# US 12,181,822 B2 · Tubular fixing member, fixing device, and image forming apparatus

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- Number: US 12,181,822 B2
- Document ID: US12181822B2
- Status: Granted
- Kind: B2
- Application number: 18/319,511
- Filed: 2023-05-18
- Published: 2024-06-27
- Granted: 2024-12-31
- Earliest claimed: 2022-12-22
- Assignees: FUJIFILM Business Innovation Corp.
- Applicants: FUJIFILM Business Innovation Corp.
- Inventors: Ryosuke Kubota
- Web page: https://patentgrep.com/patent/US12181822B2

## 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 2215/2038: the belt further entrained around one or more rotating belt support members
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

A tubular fixing member includes a first layer and a second layer that is disposed in contact with an outer circumferential side of the first layer. In a case where thermal conductivities of the first layer in an axial direction, a circumferential direction, and a thickness direction are denoted by λ1x, λ1y, and λ1z, respectively, and thermal conductivities of the second layer in the axial direction, the circumferential direction, and the thickness direction are denoted by λ2x, λ2y, and λ2z, respectively, the following requirements (1), (2), and (3) are satisfied. Requirement ⁢ ( 1 ) : λ ⁢ 1 ⁢ x < λ ⁢ 1 ⁢ z ⁢ and ⁢ λ ⁢ 1 ⁢ y < λ ⁢ 1 ⁢ z Requirement ⁢ ( 2 ) : λ ⁢ 1 ⁢ z > λ ⁢ 2 ⁢ z Requirement ⁢ ( 3 ) : λ ⁢ 2 ⁢ x > λ ⁢ 2 ⁢ y ⁢ and ⁢ ⁢ λ ⁢ 2 ⁢ x > λ ⁢ 2 ⁢ z

## Claims

### Claim 1

A tubular fixing member comprising:
a first layer; and
a second layer that is disposed in contact with an outer circumferential side of the first layer,
wherein in a case where thermal conductivities of the first layer in an axial direction, a circumferential direction, and a thickness direction are denoted by λ1x, λ1y, and λ1z, respectively, and thermal conductivities of the second layer in the axial direction, the circumferential direction, and the thickness direction are denoted by λ2x, λ2y, and λ2z, respectively, the following requirements (1), (2), and (3) are satisfied,
λ1x<λ1z and λ1y<λ1z Requirement (1):
λ1z>λ2z Requirement (2):
λ2x>λ2y and λ2x>λ2z, Requirement (3):
wherein the second layer is thinner than the first layer, and an average thickness of the second layer is in a range of 1 μm to 100 μm.

### Claim 2 (depends on 1)

The tubular fixing member according to claim 1,
wherein a ratio of a thickness of the second layer to a total thickness of the first and second layers is 1% or more and less than 10%.

### Claim 3 (depends on 2)

A fixing device comprising:
a first rotating body; and
a second rotating body that is disposed in contact with an outer surface of the first rotating body,
wherein at least one of the first rotating body or the second rotating body is the tubular fixing member according to claim 2, and
a recording medium having a surface on which a toner image is formed passes through a contact portion between the first rotating body and the second rotating body and the toner image is fixed.

### Claim 4 (depends on 3)

An image forming apparatus comprising:
an image holding body;
a charging device that charges a surface of the image holding body;
an electrostatic latent image forming device that forms an electrostatic latent image on the charged surface of the image holding body;
a developing device that develops the electrostatic latent image formed on the surface of the image holding body with a developer containing toner to form a toner image;
a transfer device that transfers the toner image onto a surface of a recording medium; and
the fixing device according to claim 3 that fixes the toner image to the recording medium.

### Claim 5 (depends on 1)

The tubular fixing member according to claim 1,
wherein the first layer contains a resin and a filler, and
a volume ratio of the filler to the first layer is 0.1% by volume or more and 60% by volume or less.

### Claim 6 (depends on 5)

A fixing device comprising:
a first rotating body; and
a second rotating body that is disposed in contact with an outer surface of the first rotating body,
wherein at least one of the first rotating body or the second rotating body is the tubular fixing member according to claim 5, and
a recording medium having a surface on which a toner image is formed passes through a contact portion between the first rotating body and the second rotating body and the toner image is fixed.

### Claim 7 (depends on 6)

An image forming apparatus comprising:
an image holding body;
a charging device that charges a surface of the image holding body;
an electrostatic latent image forming device that forms an electrostatic latent image on the charged surface of the image holding body;
a developing device that develops the electrostatic latent image formed on the surface of the image holding body with a developer containing toner to form a toner image;
a transfer device that transfers the toner image onto a surface of a recording medium; and
the fixing device according to claim 6 that fixes the toner image to the recording medium.

### Claim 8 (depends on 1)

The tubular fixing member according to claim 1,
wherein the second layer contains a resin and a filler, and
a volume ratio of the filler to the second layer is 0.1% by volume or more and 60% by volume or less.

### Claim 9 (depends on 8)

A fixing device comprising:
a first rotating body; and
a second rotating body that is disposed in contact with an outer surface of the first rotating body,
wherein at least one of the first rotating body or the second rotating body is the tubular fixing member according to claim 8, and
a recording medium having a surface on which a toner image is formed passes through a contact portion between the first rotating body and the second rotating body and the toner image is fixed.

### Claim 10 (depends on 9)

An image forming apparatus comprising:
an image holding body;
a charging device that charges a surface of the image holding body;
an electrostatic latent image forming device that forms an electrostatic latent image on the charged surface of the image holding body;
a developing device that develops the electrostatic latent image formed on the surface of the image holding body with a developer containing toner to form a toner image;
a transfer device that transfers the toner image onto a surface of a recording medium; and
the fixing device according to claim 9 that fixes the toner image to the recording medium.

### Claim 11 (depends on 1)

A fixing device comprising:
a first rotating body; and
a second rotating body that is disposed in contact with an outer surface of the first rotating body,
wherein at least one of the first rotating body or the second rotating body is the tubular fixing member according to claim 1, and
a recording medium having a surface on which a toner image is formed passes through a contact portion between the first rotating body and the second rotating body and the toner image is fixed.

### Claim 12 (depends on 11)

An image forming apparatus comprising:
an image holding body;
a charging device that charges a surface of the image holding body;
an electrostatic latent image forming device that forms an electrostatic latent image on the charged surface of the image holding body;
a developing device that develops the electrostatic latent image formed on the surface of the image holding body with a developer containing toner to form a toner image;
a transfer device that transfers the toner image onto a surface of a recording medium; and
the fixing device according to claim 11 that fixes the toner image to the recording medium.

### Claim 13 (depends on 1)

The tubular fixing member according to claim 1,
wherein the thermal conductivity of the second layer in the axial direction is in a range of 0.6 W/m·K to 2.0 W/m·K, the thermal conductivity of the second layer in the circumferential direction is in a range of 0.2 W/m·K to 1.4 W/m·K, and the thermal conductivity of the second layer in the thickness direction is in a range of 0.2 W/m·K to 1.4 W/m·K.