US5682576A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fixing device
Assignee: Canon Inc
•
Filing: 1995-06-07
•
Granted: 1997-10-28
•
Expires: 2015-06-07
Abstract
Abstract In a fixing device used in an image forming apparatus, temperature changes in a heating member are reduced by gradually reducing a power supply duty ratio while the heating member is subjected to temperature control aiming at a set temperature.
Inventors
- 👤 Hiroaki Sakai
- 👤 Masaharu Ohkubo
- 👤 Norio Hashimoto
- 👤 Takayasu Yuminamochi
- 👤 Hiroto Hasegawa
- 👤 Kazuaki Ono
- 👤 Minoru Matsuguma
- 👤 Yasunari Kobaru
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:48
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/20; G03G15/2003; G03G15/2014; G03G15/2039
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
118 words
An image fixing device comprising: a heating member for heating an image on a recording material; a temperature detecting element for detecting a temperature of said heating member; and power supply control means for controlling power supply to said heating member, said power supply control means repeating alternately a turning-off period for turning off the power supply when the detected temperature is higher than a target temperature and a turning-on period for turning on the power supply when the detected temperature is lower than the target temperature, wherein a duty ratio of the power supply during a second turning-on period is smaller than that during a first turning-on period after the detected temperature initially reaches the target temperature.
Claim 2
Dependent Claim
118 words
An image fixing device comprising: a heating member for heating an image on a recording material; a temperature detecting element for detecting a temperature of said heating member; and power supply control means for controlling power supply to said heating member, said power supply control means repeating alternately a turning-off period for turning off the power supply when the detected temperature is higher than a target temperature and a turning-on period for turning on the power supply when the detected temperature is lower than the target temperature, wherein a duty ratio of the power supply during a second turning-on period is smaller than that during a first turning-on period after the detected temperature initially reaches the target temperature.
Claim 3
Dependent Claim
23 words
A fixing device according to claim 1, wherein said power supply control means reduces the power supply duty ratio at a predetermined rate.
Claim 4
Dependent Claim
45 words
An image fixing device according to claim 1, wherein if the temperature detected by said temperature detecting element falls below the target temperature for a predetermined period of time during the turning-on period, said power supply control means gradually increases the power supply duty ratio.
Claim 5
Dependent Claim
31 words
A fixing device according to claim 3, wherein the rate of increase of the power supply duty ratio is smaller than the rate of decrease of the power supply duty ratio.
Claim 6
Dependent Claim
22 words
A fixing device according to claim 1, wherein said heating member comprises a heater, and a heating roller heated by said heater.
Claim 7
Dependent Claim
84 words
A fixing device comprising: a heating rotating member; temperature detection means for detecting a temperature of said heating rotating member; and power supply control means for controlling power supply to said heating rotating member so that the temperature detected by said temperature detection means is maintained at a set temperature, said power supply control means controlling the power supply such that a maximum power-supply-off time period is equal to or less than a time period required for one revolution of said heating rotating member.
Claim 8
Dependent Claim
84 words
A fixing device comprising: a heating rotating member; temperature detection means for detecting a temperature of said heating rotating member; and power supply control means for controlling power supply to said heating rotating member so that the temperature detected by said temperature detection means is maintained at a set temperature, said power supply control means controlling the power supply such that a maximum power-supply-off time period is equal to or less than a time period required for one revolution of said heating rotating member.
Claim 9
Dependent Claim
39 words
A fixing device according to claim 6, wherein if a predetermined time period has elapsed after turning off power supply to said heating rotating member, said power supply control means turns on power supply to said heating rotating member.
Claim 10
Dependent Claim
39 words
A fixing device according to claim 6, wherein a period including a power-supply-on time period and a power-supply-off time period for said heating rotating member is shorter than a time period of one revolution of said heating rotating member.
Claim 11
Dependent Claim
23 words
A fixing device according to claim 6, wherein said heating rotating member comprises a heater, and a heating roller heated by said heater.
References Cited (Backward Citations)
US4719489A
Cited
JPS63313182A
Cited
JPH02157878A
Cited
JPH0444077A
Cited
JPH0444078A
Cited
JPH0444081A
Cited
JPH0444082A
Cited
JPH0444079A
Cited
JPH0444080A
Cited
JPH0444083A
Cited
JPH0444075A
Cited
JPH0444076A
Cited
US5465141A
Cited
US5303016A
Cited
US5365314A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-10-27 | 2001-04-28 | 2001-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-10-27 | 2005-04-28 | 2005-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-10-27 | 2009-04-28 | 2009-10-28 | $7700.00 | Window Closed / Lapsed |