Heater, fixing device, and image forming apparatus

Patent metadata

Field	Value
Publication number	US-10795295-B2
Application number	US-201916701686-A
Country	US
Kind code	B2
Filing date	Dec 3, 2019
Priority date	Jan 31, 2019
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

A heater includes a base and at least one resistive heat generator mounted on a face of the base. At least one electrode supplies power to the at least one resistive heat generator. A conductor couples the at least one electrode with the at least one resistive heat generator. A slide layer covers the at least one resistive heat generator and the conductor. The slide layer includes a projecting portion that defines a surface of the slide layer. The projecting portion is defined by a film thickness of at least one of the conductor and the at least one resistive heat generator. The projecting portion includes an upstream projection disposed opposite a lateral end of the base in a longitudinal direction of the base and a downstream projection disposed downstream from the upstream projection in a rotation direction of an endless belt that slides over the heater.

First claim

What is claimed is:

1. A heater over which an endless belt rotatable in a rotation direction is slidable, the heater comprising:
a base that is elongate and platy;
at least one resistive heat generator mounted on a face of the base;
at least one electrode configured to supply power to the at least one resistive heat generator;
a conductor configured to couple the at least one electrode with the at least one resistive heat generator; and
a slide layer configured to cover the at least one resistive heat generator and the conductor,
the slide layer including a projecting portion configured to define a surface of the slide layer, the projecting portion defined by a film thickness of at least one of the conductor and the at least one resistive heat generator,
the projecting portion including:
an upstream projection disposed opposite a lateral end of the base in a longitudinal direction of the base; and
a downstream projection disposed downstream from the upstream projection in the rotation direction of the endless belt.

2. The heater according to claim 1 ,
wherein the downstream projection includes an upstream end in the rotation direction of the endless belt, and
wherein the upstream projection includes an upstream end disposed upstream from the upstream end of the downstream projection in the rotation direction of the endless belt.

3. The heater according to claim 1 ,
wherein the base is made of a heat resistant, insulating material.

4. The heater according to claim 1 ,
wherein the projecting portion further includes an intermediate projection configured to couple the upstream projection with the downstream projection, and
wherein the projecting portion is bulged downstream in the rotation direction of the endless belt into an arc.

5. The heater according to claim 1 ,
wherein the at least one resistive heat generator includes:
a first laminated resistive heat generator having a first film thickness that defines the downstream projection;
a second laminated resistive heat generator having a second film thickness that defines the upstream projection; and
a third laminated resistive heat generator having a third film thickness that defines the upstream projection.

6. The heater according to claim 5 ,
wherein the at least one electrode includes:
a first electrode disposed on a first lateral end of the base in the longitudinal direction of the base; and
a second electrode disposed on a second lateral end of the base in the longitudinal direction of the base.

7. The heater according to claim 6 ,
wherein the first laminated resistive heat generator is interposed between the first electrode and the second electrode and disposed on a center of the base in the longitudinal direction of the base,
wherein the second laminated resistive heat generator is interposed between the first laminated resistive heat generator and the first electrode and the third laminated resistive heat generator is interposed between the first laminated resistive heat generator and the second electrode, and
wherein the first laminated resistive heat generator, the second laminated resistive heat generator, and the third laminated resistive heat generator are connected in series to the first electrode and the second electrode through the conductor.

8. The heater according to claim 6 ,
wherein the first laminated resistive heat generator is disposed on a center of the base in the longitudinal direction of the base,
wherein the second laminated resistive heat generator and the third laminated resistive heat generator are disposed on the first lateral end and the second lateral end of the base in the longitudinal direction of the base, respectively, and
wherein the first laminated resistive heat generator, the second laminated resistive heat generator, and the third laminated resistive heat generator are connected in parallel to the first electrode and the second electrode through the conductor.

9. The heater according to claim 5 ,
wherein the at least one electrode includes:
a first electrode disposed on one lateral end of the base in the longitudinal direction of the base; and
a second electrode disposed on the one lateral end of the base in the longitudinal direction of the base.

10. The heater according to claim 9 ,
wherein the first laminated resistive heat generator is disposed on a center of the base in the longitudinal direction of the base,
wherein the second laminated resistive heat generator and the third laminated resistive heat generator are disposed on a first lateral end and a second lateral end of the base in the longitudinal direction of the base, respectively, and
wherein the first laminated resistive heat generator, the second laminated resistive heat generator, and the third laminated resistive heat generator are connected in parallel to the first electrode and the second electrode through the conductor.

11. The heater according to claim 1 ,
wherein the at least one resistive heat generator includes:
an outboard end; and
an inboard end disposed inboard from the outboard end in the longitudinal direction of the base, and
wherein the at least one resistive heat generator is inclined such that the inboard end is disposed downstream from the outboard end in the rotation direction of the endless belt.

12. The heater according to claim 1 ,
wherein the conductor includes:
an outboard end; and
an inboard end disposed inboard from the outboard end in the longitudinal direction of the base, and
wherein the conductor is inclined such that the inboard end is disposed downstream from the outboard end in the rotation direction of the endless belt.

13. The heater according to claim 1 ,
wherein the projecting portion further includes:
a plane configured to contact the endless belt; and
a plurality of arches configured to abut on the plane at both ends of the plane in the rotation direction of the endless belt, respectively.

14. A fixing device comprising:
a fixing rotator that is endless, the fixing rotator configured to rotate in a rotation direction;
a heater over which an inner circumferential surface of the fixing rotator slides; and
a pressure rotator disposed opposite the heater via the fixing rotator, the pressure rotator configured to form a fixing nip between the pressure rotator and the fixing rotator, the fixing nip through which a recording medium bearing an image formed with a developer is conveyed,
the heater including:
a base that is elongate and platy;
at least one resistive heat generator mounted on a face of the base;
at least one electrode configured to supply power to the at least one resistive heat generator;
a conductor configured to couple the at least one electrode with the at least one resistive heat generator; and
a slide layer configured to cover the at least one resistive heat generator and the conductor,
the slide layer including a projecting portion configured to define a surface of the slide layer, the projecting portion defined by a film thickness of at least one of the conductor and the at least one resistive heat generator,
the projecting portion including:
an upstream projection disposed opposite a lateral end of the base in a longitudinal direction of the base; and
a downstream projection disposed downstream from the upstream projection in the rotation direction of the fixing rotator.

15. An image forming apparatus comprising:
a developing device configured to form an image with a developer; and
a fixing device configured to fix the image on a recording medium,
the fixing device including:
a fixing rotator that is end

Assignees

• Inoue Daisuke
• Adachi Tomoya
• Furuichi Yuusuke
• Someya Yukimichi
• Ricoh Co Ltd

Inventors

• Inoue Daisuke
• Adachi Tomoya
• Furuichi Yuusuke
• Someya Yukimichi

Classifications

• G03G15/2064

  combined with pressure · CPC title

• G03G2215/2048

  Surface layer material · CPC title

• H05B3/03

  Electrodes · CPC title

• H05B3/0019

  Circuit arrangements · CPC title

• G03G15/80

  Details relating to power supplies, circuits boards, electrical connections · CPC title