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US5111249A Expired / Lapsed US ⏱️ 0.0 years remaining

Heat roller fixing device

Assignee: Konica Minolta Inc
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Filing: 1990-10-03
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Granted: 1992-05-05
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Expires: 2010-10-03
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Abstract

Abstract A fixing device for use in a copying machine for fixing a toner image on the surface of a recording sheet. The fixing device conveys the recording sheet between a pair of rollers consisting of a heating roller and a pressure roller to fix the toner image on the surface of the recording sheet by heating the toner image with the heating roller. After a number of recording sheets have been fixed as a batch, the pair of rollers separate from each other and stop rotating if the batch of recording sheets are smaller in number than a predetermined number, whereas the pair of rollers continue rotating in press contact with each other for a predetermined time interval after the batch of recording sheets have been fixed if the batch of recording sheets are larger in number than the predetermined number.

Inventors

  • 👤 Akihiro Owada

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-06 10:34
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/20; G03G15/2003; G03G15/2014; G03G15/2039; G03G15/2017; G03G15/2032; G03G2215/00; G03G2215/20

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 147 words
A thermal fixing device of a copying machine for fixing a toner image on the surface of a recording sheet, the device having a pair of rollers consisting of a heating roller and a pressure roller which convey the recording sheets therebetween, thereby heating and pressing the toner image to be fixed on the surface of the recording sheet, the device comprising: means for driving at least one of the pair of rollers to rotate; and means for controlling the driving means to stop the rotation of the rollers when a number of sheets in a batch of recording sheets less than a predetermined number have been fixed and conveyed, and controlling the driving means to continue the rotation of the rollers for a predetermined interval after a number of sheets in a batch of recording sheets greater than the predetermined number have been fixed and conveyed.
Claim 2
Dependent Claim 147 words
A thermal fixing device of a copying machine for fixing a toner image on the surface of a recording sheet, the device having a pair of rollers consisting of a heating roller and a pressure roller which convey the recording sheets therebetween, thereby heating and pressing the toner image to be fixed on the surface of the recording sheet, the device comprising: means for driving at least one of the pair of rollers to rotate; and means for controlling the driving means to stop the rotation of the rollers when a number of sheets in a batch of recording sheets less than a predetermined number have been fixed and conveyed, and controlling the driving means to continue the rotation of the rollers for a predetermined interval after a number of sheets in a batch of recording sheets greater than the predetermined number have been fixed and conveyed.
Claim 3
Dependent Claim 39 words
The thermal fixing device of claim 1, further comprising: means, controlled by the control means, for shifting the pressure roller towards pressure contact with the heating roller and away from the heating roller to separate the pair of rollers.
Claim 4
Dependent Claim 89 words
The thermal fixing device of claim 1, wherein the controlling means comprises: arithmetic means including means for determining the number of recording sheets in a batch by multiplying a required number of copy sets and a number of document sheets having been copied when the copy machine is provided with an automatic document feeder, and including means for determining the number of recording sheets by counting up the recording sheets having been exhausted after copying and fixing when the copying machine is not provided with the automatic document feeder.

References Cited (Backward Citations)

JPS5439643A Cited
JPS56109382A Cited
JPS5852667A Cited
US4595274A Cited
JPS60191277A Cited
JPS62187364A Cited
JPS64583A Cited
US4920250A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-05-05 1995-11-04 1996-05-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-05-05 1999-11-04 2000-05-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-05-05 2003-11-04 2004-05-05 $7700.00 Window Closed / Lapsed

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