Patent US4933724A successfully refreshed from Google Patents.
US4933724A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fixing device for electrophotography
Assignee: Sharp Corp
•
Filing: 1989-04-24
•
Granted: 1990-06-12
•
Expires: 2009-04-24
Abstract
Abstract A fixing device for electrophotography has a heating roller and a compression roller compressed against each other. Copy paper with toner image on its surface is passed inbetween to have the image fixed. The heating roller is hollow and contains a heater inside. To control the heat output of the heater, a temperature detector is positioned on the surface of the heating roller near the edge of the paper passing between the rollers where no toner image is formed. The wall thickness of the heating roller is reduced to about 0.8-1.5 mm for improved heat distribution characteristics.
Inventors
- 👤 Yuji Sugimoto
- 👤 Masaru Tsuji
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 21:47
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/20; G03G15/2003; G03G15/2014; G03G15/2039
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
115 words
A fixing device of an electrophotographic image forming apparatus which includes a photosensitive drum, said fixing device comprising a first roller which is hollow and contains a heater at its center section, a second roller which is in contact and rotatable with said first roller, said rollers serving to pass a copy paper sheet therebetween to fix toner images thereon, said copy paper sheet having thereon a void section where no toner image is formed, and a temperature detector which controls said heater, said temperature detector being disposed in contact with said first roller at a position on the surface thereon corresponding to said void section of said copy paper sheet passing between said rollers.
Claim 2
Dependent Claim
115 words
A fixing device of an electrophotographic image forming apparatus which includes a photosensitive drum, said fixing device comprising a first roller which is hollow and contains a heater at its center section, a second roller which is in contact and rotatable with said first roller, said rollers serving to pass a copy paper sheet therebetween to fix toner images thereon, said copy paper sheet having thereon a void section where no toner image is formed, and a temperature detector which controls said heater, said temperature detector being disposed in contact with said first roller at a position on the surface thereon corresponding to said void section of said copy paper sheet passing between said rollers.
Claim 3
Dependent Claim
20 words
The fixing device of claim 1 wherein said first roller comprises an aluminum cylinder of thermal conductivity about 0.53 cal/cm·sec·deg.
Claim 4
Dependent Claim
22 words
The fixing device of claim 1 wherein said first roller comprises a hollow aluminum housing with thickness about 0.8 to 1.5 mm.
Claim 5
Dependent Claim
36 words
The fixing device of claim 1 wherein said second roller includes a central shaft, a silicone rubber roller around said central shaft, and a tubular layer of ethylene tetrafluoride resin formed on said silicone rubber roller.
Claim 6
Dependent Claim
13 words
The fixing device of claim 1 wherein said temperature detector includes a thermister.
References Cited (Backward Citations)
US3268351A
Cited
US3690176A
Cited
US3968343A
Cited
US4309591A
Cited
US4348579A
Cited
US4329565A
Cited
JPS5763570A
Cited
US4514486A
Cited
US4572648A
Cited
US4627813A
Cited
JPS60151683A
Cited
US4588281A
Cited
JPS62231978A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-06-11 | 1993-12-11 | 1994-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-11 | 1997-12-11 | 1998-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-11 | 2001-12-11 | 2002-06-12 | $7700.00 | Window Closed / Lapsed |