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US5822669A Expired / Lapsed US ⏱️ 0.0 years remaining

Induction heat fusing device

Assignee: Minolta Co Ltd
•
Filing: 1996-08-12
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Granted: 1998-10-13
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Expires: 2016-08-12
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Abstract

Abstract An induction heating device for printers, copiers and the like includes a magnetic coil assembly and a heated metal body that form a closed magnetic circuit. To compensate for the effects of heat radiation at the ends of the heated metal body, a greater amount of heat is generated at the ends of the body than at the center thereof. In one approach, the amount of heat is varied by changing physical parameters of the magnetic circuit, such as the spacing of the coil assemblies from the heated body, the relative sizes of the cores, and/or the relative magnetic permeability of the cores. In another approach, the electrical connection of the coils of multiple assemblies are arranged such that the coils in the center of the heated body are in parallel, and the coils at the ends of the body are in series with the parallel central coils.

Inventors

  • 👤 Eiji Okabayashi
  • 👤 Takeshi Kato
  • 👤 Satoru Yoneda

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 03:53
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/20; G03G15/2003; G03G15/2014; G03G15/2053; H; H05; H05B; H05B6/00; H05B6/02; H05B6/10; H05B6/14; H05B6/145

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 119 words
An induction heat fixing device comprising: a heat member formed by an electrically conductive member and having a hollow space in its interior; a pressure member disposed in pressing contact with the heat member; a plurality of cores disposed within the heat member, at least some of said cores having a tapered surface which faces the heat member and being disposed such that the distance between the tapered surface of the cores and the interior surface of the heat member is greater in a direction toward the center of the heat member and less in a direction toward an edge of the heat member; coils provided around the cores; and means for passing an alternating current through the coils.
Claim 2
Dependent Claim 119 words
An induction heat fixing device comprising: a heat member formed by an electrically conductive member and having a hollow space in its interior; a pressure member disposed in pressing contact with the heat member; a plurality of cores disposed within the heat member, at least some of said cores having a tapered surface which faces the heat member and being disposed such that the distance between the tapered surface of the cores and the interior surface of the heat member is greater in a direction toward the center of the heat member and less in a direction toward an edge of the heat member; coils provided around the cores; and means for passing an alternating current through the coils.
Claim 3
Dependent Claim 81 words
An induction heat fixing device comprising: a heat member formed by an electrically conductive member and having a hollow space in its interior; a pressure member disposed in pressing contact with the heat member; a plurality of cores disposed within the heat member; coils provided around the cores, with the distances between at least some of the coils and the interior surface of the heat member being different from each other; and means for passing an alternating current through the coils.
Claim 4
Dependent Claim 81 words
An induction heat fixing device comprising: a heat member formed by an electrically conductive member and having a hollow space in its interior; a pressure member disposed in pressing contact with the heat member; a plurality of cores disposed within the heat member; coils provided around the cores, with the distances between at least some of the coils and the interior surface of the heat member being different from each other; and means for passing an alternating current through the coils.
Claim 5
Dependent Claim 74 words
An induction heat fixing device comprising: a heat member formed by an electrically conductive member and having a hollow space in its interior; a pressure member disposed in pressing contact with the heat member; a plurality of cores disposed within the heat member; coils provided around the cores, said coils being sequentially connected in order to form a parallel connection and a series connection; and means for passing an alternating current through the coils.
Claim 6
Dependent Claim 74 words
An induction heat fixing device comprising: a heat member formed by an electrically conductive member and having a hollow space in its interior; a pressure member disposed in pressing contact with the heat member; a plurality of cores disposed within the heat member; coils provided around the cores, said coils being sequentially connected in order to form a parallel connection and a series connection; and means for passing an alternating current through the coils.
Claim 7
Dependent Claim 59 words
The induction heat fixing device of claim 3 wherein said coils include a first set of coils connected in parallel with one another, a second coil set connected in series with said first set of coils on one side thereof, and a third coil set connected in series with said first set of coils on the opposite side thereof.
Claim 8
Dependent Claim 28 words
The induction heat fixing device of claim 4 wherein each of said second and third coil sets contains a plurality of coils connected in parallel with one another.
Claim 9
Dependent Claim 33 words
The induction heat fixing device of claim 5 wherein the number of coils in said first set is one greater than the number of coils in each of said second and third sets.
Claim 10
Dependent Claim 33 words
The induction heat fixing device of claim 4 wherein the number of coils in said first set is one greater than the number of coils in each of said second and third sets.
Claim 11
Dependent Claim 109 words
An induction heat fixing device, comprising: a heat member formed by an electrically conductive member and having a hollow space in its interior; a pressure member disposed in pressing contact with the heat member; a core disposed within the heat member, said core having a tapered surface which is oriented such that the distance between the tapered surface of the core and the interior surface of the heat member is greater in a direction toward the center of the heat member and less in a direction toward an edge of the heat member; a coil provided around the core; and means for passing an alternating current through the coil.
Claim 12
Dependent Claim 109 words
An induction heat fixing device, comprising: a heat member formed by an electrically conductive member and having a hollow space in its interior; a pressure member disposed in pressing contact with the heat member; a core disposed within the heat member, said core having a tapered surface which is oriented such that the distance between the tapered surface of the core and the interior surface of the heat member is greater in a direction toward the center of the heat member and less in a direction toward an edge of the heat member; a coil provided around the core; and means for passing an alternating current through the coil.
Claim 13
Dependent Claim 135 words
An induction heat fixing device comprising: a heat member formed by an electrically conductive member and having a hollow space in its interior; a pressure member disposed in pressing contact with the heat member; a plurality of cores disposed within the heat member, with the lengths of at least some of the cores being different from each other: coils provided around the cores; and, means for passing an alternating current through the coils; wherein at least some of said cores have a tapered surface which faces the heat member and are disposed such that the distance between the tapered surface of the cores and the interior surface of the heat member is greater in a direction toward the center of the heat member and less in a direction toward an edge of the heat member.
Claim 14
Dependent Claim 135 words
An induction heat fixing device comprising: a heat member formed by an electrically conductive member and having a hollow space in its interior; a pressure member disposed in pressing contact with the heat member; a plurality of cores disposed within the heat member, with the lengths of at least some of the cores being different from each other: coils provided around the cores; and, means for passing an alternating current through the coils; wherein at least some of said cores have a tapered surface which faces the heat member and are disposed such that the distance between the tapered surface of the cores and the interior surface of the heat member is greater in a direction toward the center of the heat member and less in a direction toward an edge of the heat member.

References Cited (Backward Citations)

US5074019A Cited
US5568240A Cited
US5526103A Cited
US5552582A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2001-10-12 2002-04-13 2002-10-13 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2005-10-12 2006-04-13 2006-10-13 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2009-10-12 2010-04-13 2010-10-13 $7700.00 Window Closed / Lapsed

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