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US5394231A Expired / Lapsed US ⏱️ 0.0 years remaining

Image forming apparatus capable of forming an erasable image

Assignee: Ricoh Co Ltd
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Filing: 1993-07-30
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Granted: 1995-02-28
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Expires: 2013-07-30
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Abstract

Abstract An image forming apparatus capable of forming both of erasable images and images to be stored, and increasing the number of times that a single sheet with an image can be repetitively decolorized and reused. The apparatus includes a photoconductive element for electrostatically forming a latent image representative of image data. A developing device develops the latent image formed on the photoconductive element by either of an ordinary undecolorizable toner and a decolorizable toner.

Inventors

  • 👤 Kazuhisa Sudo
  • 👤 Mitsuo Tanaka
  • 👤 Chikara Imai
  • 👤 Koji Suzuki
  • 👤 Norimasa Sohmiya
  • 👤 Sadao Takahashi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 14:54
CPC Classifications
G; G03; G03G; G03G13/00; G03G13/06; G03G13/08; G03G15/00; G03G15/04; G03G15/04018; G03G9/00; G03G9/08; G03G9/09; G03G9/0926

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 94 words
An image forming apparatus capable of forming an erasable image, comprising: a photoconductive element for electrostatically forming a latent image representative of image data; and a developing device for developing latent image formed on said photoconductive element by an ordinary undecolorizable toner and a decolorizable toner, wherein a density of said decolorizable toner formed on said photoconductive element is less than a density of said undecolorizable toner formed on said photoconductive element, said decolorizable toner defined by a toner which has a visible color when said latent image is formed and transparent when treated.
Claim 2
Dependent Claim 94 words
An image forming apparatus capable of forming an erasable image, comprising: a photoconductive element for electrostatically forming a latent image representative of image data; and a developing device for developing latent image formed on said photoconductive element by an ordinary undecolorizable toner and a decolorizable toner, wherein a density of said decolorizable toner formed on said photoconductive element is less than a density of said undecolorizable toner formed on said photoconductive element, said decolorizable toner defined by a toner which has a visible color when said latent image is formed and transparent when treated.
Claim 3
Dependent Claim 29 words
An apparatus as claimed in claim 1, wherein said developing device comprises a first developing unit storing the undecolorizable toner, and a second developing unit storing the decolorizable toner.
Claim 4
Dependent Claim 24 words
An apparatus as claimed in claim 2, further comprising selecting means for selecting either of said first developing unit and said second developing unit.
Claim 5
Dependent Claim 22 words
An apparatus as claimed in claim 3, wherein said selecting means comprises a switch provided on an operation board of said apparatus.
Claim 6
Dependent Claim 29 words
An apparatus as claimed in claim 3, further comprising displaying means for displaying one of said first developing unit and said second developing unit selected by said selecting means.
Claim 7
Dependent Claim 34 words
An apparatus as claimed in claim 3, further comprising a transferring device for transferring a developed toner image to a sheet, and a fixing device for fixing the transferred toner image on said sheet.
Claim 8
Dependent Claim 45 words
An apparatus as claimed in claim 6, further comprising temperature setting means for selecting a high fixing temperature for said fixing device when said first developing unit is selected and a low fixing temperature for said fixing device when said second developing unit is selected.
Claim 9
Dependent Claim 45 words
An apparatus as claimed in claim 6, further comprising pressure setting means for selecting a high fixing pressure for said fixing device when said first developing unit is selected and a low fixing pressure for said fixing unit when said second developing unit is selected.
Claim 10
Dependent Claim 47 words
An apparatus as claimed in claim 6, further comprising density setting means for selecting a high density for an image to be formed on a sheet when said first developing unit is selected and a low density for said image when said second developing unit is selected.
Claim 11
Dependent Claim 105 words
An apparatus as claimed in claim 6, further comprising: allowing an operator to mark means for marking a desired area of an image to be formed on a sheet; and marked latent image forming means for selectively electrostatically forming a first latent image corresponding to an image portion lying in the desired area or a second latent image corresponding to an image portion lying outside of the said desired area; said apparatus developing one of the first and second latent images by the undecolorizable toner of said first developing unit, and developing the other latent image by the decolorizable toner of said second developing unit.

References Cited (Backward Citations)

US4599630A Cited
US4532200A Cited
US4620204A Cited
US4734735A Cited
US5045420A Cited
US5296439A Cited
US5234783A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-02-27 1998-08-29 1999-02-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-02-27 2002-08-29 2003-02-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-02-27 2006-08-29 2007-02-28 $7700.00 Window Closed / Lapsed

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