IMAGE FIXING DEVICE

• US 20200133179A1
• Filed: 10/29/2019
• Published: 04/30/2020
• Est. Priority Date: 10/31/2018
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Fukamachi, Asuna, Tsuzaki, Shohei, Yoshida, Keisuke, Kozuma, Takeshi
• Granted Patent: US 10,859,953 B2
• Time in Patent Office: Days
• CPC Class Codes: G03G 15/2017 Structural details of the fixing unit in general, e.g. cooling means, heat shielding means G03G15/2053 takes precedence
• CPC Class Codes: G03G 15/2053 Structural details of heat elements, e.g. structure of roller or belt, eddy current, induction heating
• CPC Class Codes: G03G 15/2057 relating to the chemical composition of the heat element and layers thereof
• CPC Class Codes: G03G 2215/2016 Heating belt
• CPC Class Codes: G03G 2215/2035 the fixing nip having a stationary belt support member opposing a pressure member

Abstract

An image fixing device for fixing an image on a sheet includes a rotatable fixing film; a heater provided on an inner surface of the fixing belt; a rotatable pressing member provided in contact with an outer peripheral surface of the film to press against the heater through the film, thus forming a nip configured to nip and feed the sheet; a holding member including a guide portion configured to guide the rotation of the fixed in the field and to hold the heater; and a metal sheet which covers the heater and an area of guide portion slidable relative to the film and which is slidable on an inner surface of the film. The metal sheet has a thermal conductivity ≥10 W/(m·° C.) and has a thickness more than 0 μm and not more than 50 μm.

Claims

1. An image fixing device for fixing an image on a recording material, said fixing device comprising:

a rotatable fixing film;

a heater provided on an inner surface of said fixing belt;

a rotatable pressing member provided in contact with an outer peripheral surface of said fixing film to press against said heater through said fixing film, thus forming a nip configured to nip and feed the recording material;

a holding member including a guide portion configured to guide the rotation of said fixed in the field and to hold said heater; and

a metal sheet which covers said heater and an area of guide portion slidable relative to said fixing film and which is slidable on an inner surface of said fixing film;

wherein said metal sheet has a thermal conductivity ≥

10 W/(m·

°

C.) and has a thickness more than 0 μ

m and not more than 50 μ

m.

2. An image fixing device according to claim 1, wherein said fixing film includes a metal layer having a thickness larger than that of said metal sheet.

3. An image fixing device according to claim 1, wherein said metal sheet covers, with respect to a rotational moving direction of said fixing film, an area larger than the area of said heater and the area of guide portion slidable relative to said fixing film and which is slidable on an inner surface of said fixing film.

4. An image fixing device according to claim 1, wherein said metal sheet has a Vickers hardness of not less than 60.

5. An image fixing device according to claim 1, wherein said fixing film includes a metal base layer, an elastic layer provided on said base layer and a parting layer provided on said elastic layer.

6. An image fixing device according to claim 1, wherein said heater is a planar heater.

7. An image fixing device according to claim 1, wherein said holding member is made of resin material.

8. An image fixing device according to claim 1, wherein said holding member includes a projected portion projecting outwardly of said fixing film at a position downstream of said heater in the rotational direction of said fixed in film to separate the recording material from said fixing film.

9. An image fixing device according to claim 1, wherein said metal sheet has a bending stiffness higher than that of said fixing film.