# US 11,029,632 B2 · Fixing apparatus providing a fixing apparatus capable of suppressing a temperature rise in a non-sheet-passing portion without degrading first print out time

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- Number: US 11,029,632 B2
- Document ID: US11029632B2
- Status: Granted
- Kind: B2
- Application number: 16/397,809
- Filed: 2019-04-29
- Published: 2019-11-07
- Granted: 2021-06-08
- Earliest claimed: 2018-05-02
- Assignees: Canon Kabushiki Kaisha
- Applicants: Canon Kabushiki Kaisha
- Inventors: Tatsuya Kinukawa; Masashi Tanaka; Sho Taguchi; Naofumi Murata
- Web page: https://patentgrep.com/patent/US11029632B2

## CPC

- G03G 15/2057: {relating to the chemical composition of the heat element and layers thereof}
- G03G 15/2053: {Structural details of heat elements, e.g. structure of roller or belt, eddy current, induction heating}
- G03G 15/2064: {combined with pressure}
- G03G 2215/2035: the fixing nip having a stationary belt support member opposing a pressure member
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

A fixing apparatus includes a thermal conductive member that is in contact with a heater and has a thermal conductivity higher than the thermal conductivity of a base material of the heater, and a thermal-resistant member that is disposed between the thermal conductive member and a support member configured to support the heater, a thermal resistance in a thickness direction of the thermal-resistant member being higher than the thermal resistance in the thickness direction of the thermal conductive member.

## Claims

### Claim 1

A fixing apparatus for fixing a toner image formed on a recording material to the recording material, the fixing apparatus comprising:
a rotatable cylindrical film;
a heater including a heat generating resistor formed on a substrate, the heater having a first surface in contact with an inner peripheral surface of the film and a second surface disposed on an opposite side of the first surface;
a support member configured to support the heater;
a pressure member configured to form a nip with the heater through the film to heat the toner image and fix the toner image onto the recording material at the nip;
a thermal conductive member having a thermal conductivity higher than the thermal conductivity of the substrate, the thermal conductive member being disposed above the second surface; and
a thermal-resistant member disposed between the thermal conductive member and the substrate, a thermal resistance in a thickness direction of the thermal-resistant member being higher than the thermal resistance in the thickness direction of the thermal conductive member, wherein the thermal conductivity in the thickness direction of the thermal-resistant member is less than or equal to 2 [W/mK].

### Claim 2 (depends on 1)

The fixing apparatus according to claim 1, wherein the thermal conductivity of the thermal-resistant member is lower than the thermal conductivity of the thermal conductive member.

### Claim 3 (depends on 1)

The fixing apparatus according to claim 1, wherein a heat capacity in a plane direction orthogonal to the thickness direction of the thermal conductive member is greater than the heat capacity in the plane direction orthogonal to the thickness direction of the thermal-resistant member.

### Claim 4 (depends on 1)

The fixing apparatus according to claim 1, wherein the thermal-resistant member comprises polyimide as a main material.

### Claim 5 (depends on 1)

The fixing apparatus according to claim 1, wherein the thermal conductivity in the thickness direction of the thermal conductive member is greater than or equal to 80 [W/mK].

### Claim 6 (depends on 1)

The fixing apparatus according to claim 1, wherein the thermal conductive member comprises metal as a main material.

### Claim 7 (depends on 1)

The fixing apparatus according to claim 1, wherein a thermal resistance X in the thickness direction of the thermal-resistant member is greater than 2.0 [K/W] and less than 12.5 [K/W].

### Claim 8 (depends on 7)

The fixing apparatus according to claim 7, wherein the following condition is satisfied:
0.09X+2.85<Y<2.55X+2.6 [log 10 (J/K·m2)], where Y [log 10 (J/K·m2)] represents a logarithm of a heat capacity per unit area on a surface of the thermal conductive member that is in contact with the heater.

### Claim 9 (depends on 5)

The fixing apparatus according to claim 5, wherein the thermal conductive member is made of material at least one of iron, copper, gold, silver, nickel, brass, silicone rubber, and carbon graphite.

### Claim 10

A fixing apparatus for fixing a toner image formed on a recording material to the recording material, the fixing apparatus comprising:
a rotatable cylindrical film;
a heater including a substrate made of a ceramic material, a heat generating resistor formed on the substrate, and a glass coat layer covering the heat generating resistor, the heater having a first surface which is a surface of the glass coat layer in contact with an inner peripheral surface of the film and a second surface disposed on an opposite side of the first surface;
a support member configured to support the heater;
a pressure member configured to form a nip with the heater through the film to heat the toner image and fix the toner image onto the recording material at the nip;
a thermal conductive member having a thermal conductivity higher than the thermal conductivity of the substrate, the thermal conductive member being disposed above the second surface; and
a thermal-resistant member disposed between the thermal conductive member and the substrate, a thermal resistance in a thickness direction of the thermal-resistant member being higher than the thermal resistance in the thickness direction of the thermal conductive member.

### Claim 11 (depends on 10)

The fixing apparatus according to claim 10, wherein the thermal conductivity of the thermal-resistant member is lower than the thermal conductivity of the thermal conductive member.

### Claim 12 (depends on 10)

The fixing apparatus according to claim 10, wherein a heat capacity in a plane direction orthogonal to the thickness direction of the thermal conductive member is greater than the heat capacity in the plane direction orthogonal to the thickness direction of the thermal-resistant member.

### Claim 13 (depends on 12)

The fixing apparatus according to claim 12, wherein the thermal-resistant member is made of material at least one of perfluoroalkoxy alkane (PFA), polytetrafluoroethylene (PTFE), and tetrafluoroethylene-hexafluoropropylene copolymer (FEP).

### Claim 14 (depends on 10)

The fixing apparatus according to claim 10, wherein the thermal conductivity in the thickness direction of the thermal-resistant member is less than or equal to 2 [W/mK].

### Claim 15 (depends on 14)

The fixing apparatus according to claim 14, wherein the thermal-resistant member is made of material at least one of polyimide, perfluoroalkoxy alkane (PFA), polytetrafluoroethylene (PTFE), and tetrafluoroethylene-hexafluoropropylene copolymer (FEP), as a main material.

### Claim 16 (depends on 10)

The fixing apparatus according to claim 10, wherein the thermal conductivity in the thickness direction of the thermal conductive member is greater than or equal to 80 [W/mK].

### Claim 17 (depends on 16)

The fixing apparatus according to claim 16, wherein the thermal conductive member is made of material at least one of iron, copper, gold, silver, nickel, brass, silicone rubber, and carbon graphite.

### Claim 18 (depends on 10)

The fixing apparatus according to claim 10, wherein a thermal resistance X in the thickness direction of the thermal-resistant member is greater than 2.0 [K/W] and less than 12.5 [K/W].

### Claim 19 (depends on 18)

The fixing apparatus according to claim 18, wherein the following condition is satisfied:
0.09X+2.85<Y<2.55X+2.6 [log 10 (J/K·m2)], and
where Y [log 10 (J/K·m2)] represents a logarithm of a heat capacity per unit area on a surface of the thermal conductive member that is in contact with the heater.