US3902801A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color corrected printing system
Assignee: Xerox Corp
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Filing: 1973-12-03
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Granted: 1975-09-02
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Expires: 1993-12-03
Abstract
Abstract A color process in which color copies of an original document containing color information are reproduced. In this process, successive single color electrostatic latent images are recorded on an image bearing member. Each successive single color electrostatic image is developed with particles containing a predetermined colorant therein. These particles are transferred from the single color electrostatic latent images in a prescribed sequence. The sequence of transfer is such that the colorant of each successive layer of transferred particles corrects for the impurities contained in the colorant of the previously transferred layer of particles. The final color rendition of the copy is, thereby, color corrected so as to substantially approximate that of the original document.
Inventors
- 👤 Richard F Lehman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:57
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/01; G03G15/0105; G03G15/0131
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
222 words
An electrophotographic printing machine of the type having means for charging a photoconductive member to a substantially uniform potential, including: means for exposing the charged photoconductive member to successive single color light images recording successive single color electrostatic latent images on the photoconductive member; a plurality of developer units, each unit being arranged to act on the photoconductive member to bring into operative communication with successive single color electrostatic latent images recorded thereon toner particles having a dominant colorant and a minor colorant impurity therein for rendering visible the electrostatic latent image; means for transferring toner particles from successive single color electrostatic latent images to a sheet of support material in a predetermined sequence wherein at least the second successive layer of toner particles transferred to the sheet of support material comprises the dominant colorant corresponding in color to the color the minor colorant impurity contained in the first layer of toner particles transferred to the sheet of support material resulting in the superimposed layers of toner particles having a composite color substantially correcting for the minor colorant impurity contained in the first transferred layer of toner particles; and means for regulating electrically said transfer means so that successively thinner layers of toner particles are transferred from the photoconductive member to the sheet of support material in superimposed registration with one another.
Claim 2
Dependent Claim
222 words
An electrophotographic printing machine of the type having means for charging a photoconductive member to a substantially uniform potential, including: means for exposing the charged photoconductive member to successive single color light images recording successive single color electrostatic latent images on the photoconductive member; a plurality of developer units, each unit being arranged to act on the photoconductive member to bring into operative communication with successive single color electrostatic latent images recorded thereon toner particles having a dominant colorant and a minor colorant impurity therein for rendering visible the electrostatic latent image; means for transferring toner particles from successive single color electrostatic latent images to a sheet of support material in a predetermined sequence wherein at least the second successive layer of toner particles transferred to the sheet of support material comprises the dominant colorant corresponding in color to the color the minor colorant impurity contained in the first layer of toner particles transferred to the sheet of support material resulting in the superimposed layers of toner particles having a composite color substantially correcting for the minor colorant impurity contained in the first transferred layer of toner particles; and means for regulating electrically said transfer means so that successively thinner layers of toner particles are transferred from the photoconductive member to the sheet of support material in superimposed registration with one another.
Claim 3
Dependent Claim
23 words
A printing machine as recited in claim 1, further including means for fixing the transferred toner particles to the sheet of support material.
Claim 4
Dependent Claim
48 words
A printing machine as recited in claim 1 wherein each of said developing units deposits toner particles having a dominant colorant complementary in color to the single color light image exposing the charged photoconductive surface for rendering visible the corresponding single color electrostatic latent image recorded thereon therewith.
Claim 5
Dependent Claim
198 words
A printing machine as recited in claim 3, wherein: said plurality of developing units included a first developing unit arranged to deposit toner particles containing a dominant cyan colorant with a minor magenta colorant impurity therein on an electrostatic latent image formed from a red filtered light image, a second developer unit arranged to deposit toner particles containing a dominant magenta colorant with a minor yellow impurity therein on an electrostatic latent image formed from a green filtered light image, and a third developer unit arranged to deposit toner particles containing dominant yellow colorant on an electrostatic latent image formed from a blue filtered light image; and said transferring means is adapted to transfer successive layers of toner powder images to the sheet of support material such that the layer of toner particles having the dominant magenta colorant with the minor yellow colorant impurity are superimposed over the layer of toner particles having the dominant cyan colorant with the minor magenta colorant impurity and the layer of toner particles having the dominant yellow colorant are superimposed over both of the first transferred layers of toner particles resulting in the superimposed layers of toner particles being substantially color corrected.
References Cited (Backward Citations)
US3724943A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-01 | 1979-03-03 | 1979-09-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-01 | 1983-03-03 | 1983-09-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-01 | 1987-03-03 | 1987-09-02 | $7700.00 | Window Closed / Lapsed |