Developing cartridge having a frame rotatably supporting a developing roller

Patent metadata

Field	Value
Publication number	US-9529298-B2
Application number	US-201514737975-A
Country	US
Kind code	B2
Filing date	Jun 12, 2015
Priority date	Jun 17, 2014
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

A developing cartridge includes a developing roller 210 d that develops, by way of a developer, an electrostatic latent image that is formed on an image bearing member 207 ; a developer regulating member that regulates the thickness of a developer carried on the developing roller 210 d ; and a frame 214 a that rotatably supports the developing roller 210 d and supports the developer regulating member. The frame 214 a has a developing roller support section 214 a 1 that rotatably supports an outer peripheral face 210 d 6 of at least one end of the developing roller 210 d . The developing roller support section 214 a 1 has a clearance at a position that, when viewed in the axial direction of the developing roller 210 d , overlaps a contact region at which the developing roller 210 d is in contact with the image bearing member 207.

First claim

What is claimed is:

1. A developing cartridge comprising:
a developing roller that develops an electrostatic latent image that is formed on an image bearing member;
a developer regulating member that regulates a thickness of developer carried on the developing roller; and
a frame that rotatably supports the developing roller and supports the developer regulating member,
wherein the frame has a developing roller support section that rotatably supports an outer peripheral surface of at least one end of the developing roller,
wherein the developing roller support section has a clearance at a position that, when viewed in an axial direction of the developing roller, overlaps a contact region at which the developing roller is in contact with the image bearing member, and
wherein a lubricant is interposed between the developing roller and the developing roller support section, and the developing roller support section has a lubricant introduction section in which a clearance that becomes gradually narrower, in a rotation direction of the developing roller, as approaching a contact section with the outer peripheral surface of the developing roller, is formed between the developing roller support section and the outer peripheral surface of the developing roller, the lubricant introduction section being provided upstream of the contact section in the rotation direction.

2. The developing cartridge according to claim 1 , wherein the developing roller support section has an arcuate support surface corresponding to part of the outer peripheral surface of the developing roller.

3. The developing cartridge according to claim 1 , wherein the clearance of the developing roller support section, at the position that overlaps the contact region when viewed in an axial direction of the developing roller, is formed by cutting out a part of the developing roller support section that surrounds the outer peripheral surface of the developing roller.

4. The developing cartridge according to claim 1 , wherein the developing roller support section rotatably supports the developing roller through contact of a planar support surface of the developing roller support section with the outer peripheral surface of the developing roller.

5. The developing cartridge according to claim 1 , wherein the developing roller support section rotatably supports the developing roller through leading ends of a plurality of protrusions contacting the outer peripheral surface of the developing roller.

6. The developing cartridge according to claim 1 , further comprising:
an elastic coat layer formed on an outer periphery of the developing roller; and
a regulating member that is attached to the outer periphery of the developing roller and regulates a squashing amount of the coat layer caused by pressure-contact of the image bearing member against the coat layer,
wherein the regulating member is positioned in the axial direction of the developing roller by the coat layer and the developing roller support section.

7. The developing cartridge according to claim 1 , further comprising a conductive member that is integrally formed with the frame and that transmits developing bias to the developing roller through contact with an inner peripheral face of the developing roller.

8. The developing cartridge according to claim 1 , wherein the frame is provided with a conductive section that is formed of a conductive resin that (i) is formed integrally with the frame and (ii) transmits, as part of the developing roller support section, developing bias to the developing roller through contact with the outer peripheral surface of the developing roller.

9. The developing cartridge according to claim 1 , wherein the developing roller has a cylindrical shape, and
wherein a magnet member is enclosed in the developing roller.

10. The developing cartridge according to claim 9 , wherein a weak magnetic force section, which is an end of the magnet member in the axial direction of the developing roller and at which a magnetic force is smaller than a central portion of the magnetic member, is positioned further outward than a region in which the developer regulating member regulates the thickness of the developer in the axial direction of the developing roller.

11. The developing cartridge according to claim 10 , wherein the developing roller support section rotatably supports the developing roller through contact with the outer peripheral surface of the developing roller at a position that overlaps a region at which the weak magnetic force section of the magnet member is positioned in the axial direction of the developing roller.

12. The developing cartridge according to claim 1 , further comprising a developer container that accommodates the developer.

13. The developing cartridge according to claim 1 , wherein the developing roller support section rotatably supports an end of the developing roller on a non-driven side opposite the side of an end to which a rotational driving force is transmitted.

14. A process cartridge for performing an image formation process of forming an image on a recording material by way of developer, the process cartridge being configured to be detachably attached to an apparatus body of an image forming apparatus, the process cartridge comprising the developing cartridge according to claim 1 .

15. An image forming apparatus for forming an image on a recording material by way of developer, the image forming apparatus comprising the developing cartridge according to claim 1 .

16. The developing cartridge according to claim 1 , wherein the frame has a developing frame and a bearing member.

17. The developing cartridge according to claim 1 , wherein the lubricant is grease.

18. A developing cartridge comprising:
a developing roller that develops an electrostatic latent image that is formed on an image bearing member;
a developer regulating member that regulates a thickness of developer carried on the developing roller;
a frame that rotatably supports the developing roller and supports the developer regulating member, and
a conductive member that is integrally formed with the frame and that transmits developing bias to the developing roller through contact with an inner peripheral face of the developing roller, the conductive member being integrally formed with the frame in such a manner that a predetermined distance for suppressing leakage of developing bias is secured between the conductive member and the image bearing member,
wherein the frame has a developing roller support section that rotatably supports an outer peripheral surface of at least one end of the developing roller, and
wherein the developing roller support section has a clearance at a position that, when viewed in an axial direction of the developing roller, overlaps a contact region at which the developing roller is in contact with the image bearing member.

19. A developing cartridge comprising:
a developing roller that develops an electrostatic latent image that is formed on an image bearing member;
a developer regulating member that regulates a thickness of developer carried on the developing roller; and
a frame that rotatably supports the developing roller and supports the developer regulating member,
wherein the frame has a developing roller support section that rotatably supports an outer peripheral surface of at least one end of the developing roller,
wherein the developing roller support section has a clearance at a position that, when viewed in an axial direction of the developing roller, overlap

Assignees

• Canon Kk

Inventors

• Sato Kensuke
• Sato Masaaki

Classifications

• G03G15/0812 Primary

  characterised by the developer regulating means, e.g. structure of doctor blade · CPC title

• G03G2215/0872

  Housing of developing device · CPC title

• G03G15/0921

  Details concerning the magnetic brush roller structure, e.g. magnet configuration · CPC title

• G03G21/1814

  Details of parts of process cartridge, e.g. for charging, transfer, cleaning, developing (G03G21/1835 takes precedence) · CPC title

• G03G15/0806 Primary

  on a donor element, e.g. belt, roller (complete developer unit G03G15/0896) · CPC title