Patent US6078781A successfully refreshed from Google Patents.
US6078781A
Expired / Lapsed
US
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Fixing device using an induction heating unit
Assignee: Toshiba Corp
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Filing: 1999-01-06
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Granted: 2000-06-20
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Expires: 2019-01-06
Abstract
Abstract A fixing device of the present invention includes a first roller that is made of a conductive material, and is rotated and driven; a second roller that is in contact with the first roller in the pressed state; and an induction heating unit that is arranged at the first roller side and concentrates the induction heating to the nip portion of the first roller and change a developer image formed on a fixing medium to a fixed imaged. This induction heating unit of the fixing device is made of a high permeable material, has a core that is open at the surface opposite to the first roller and a coil wound round the core and generates magnetic flux on the core when high frequency current is supplied to the core and has a high projecting portion so that a part of the core closes the first roller.
Inventors
- 👤 Osamu Takagi
- 👤 Satoshi Kinouchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:36
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/20; G03G15/2003; G03G15/2014; G03G15/2017; G03G15/2032; G03G15/2053; H; H05; H05B; H05B6/00; H05B6/02; H05B6/10; H05B6/14; H05B6/145; G03G2215/00; G03G2215/20; G03G2215/2003; G03G2215/2016; G03G2215/2035
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
77 words
A fixing device that is provided with: a core and a magnetic field generator comprising a coil wound round the core, generates eddy current on a heater by the magnetic field generator and fixes a developer image formed on a recording medium by the heat generated on the heater based on the eddy current; wherein the core is composed by laminating and bonding a plurality of core elements having at least more than one cross sectional shapes.
Claim 2
Dependent Claim
77 words
A fixing device that is provided with: a core and a magnetic field generator comprising a coil wound round the core, generates eddy current on a heater by the magnetic field generator and fixes a developer image formed on a recording medium by the heat generated on the heater based on the eddy current; wherein the core is composed by laminating and bonding a plurality of core elements having at least more than one cross sectional shapes.
Claim 3
Dependent Claim
22 words
A fixing device according to claim 1, further comprising: a support member to support the magnetic field generator separately from the heater.
Claim 4
Dependent Claim
29 words
A fixing device according to claim 1, wherein a bonding agent that is used for the bonding has a heat resisting temperature higher than a temperature for the fixing.
Claim 5
Dependent Claim
22 words
A fixing device according to claim 1, wherein the magnetic field generator fixes the coil to the core by filling an impregnate.
Claim 6
Dependent Claim
34 words
A fixing device according to claim 1, wherein the magnetic field generator fixes the coil to the core by filling an impregnate having a heat resisting temperature higher than a temperature for the fixing.
Claim 7
Dependent Claim
25 words
A fixing device according to claim 1, wherein the core inserts a gap forming member to form a definite gap between the laminated core elements.
Claim 8
Dependent Claim
24 words
A fixing device according to claim 6, wherein the gap forming member is one of insulation material, non-magnetic material and low heat conductive material.
Claim 9
Dependent Claim
196 words
A fixing device comprising: a first roller that is made of a conductive material, and driven to be rotated; a second roller that is in contact with the first roller to pass a fixing medium on which a developer image formed between these rollers; an induction heating unit that is arranged at the first roller side and concentrates the induction heating to a nip portion of the first roller to change the developer image formed on the fixing medium to a fixed image; a first controller to control the first roller to be rotated at the time of warm-up and at the time of ready similarly at the time of executing the fixing and differentiates its rotating speed at the time of warm-up and ready and at the time of executing the fixing; and a second controller to control the induction heating unit to vary the operating current thereof from the normal current level when the rotating speed of the first roller is reduced; wherein the first controller decreases the rotating speed of the first roller at the time of warm-up and ready to a speed lower than that at the time of executing the fixing.
Claim 10
Dependent Claim
196 words
A fixing device comprising: a first roller that is made of a conductive material, and driven to be rotated; a second roller that is in contact with the first roller to pass a fixing medium on which a developer image formed between these rollers; an induction heating unit that is arranged at the first roller side and concentrates the induction heating to a nip portion of the first roller to change the developer image formed on the fixing medium to a fixed image; a first controller to control the first roller to be rotated at the time of warm-up and at the time of ready similarly at the time of executing the fixing and differentiates its rotating speed at the time of warm-up and ready and at the time of executing the fixing; and a second controller to control the induction heating unit to vary the operating current thereof from the normal current level when the rotating speed of the first roller is reduced; wherein the first controller decreases the rotating speed of the first roller at the time of warm-up and ready to a speed lower than that at the time of executing the fixing.
Claim 11
Dependent Claim
122 words
A fixing device comprising: a heating member that moves at a speed equal to a moving speed of a fixing medium and by contacting the fixing medium, fixes an image on the fixing medium by heating it; and an induction heating unit to heat the heating member; wherein the induction heating unit has a core element and a coil element wound round the core element and the core element is divided into plural portions on a surface inclined at a specified angle against a surface that is vertical to the surface of a fixing medium and parallel to a conveying direction of the fixing medium, the divided plural portions of the core element are bonded by bonding agent into one united body.
Claim 12
Dependent Claim
122 words
A fixing device comprising: a heating member that moves at a speed equal to a moving speed of a fixing medium and by contacting the fixing medium, fixes an image on the fixing medium by heating it; and an induction heating unit to heat the heating member; wherein the induction heating unit has a core element and a coil element wound round the core element and the core element is divided into plural portions on a surface inclined at a specified angle against a surface that is vertical to the surface of a fixing medium and parallel to a conveying direction of the fixing medium, the divided plural portions of the core element are bonded by bonding agent into one united body.
Claim 13
Dependent Claim
109 words
A fixing device comprising: a heating member that moves at a speed equal to a moving speed of a fixing medium and by contacting the fixing medium, fixes an image on the fixing medium by heating it; and an induction heating unit to heat the heating member; wherein the induction heating unit has a core element and a coil element wound round the core element, and the core element is divided into plural portions on the dividing surfaces that have a surface vertical to a conveying direction of the fixing medium, the divided plural portions of the core element are bonded by a bonding agent into one united body.
Claim 14
Dependent Claim
109 words
A fixing device comprising: a heating member that moves at a speed equal to a moving speed of a fixing medium and by contacting the fixing medium, fixes an image on the fixing medium by heating it; and an induction heating unit to heat the heating member; wherein the induction heating unit has a core element and a coil element wound round the core element, and the core element is divided into plural portions on the dividing surfaces that have a surface vertical to a conveying direction of the fixing medium, the divided plural portions of the core element are bonded by a bonding agent into one united body.
Claim 15
Dependent Claim
87 words
A fixing device comprising: a heating member that moves at a speed equal to the moving speed of a fixing medium and by contacting the fixing medium, fixes an image on the fixing medium by heating it; and an induction heating unit to heat the heating member; wherein the induction heating unit has a core element and a coil element wound round this core element and the heating member is made by combining a magnetic material and a high heat permeable material by the fusing and forging.
Claim 16
Dependent Claim
87 words
A fixing device comprising: a heating member that moves at a speed equal to the moving speed of a fixing medium and by contacting the fixing medium, fixes an image on the fixing medium by heating it; and an induction heating unit to heat the heating member; wherein the induction heating unit has a core element and a coil element wound round this core element and the heating member is made by combining a magnetic material and a high heat permeable material by the fusing and forging.
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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) | 2003-06-20 | 2003-12-20 | 2004-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-06-20 | 2007-12-20 | 2008-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-06-20 | 2011-12-20 | 2012-06-20 | $7700.00 | Window Closed / Lapsed |