Belt-type fixing device

• US 20040184849A1
• Filed: 03/22/2004
• Published: 09/23/2004
• Est. Priority Date: 03/20/2003
• Status: Active Grant

• Current Assignee: Konica Minolta Business Technologies Incorporated (Konica Minolta Inc.)
• Original Assignee: Konica Minolta Business Technologies Incorporated (Konica Minolta Inc.)
• Inventors: Yonekawa, Noboru
• Granted Patent: US 7,171,150 B2
• Time in Patent Office: Days
• US Class Current: 399/329
• CPC Class Codes: G03G 15/2064 combined with pressure
• CPC Class Codes: G03G 2215/2016 Heating belt
• CPC Class Codes: G03G 2215/2038 the belt further entrained around one or more rotating belt support members

Abstract

A belt-type fixing device is provided in which a nip pressure distribution in a fixing nip is made generally uniform with respect to a paper feeding. direction and which thereby prevents occurrence of image noise even when a thick paper is fed.

The belt-type fixing device has: an endless-sheet-like fixing belt, a pressurizing roller which has elasticity and on which a paper is passed through a fixing nip that is contact part between the pressurizing roller and an outer circumferential surface of the belt member, and a nip forming member which is provided in contact with an inner surface of the fixing belt, which relatively presses the fixing belt against the pressurizing roller, of which an opposite surface pressing the pressurizing roller is formed as a curved surface extending along an outer circumferential surface of the pressurizing roller, and of which the opposite surface is composed of an elastic layer.

Claims

1. A belt-type fixing device comprising:

an endless-sheet-like fixing belt,

a pressurizing roller which has elasticity and on which a paper is passed through a fixing nip that is contact part between the pressurizing roller and an outer circumferential surface of the fixing belt, and

a nip forming member which is provided in contact with an inner surface of the fixing belt, which relatively presses the fixing belt against the pressurizing roller, of which an opposite surface pressing the pressurizing roller is formed as a curved surface extending along an outer circumferential surface of the pressurizing roller, and of which the opposite surface is composed of an elastic layer.

2. A belt-type fixing device as claimed in claim 1, wherein the elastic layer of the nip forming member has a thickness of 0.3 to 2.0 mm.

3. A belt-type fixing device as claimed in claim 1, wherein a low-friction layer having a thickness of 5 to 300 μ

m is provided on the elastic layer of the nip forming member.

4. A belt-type fixing device as claimed in claim 1, wherein a quantity of deformation of the pressurizing roller is larger than a quantity of deformation of the elastic layer of the nip forming member.

5. A belt-type fixing device as claimed in claim 1, wherein the fixing belt is driven to rotate by the pressurizing roller that is driven to rotate.

6. A belt-type fixing device as claimed in claim 1, further comprising a heating roller, wherein the fixing belt is wound around the nip forming member and around the heating roller.

7. A belt-type fixing device comprising:

an endless-sheet-like fixing belt including an elastic layer,

a pressurizing roller which has elasticity and on which a paper is passed through a fixing nip that is contact part between the pressurizing roller and an outer circumferential surface of the fixing belt, and

a nip forming member which is provided in contact with an inner surface of the fixing belt, which relatively presses the fixing belt against the pressurizing roller, and of which an opposite surface pressing the pressurizing roller is formed as a curved surface extending along an outer circumferential surface of the pressurizing roller.

8. A belt-type fixing device as claimed in claim 7, wherein the elastic layer of the fixing belt has a thickness of 0.3 to 1.0 mm.

9. A belt-type fixing device as claimed in claim 7, wherein a mold release layer is provided on the elastic layer in the fixing belt.

10. A belt-type fixing device as claimed in claim 7, wherein the fixing belt is driven to rotate by the pressurizing roller that is driven to rotate.

11. A belt-type fixing device as claimed in claim 7, further comprising a heating roller, wherein the fixing belt is wound around the nip forming member and around the heating roller.

12. A belt-type fixing device comprising:

an endless-sheet-like fixing belt,

a pressurizing roller which has elasticity and on which a paper is passed through a fixing nip that is contact part between the pressurizing roller and an outer circumferential surface of the fixing belt,

a nip forming member which is provided in contact with an inner surface of the fixing belt, which relatively presses the fixing belt against the pressurizing roller, and of which an opposite surface pressing the pressurizing roller is formed as a curved surface extending along an outer circumferential surface of the pressurizing roller, and

an elastic member which is provided in contact part of the nip forming member abutting on the fixing belt and of which a surface opposite to the pressurizing roller has a radius of curvature substantially equal to a radius of curvature of the outer circumferential surface of the pressurizing roller.