Image heating apparatus

Patent metadata

Field	Value
Publication number	US-9541869-B2
Application number	US-201314030208-A
Country	US
Kind code	B2
Filing date	Sep 18, 2013
Priority date	Sep 25, 2012
Publication date	Jan 10, 2017
Grant date	Jan 10, 2017

Abstract

An image heating apparatus includes first and second rotatable members for heating a toner image therebetween; an endless belt for heating the first rotatable member while being rotated by the first rotatable member; first and second rollers provided inside the endless belt in this order along a rotational moving direction of the first rotatable member and for urging the endless belt toward the first rotatable member; a holding mechanism for rotatably holding the first and second rollers, the first roller being movable relative to the second roller; an urging mechanism for urging the holding mechanism toward the first rotatable member; and an urging member for urging the first roller in a direction away from the second roller.

First claim

What is claimed is:

1. An image heating apparatus comprising:
first and second rotatable members configured and positioned to heat a toner image on a sheet therebetween;
an endless belt configured and positioned to heat said first rotatable member by contacting an outer surface of said first rotatable member;
first and second rollers provided inside of said endless belt and configured to rotatably support said endless belt;
a first bearing mounted on said first roller and configured to rotatably support said first roller;
a second bearing mounted on said second roller and configured to rotatably support said second roller;
a holding mechanism configured and positioned to hold said first bearing and said second bearing so as to permit movements of said first bearing relative to said second bearing in a direction away from each other; and
a coil spring provided so as to directly contact said first bearing and said second bearing and configured to urge said first bearing relative to said second bearing in the direction away from each other,
wherein said holding mechanism includes a spring holder extending along the direction in which said first and second bearings move away from each other and configured to hold said coil spring to regulate an expansion and contraction direction of said coil spring.

2. The apparatus according to claim 1 , further comprising a moving mechanism configured and positioned to move said holding mechanism between a position in which said endless belt contacts said first rotatable member and a position in which said endless belt is spaced from said first rotatable member.

3. The apparatus according to claim 1 , further comprising a driving mechanism configured and positioned to rotationally drive said first rotatable member, wherein said endless belt is rotated by rotation of said first rotatable member.

4. The apparatus according to claim 1 , wherein said holding mechanism includes a hole portion configured and positioned to engage with said first bearing so as to permit the movements of said first bearing relative to said second bearing.

5. The apparatus according to claim 1 , further comprising a cleaning rotatable member disposed opposed to said second roller through said endless belt and configured to clean said endless belt.

6. The apparatus according to claim 5 , wherein said second roller is held by said holding mechanism so as to be substantially immovable relative to said holding mechanism.

7. The apparatus according to claim 1 , further comprising a first heater provided inside of said first roller and a second heater provided inside of said second roller.

8. The apparatus according to claim 1 , wherein said first rotatable member is a roller disposed in a side contacting the toner image on the sheet.

9. The apparatus according to claim 1 , wherein said first roller and said second roller urge said endless belt toward first rotatable member so that said endless belt contacts the outer surface of said first rotatable member.

10. The apparatus according to claim 1 , wherein said first roller and said second roller are disposed inside said endless belt in this order along a rotational moving direction of said first rotatable member.

Assignees

• Canon Kk

Inventors

• Hasegawa Takuya

Classifications

• G03G15/2017 Primary

  Structural details of the fixing unit in general, e.g. cooling means, heat shielding means (G03G15/2053 takes precedence) · CPC title

• G03G15/2053 Primary

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

• G03G2215/2019

  the belt not heating the toner or medium directly, e.g. heating a heating roller · CPC title