Patent US4294902A successfully refreshed from Google Patents.
US4294902A
Expired / Lapsed
US
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Image formation method having translucent particles containing a coloring agent and a colorless dye former
Assignee: Panasonic Holdings Corp
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Filing: 1978-08-17
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Granted: 1981-10-13
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Expires: 1998-08-17
Abstract
Abstract The present invention is directed to a method and an apparatus for formation of images by particles on a photosensitive plate. Particles employed are translucent, whereby a charge holding the particles to the photosensitive plate may be efficiently removed from selected particles by image-wise light from an original document, etc., so ensuring production of well-defined images. For production of color images, there is employed a panchromatized plate and particles which are transparent to different types of light and have associated therewith dye material permitting production of clearly defined color images, it being made possible to obtain a color copy of an original document in a process requiring only one exposure stage and only one development stage.
Inventors
- 👤 Yuji Takashima
- 👤 Eisuke Ishida
- 👤 Hisanori Nishiguchi
- 👤 Kimiaki Yoshino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:59
CPC Classifications
G; G03; G03G; G03G13/00; G03G13/01; G03G13/016; G03G5/00; G03G5/12; G03G2217/00; G03G2217/0041
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
208 words
Image formation method comprising steps of: a. imparting a charge to a photoconductive member combined with an electrically conductive support member; b. spreading on the surface of the charged photoconductive member a mixture of particles comprising at least one type of non-photoconductive, translucent particles containing a coloring agent and a colorless dye which is capable of developing a color different from that transmitted by said translucent particles; c. causing said translucent particles to electrostantially adhere to said surface through electrostatic attraction; d. subjecting the charged photoconductive member bearing said translucent particles to light image exposure through said translucent particles, thereby selectively weakening and attenuating the charge on a portion of said photoconductive member below said translucent particles through which the light of said light image has passed, whereby the electrostatic attraction of said particles to said photoconductive member is selectively weakened in relation to the degree of said light exposure; e. exerting a force on said translucent particles to remove those translucent particles with selectively weakened attraction for said photoconductive member and to thereby obtain a particle image; and f. bringing said particle image into close contact with a color developing agent which develops said colorless dye into a color different from that transmitted by said translucent particles.
Claim 2
Dependent Claim
208 words
Image formation method comprising steps of: a. imparting a charge to a photoconductive member combined with an electrically conductive support member; b. spreading on the surface of the charged photoconductive member a mixture of particles comprising at least one type of non-photoconductive, translucent particles containing a coloring agent and a colorless dye which is capable of developing a color different from that transmitted by said translucent particles; c. causing said translucent particles to electrostantially adhere to said surface through electrostatic attraction; d. subjecting the charged photoconductive member bearing said translucent particles to light image exposure through said translucent particles, thereby selectively weakening and attenuating the charge on a portion of said photoconductive member below said translucent particles through which the light of said light image has passed, whereby the electrostatic attraction of said particles to said photoconductive member is selectively weakened in relation to the degree of said light exposure; e. exerting a force on said translucent particles to remove those translucent particles with selectively weakened attraction for said photoconductive member and to thereby obtain a particle image; and f. bringing said particle image into close contact with a color developing agent which develops said colorless dye into a color different from that transmitted by said translucent particles.
Claim 3
Dependent Claim
12 words
The method according to claim 1 wherein said colorless dye is sublimable.
Claim 4
Dependent Claim
57 words
The method according to claim 2 wherein said image is developed by bringing said particle image into close contact with an image-receiving material containing a color developing agent and applying heat to said particle image whereby said colorless sublimable dyestuff sublimes onto said image receiving material to form a colored image by reaction with said developing agent.
Claim 5
Dependent Claim
49 words
The method according to claim 1 wherein said mixture is composed of particles of at least two kinds of non-photoconductive translucent particles, each of said at least two kinds of non-photoconductive translucent particles being capable of transmitting and developing relatively different kinds of colors with respect to each other.
Claim 6
Dependent Claim
76 words
The method according to claim 1 wherein said mixture is composed of particles of a first non-photoconductive translucent material containing a sublimable colorless dye which only transmits red light and which develops the color cyan, a second non-photoconductive translucent material having sublimable colorless dye which only transmits green light and which develops the color magenta; and a third non-photoconductive translucent material having sublimable colorless dye which only transmits blue light and which develops the color yellow.
Claim 7
Dependent Claim
18 words
The method according to claim 1 wherein said force exerted on said translucent particles is a vibratory force.
Claim 8
Dependent Claim
18 words
The method according to claim 1 wherein said force exerted on said translucent particles is an electrostatic force.
Claim 9
Dependent Claim
23 words
The method according to claim 1 wherein said force exerted on said translucent particles is the force of air caused by an air-jet.
Claim 10
Dependent Claim
21 words
The method according to claim 2 wherein said colorless agent is not sublimable under conditions in which the sublimable dye sublimes.
Claim 11
Dependent Claim
21 words
The method according to claim 3 wherein said colorless agent is not sublimable under conditions in which the sublimable dye sublimes.
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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) | 1984-10-12 | 1985-04-13 | 1985-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-12 | 1989-04-13 | 1989-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-12 | 1993-04-13 | 1993-10-13 | $7700.00 | Window Closed / Lapsed |