IMAGE FORMING APPARATUS

• US 20070230993A1
• Filed: 03/28/2007
• Published: 10/04/2007
• Est. Priority Date: 03/31/2006
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Takeuchi, Yasushi
• Granted Patent: US 7,433,626 B2
• Time in Patent Office: Days
• US Class Current: 399/101
• CPC Class Codes: G03G 15/161 with means for handling the intermediate support, e.g. heating, cleaning, coating with a transfer agent
• CPC Class Codes: G03G 21/0076 Plural or sequential cleaning devices
• CPC Class Codes: G03G 2221/001 Plural sequential cleaning devices

Abstract

An image forming apparatus includes an image carrying member for carrying a toner image; toner image forming means for forming the toner image on the image carrying member; transfer means for transferring the toner image formed on said image carrying member onto a recording material; a cleaning member for electrostatically collecting a toner remaining on the image carrying member after the toner image is transferred onto the recording material; and a power source for applying a voltage having an absolute value less than that of an electric discharge start voltage to said cleaning member so that the cleaning member collects the toner from said image carrying member and applying a voltage having an absolute value equal to or more than that of the electric discharge start voltage to the cleaning member so that a toner accumulated on said cleaning member is moved to the image carrying member.

Claims

1. An image forming apparatus comprising:

an image carrying member for carrying a toner image;

toner image forming means for forming the toner image on said image carrying member;

transfer means for transferring the toner image formed on said image carrying member onto a recording material;

a cleaning member for electrostatically collecting a toner remaining on said image carrying member after the toner image is transferred onto the recording material; and

a power source for applying a voltage having an absolute value less than that of an electric discharge start voltage to said cleaning member so that said cleaning member collects the toner from said image carrying member and for applying a voltage having an absolute value equal to or more than that of the electric discharge start voltage to said cleaning member so that a toner accumulated on said cleaning member is moved to said image carrying member.

2. An apparatus according to claim 1, wherein said cleaning member has a collecting area and a cleaning area, and

wherein the voltage having the absolute value less than that of the electric discharge start voltage is applied to said cleaning member when an image area of said image carrying member is present in the cleaning area, and the voltage having the absolute value equal to or more than that of the electric discharge start voltage is applied to said cleaning member when a non-image area of said image carrying member is present in the cleaning area.

3. An apparatus according to claim 2, wherein said cleaning member comprises a brush rotatable in contact with said image carrying member.

4. An apparatus according to claim 3, wherein said toner image forming means comprises an electrostatic image bearing member for bearing an electrostatic image, a developing device for developing the electrostatic image on the electrostatic image bearing member to form the toner image, a member for transferring the toner image formed on the electrostatic image bearing member, and an electrostatic image bearing member cleaning apparatus for removing the toner from the electrostatic image bearing member, and

wherein the toner moved from said cleaning member to said image carrying member by applying the voltage having the absolute value equal to or more than that of the electric discharge start voltage to the cleaning member is collected by the electrostatic image bearing member cleaning apparatus.

5. An image forming apparatus comprising:

an image carrying member for carrying a toner image;

a transfer member, pressed against and image carrying member to form a nip between said transfer member and said image carrying member for transferring the toner image formed on said image carrying member onto a recording material nipped in the nip;

a cleaning member for electrostatically collecting a toner deposited on said transfer member; and

a power source for applying a voltage having an absolute value less than that of an electric discharge start voltage to said cleaning member so that said cleaning member collects the toner from said image carrying member and for applying a voltage having an absolute value equal to or more than that of the electric discharge start voltage to said cleaning member so that a toner accumulated on said cleaning member is moved to said transfer member.

6. An apparatus according to claim 5, wherein said cleaning member has a collecting area and a cleaning area, and

wherein the voltage having the absolute value less than that of the electric discharge start voltage is applied to said cleaning member when the recording material is present in the nip, and the voltage having the absolute value equal to or more than that of the electric discharge start voltage is applied to said cleaning member when the recording material is not present in the nip.

7. An apparatus according to claim 6, wherein said cleaning member comprises a brush rotatable in contact with said transfer member.

8. An apparatus according to claim 7, wherein the toner moved from said cleaning member to said transfer member by applying the voltage having the absolute value equal to or more than that of an electric discharge threshold to the cleaning member is moved to said image carrying member and collected by an image carrying member cleaning apparatus for collecting the toner moved to said image carrying member.