer cartridge, wherein the housing includes the first curved surface and the second curved surface.
The developing cartridge according to any one of claims 12 to 15, wherein
A first roller which is rotatable about a rotation axis extending in the second direction and which is located farther from the agitator shaft than the developing roller in the first direction, and rotates in the rotation direction together with the housing A first roller having the first curved surface, which is possible;
A second roller that is rotatable about a rotation axis extending in the second direction and is located farther from the agitator shaft than the developing roller in the first direction, and rotates in the rotation direction together with the housing A second roller, which is possible, having the second curved surface;
The developer cartridge further comprising:
17. The developing cartridge according to claim 16, wherein
The distance between the developing roller and the first roller in the first direction is a constant distance,
A developing cartridge characterized in that a distance between the developing roller and the second roller in the first direction is a fixed distance.
The developing cartridge according to claim 16 or 17, wherein
The diameter of the outer peripheral surface of the first roller is smaller than the diameter of the outer peripheral surface of the developing roller,
The diameter of the outer peripheral surface of the first roller is smaller than the diameter of the outer peripheral surface of the developing roller.
The developing cartridge according to any one of claims 16 to 18, wherein
The developer cartridge, wherein the housing includes an axis of the first roller and an axis of the second roller.
The developer cartridge according to any one of claims 12 to 19, wherein
The developing cartridge can be mounted on a drum unit having a photosensitive drum rotatable about a rotating shaft extending in the second direction,
When the developing cartridge is mounted on the drum unit, the outer peripheral surface of the developing roller contacts the outer peripheral surface of the photosensitive drum,
The developing cartridge according to claim 1, wherein the first curved surface and the second curved surface are in contact with the outer peripheral surface of the photosensitive drum in a state where the developing cartridge is mounted on the drum unit.
21. The developing cartridge according to claim 20, wherein
In the state where the developing cartridge is mounted on the drum unit, after the housing, the developing roller, the first curved surface, and the second curved surface rotate in the rotation direction with respect to the drum unit, An outer peripheral surface of the developing roller contacts an outer peripheral surface of the photosensitive drum, and the first curved surface and the second curved surface contact an outer peripheral surface of the photosensitive drum.
22. The developing cartridge according to claim 21, wherein
A developing cartridge, wherein an outer peripheral surface of the developing roller contacts an outer peripheral surface of the photosensitive drum after the first curved surface and the second curved surface contact the outer peripheral surface of the photosensitive drum.
The developing cartridge according to any one of claims 1 to 22, wherein
The developing cartridge according to claim 1, wherein the rotation shaft extends from the outer surface of the housing in the second direction.
The developing cartridge according to any one of claims 1 to 23, wherein
The developing cartridge according to claim 1, further comprising: a pressing receiving surface positioned closer to the other end than the pivot shaft in the first direction, the pressing receiving surface receiving the pressing force.
25. The developing cartridge according to claim 24, wherein
The developing cartridge according to claim 1, wherein the pressing receiving surface receives the pressing force along the rotation direction.
The developing cartridge according to any one of claims 9 to 11 or any one of claims 20 to 22.
The developing roller is
A developing roller shaft extending in the second direction along the rotation axis;
A developing cartridge characterized in that the developing roller shaft and the drum unit are not in contact with each other.
The developing cartridge according to any one of claims 1 to 26, wherein
3. The developing cartridge according to claim 1, wherein the housing is pivotable in the pivoting direction about the pivot shaft according to an external force.