IMAGE FORMING APPARATUS

• US 20120282001A1
• Filed: 04/26/2012
• Published: 11/08/2012
• Est. Priority Date: 05/02/2011
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Akashi, Kazukiyo, Mochizuki, Jun, Shirafuji, Yasuhito, Takeuchi, Yasushi
• Granted Patent: US 8,874,015 B2
• Time in Patent Office: Days
• US Class Current: 399/308
• CPC Class Codes: G03G 15/0131 for transferring a pattern to a second base
• CPC Class Codes: G03G 15/0189 primary transfer to an intermediate transfer belt G03G15/0184 takes precedence
• CPC Class Codes: G03G 15/1605 using at least one intermediate support G03G15/1625 takes precedence
• CPC Class Codes: G03G 15/1615 relating to the driving mechanism for the intermediate support, e.g. gears, couplings, belt tensioning
• CPC Class Codes: G03G 15/162 details of the the intermediate support, e.g. chemical composition
• CPC Class Codes: G03G 2215/0129 horizontal medium transport path at the secondary transfer
• CPC Class Codes: G03G 2215/1614 Transfer roll

Abstract

A first transfer inner roller and a first transfer outer roller are arranged such that the leading edge of a recording material is pressed against an intermediate transfer member on the downstream side of an upstream side transfer portion to change a traveling direction of the recording material.

Claims

1. An image forming apparatus comprising:

an image bearing member configured to bear a toner image;

a movable intermediate transfer member configured to bear the toner image transferred thereto from the image bearing member; and

a transfer unit configured to transfer the toner image from the intermediate transfer member to a recording material,

wherein the transfer unit comprises;

a first transfer inner roller for supporting the intermediate transfer member from an inner peripheral surface and transferring the toner image to the recording material from the intermediate transfer member;

a second transfer inner roller arranged on the downstream side of the first transfer inner roller in the moving direction of the intermediate transfer member and supporting the intermediate transfer member from the inner peripheral surface and transferring the toner image to the recording material from the intermediate transfer member;

a first transfer outer roller arranged so as to be deviated downstream from the first transfer inner roller in the moving direction of the intermediate transfer member and forming a first transfer portion configured to pinch the intermediate transfer member between itself and the first transfer inner roller and to transfer the toner image to the recording material from the intermediate transfer member; and

a second transfer outer roller forming a second transfer portion configured to pinch the intermediate transfer member between itself and the second transfer inner roller and to transfer the toner image to the recording material from the intermediate transfer member,

wherein the first transfer inner roller and the first transfer outer roller are arranged such that the first transfer inner roller has a portion pushing the intermediate transfer member toward the side where the first transfer outer roller is arranged beyond an extension of the intermediate transfer belt between the first transfer portion and the second transfer portion.

2. The image forming apparatus according to claim 1, wherein the second transfer outer roller is arranged so as to be deviated upstream from the first transfer inner roller in the moving direction of the intermediate transfer member, and

wherein the second transfer inner roller and the second transfer outer roller are arranged such that the second transfer inner roller has a portion pushing the intermediate transfer member toward the side where the second transfer outer roller is arranged beyond the extension of the intermediate transfer belt between the first transfer portion and the second transfer portion.

3. The image forming apparatus according to claim 2, wherein the portion of the intermediate transfer belt pushed by the first transfer inner roller is smaller than the portion of the intermediate transfer belt pushed by the second transfer inner roller.

4. The image forming apparatus according to claim 2, wherein a first angle formed by a first normal perpendicular to a straight line connecting a rotation center of the first transfer inner roller and a rotation center of the first transfer outer roller and by an extension of the intermediate transfer belt between the first transfer portion and the second transfer portion, is larger than a second angle formed by a second normal perpendicular to a straight line connecting a rotation center of the second transfer inner roller and a rotation center of the second transfer outer roller and by an extension of the intermediate transfer belt between the first transfer portion and the second transfer portion.

5. The image forming apparatus according to claim 4, wherein the first angle is not less than 10°

and not more than 40°

.

6. The image forming apparatus according to claim 4, wherein the second angle is not less than 15°

and not more than 40°

.