Image forming apparatus having simultaneous development and cleaning

Patent metadata

Field	Value
Publication number	US-9547273-B2
Application number	US-201514733082-A
Country	US
Kind code	B2
Filing date	Jun 8, 2015
Priority date	Jun 13, 2014
Publication date	Jan 17, 2017
Grant date	Jan 17, 2017

Abstract

When an outer diameter of a charging member is defined as Hc, a ratio of the circumferential velocity of the charging member to the circumferential velocity of an image bearing member is defined as Rc, an outer diameter of a developer bearing member is defined as Hd, and a ratio of the circumferential velocity of the developer bearing member to the circumferential velocity of the image bearing member is defined as Rd, the relationship Hc/Rc≧Hd/Rd is satisfied.

First claim

What is claimed is:

1. An image forming apparatus, comprising:
an image bearing member;
a charging member that is configured to rotate while contacting the image bearing member and charge the image bearing member; and
a developer bearing member that is configured to rotate while contacting the image bearing member and supply developer to the image bearing member, and that collects the developer remaining on the image bearing member after a developer image formed on the image bearing member is transferred to a recording material,
wherein the image bearing member and the charging member move in a same direction at a first contact portion between the image bearing member and the charging member,
wherein the image bearing member and the developer bearing member move in a same direction at a second contact portion between the image bearing member and the developer bearing member, and
wherein
if an outer diameter of the charging member is defined as Hc,
a ratio of a circumferential velocity of the charging member to a circumferential velocity of the image bearing member is defined as Rc,
an outer diameter of the developer bearing member is defined as Hd, and
a ratio of a circumferential velocity of the developer bearing member to the circumferential velocity of the image bearing member is defined as Rd,
a relationship:
Hc/Rc≧Hd/Rd

is satisfied.

2. The image forming apparatus according to claim 1 , wherein 3(Hd/Rd)≧Hc/Rc≧Hd/Rd is satisfied.

3. The image forming apparatus according to claim 1 , wherein Hc/Rc=Hd/Rd is satisfied.

4. The image forming apparatus according to claim 1 , wherein the circumferential velocity of the developer bearing member and the circumferential velocity of the image bearing member are different.

5. The image forming apparatus according to claim 1 , wherein the circumferential velocity of the charging member and the circumferential velocity of the image bearing member are different.

6. The image forming apparatus according to claim 1 , wherein the circumferential velocity of the charging member is faster than the circumferential velocity of the image bearing member.

7. The image forming apparatus according to claim 1 , further comprising a developing apparatus provided with the developer bearing member and a developer storage unit that houses the developer supplied to the developer bearing member and the developer collected by the developer bearing member.

8. The image forming apparatus according to claim 1 , further comprising:
an exposure unit that forms an electrostatic latent image on the image bearing member by exposing the image bearing member charged by the charging member; and
a transfer member that transfers, to the recording material, a developer image formed on the image bearing member as a result of the developer being supplied to the electrostatic latent image by the developer bearing member.

9. The image forming apparatus according to claim 8 , further comprising a neutralizing member that is provided between the charging member and the transfer member in a direction of rotation of the image bearing member and that neutralizes the charge on the image bearing member.

10. The image forming apparatus according to claim 1 , wherein the developer is one-component developer.

11. The image forming apparatus according to claim 1 , further comprising a charge-imparting member that imparts a charge to the developer so that the developer is supplied from the developer bearing member to the image bearing member.

12. The image forming apparatus according to claim 1 , wherein the developer is magnetic developer.

Assignees

• Canon Kk

Inventors

• Ito Motonari
• Adachi Motoki
• Sunahara Satoshi
• Tamagaki Kuniaki

Classifications

• G03G15/505

  Detecting the speed, e.g. for continuous control of recording starting time · CPC title

• G03G15/065 Primary

  Arrangements for controlling the potential of the developing electrode · CPC title

• G03G15/0233 Primary

  Structure, details of the charging member, e.g. chemical composition, surface properties · CPC title

• G03G2215/025

  using contact charging means having lateral dimensions related to other apparatus means, e.g. photodrum, developing roller · CPC title

• G03G15/0896

  Arrangements or disposition of the complete developer unit or parts thereof not provided for by groups G03G15/08 - G03G15/0894 · CPC title