# US 11,906,916 B2 · Heating device, fixing device, drying device, laminator, and image forming apparatus

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- Number: US 11,906,916 B2
- Document ID: US11906916B2
- Status: Granted
- Kind: B2
- Application number: 17/739,509
- Filed: 2022-05-09
- Published: 2022-12-01
- Granted: 2024-02-20
- Earliest claimed: 2021-05-31
- Assignees: Ricoh Company, Ltd.
- Applicants: Yuusuke Furuichi; Hiroshi Seo; Tomoya Adachi; Daisuke Hirano
- Inventors: Yuusuke Furuichi; Hiroshi Seo; Tomoya Adachi; Daisuke Hirano
- Web page: https://patentgrep.com/patent/US11906916B2

## CPC

- G03G 15/2017: {Structural details of the fixing unit in general, e.g. cooling means, heat shielding means (G03G15/2053 takes precedence)}
- G03G 15/2053: {Structural details of heat elements, e.g. structure of roller or belt, eddy current, induction heating}
- G03G 15/206: {Structural details or chemical composition of the pressure elements and layers thereof}
- G03G 21/1652: {Electrical connection means}
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

A heating device includes a planar heater, a rotator, a pressure rotator, a heating device frame, a resistor, and a discharger. The pressure rotator has a conductive outer surface and presses the rotator. The heating device frame holds the pressure rotator. The discharger is in contact with the conductive outer surface of the pressure rotator and grounded via the resistor and the heating device frame.

## Claims

### Claim 1

A heating device comprising:
a planar heater;
a rotator including a conductive layer, the rotator grounded via the conductive layer;
a pressure rotator having a conductive outer surface and being configured to press the rotator;
a heating device frame holding the pressure rotator;
a resistor;
a rectifier coupled in series to the resistor;
a discharger being in contact with the conductive outer surface of the pressure rotator and grounded via the rectifier, the resistor, and the heating device frame; and
another rectifier coupled to the conductive layer, the another rectifier configured to flow a current in a direction opposite to a current flowing through the rectifier, wherein the rectifier and the another rectifier are grounded via the resistor, and the rectifier is coupled in series to the discharger.

### Claim 2 (depends on 1)

The heating device according to claim 1,
wherein a resistance value of the resistor is (10/3.5)×104 Ω or more.

### Claim 3 (depends on 1)

The heating device according to claim 1,
wherein a resistance value of the resistor is 1.0 ×105 Ω or more.

### Claim 4 (depends on 1)

The heating device according to claim 1, further comprising at least two resistors including the resistor,
wherein the discharger is grounded via the at least two resistors coupled in series.

### Claim 5 (depends on 4)

The heating device according to claim 4,
wherein a resistance value of each of the at least two resistors is (10/3.5)×104 Ω or more.

### Claim 6 (depends on 4)

The heating device according to claim 4,
wherein a resistance value of each of the at least two resistors is 1.0×105 Ω or more.

### Claim 7 (depends on 1)

The heating device according to claim 1,
wherein the pressure rotator includes a non-conductive intermediate layer having a thickness of 2.5 mm or more and 6.0 mm or less.

### Claim 8 (depends on 7)

The heating device according to claim 7,
wherein the thickness of the intermediate layer is larger than or equal to 2.5 mm in a pressure state in which the pressure rotator is pressed against the rotator.

### Claim 9 (depends on 1)

The heating device according to claim 1, further comprising a ball bearing,
wherein the heating device frame holds the pressure rotator via the ball bearing.

### Claim 10 (depends on 1)

The heating device according to claim 1,
wherein the rectifier is disposed between the heating device frame and the discharger in a path of current flowing between the heating device frame and the discharger.

### Claim 11 (depends on 1)

The heating device according to claim 1, further comprising another resistor,
wherein the rotator is grounded via said another resistor.

### Claim 12 (depends on 1)

A fixing device comprising:
the heating device according to claim 1.

### Claim 13 (depends on 1)

A dryer comprising
the heating device according to claim 1.

### Claim 14 (depends on 1)

A laminator comprising:
the heating device according to claim 1.

### Claim 15 (depends on 1)

The heating device according to claim 1, wherein the rotator is grounded via the conductive layer and the hea4ting device frame.