Image forming apparatus having an image bearing member charged with predetermined polarity and potential

Patent metadata

Field	Value
Publication number	US-9727002-B2
Application number	US-201615226635-A
Country	US
Kind code	B2
Filing date	Aug 2, 2016
Priority date	Jun 13, 2014
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

Fluctuations in chargeability in an initial state are expected to be small. If a charging member is new, an image forming apparatus performs a supply operation for supplying a developer or a lubricant prior to an image forming operation in such a manner that the developer or the lubricant adheres to a surface of the charging member.

First claim

What is claimed is:

1. An image forming apparatus comprising:
an image bearing member configured to bear a developer image;
a charging member configured to contact the image bearing member;
a storage unit configured to store information about the charging member; and
a developing unit configured to supply developer having a predetermined polarity to the image bearing member to form a developer image, and to collect developer remaining on the image bearing member after the developer image is transferred,
a cartridge configured to be detachable from the image forming apparatus and including at least the image bearing member, the charging member and the storage unit;
wherein, in a case where the charging member is new, a supply operation for supplying developer or lubricant is performed prior to an image forming operation in such a manner that the developer or the lubricant having a polarity different from the predetermined polarity adheres to a surface of the charging member, and
wherein, in a case where there is no usage history of the charging member, the supply operation is performed.

2. The image forming apparatus according to claim 1 , wherein a circumferential speed of the charging member is higher than that of the image bearing member.

3. The image forming apparatus according to claim 1 , wherein, the developing unit includes a developer bearing member configured to bear developer, and
wherein the supply operation is performed after the developer bearing member contacts the image bearing member.

4. The image forming apparatus according to claim 1 , wherein at least one of temperature information and humidity information of the image forming apparatus is acquired to change an operation time of the supply operation based on the information.

5. The image forming apparatus according to claim 1 , wherein in the supply operation, the developer that is caused to adhere to a surface of the charging member is fogging developer.

6. The image forming apparatus according to claim 1 , wherein the supply operation is performed in a state where a voltage is not applied to the transfer unit or the transfer unit and the image bearing member are separated.

7. The image forming apparatus according to claim 1 , wherein a voltage applied to the charging member in the supply operation is a voltage that is not discharged to the image bearing member.

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

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

Assignees

• Canon Kk

Inventors

• Iwayama Hiroyoshi
• Hiramatsu Takashi
• Matsukawa Akihisa
• Sunahara Satoshi

Classifications

• G03G21/10

  Collecting or recycling waste developer · CPC title

• G03G21/0094 Primary

  fatigue treatment of the photoconductor · CPC title

• G03G15/0216

  by bringing a charging member into contact with the member to be charged, e.g. roller, brush chargers · CPC title

• G03G21/0064

  using the developing unit, e.g. cleanerless or multi-cycle apparatus · CPC title

• G03G15/0808

  characterised by the developer supplying means, e.g. structure of developer supply roller · CPC title