US5319428A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color image forming apparatus
Assignee: Konica Minolta Inc
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Filing: 1992-10-30
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Granted: 1994-06-07
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Expires: 2012-10-30
Abstract
Abstract In a color image forming apparatus provided with a fixing roller and a pressure roller equipped with a heater therein, which is in press contact with the fixing roller. The completion timing of warm-up of the fixing device is determined by the time at which either the detected temperature of the fixing roller or the heating time of the heater reaches a predetermined value.
Inventors
- 👤 Masami Maruko
- 👤 Naoki Tajima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:09
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/01; G03G15/0105; G03G15/20; G03G15/2003; G03G15/2014; G03G15/2039; G03G15/205
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
163 words
A color image forming apparatus comprising: fixing means including: a single heater-less fixing roller; and a single pressure roller including a heater, for directly heating said pressure roller, said pressure roller being in pressure contact with said heater-less fixing roller for pressing against and transmitting heat only in a direction toward said heater-less fixing roller, such that said heater indirectly heats said fixing roller via said pressure roller; a detector for detecting a temperature of a circumferential surface of said heater-less fixing roller; clock means for counting a period of time during which said heater is directly heating said pressure roller and indirectly heating said heater-less fixing roller; and control means for controlling a completion of a warm-up of said fixing means so that said completion of said warm-up is set when one of a detected temperature of said heater-less fixing roller detected by said detector reaches a predetermined temperature and when the counted period of time reaches a predetermined period of time.
Claim 2
Dependent Claim
163 words
A color image forming apparatus comprising: fixing means including: a single heater-less fixing roller; and a single pressure roller including a heater, for directly heating said pressure roller, said pressure roller being in pressure contact with said heater-less fixing roller for pressing against and transmitting heat only in a direction toward said heater-less fixing roller, such that said heater indirectly heats said fixing roller via said pressure roller; a detector for detecting a temperature of a circumferential surface of said heater-less fixing roller; clock means for counting a period of time during which said heater is directly heating said pressure roller and indirectly heating said heater-less fixing roller; and control means for controlling a completion of a warm-up of said fixing means so that said completion of said warm-up is set when one of a detected temperature of said heater-less fixing roller detected by said detector reaches a predetermined temperature and when the counted period of time reaches a predetermined period of time.
Claim 3
Dependent Claim
45 words
The apparatus of claim 1, wherein said control means controls one of a predetermined temperature and a predetermined period of time according to a size of a recording sheet to be used and a color of a toner to be fixed by said fixing means.
Claim 4
Dependent Claim
44 words
The apparatus of claim 1, wherein said control means controls a temperature on a circumferential surface of said pressure roller according to a size of a recording sheet to be used and a color of a toner to be fixed by said fixing means.
Claim 5
Dependent Claim
47 words
The apparatus of claim 1, wherein said control means controls said heater to lower a circumferential surface temperature of said pressure roller when the detected temperature of said heater-less fixing roller exceeds the predetermined temperature to thereby indirectly lower the detected temperature of said heater-less fixing roller.
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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) | 1997-06-06 | 1997-12-06 | 1998-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-06 | 2001-12-06 | 2002-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-06-06 | 2005-12-06 | 2006-06-07 | $7700.00 | Window Closed / Lapsed |