# US 5,347,348 A · Image fixing apparatus with detector for detecting movement of endless belt

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- Number: US 5,347,348 A
- Document ID: US5347348A
- Status: Granted
- Kind: A
- Application number: 08/167,623
- Filed: 1993-12-16
- Granted: 1994-09-13
- Earliest claimed: 1989-09-27
- Assignees: Canon Kabushiki Kaisha
- Inventors: Tsunetoshi Nagata
- Web page: https://patentgrep.com/patent/US5347348A

## CPC

- G03G 15/2064: {combined with pressure}
- B65G 23/44: Belt or chain tensioning arrangements
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- B65G: TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS (packaging B65B; handling thin or filamentary materials, e.g. paper sheets or thread, B65H; cranes B66C; portable mobile or lifting or hauling appliances, e.g. hoists, B66D; devices for lifting or lowering goods for loading or unloading purposes, e.g. fork-lift trucks, B66F9/00; emptying bottles, jars, casks, barrels or similar containers, not otherwise provided for, B67C9/00; delivering or transferring liquids B67D; filling or discharging vessels for liquefied, solidified or compressed gases F17C; pipe-line systems for fluids F17D)

## Abstract

An image fixing apparatus includes a heater; a rotatable endless film, wherein an unfixed image on a recording material is heated and fixed by heat from the heater through the endless film; a displaceable member made of heat resistive resin material displaceable in accordance with movement of the endless film in a direction perpendicular to movement of the endless film; detecting element for detecting the displaceable member, the detecting element detecting the displaceable member to detect a lateral shift of the endless film.

## Claims

### Claim 1

An image heating apparatus, comprising:
a heater;
an endless belt movable in sliding contact with said heater;
a first roller, disposed downstream of said heater with respect to a movement direction of said endless belt, said endless belt being stretched around said first roller;
a second roller, disposed upstream of said heater with respect to the movement direction of said endless belt, said endless belt being stretched around said second roller;
a displaceable member contacting an edge of said endless belt at a position downstream of said first roller and upstream of said second roller, said movable means comprising heat insulative resin; and
a photosensor for optically detecting said displaceable member to determine a lateral shift of said endless belt.

### Claim 2 (depends on 1)

An apparatus according to claim 1, further including means for laterally shifting said endless belt in a direction opposite from a direction of a lateral shift detected by said photosensor.

### Claim 3 (depends on 2)

An apparatus according to claim 2, wherein said lateral shifting means laterally shifts the endless belt such that said endless belt is maintained in a predetermined range.

### Claim 4 (depends on 1)

An apparatus according to claim 1, wherein said first roller drives said endless belt, and said second roller is driven by said endless belt.

### Claim 5 (depends on 1)

An apparatus according to claim 1, wherein the heat insulative resin is pholyphenylene sulfide or polyamide.

### Claim 6 (depends on 1)

An apparatus according to claim 1, wherein said displaceable means comprises a rotatable pulley contactable to said endless belt.

### Claim 7 (depends on 1)

An apparatus according to claims 1, said endless belt comprises a reinforced lateral edge.

### Claim 8 (depends on 1)

An apparatus according to claim 1, wherein said photosensor is disposed outside said heater in a direction of lateral shift of said endless belt.