# US 12,517,451 B2 · Image forming apparatus that limits maximum power supplied to heating member for predetermined specific period of time when power supply to heating member is resumed

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- Number: US 12,517,451 B2
- Document ID: US12517451B2
- Status: Granted
- Kind: B2
- Application number: 18/640,337
- Filed: 2024-04-19
- Published: 2024-10-31
- Granted: 2026-01-06
- Earliest claimed: 2023-04-26
- Assignees: KYOCERA Document Solutions Inc.
- Applicants: KYOCERA Document Solutions Inc.
- Inventors: Akihiro Kondo; Ryohei Tokunaga; Yuta Kitabayashi; Rina Kikugawa; Hiroki Kawasaki; Shunsaku Fujii; Yuto Masaoka
- Web page: https://patentgrep.com/patent/US12517451B2

## CPC

- G03G 15/205: {specially for the mode of operation, e.g. standby, warming-up, error (G03G15/2046 takes precedence)}
- G03G 15/2039: {with means for controlling the fixing temperature}
- G03G 15/2064: {combined with pressure}
- G03G 15/5004: {Power supply control, e.g. power-saving mode, automatic power turn-off}
- G03G 2215/00772: of temperature influencing copy sheet handling
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

An image forming apparatus according to an aspect of the present disclosure includes a fixing device and a controller. The fixing device includes a fixing member, a pressure member, a heating member, and a temperature sensor. The controller cuts off power supply to the heating member when the temperature detected by the temperature sensor has risen to a cutoff temperature higher than the target temperature and thereafter resumes power supply to the heating member when the detected temperature has fallen below the cutoff temperature, and performs the PID control while limiting a maximum power supplied to the heating member to an upper limit power, which is a power supplied to the heating member at the time when the detected temperature has risen to the cutoff temperature, during a period from when power supply is resumed until a predetermined specific period of time elapses.

## Claims

### Claim 1

An image forming apparatus comprising:
a fixing device including:
a fixing member;
a pressure member disposed to face the fixing member, the pressure member forming a nip portion between the pressure member and the fixing member into which a recording medium to be fixed is inserted;
a heating member configured to heat the fixing member; and
a temperature sensor configured to detect a temperature of the heating member or the fixing member; and
a controller including a processor, the controller being configured to drive, by the processor executing a control program, the heating member using proportional-integral-differential (PID) control to bring the temperature detected by the temperature sensor to a predetermined target temperature,
wherein the controller is configured to:
cut off power supply to the heating member when the detected temperature has risen to a predetermined cutoff temperature higher than the target temperature and then resume power supply to the heating member when the detected temperature has fallen below the cutoff temperature; and
perform the PID control while limiting a maximum power supplied to the heating member to an upper limit power, which is a power supplied to the heating member at a time when the detected temperature has risen to the cutoff temperature, during a period from when power supply to the heating member is resumed until a predetermined specific period of time elapses.

### Claim 2 (depends on 1)

The image forming apparatus according to claim 1, wherein
the controller is configured to cut off power supply to the heating member when the detected temperature has risen again to the cutoff temperature after power supply to the heating member is resumed and then continue the PID control using a power supplied to the heating member at a time when the detected temperature has risen again to the cutoff temperature as the upper limit power for the maximum power supplied to the heating member.

### Claim 3 (depends on 1)

The image forming apparatus according to claim 1, wherein
the fixing member is an endless belt,
the heating member is a planar heater disposed inside the fixing member, the planar heater facing an inner peripheral surface of the fixing member, and
the temperature sensor is configured to detect the temperature of the heating member.

### Claim 4 (depends on 1)

The image forming apparatus according to claim 1, wherein
the controller is configured to continue to calculate a power instructed by the PID control based on the detected temperature while power supply to the heating member is cut off.