Process cartridge and image forming apparatus incorporating same

Patent metadata

Field	Value
Publication number	US-11813874-B2
Application number	US-202117467468-A
Country	US
Kind code	B2
Filing date	Sep 7, 2021
Priority date	Sep 10, 2020
Publication date	Nov 14, 2023
Grant date	Nov 14, 2023

Abstract

A process cartridge includes an image bearer, a developer bearer, and a positioning member. The image bearer is rotatable. The developer bearer is rotatable and opposite to the image bearer. The positioning member determines an opposing distance between the image bearer and the developer bearer, and includes a fitting portion and a groove. A fitted portion of the image bearer rotatably fits to the fitting portion. The groove extends from a ceiling portion to a bottom portion. A shaft portion of the developer bearer is slidingly movable in the groove. The groove is formed such that the shaft portion of the developer bearer contacts the bottom portion and is supported by the bottom portion. The ceiling portion of the groove is open upward so that the shaft portion of the developer bearer is insertable to and removable from the groove.

First claim

The invention claimed is:

1. A process cartridge comprising:
an image bearer that is rotatable;
a developer bearer that is rotatable and opposite to the image bearer; and
a positioner configured to determine an opposing distance between the image bearer and the developer bearer, the positioner including:
a fitting portion to which a fitted portion of the image bearer rotatably fits; and
a groove that extends from a ceiling portion to a bottom portion and in which a shaft portion of the developer bearer is slidingly movable,
wherein the shaft portion of the developer bearer contacts the bottom portion and is supported by the bottom portion due to the groove,
wherein the ceiling portion of the groove is open upward so that the shaft portion of the developer bearer is insertable to and removable from the groove,
wherein there is a gap between a surface of the developer bearer and a surface of the image bearer, and
wherein the groove has a curved surface, in which a distance from a rotation center of the image bearer to the curved surface is constant, at a part of the bottom portion so that the gap is constant at the part of the bottom portion.

2. The process cartridge according to claim 1 , further comprising:
a developing structure accommodating developer inside and including a developing case; and
a cartridge case different from the developing case,
wherein the developing structure is detachably installed in the process cartridge,
wherein the developer bearer is rotatably held in the developing structure,
wherein the positioner is detachably coupled to the developing case and the cartridge case, and
wherein the developing structure, together with the developer bearer, is attachable to and detachable from the positioner coupled to the cartridge case by movement of the shaft portion of the developer bearer between the ceiling portion and the bottom portion while coupling of the positioner with the developing case is released.

3. The process cartridge according to claim 2 ,
wherein the positioner is detachably coupled to the developing case.

4. The process cartridge according to claim 1 ,
wherein the groove extends in a direction inclined toward the image bearer with respect to a direction orthogonal to a virtual line connecting a rotation center of the image bearer and a rotation center of the developer bearer.

5. The process cartridge according to claim 1 ,
wherein the groove includes two face portions facing each other across the shaft portion of the developer bearer,
wherein the two face portions include one face portion closer to the image bearer than the other face portion, and
wherein at least the one face portion closer to the image bearer is formed such that a part of the one face portion closer to the bottom portion is closer to the rotation center of the image bearer than another part of the one face portion closer to the ceiling portion.

6. The process cartridge according to claim 5 ,
wherein the distance from the rotation center of the image bearer to the one face portion closer to the image bearer is constant at the part of the bottom portion.

7. The process cartridge according to claim 1 , further comprising a restrictor to restrict an upward movement of the shaft portion supported by the bottom portion of the groove,
wherein the restrictor is detachably attached with respect to the positioner.

8. The process cartridge according to claim 1 ,
wherein the rotation center of the image bearer is disposed below a rotation center of the developer bearer when the process cartridge is in an installed orientation within an image forming apparatus which is in an upright orientation.

9. An image forming apparatus comprising:
a main body; and
the process cartridge according to claim 1 ,
wherein the process cartridge is detachably attached with respect to the main body.

10. A process cartridge comprising:
an image bearer that is rotatable;
a developer bearer that is rotatable and opposite to the image bearer; and
a positioner configured to determine an opposing distance between the image bearer and the developer bearer, the positioner including:
a fitting portion to which a fitted portion of the image bearer rotatably fits; and
a groove that extends from a ceiling portion to a bottom portion and in which a shaft portion of the developer bearer is slidingly movable;
wherein the shaft portion of the developer bearer contacts the bottom portion and is supported by the bottom portion due to the groove,
wherein the ceiling portion of the groove is open upward so that the shaft portion of the developer bearer is insertable to and removable from the groove,
wherein there is a gap between a surface of the developer bearer and a surface of the image bearer, and
wherein the groove guides a structure including the developer bearer in a direction orthogonal to a virtual line connecting a rotation center of the image bearer and a rotation center of the developer bearer.

11. A process cartridge comprising:
an image bearer that is rotatable;
a developer bearer that is rotatable and opposite to the image bearer; and
a positioner configured to determine an opposing distance between the image bearer and the developer bearer, the positioner including:
a fitting portion to which a fitted portion of the image bearer rotatably fits; and
a groove that extends from a ceiling portion to a bottom portion and in which a shaft portion of the developer bearer is slidingly movable,
wherein the shaft portion of the developer bearer contacts the bottom portion and is supported by the bottom portion due to the groove,
wherein the ceiling portion of the groove is open upward so that the shaft portion of the developer bearer is insertable to and removable from the groove, and
wherein the groove guides a structure including the developer bearer in a direction orthogonal to a virtual line connecting a rotation center of the image bearer and a rotation center of the developer bearer.

12. The process cartridge according to claim 11 , further comprising:
a developing structure accommodating developer inside and including a developing case; and
a cartridge case different from the developing case,
wherein the developing structure is detachably installed in the process cartridge,
wherein the developer bearer is rotatably held in the developing structure,
wherein the positioner is detachably coupled to the developing case and the cartridge case, and
wherein the developing structure, together with the developer bearer, is attachable to and detachable from the positioner coupled to the cartridge case by movement of the shaft portion of the developer bearer between the ceiling portion and the bottom portion while coupling of the positioner with the developing case is released.

13. The process cartridge according to claim 12 ,
wherein the positioner is detachably coupled to the developing case.

14. The process cartridge according to claim 11 ,
wherein the groove includes two face portions facing each other across the shaft portion of the developer bearer,
wherein the two face portions include one face portion closer to the image bearer than the other face portion, and
wherein at least the one face portion closer to the image bearer is formed such that a part of the one face portion closer to the bottom portion is closer to the rotation center of the image bearer than another part of the one face portion closer to the ceiling portion.

15. The process cartridge according to claim 14 ,
wherein a distance from the rotation center of the image bearer to the one face portion closer to

Assignees

• Kubo Tatsuya
• Karasawa Shinya
• Yogosawa Kazuki
• TSUCHIYA Yuuki
• Ricoh Co Ltd

Inventors

• Kubo Tatsuya
• Karasawa Shinya
• Yogosawa Kazuki
• TSUCHIYA Yuuki

Classifications

• B41J2/1752 Primary

  Mounting within the printer · CPC title

• B41J2/17553

  Outer structure · CPC title

• G03G15/0813 Primary

  characterised by means in the developing zone having an interaction with the image carrying member, e.g. distance holders · CPC title