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US6597879B2 Expired / Lapsed US ⏱️ 0.0 years remaining

Fixing unit

Assignee: Oki Electric Industry Co Ltd
•
Filing: 2002-05-21
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Granted: 2003-07-22
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Expires: 2022-05-21
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Abstract

Abstract A fixing unit fixes a developing material deposited on a recording medium by heating and pressing the recording medium. The fixing unit includes a first number of heating members that apply heat to the recording medium and a second number of switches that supply electric power to the first number of heating members. Each of the heating members receives electric power through a series circuit of the switches. Each of the switches responds to a surface temperature of a corresponding one of the heating members so that when the surface temperature exceeds a predetermined value, the electric power is shut off.

Inventors

  • 👤 Naoji Akutsu
  • 👤 Akinori Kumonaka

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 04:59
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/20; G03G15/2003; G03G15/2014; G03G15/2039; G03G15/2042; G03G15/2053

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 154 words
A fixing unit that fixes a developing material deposited on a recording medium by heating and pressing the recording medium, comprising: a first number of heating members that apply heat to the recording medium; a second number of temperature-sensitive shut-off devices in a first series connection; and wherein each of said first number of heating members and the first series connection form a second series connection in such a way that each of said first number of heating members receives electric power through the first series connection of said second number of temperature-sensitive shut-off devices, each of said second number of temperature-sensitive shut-off devices receiving heat from a surface of a corresponding one of said first number of heating members to turn off the electric power in response to a temperature of the surface, the electric power supplied to the heating members being shut off simultaneously when the surface temperature exceeds a predetermined value.
Claim 2
Dependent Claim 154 words
A fixing unit that fixes a developing material deposited on a recording medium by heating and pressing the recording medium, comprising: a first number of heating members that apply heat to the recording medium; a second number of temperature-sensitive shut-off devices in a first series connection; and wherein each of said first number of heating members and the first series connection form a second series connection in such a way that each of said first number of heating members receives electric power through the first series connection of said second number of temperature-sensitive shut-off devices, each of said second number of temperature-sensitive shut-off devices receiving heat from a surface of a corresponding one of said first number of heating members to turn off the electric power in response to a temperature of the surface, the electric power supplied to the heating members being shut off simultaneously when the surface temperature exceeds a predetermined value.
Claim 3
Dependent Claim 21 words
The fixing unit according to claim 1 , wherein said first number of heating elements are in parallel with each other.
Claim 4
Dependent Claim 16 words
The fixing unit according to claim 2 , wherein said temperature-sensitive shut-off devices are overtemperature thermostats.
Claim 5
Dependent Claim 16 words
The fixing unit according to claim 2 , wherein said temperature-sensitive shut-off devices are thermal fuses.
Claim 6
Dependent Claim 18 words
The fixing unit according to claim 1 , wherein said first number is equal to said second number.
Claim 7
Dependent Claim 16 words
The fixing unit according to claim 5 , wherein said temperature-sensitive shut-off devices are overtemperature thermostats.
Claim 8
Dependent Claim 16 words
The fixing unit according to claim 5 , wherein said temperature-sensitive shut-off devices are thermal fuses.
Claim 9
Dependent Claim 68 words
The fixing unit according to claim 1 , wherein said first number of heating members include two heating members and said second number of temperature-sensitive shut-off devices includes two temperature-sensitive shut-off devices, wherein the two temperature-sensitive shut-off devices form a series circuit with each other and the two heating members form a parallel circuit with each other, the series circuit being connected in series with the parallel circuit.
Claim 10
Dependent Claim 68 words
The fixing unit according to claim 1 , wherein said first number of heating members includes three heating members and said second number of temperature-sensitive shut-off devices includes three temperature-sensitive shut-off devices, wherein the three temperature-sensitive shut-off devices form a series circuit with each other and the three heating members form a parallel circuit with each other, the series circuit being connected in series with the parallel circuit.
Claim 11
Dependent Claim 96 words
The fixing unit according to claim 1 , wherein said first number of heating members includes two heating members and said second number of temperature-sensitive shut-off devices includes four temperature-sensitive shut-off devices, wherein a first one of the two heating members forms a first series circuit with the first two of the four temperature-sensitive shut-off devices and a second one of the two heating members forms a second series circuit with the second two of the four temperature-sensitive shut-off devices, the first series circuit and second series circuit being connected in parallel with a power source.
Claim 12
Dependent Claim 16 words
The fixing unit according to claim 1 , wherein said temperature-sensitive shut-off devices are overtemperature thermostats.
Claim 13
Dependent Claim 16 words
The fixing unit according to claim 1 , wherein said temperature-sensitive shut-off devices are thermal fuses.

References Cited (Backward Citations)

US5041718A Cited
US6097904A Cited
US6301454B1 Cited
US6333490B1 Cited
US6385410B1 Cited
US6292647B1 Cited
US20020043523A1 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2006-07-21 2007-01-20 2007-07-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2010-07-21 2011-01-20 2011-07-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2014-07-21 2015-01-20 2015-07-22 $7700.00 Window Closed / Lapsed

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