Image forming apparatus

• US 20060153610A1
• Filed: 12/30/2005
• Published: 07/13/2006
• Est. Priority Date: 01/07/2005
• Status: Active Grant

• Current Assignee: OKI Electric Industry Company Limited
• Original Assignee: Oki Data Corporation (OKI Electric Industry Company Limited)
• Inventors: Ishikuro, Takemasa
• Granted Patent: US 7,664,454 B2
• Time in Patent Office: Days
• US Class Current: 399/401
• CPC Class Codes: G03G 15/231 Arrangements for copying on both sides of a recording or image-receiving material
• CPC Class Codes: G03G 2215/0119 Linear arrangement adjacent plural transfer points

Abstract

An image forming apparatus includes a medium transporting mechanism. A first transporting section transports a recording medium on which an image is formed. A second transporting section receives the recording medium from the first transporting section and then further transports the recording medium. The second transporting section has a smaller transporting force than the first transporting section. A controller controls the second transporting section in such a way that the second transporting section transports the recording medium at a higher speed than the first transporting section.

Claims

1. An image forming apparatus comprising:

a first transporting section that transports a recording medium on which an image is formed;

a second transporting section that receives the recording medium from said first transporting section and then further transports the recording medium, said second transporting section having a smaller transporting force than said first transporting section;

a controller that controls said second transporting section in such a way that said second transporting section transports the recording medium at a higher speed than said first transporting section.

2. The image forming apparatus according to claim 1, wherein said first transporting section and said second transporting section are related such that

Vf<

Vr≦

1.05×

Vf

where Vr is a transporting speed of said second transporting section and Vf is a transporting speed of said first transporting section.

3. The image forming apparatus according to claim 1, wherein said first transporting section is a fixing unit that fixes a developer deposited on the recording medium while also transporting the recording medium.

4. The image forming apparatus according to claim 1, wherein said second transporting section includes an idle roller and a transporting roller that is driven by said controller in rotation, the transporting roller and the idle roller rotating under control of said controller while also holding the recording medium between them in a sandwiched relation, said idle roller rotating in contact with a side of the recording paper on which the image has been formed.

5. The image forming apparatus according to claim 1, wherein the idle roller is in pressure contact with the transporting roller such that the idle roller and the transporting roller exert a transporting force on the recording medium, the transporting force being not larger than ¼

of a transporting force exerted by said first transporting section on the recording medium.

6. The image forming apparatus according to claim 1, wherein said second transporting section includes a transporting roller that is driven to rotate in contact with the recording medium under control of said controller, the transporting roller having a surface with a static friction coefficient such that 0.3≦

μ

≦

2.5 where μ

is the static friction coefficient of the surface of the transporting roller.

7. The image forming apparatus according to claim 1, wherein said controller controls said second transporting section in such a way that said second transporting section causes the recording medium received from said first transporting section to switch back.

8. The image forming apparatus according to claim 7, wherein said second transporting section has a smaller transporting force when the recording medium advances in a forward direction before it has switched back than when the recording medium advances in a rearward direction after it has switched back.

9. The image forming apparatus according to claim 8, said second transporting section includes a switchback roller that rotates in contact with the recording medium under control of said controller;

wherein when said second transporting section causes the recording medium to advance in the forward direction before it has switched back, an area on the switchback roller sanded in a first direction contacts the recording medium;

wherein when said second transporting section causes the recording medium to advance in the rearward direction after it has switched back, an area on the switchback roller sanded in a second direction opposite to the first direction contacts the recording medium.