Nip forming device and image forming apparatus

Patent metadata

Field	Value
Publication number	US-11947296-B2
Application number	US-202318151091-A
Country	US
Kind code	B2
Filing date	Jan 6, 2023
Priority date	Mar 4, 2022
Publication date	Apr 2, 2024
Grant date	Apr 2, 2024

Abstract

A nip forming device includes an endless film and a pressure rotator that presses against a heater via the endless film. A driver drives and rotates the pressure rotator to cause the pressure rotator to drive and rotate the endless film. A controller controls the driver to drive and rotate the pressure rotator, based on a temperature of the pressure rotator, that is detected by a detector, in a forward direction to convey a conveyed object and to interrupt forward rotation of the pressure rotator. In response to a determination that the temperature of the pressure rotator is higher than a predetermined temperature when a job of the nip forming device is finished, the controller controls the driver to drive and rotate the pressure rotator for a predetermined time in a backward direction opposite to the forward direction and to interrupt backward rotation of the pressure rotator.

First claim

The invention claimed is:

1. A nip forming device comprising:
an endless film that is flexible, the endless film configured to rotate;
a heater configured to heat the endless film;
a pressure rotator configured to press against the heater via the endless film to form a nip between the endless film and the pressure rotator, the nip through which a conveyed object is conveyed;
a driver configured to drive and rotate the pressure rotator to cause the pressure rotator to drive and rotate the endless film;
a detector configured to detect a temperature of the pressure rotator; and
a controller configured to control the driver to drive and rotate the pressure rotator based on the temperature of the pressure rotator,
the controller configured to:
control the driver to drive and rotate the pressure rotator in a forward direction to convey the conveyed object in a conveyance direction and to interrupt forward rotation of the pressure rotator; and
in response to a determination that the temperature of the pressure rotator is higher than a predetermined temperature when a job of the nip forming device is finished, control the driver to drive and rotate the pressure rotator for a predetermined time in a backward direction opposite to the forward direction and to interrupt backward rotation of the pressure rotator.

2. The nip forming device according to claim 1 ,
wherein the controller is configured to control the driver to drive and rotate the pressure rotator in the backward direction continuously.

3. The nip forming device according to claim 1 ,
wherein the controller is configured to control the driver to drive and rotate the pressure rotator in the backward direction intermittently.

4. The nip forming device according to claim 3 ,
wherein the pressure rotator is configured to drive and rotate the endless film intermittently by 80 degrees for one driving.

5. The nip forming device according to claim 1 ,
wherein the controller is configured to control the driver to drive and rotate the pressure rotator in the backward direction so as to cause the pressure rotator to rotate the endless film to a first stop position, and
wherein the controller is configured to control the driver to drive and rotate the pressure rotator in the backward direction so as to cause the pressure rotator to further rotate the endless film to a second stop position that is different from the first stop position.

6. The nip forming device according to claim 1 ,
wherein the controller is configured to control the driver to drive and rotate the pressure rotator in the backward direction at a rotation speed that is lower than a rotation speed at which the pressure rotator rotates in the forward direction to convey the conveyed object.

7. The nip forming device according to claim 1 ,
wherein the controller is configured to control the driver to drive and rotate the pressure rotator in the backward direction after the pressure rotator conveys a predetermined number or more of conveyed objects.

8. The nip forming device according to claim 1 ,
wherein the controller is configured to:
start a sleep mode when a predetermined time elapses after the pressure rotator interrupts conveyance of the conveyed object in the conveyance direction; and
control the driver to interrupt the backward rotation of the pressure rotator when the sleep mode starts.

9. The nip forming device according to claim 1 , further comprising a separator disposed downstream from the nip in the conveyance direction of the conveyed object, the separator configured to separate the conveyed object from the endless film.

10. The nip forming device according to claim 1 ,
wherein the detector includes a thermistor disposed opposite the pressure rotator.

11. The nip forming device according to claim 1 ,
wherein the pressure rotator includes a roller.

12. A nip forming device comprising:
an endless film that is flexible, the endless film configured to rotate;
a heater configured to heat the endless film;
a nip former disposed opposite an inner circumferential face of the endless film;
a pressure rotator configured to press against the nip former via the endless film to form a nip between the endless film and the pressure rotator, the nip through which a conveyed object is conveyed;
a driver configured to drive and rotate the pressure rotator to cause the pressure rotator to drive and rotate the endless film;
a detector configured to detect a temperature of the pressure rotator; and
a controller configured to control the driver to drive and rotate the pressure rotator based on the temperature of the pressure rotator,
the controller configured to:
control the driver to drive and rotate the pressure rotator in a forward direction to convey the conveyed object in a conveyance direction and to interrupt forward rotation of the pressure rotator; and
in response to a determination that the temperature of the pressure rotator is higher than a predetermined temperature when a job of the nip forming device is finished, control the driver to drive and rotate the pressure rotator for a predetermined time in a backward direction opposite to the forward direction and to interrupt backward rotation of the pressure rotator.

13. The nip forming device according to claim 12 ,
wherein the nip former includes a pad.

14. An image forming apparatus comprising:
an image forming device configured to form an image;
a nip forming device configured to fix the image on a conveyed object,
the nip forming device including:
an endless film that is flexible, the endless film configured to rotate;
a heater configured to heat the endless film;
a pressure rotator configured to press against the heater via the endless film to form a nip between the endless film and the pressure rotator, the nip through which the conveyed object is conveyed; and
a detector configured to detect a temperature of the pressure rotator;

a driver configured to drive and rotate the pressure rotator to cause the pressure rotator to drive and rotate the endless film; and
a controller configured to control the driver to drive and rotate the pressure rotator based on the temperature of the pressure rotator,
the controller configured to:
control the driver to drive and rotate the pressure rotator in a forward direction to convey the conveyed object in a conveyance direction and to interrupt forward rotation of the pressure rotator; and
in response to a determination that the temperature of the pressure rotator is higher than a predetermined temperature when a job of the nip forming device is finished, control the driver to drive and rotate the pressure rotator for a predetermined time in a backward direction opposite to the forward direction and to interrupt backward rotation of the pressure rotator.

15. The image forming apparatus according to claim 14 ,
wherein the controller is configured to control the driver to drive and rotate the pressure rotator in the backward direction continuously.

16. The image forming apparatus according to claim 14 ,
wherein the controller is configured to control the driver to drive and rotate the pressure rotator in the backward direction intermittently.

17. The image forming apparatus according to claim 16 ,
wherein the pressure rotator is configured to drive and rotate the endless film intermittently by 80 degrees for one driving.

18. The image forming apparatus according to claim 14 ,
wherein the controller is configured to control the driver to drive and rotate the pressure rotator in the

Assignees

• Shimada Hiroyuki
• Adachi Tomoya
• Someya Yukimichi
• Furuichi Yuusuke
• Ricoh Co Ltd

Inventors

• Shimada Hiroyuki
• Adachi Tomoya
• Someya Yukimichi
• Furuichi Yuusuke

Classifications

• G03G15/2064 Primary

  combined with pressure · CPC title

• G03G15/2053 Primary

  Structural details of heat elements, e.g. structure of roller or belt, eddy current, induction heating · CPC title

• G03G15/5004

  Power supply control, e.g. power-saving mode, automatic power turn-off · CPC title

• G03G2215/2025

  the fixing nip having a rotating belt support member opposing a pressure member · CPC title