US5839043A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal fixing apparatus and inductively heated sleeve
Assignee: Minolta Co Ltd
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Filing: 1996-09-04
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Granted: 1998-11-17
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Expires: 2016-09-04
Abstract
Abstract An induction heating type fixing apparatus comprises a fixing sleeve formed of a flexible thin electrically conductive magnetic material, a coil for producing an induced eddy current in the fixing sleeve to generate heat therein, a holder adapted to retain the coil and disposed stationarily in the fixing sleeve, and a pressing roller pressed against the holder through the fixing sleeve. A sheet carrying thereon an unfixed toner is conveyed as nipped between the fixing sleeve and the pressing roller. The toner on the sheet is melted by the heat of the sleeve itself and exposed to the pressure exerted between the holder and the pressing roller and fixed on the sheet. The holder is provided with a separating member adapted to effect the curvature separation of the sheet from the fixing sleeve. The holder is further provided with a heat-diffusing member made of a material with good thermal conductivity characteristics and non-magnetic properties.
Inventors
- 👤 Eiji Okabayashi
- 👤 Taizou Oonishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:46
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/20; G03G15/2003; G03G15/2014; G03G15/2053; G03G15/2064
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
189 words
A fixing apparatus for causing a toner deposited on a sheet to be thermally fused and fixed on said sheet, comprising: a thin sleeve with flexibility composed of a base layer and a surface layer touching to said sheet, at least said surface layer is made of metal, a coil adapted to generate a magnetic field in response to a high-frequency current supplied from a current supplying means and to produce an induced eddy current in said sleeve to generate heat therein, a retaining member adapted to retain said coil and disposed stationarily in said sleeve, pressing means pressed against said retaining member through said sleeve and enabled to nip said sheet carrying an unfixed toner thereon in cooperation with said sleeve and to move said sheet together with said sleeve, and at least a first heat-diffusing member extended in a direction perpendicular to a direction of conveyance of said sheet and formed of a material with good thermal conductivity characteristics and non-magnetic properties, said first heat-diffusing member disposed in said sleeve so as to contact said sleeve at a contact part between said sleeve and said pressing means.
Claim 2
Dependent Claim
189 words
A fixing apparatus for causing a toner deposited on a sheet to be thermally fused and fixed on said sheet, comprising: a thin sleeve with flexibility composed of a base layer and a surface layer touching to said sheet, at least said surface layer is made of metal, a coil adapted to generate a magnetic field in response to a high-frequency current supplied from a current supplying means and to produce an induced eddy current in said sleeve to generate heat therein, a retaining member adapted to retain said coil and disposed stationarily in said sleeve, pressing means pressed against said retaining member through said sleeve and enabled to nip said sheet carrying an unfixed toner thereon in cooperation with said sleeve and to move said sheet together with said sleeve, and at least a first heat-diffusing member extended in a direction perpendicular to a direction of conveyance of said sheet and formed of a material with good thermal conductivity characteristics and non-magnetic properties, said first heat-diffusing member disposed in said sleeve so as to contact said sleeve at a contact part between said sleeve and said pressing means.
Claim 3
Dependent Claim
17 words
A fixing apparatus according to claim 1, wherein said heat-diffusing member is disposed on said retaining member.
Claim 4
Dependent Claim
61 words
A fixing apparatus according to claim 1, further comprising; a second heat-diffusing member having smaller thermal conductivity than said heat-diffusing member and control means for selectively switching the positions of said first and second heat-diffusing members thereby enabling either of said first and second heat-diffusing members to contact said sleeve at the contact part between said sleeve and said pressing means.
Claim 5
Dependent Claim
28 words
A fixing apparatus according to claim 3, wherein said control means switches the position of said first and second heat-diffusing members based on the temperature of said sleeve.
Claim 6
Dependent Claim
49 words
A fixing apparatus according to claim 4, wherein said control means sets said second heat-diffusing member at the contact position with said sleeve until the temperature of said sleeve reaches a prescribed level and sets said first heat-diffusing member at said position after said sleeve reaches said prescribed temperature.
Claim 7
Dependent Claim
33 words
A fixing apparatus according to claim 3, wherein said control means switches the positions of said first and second heat-diffusing members based on the total number of said sheets to be continuously supplied.
Claim 8
Dependent Claim
51 words
A fixing apparatus according to claim 6, wherein said control means sets said second heat-diffusing member at the contact position with said sleeve when the number of continuously supplied sheets is less than a prescribed sum and sets said first heat-diffusing member at said position when said number surpasses said sum.
Claim 9
Dependent Claim
28 words
A fixing apparatus according to claim 3, wherein said control means switches the positions of said first and second heat-diffusing members based on the size of said sheet.
Claim 10
Dependent Claim
54 words
A fixing apparatus according to claim 8, wherein said control means sets said first heat-diffusing member at the contact position with said sleeve when said sheets have a size smaller than a prescribed size and sets said second heat-diffusing member at said position when said sheets have a size larger than said prescribed size.
Claim 11
Dependent Claim
20 words
A fixing apparatus according to claim 3, wherein said first and second heat-diffusing members are disposed on said retaining member.
Claim 12
Dependent Claim
186 words
A fixing apparatus for causing a toner deposited on a sheet to be thermally fused and fixed on said sheet, comprising; a heating element formed of a flexible material of a small section thickness, a heat source for heating said heating element, a retaining member adapted to retain said heat source and disposed stationarily, pressing means pressed against said retaining member through said heating element and adapted to nip a sheet carrying an unfixed toner in cooperation with said heating element and advance said sheet together with said heating element, a first heat-diffusing member made of a material with good thermal conductivity characteristics and extended in a direction perpendicular to the direction of conveyance of said sheet, a second heat-diffusing member possessing smaller thermal conductivity than said first heat-diffusing member and extended in a direction perpendicular to the direction of conveyance of said sheet, and control means for selectively switching the positions of said first and second heat-diffusing members thereby causing either of said first and second heat-diffusing members to contact said heating element at the contact part between said heating element and said pressing means.
Claim 13
Dependent Claim
186 words
A fixing apparatus for causing a toner deposited on a sheet to be thermally fused and fixed on said sheet, comprising; a heating element formed of a flexible material of a small section thickness, a heat source for heating said heating element, a retaining member adapted to retain said heat source and disposed stationarily, pressing means pressed against said retaining member through said heating element and adapted to nip a sheet carrying an unfixed toner in cooperation with said heating element and advance said sheet together with said heating element, a first heat-diffusing member made of a material with good thermal conductivity characteristics and extended in a direction perpendicular to the direction of conveyance of said sheet, a second heat-diffusing member possessing smaller thermal conductivity than said first heat-diffusing member and extended in a direction perpendicular to the direction of conveyance of said sheet, and control means for selectively switching the positions of said first and second heat-diffusing members thereby causing either of said first and second heat-diffusing members to contact said heating element at the contact part between said heating element and said pressing means.
Claim 14
Dependent Claim
29 words
A fixing apparatus according to claim 11, wherein said control means switches the positions of said first and second heat-diffusing members based on the temperature of said heating element.
Claim 15
Dependent Claim
52 words
A fixing apparatus according to claim 12, wherein said control means sets said second heat-diffusing member at the contact position with said heating element until the temperature of said heating element reaches a prescribed level and sets said first heat-diffusing member at said position after said heating element reaches said prescribed temperature.
Claim 16
Dependent Claim
29 words
A fixing apparatus according to claim 11, wherein said control means switches the positions of said first and second heat-diffusing members based on the number of continuously supplied sheets.
Claim 17
Dependent Claim
52 words
A fixing apparatus according to claim 14, wherein said control means sets said second heat-diffusing member at the contact position with said heating element when the number of continuously supplied sheets is less than a prescribed sum and sets said first heat-diffusing member at said position when said number surpasses said sum.
Claim 18
Dependent Claim
28 words
A fixing apparatus according to claim 11, wherein said control means switches the positions of said first and second heat-diffusing members based on the size of said sheet.
Claim 19
Dependent Claim
55 words
A fixing apparatus according to claim 16, wherein said control means sets said first heat-diffusing member at the contact position with said heating element when said sheets have a size smaller than a prescribed size and sets said second heat-diffusing member at said position when said sheets have a size larger than said prescribed size.
Claim 20
Dependent Claim
20 words
A fixing apparatus according to claim 11, wherein said first and second heat-diffusing members are disposed on said retaining member.
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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) | 2001-11-16 | 2002-05-18 | 2002-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-11-16 | 2006-05-18 | 2006-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-11-16 | 2010-05-18 | 2010-11-17 | $7700.00 | Window Closed / Lapsed |