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US5555074A Expired / Lapsed US ⏱️ 0.0 years remaining

Electrophotographic apparatus and electrophotographic method

Assignee: Ricoh Printing Systems Ltd
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Filing: 1995-01-10
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Granted: 1996-09-10
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Expires: 2015-01-10
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Abstract

Abstract The disclosure is concerned with an electrophotographic apparatus comprising a toner image supporting member on which a toner image developed on an electrostatic latent image is formed, transferring means for transferring the toner image on said toner image supporting member to a recording medium, conveying means for bringing the recording medium into contact with the image supporting member, a fixing roller and a compression roller in contact with each other to fix the toner image on the recording medium, heating means disposed inside at least one of the fixing roller and the compression roller, wherein there are provided temperature detection means for detecting the surface temperature of the fixing roller and state detection means for detecting the state of the fixing apparatus before starting of the fixing apparatus.

Inventors

  • 👤 Hideyuki Haragakiuchi
  • 👤 Hiroyuki Tadokoro
  • 👤 Nobuaki Fukasawa
  • 👤 Isamu Terashima
  • 👤 Akira Sasaki
  • 👤 Kazuyoshi Matsuo
  • 👤 Katuyoshi Onose
  • 👤 Masashi Okuhama

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 05:56
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/20; G03G15/2003; G03G15/2014; G03G15/2039; G03G2215/00; G03G2215/20; G03G2215/207; G03G2215/2074

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 172 words
An electrophotographic apparatus comprising: a toner image supporting member on which a toner image developed on an electrostatic latent image is formed; a recording medium feeder that brings the recording medium into contact with said toner image supporting member; a fixing apparatus including: a fixing roller; and a compression roller in contact with each other to fix the toner image on the recording medium; a heater disposed inside at least one of said fixing roller and said compression roller; a temperature detector coupled to the surface temperature of said fixing roller; a state detector detecting the state of said fixing apparatus before said fixing apparatus is powered on; and a fixing voltage controller that controls a fixing voltage applied to said heater based on a temperature characteristic measured by said temperature detector, said fixing voltage controller includes a first control characteristic changing means for changing a control point of the fixing voltage by a plurality of fixing voltage control characteristics on the basis of the temperature characteristic measured by said temperature detector.
Claim 2
Dependent Claim 172 words
An electrophotographic apparatus comprising: a toner image supporting member on which a toner image developed on an electrostatic latent image is formed; a recording medium feeder that brings the recording medium into contact with said toner image supporting member; a fixing apparatus including: a fixing roller; and a compression roller in contact with each other to fix the toner image on the recording medium; a heater disposed inside at least one of said fixing roller and said compression roller; a temperature detector coupled to the surface temperature of said fixing roller; a state detector detecting the state of said fixing apparatus before said fixing apparatus is powered on; and a fixing voltage controller that controls a fixing voltage applied to said heater based on a temperature characteristic measured by said temperature detector, said fixing voltage controller includes a first control characteristic changing means for changing a control point of the fixing voltage by a plurality of fixing voltage control characteristics on the basis of the temperature characteristic measured by said temperature detector.
Claim 3
Dependent Claim 25 words
The electrophotographic apparatus according to in claim 1, wherein said temperature detector includes: a sensor detecting the temperature of the surface of said fixing roller;
Claim 4
Dependent Claim 35 words
The electrophotographic apparatus according to claim 1, wherein said fixing voltage controller includes a second control characteristic changing means for changing the control point of the fixing voltage according to time of the temperature change.
Claim 5
Dependent Claim 71 words
An electrophotographic method comprising the steps of: preparing for electrophography; forming a toner image on a photosensitive medium; judging a surface temperature of a fixing roller based on information detected by a temperature detector; changing a control point of a fixing voltage based on the step of judging the surface temperature; and compensating a surface temperature drop of the fixing roller occurred by passing a recording medium through the fixing apparatus.
Claim 6
Dependent Claim 71 words
An electrophotographic method comprising the steps of: preparing for electrophography; forming a toner image on a photosensitive medium; judging a surface temperature of a fixing roller based on information detected by a temperature detector; changing a control point of a fixing voltage based on the step of judging the surface temperature; and compensating a surface temperature drop of the fixing roller occurred by passing a recording medium through the fixing apparatus.
Claim 7
Dependent Claim 58 words
The electrophotographic method according to claim 4, further comprising: superposing toner images each having different colors on the recording medium, to form a color image; judging the surface temperature drop of the fixing roller for each page of the recording medium; and compensating the surface temperature drop of the fixing roller for each page of the recording medium.
Claim 8
Dependent Claim 34 words
The electrophotographic method according to claim 5, wherein step for compensating compensates the surface temperature drop of the fixing roller in accordance with the kind of recording medium and the number of color superpositions.
Claim 9
Dependent Claim 67 words
The electrophotographic method according to claim 4, wherein the surface temperature drop of the fixing roller for each page is compensated. a plurality of variable resistors that transforms the output current of said sensor into a plurality of voltage signals; and a plurality of comparators that judges and outputs a plurality of setting temperature signals after comparing the voltage signals with a plurality of comparison standard signals.
Claim 10
Dependent Claim 24 words
The electrophotographic method according to claim 7, wherein the surface temperature of the fixing roller is controlled to a specified state by a heater.
Claim 11
Dependent Claim 198 words
An electrophotographic apparatus comprising: a toner image supporting member on which toner images, each having a different color, developed on an electrostatic latent image are formed; a transferring means tier transferring and superposing the toner images on said toner image supporting member to an intermediate transfer member; a recording medium feeder that brings the said recording medium into contact with said intermediate transfer member; a fixing apparatus including: a fixing roller; and a compression roller in contact with each other to fix the toner images on said recording medium; a heater disposed inside at least one of said fixing roller and said compression roller; a temperature detector coupled to the surface of said fixing roller; a state detection means for detecting the state of the fixing apparatus before said fixing apparatus is powered on; and a fixing voltage controller that controls a fixing voltage applied to said heater based on a temperature characteristic measured by said temperature detector, said fixing voltage controller includes a first control characteristic changing means for changing a control point of the fixing voltage by a plurality of fixing voltage control characteristics on the basis of the temperature characteristic measured by said temperature detector.`
Claim 12
Dependent Claim 198 words
An electrophotographic apparatus comprising: a toner image supporting member on which toner images, each having a different color, developed on an electrostatic latent image are formed; a transferring means tier transferring and superposing the toner images on said toner image supporting member to an intermediate transfer member; a recording medium feeder that brings the said recording medium into contact with said intermediate transfer member; a fixing apparatus including: a fixing roller; and a compression roller in contact with each other to fix the toner images on said recording medium; a heater disposed inside at least one of said fixing roller and said compression roller; a temperature detector coupled to the surface of said fixing roller; a state detection means for detecting the state of the fixing apparatus before said fixing apparatus is powered on; and a fixing voltage controller that controls a fixing voltage applied to said heater based on a temperature characteristic measured by said temperature detector, said fixing voltage controller includes a first control characteristic changing means for changing a control point of the fixing voltage by a plurality of fixing voltage control characteristics on the basis of the temperature characteristic measured by said temperature detector.`

References Cited (Backward Citations)

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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) 1999-09-10 2000-03-11 2000-09-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2003-09-10 2004-03-11 2004-09-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2007-09-10 2008-03-11 2008-09-10 $7700.00 Window Closed / Lapsed

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