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US5819150A Expired / Lapsed US ⏱️ 0.0 years remaining

Image heating apparatus

Assignee: Canon Inc
•
Filing: 1997-06-26
•
Granted: 1998-10-06
•
Expires: 2017-06-26
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Abstract

Abstract An image heating apparatus is constructed by a heat generating member having a conductive layer and a magnetic field generating apparatus for generating a magnetic field. The magnetic field generating apparatus has an exciting coil and an electric power is supplied from a power source to the exciting coil by a switching circuit. An eddy current is generated in the heating member by the magnetic field generated by the magnetic field generating apparatus, the heat generating member generates a heat by the eddy current, and an image on a recording material is heated by the heat. The exciting coil has a first coil portion and a second coil portion for matching the impedances of the first coil portion and the heat generating member. The first coil portion and the second coil portion are neighboring. The magnetic coupling between the second coil portion and the heat generating member is weaker than that between the first coil portion and the heat generating member. The second coil portion is away from the heat generating member than the first coil portion. The first coil portion and the second coil portion are serially connected. The number of turns of the second coil portion is smaller than that of the first coil portion.

Inventors

  • 👤 Minoru Hayasaki
  • 👤 Hiroshi Mano
  • 👤 Atsuyoshi Abe
  • 👤 Kiyofumi Nakane

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 04:20
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/20; G03G15/2003; G03G15/2014; G03G15/2053

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 131 words
An image heating apparatus comprising: a heat generating member having a conductive layer; and magnetic field generating means for generating a magnetic field, said magnetic field generating means having an exciting coil to which an electric power is supplied from a power source by a switching circuit; wherein an eddy current is generated in said heating member by the magnetic field generated by said magnetic field generating means and said heat generating member generates a heat by said eddy current, so that an image on a recording material is heated by said heat, and wherein said exciting coil has a first coil portion, and a second coil portion for matching an impedance of said first coil portion and an impedance of said heat generating member, both of which are mutually neighbored.
Claim 2
Dependent Claim 131 words
An image heating apparatus comprising: a heat generating member having a conductive layer; and magnetic field generating means for generating a magnetic field, said magnetic field generating means having an exciting coil to which an electric power is supplied from a power source by a switching circuit; wherein an eddy current is generated in said heating member by the magnetic field generated by said magnetic field generating means and said heat generating member generates a heat by said eddy current, so that an image on a recording material is heated by said heat, and wherein said exciting coil has a first coil portion, and a second coil portion for matching an impedance of said first coil portion and an impedance of said heat generating member, both of which are mutually neighbored.
Claim 3
Dependent Claim 36 words
An apparatus according to claim 1, wherein a magnetic coupling between said second coil portion and said heat generating member is weaker than a magnetic coupling between said first coil portion and said heat generating member.
Claim 4
Dependent Claim 23 words
An apparatus according to claim 1, wherein said second coil portion is away from said heat generating member than said first coil portion.
Claim 5
Dependent Claim 19 words
An apparatus according to claim 1, wherein said first coil portion and said second coil portion are serially connected.
Claim 6
Dependent Claim 28 words
An apparatus according to claim 1, wherein the number of turns of said second coil portion is smaller than the number of turns of said first coil portion.
Claim 7
Dependent Claim 27 words
An apparatus according to claim 1, further comprising a supporting member for supporting said exciting coil and located between said heat generating member and said exciting coil.
Claim 8
Dependent Claim 15 words
An apparatus according to claim 6, wherein said supporting member is an electrically insulating material.
Claim 9
Dependent Claim 28 words
An apparatus according to claim 1, wherein a density of windings of said second coil portion is smaller than a density of windings of said first coil portion.
Claim 10
Dependent Claim 15 words
An apparatus according to claim 1, wherein said heat generating member is an endless film.
Claim 11
Dependent Claim 16 words
An apparatus according to claim 9, wherein said exciting coil is located inside of said film.
Claim 12
Dependent Claim 46 words
An apparatus according to claim 1, further comprising a backup member for forming a nip together with said heat generating member, wherein a recording material holding a non-fixed image is sandwiched and conveyed by said nip, and said non-fixed image is fixed onto the recording material.

References Cited (Backward Citations)

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US4570044A Cited
US4912514A Cited
US5534987A Cited
US5552874A Cited
EP0649072A1 Cited
US5526103A Cited
US5666627A Cited
US5552582A Cited
JPH0844226A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2001-10-05 2002-04-06 2002-10-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2005-10-05 2006-04-06 2006-10-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2009-10-05 2010-04-06 2010-10-06 $7700.00 Window Closed / Lapsed

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