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US4524117A Expired / Lapsed US ⏱️ 0.0 years remaining

Electrophotographic method for the formation of two-colored images

Assignee: Kyocera Mita Industrial Co Ltd
•
Filing: 1984-06-15
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Granted: 1985-06-18
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Expires: 2004-06-15
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Abstract

Abstract An electrophotographic method for the formation of two-colored images comprising: (1) uniformly charging the surface of a photoreceptor having a conductive substance and a photoconductive layer formed on the conductive substance, said photoconductive layer being sensitive to a first color, (2) exposing a two-colored original, to form on said photoconductive layer an electrostatic latent image, which corresponds to a second color region in the original, with the same polarity as the electric charges on the surface of said photoconductive layer, (3) subjecting the surface of said photoreceptor to a reversal development treatment by the use of a photoconductive color toner charged with the same polarity as the electric charges constituting said electrostatic latent image, to develop the non-charged region with the photoconductive color toner, (4) subjecting said electrostatic latent image to a normal development treatment by the use of an insulative toner having a color different from the color of said photoconductive color toner, and (5) charging the color toners on said photoconductive layer with a different polarity from the charging polarity in process (1) and simultaneously exposing said original through a filter shielding against said first color, thereby providing a practical method for the formation of a desired two colored distinct image corresponding to the original.

Inventors

  • 👤 Kouji Maekawa
  • 👤 Mamoru Kato
  • 👤 Syoji Nakagama
  • 👤 Yumiko Sano

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-06 12:39
CPC Classifications
G; G03; G03G; G03G13/00; G03G13/01

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 188 words
An electrophotographic method for the formation of two-colored images comprising: (1) uniformly charging the surface of a photoreceptor having a conductive substance and a photoconductive layer formed on the conductive substance, said photoconductive layer being sensitive to a first color, (2) exposing a two-colored original, to form on said photoconductive layer an electrostatic latent image, which corresponds to a second color region in the original, with the same polarity as the electric charges on the surface of said photoconductive layer, (3) subjecting the surface of said photoreceptor to a reversal development treatment by the use of a photoconductive color toner charged with the same polarity as the electric charges constituting said electrostatic latent image, to develop the non-charged region with the photoconductive color toner, (4) subjecting said electrostatic latent image to a normal development treatment by the use of an insulative toner having a color different from the color of said photoconductive color toner, and (5) charging the color toners on said photoconductive layer with a different polarity from the charging polarity in process (1) and simultaneously exposing said original through a filter shielding against said first color.
Claim 2
Dependent Claim 188 words
An electrophotographic method for the formation of two-colored images comprising: (1) uniformly charging the surface of a photoreceptor having a conductive substance and a photoconductive layer formed on the conductive substance, said photoconductive layer being sensitive to a first color, (2) exposing a two-colored original, to form on said photoconductive layer an electrostatic latent image, which corresponds to a second color region in the original, with the same polarity as the electric charges on the surface of said photoconductive layer, (3) subjecting the surface of said photoreceptor to a reversal development treatment by the use of a photoconductive color toner charged with the same polarity as the electric charges constituting said electrostatic latent image, to develop the non-charged region with the photoconductive color toner, (4) subjecting said electrostatic latent image to a normal development treatment by the use of an insulative toner having a color different from the color of said photoconductive color toner, and (5) charging the color toners on said photoconductive layer with a different polarity from the charging polarity in process (1) and simultaneously exposing said original through a filter shielding against said first color.
Claim 3
Dependent Claim 22 words
A method according to claim 1, wherein said exposure in process (2) is carried out through a filter transmitting the first color.
Claim 4
Dependent Claim 32 words
A method according to claim 1, wherein said photoconductive color toner is of a two-component developer system having a sensitivity to any color wavelength other than at least the first color wavelength.
Claim 5
Dependent Claim 20 words
A method according to claim 3, wherein said photoconductive color toner comprises pigments, resin binders, sensitizing agents, and toner-blocking agents.
Claim 6
Dependent Claim 15 words
A method according to claim 1, wherein said insulative toner mainly consists of carbon black.
Claim 7
Dependent Claim 17 words
A method according to claim 1, wherein said normal development is carried out using a non-contact development.
Claim 8
Dependent Claim 23 words
A method according to claim 6, wherein said non-contact development is a toner projection development, a touch-down development, or a powder cloud development.

References Cited (Backward Citations)

US3748125A Cited
US4007045A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1988-06-17 1988-12-17 1989-06-18 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1992-06-17 1992-12-17 1993-06-18 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1996-06-17 1996-12-17 1997-06-18 $7700.00 Window Closed / Lapsed

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