US4878092A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of controlling a fixing unit of an image forming apparatus
Assignee: Ricoh Co Ltd
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Filing: 1988-05-27
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Granted: 1989-10-31
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Expires: 2008-05-27
Abstract
Abstract A method of controlling a fixing unit which is installed in an electrophotographic copier, facsimile apparatus or like image forming apparatus and includes a fixing roller and a pressing roller. A secure fixing temperature of the fixing unit is selectively set to at least two different temperatures.
Inventors
- 👤 Atsushi Arai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:01
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/20; G03G15/2003; G03G15/2014; G03G15/2039
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
94 words
In a method of controlling a fixed unit which is installed in a copier which includes a fixing roller and a pressing roller and in which copier said fixing unit is operated to fix a toner image on a sheet of copy paper when the fixing roller is at a secure fixing temperature defined as a lower limit at temperatures above which the toner image can be satisfactorily fixed, the improvement comprising: selectively establishing at least two temperatures as secure fixing temperatures of the fixing unit in dependence on at least one predetermined condition.
Claim 2
Dependent Claim
94 words
In a method of controlling a fixed unit which is installed in a copier which includes a fixing roller and a pressing roller and in which copier said fixing unit is operated to fix a toner image on a sheet of copy paper when the fixing roller is at a secure fixing temperature defined as a lower limit at temperatures above which the toner image can be satisfactorily fixed, the improvement comprising: selectively establishing at least two temperatures as secure fixing temperatures of the fixing unit in dependence on at least one predetermined condition.
Claim 3
Dependent Claim
66 words
A method as claimed in claim 1, wherein the secure fixing temperature differs from a time when at least one of a condition that more than a predetermined number of copies have been produced and a condition that a predetermined period of time has not expired after turn-on of a power supply is satisfied to a time when none of said two conditions have been satisfied.
Claim 4
Independent Claim
113 words
A method of controlling a fixing unit which is installed in a copier and constituted by a fixing roller and a pressing roller and in which copier said fixing unit is operated to fix a toner image on a sheet of copy paper when the fixing roller is at a secure fixing temperature defined as a lower limit at temperatures above which the toner image can be satisfactorily fixed, comprising the steps of: (a) turning on a power supply; (b) setting the secure fixing temperature to a first temperature; and (c) changing the secure fixing temperature to a second temperature when a predetermined condition is reached after the turn-on of the power supply.
Claim 5
Independent Claim
113 words
A method of controlling a fixing unit which is installed in a copier and constituted by a fixing roller and a pressing roller and in which copier said fixing unit is operated to fix a toner image on a sheet of copy paper when the fixing roller is at a secure fixing temperature defined as a lower limit at temperatures above which the toner image can be satisfactorily fixed, comprising the steps of: (a) turning on a power supply; (b) setting the secure fixing temperature to a first temperature; and (c) changing the secure fixing temperature to a second temperature when a predetermined condition is reached after the turn-on of the power supply.
Claim 6
Dependent Claim
28 words
A method as claimed in claim 3, wherein the predetermined condition is that a predetermined number of copies have been produced after the turn-on of the power supply.
Claim 7
Dependent Claim
27 words
A method as claimed in claim 3, wherein the predetermined condition is that a predetermined period of time has expired after the turn-on of the power supply.
Claim 8
Dependent Claim
48 words
A method as claimed in claim 3, wherein the predetermined condition is at least one of that a predetermined number of copies have been produced after the turn-on of the power supply and that a predetermined period of time has expired after the turn-on of the power supply.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-10-30 | 1993-05-01 | 1993-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-30 | 1997-05-01 | 1997-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-30 | 2001-05-01 | 2001-10-31 | $7700.00 | Window Closed / Lapsed |