Fixing device and image forming apparatus

Patent metadata

Field	Value
Publication number	US-9874839-B2
Application number	US-201615178079-A
Country	US
Kind code	B2
Filing date	Jun 9, 2016
Priority date	Jun 23, 2015
Publication date	Jan 23, 2018
Grant date	Jan 23, 2018

Abstract

A fixing device includes a fixing rotator rotatable in a predetermined direction of rotation and a nip formation pad disposed inside the fixing rotator. A pressure rotator presses against the nip formation pad via the fixing rotator to form a fixing nip between the fixing rotator and the pressure rotator. A heat generator is disposed inside the fixing rotator to heat the fixing rotator. A reflector is interposed between the heat generator and the nip formation pad. The reflector includes a reflection face to reflect radiant heat radiated from the heat generator. The reflection face includes a reflection portion disposed opposite the heat generator at various angles. A support is provided separately from the nip formation pad and supports the reflector.

First claim

What is claimed is:

1. A fixing device comprising:
a fixing rotator rotatable in a predetermined direction of rotation;
a nip formation pad disposed inside the fixing rotator;
a pressure rotator to press against the nip formation pad via the fixing rotator to form a fixing nip between the fixing rotator and the pressure rotator;
a heat generator disposed inside the fixing rotator to heat the fixing rotator;
a reflector interposed between the heat generator and the nip formation pad, the reflector including a reflection face to reflect radiant heat radiated from the heat generator, the reflection face including a reflection portion disposed opposite the heat generator at various angles; and
a support including a supporting side plate at each end of the reflector which support the reflector, the supporting side plates being separate from the nip formation pad.

2. The fixing device according to claim 1 ,
wherein the nip formation pad includes:
a slide portion over which an inner circumferential surface of the fixing rotator slides; and
a reinforcement projecting from the slide portion inward toward an interior of the fixing rotator.

3. The fixing device according to claim 2 ,
wherein the reinforcement includes a side face disposed opposite the heat generator.

4. The fixing device according to claim 2 ,
wherein the reflector further includes:
a first plane parallel to the reinforcement; and
a second plane parallel to the reinforcement and stepped with respect to the first plane, and
wherein the reflection portion includes a tilt plane bridging the first plane and the second plane.

5. The fixing device according to claim 2 ,
wherein the support supports the reinforcement of the nip formation pad.

6. The fixing device according to claim 2 ,
wherein the reflector is secured to the support with a predetermined interval between the reflector and the reinforcement of the nip formation pad.

7. The fixing device according to claim 2 ,
wherein the reflection portion includes a projection projecting from the reflection face toward the heat generator.

8. The fixing device according to claim 7 ,
wherein the reflector supported by the support is interposed between the heat generator and the reinforcement and a center of the heat generator in a direction perpendicular to an axial direction of the fixing rotator is on a hypothetical extension extending from the projection in a projection direction of the projection.

9. A fixing device comprising:
a fixing rotator rotatable in a predetermined direction of rotation;
a nip formation pad disposed inside the fixing rotator;
a pressure rotator to press against the nip formation pad via the fixing rotator to form a fixing nip between the fixing rotator and the pressure rotator;
a heat generator disposed inside the fixing rotator to heat the fixing rotator;
a reflector interposed between the heat generator and the nip formation pad,
the reflector including a reflection face to reflect radiant heat radiated from the heat generator, the reflection face including a reflection portion disposed opposite the heat generator at various angles; and
a support being provided separately from the nip formation pad and supporting the reflector,
wherein the nip formation pad includes:
a slide portion over which an inner circumferential surface of the fixing rotator slides; and
a reinforcement projecting from the slide portion inward toward an interior of the fixing rotator,

wherein the reflection portion includes a projection projecting from the reflection face toward the heat generator, and
wherein the projection includes a gable projecting from the reflection face toward the heat generator.

10. The fixing device according to claim 9 ,
wherein the support includes a pentagonal slot into which the heat generator is inserted.

11. The fixing device according to claim 10 ,
wherein the slot includes a V-shaped portion disposed opposite and projected toward the gable of the projection of the reflector, the V-shaped portion bearing the heat generator.

12. The fixing device according to claim 11 , further comprising a lock pressing the heat generator against the V-shaped portion of the slot.

13. The fixing device according to claim 1 ,
wherein the support supports the heat generator.

14. The fixing device according to claim 1 ,
wherein the reflection portion includes an arch projecting from the reflection face toward the heat generator.

15. The fixing device according to claim 1 ,
wherein the reflection portion includes a recess recessed with respect to the heat generator.

16. The fixing device according to claim 1 , further comprising a tension applicator anchored to the support and the reflector to apply tension to the reflector outward in an axial direction of the fixing rotator.

17. The fixing device according to claim 16 ,
wherein the tension applicator includes a flat spring.

18. The fixing device according to claim 17 ,
wherein the flat spring includes:
a first end secured to the support; and
a second end inserted into the reflector to define an L-shape with the first end.

19. The fixing device according to claim 1 ,
wherein the reflection portion reflects the radiant heat radiated from the heat generator in a direction not directed to the heat generator.

20. The fixing device according to claim 1 , wherein:
each of the side plates includes v-shaped portion including a downward projection,
the reflector has an upward projection, and
the downward projection of the v-shaped portion is disposed opposite to the upward projection of the reflector.

21. An image forming apparatus comprising:
an image forming device to form a toner image; and
a fixing device disposed downstream from the image forming device in a recording medium conveyance direction to fix the toner image on a recording medium,
the fixing device including:
a fixing rotator rotatable in a predetermined direction of rotation;
a nip formation pad disposed inside the fixing rotator;
a pressure rotator to press against the nip formation pad via the fixing rotator to form a fixing nip between the fixing rotator and the pressure rotator;
a heat generator disposed inside the fixing rotator to heat the fixing rotator;
a reflector interposed between the heat generator and the nip formation pad,
the reflector including a reflection face to reflect radiant heat radiated from the heat generator, the reflection face including a reflection portion disposed opposite the heat generator at various angles; and

a support including a supporting side plate at each end of the reflector which support the reflector, the supporting side plates being separate from the nip formation pad.

Assignees

• Sawada Kazunari
• Ishii Kenji
• Kishi Kazuhito
• Seki Takayuki
• Yoshinaga Hiroshi
• Seto Takashi
• Takagi Hiromasa
• Fujimoto Ippei
• Hase Takamasa
• Ogino Yasuhiko
• Kobashigawa Shohta
• Ricoh Co Ltd

Inventors

• Sawada Kazunari
• Ishii Kenji
• Kishi Kazuhito
• Seki Takayuki
• Yoshinaga Hiroshi
• Seto Takashi
• Takagi Hiromasa
• Fujimoto Ippei
• Hase Takamasa
• Ogino Yasuhiko
• Kobashigawa Shohta

Classifications

• G03G2215/2025

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

• G03G15/2053 Primary

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