Patent US5300996A successfully refreshed from Google Patents.
US5300996A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fixing apparatus
Assignee: Ricoh Co Ltd
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Filing: 1992-06-03
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Granted: 1994-04-05
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Expires: 2012-06-03
Abstract
Abstract A fixing apparatus for fixing an image on a record sheet comprises a fixing roller in which a heater is disposed, a pressing roller urged against the fixing roller, heat pipes extending in either one of the fixing and pressing rollers in a longitudinal direction thereof, and a temperature detection / control device for detecting to control a temperature of the fixing roller. In a typical embodiment, the heat pipes are disposed in the fixing roller to extend both through an imaging portion, through which a record sheet passes, and through a non-imaging portion, through which no record sheet passes and the temperature detection / control device has a temperature detection device for detecting a temperature of the fixing roller in contact with the non-imaging portion. The temperature detection / control device is provided with a temperature regulating device for interrupting electricity to the heater when the fixing roller exceeds a predetermined temperature. In another embodiment, at least one of heat pipes is provided in the fixing roller in parallel with an axis of the fixing roller, and a core of the fixing roller is produced by extrusion.
Inventors
- 👤 Hiroshi Yokoyama
- 👤 Yutaka Fukuchi
- 👤 Atsushi Arai
- 👤 Masahiko Sato
- 👤 Toshiaki Higaya
- 👤 Jun Okamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:03
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/0033; H05B3/0038; H05B3/0066; G; G03; G03G; G03G15/00; G03G15/20; G03G15/2003; G03G15/2014; G03G15/2039; G03G15/2042; G03G15/2053
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
207 words
A fixing apparatus for fixing an image on a record sheet, comprising: a tubular fixing roller; a pressing roller urged against said fixing roller; a heater received in said fixing roller for heating said fixing roller; at least one heat pipe embedded in said fixing roller so as to extend in a longitudinal direction of said fixing roller for improving a thermal conductivity; and temperature detection/control means for detecting a temperature of said fixing roller and controlling said heater so as to adjust said temperature of said fixing roller based on said detected temperature; `said fixing roller having an imaging portion at a center thereof and having non-imaging portions at both ends thereof, and said heat pipe being disposed in said fixing roller so as to extend through said imaging portion and said non-imaging portions, said temperature detection/control means comprising temperature detection means for detecting said temperature of said fixing roller at said non-imaging portion, said temperature detection/control means comprising temperature regulating means for interrupting electricity to said heater when said fixing roller exceeds a predetermined temperature, said temperature detecting means and said temperature regulating means being in contact with said fixing roller at different positions which are offset in the longitudinal direction of said fixing roller.
Claim 2
Dependent Claim
207 words
A fixing apparatus for fixing an image on a record sheet, comprising: a tubular fixing roller; a pressing roller urged against said fixing roller; a heater received in said fixing roller for heating said fixing roller; at least one heat pipe embedded in said fixing roller so as to extend in a longitudinal direction of said fixing roller for improving a thermal conductivity; and temperature detection/control means for detecting a temperature of said fixing roller and controlling said heater so as to adjust said temperature of said fixing roller based on said detected temperature; `said fixing roller having an imaging portion at a center thereof and having non-imaging portions at both ends thereof, and said heat pipe being disposed in said fixing roller so as to extend through said imaging portion and said non-imaging portions, said temperature detection/control means comprising temperature detection means for detecting said temperature of said fixing roller at said non-imaging portion, said temperature detection/control means comprising temperature regulating means for interrupting electricity to said heater when said fixing roller exceeds a predetermined temperature, said temperature detecting means and said temperature regulating means being in contact with said fixing roller at different positions which are offset in the longitudinal direction of said fixing roller.
Claim 3
Dependent Claim
36 words
A fixing apparatus according to claim 1, wherein said heat pipe is at least three in number, and at least one of said heat pipes is in parallel with the longitudinal axis of said fixing roller.
Claim 4
Dependent Claim
31 words
A fixing apparatus according to claim 1, wherein said heat pipe is embedded in a core of said fixing roller, and said core of said fixing roller is produced by extrusion.
Claim 5
Dependent Claim
24 words
A fixing apparatus according to claim 1, wherein both ends of said fixing roller are made of a material having a low thermal conductivity.
Claim 6
Dependent Claim
29 words
A fixing apparatus according to claim 1, wherein said pipe is shorter in the longitudinal direction of said fixing roller than a sheet passage area of said fixing roller.
Claim 7
Dependent Claim
33 words
A fixing apparatus according to claim 1, wherein a heating portion of said heater is shorter in a longitudinal direction of said fixing roller than a sheet passage area of said fixing roller.
Claim 8
Dependent Claim
20 words
A fixing apparatus according to claim 6, wherein said heating portion of said heater is shorter than said heat pipe.
Claim 9
Dependent Claim
35 words
A fixing apparatus according to claim 1, wherein said heat pipe is at least three in number, and at least one of said heat pipes is embedded in an elastic layer of said pressing roller.
Claim 10
Dependent Claim
25 words
A fixing apparatus according to claim 2, wherein all of said heat pipes are provided in parallel with the longitudinal axis of said fixing roller.
Claim 11
Dependent Claim
43 words
A fixing apparatus according to claim 2, wherein one of said heat pipes is in parallel with said longitudinal axis of said fixing roller, and the others of said heat pipes are oblique with respect to said longitudinal axis of said fixing roller.
Claim 12
Dependent Claim
20 words
A fixing apparatus according to claim 8, wherein said heat pipes are supported by support means outside said elastic layer.
Claim 13
Dependent Claim
227 words
A fixing apparatus for fixing an image on a record sheet, comprising: a tubular fixing roller; a pressing roller urged against said fixing roller; a heater received in said fixing roller for heating said fixing roller; at least one heat pipe embedded in a core of said pressing roller so as to extend in a longitudinal direction of said pressing roller for improving a thermal conductivity, at least a portion of said heat pipe being in an elastic layer of said pressing roller, and temperature detection/control means for detecting a temperature of said fixing roller and controlling said heater so as to adjust said temperature of said fixing roller based on said detected temperature; `said fixing roller having an imaging portion at a center thereof and having non-imaging portions at both ends thereof, and said heat pipe being disposed in said pressing roller so as to extend through said imaging portion and said non-imaging portions, said temperature detection/control means comprising temperature detection means for detecting said temperature of said fixing roller at said non-imaging portion, said temperature detection/control means comprising temperature regulating means for interrupting electricity to said heater when said fixing roller exceeds a predetermined temperature, said temperature detecting means and said temperature regulating means being in contact with said fixing roller at different positions which are offset in the longitudinal direction of said fixing roller.
Claim 14
Dependent Claim
227 words
A fixing apparatus for fixing an image on a record sheet, comprising: a tubular fixing roller; a pressing roller urged against said fixing roller; a heater received in said fixing roller for heating said fixing roller; at least one heat pipe embedded in a core of said pressing roller so as to extend in a longitudinal direction of said pressing roller for improving a thermal conductivity, at least a portion of said heat pipe being in an elastic layer of said pressing roller, and temperature detection/control means for detecting a temperature of said fixing roller and controlling said heater so as to adjust said temperature of said fixing roller based on said detected temperature; `said fixing roller having an imaging portion at a center thereof and having non-imaging portions at both ends thereof, and said heat pipe being disposed in said pressing roller so as to extend through said imaging portion and said non-imaging portions, said temperature detection/control means comprising temperature detection means for detecting said temperature of said fixing roller at said non-imaging portion, said temperature detection/control means comprising temperature regulating means for interrupting electricity to said heater when said fixing roller exceeds a predetermined temperature, said temperature detecting means and said temperature regulating means being in contact with said fixing roller at different positions which are offset in the longitudinal direction of said fixing roller.
Claim 15
Dependent Claim
19 words
A fixing apparatus according to claim 12, wherein said heat pipe is formed in an integral with said core.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-04-04 | 1997-10-04 | 1998-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-04-04 | 2001-10-04 | 2002-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-04-04 | 2005-10-04 | 2006-04-05 | $7700.00 | Window Closed / Lapsed |