US4230784A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatic image forming process and particles comprising reactive sublimable dye, subliming developer and conductive substance
Assignee: Panasonic Holdings Corp
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Filing: 1978-09-13
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Granted: 1980-10-28
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Expires: 1998-09-13
Abstract
Abstract Image forming particles for use in electrostatic image formation, which particles have a light transmitting property, said particles comprising an electrically conductive material and subliming substance. The electrically conductive particles exhibit superior translucency which enables a charge preliminarily imparted to a photoconductive support member to be readily erased upon exposure to light image from an original, with consequent reduction of electrostatic attraction between the particles and the support member to minimum for presenting clear and definite images without fogging. Furthermore, the particles are electrically independent due to absence of electrostatic attraction therebetween and because of their electrical conductivity adhere to the support member by electrostatic induction of the charge imparted to the latter without adhesion between the particles, thus being uniformly arranged on the support member in one single layer and as close to each other as possible, thus offering resultant images of superior quality.
Inventors
- 👤 Hisanori Nishiguchi
- 👤 Eisuke Ishida
- 👤 Yuji Takashima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:54
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/22; G03G15/34; G03G15/342; G03G9/00; G03G9/08; G03G9/0821; G03G9/0823; G03G9/0825; G03G9/09; G03G9/0926
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
286 words
Image forming particles for use in an electrostatic image formation process which comprises the steps of: (1) providing a photoconductive support member and said image forming particles; (2) imparting to said photoconductive support an electrostatic charge, whereby said image forming particles are caused to adhere to the surface of said photocondutive support by electrostatic induction; (3) exposing the charged photoconductive support member of (2) having said particles adhered thereto by electrostatic force, to a light image, the charge of the photoconductive support member at portions thereof being exposed to the light through the particles being attenuated, whereby the image of said particles is formed on said support by utilizing the difference in electrostatic attraction between the photoconductive support member and said image forming particles, said image on said support corresponding to said light image; (4) heating the particles on the photoconductive support member obtained by the step (3) to cause a sublimable substance contained in said particles to be sublimed, whereby the colored image is obtained by causing said sublimable substance to adhere to said photoconductive support member or image receptor containing therein developing color agent which forms the colored image through reaction with said sublimable substance; said particles comprising a sublimable substance selected from the group consisting of a colored subliming dye, a subliming colorless dye which is colorless in its normal state and develops color upon reaction with developing agent and a subliming developing agent which is colorless in its normal state and develops color upon reaction with a colorless dye and an electrically conductive substance which facilitates the electrostatic induction of said particles, and said particles being capable of transmitting light and having a specific resistance of less than 10 10 ohm cm.
Claim 2
Dependent Claim
286 words
Image forming particles for use in an electrostatic image formation process which comprises the steps of: (1) providing a photoconductive support member and said image forming particles; (2) imparting to said photoconductive support an electrostatic charge, whereby said image forming particles are caused to adhere to the surface of said photocondutive support by electrostatic induction; (3) exposing the charged photoconductive support member of (2) having said particles adhered thereto by electrostatic force, to a light image, the charge of the photoconductive support member at portions thereof being exposed to the light through the particles being attenuated, whereby the image of said particles is formed on said support by utilizing the difference in electrostatic attraction between the photoconductive support member and said image forming particles, said image on said support corresponding to said light image; (4) heating the particles on the photoconductive support member obtained by the step (3) to cause a sublimable substance contained in said particles to be sublimed, whereby the colored image is obtained by causing said sublimable substance to adhere to said photoconductive support member or image receptor containing therein developing color agent which forms the colored image through reaction with said sublimable substance; said particles comprising a sublimable substance selected from the group consisting of a colored subliming dye, a subliming colorless dye which is colorless in its normal state and develops color upon reaction with developing agent and a subliming developing agent which is colorless in its normal state and develops color upon reaction with a colorless dye and an electrically conductive substance which facilitates the electrostatic induction of said particles, and said particles being capable of transmitting light and having a specific resistance of less than 10 10 ohm cm.
Claim 3
Dependent Claim
20 words
Image forming particles as claimed in claim 1, wherein said electrically conductive material is dispersed in each of said particles.
Claim 4
Dependent Claim
28 words
Image forming particles as claimed in claim 1, wherein said electrically conductive material is formed into an electrically conductive layer provided on surface of each of said particles.
Claim 5
Dependent Claim
30 words
Image forming particles as claimed in claim 3, wherein said electrically conductive layer has sufficient permeability to gases to permit escape of said sublimable substance from said particles when heated.
Claim 6
Dependent Claim
20 words
Image forming particles as claimed in claim 1 wherein said subliming substance is uniformly dispersed in each of the particles.
Claim 7
Dependent Claim
26 words
Image forming particles as claimed in claim 1, wherein said particles comprise a layer containing said sublimable substance and a layer containg said electrically conductive material.
Claim 8
Dependent Claim
43 words
Image forming particles as claimed in claim 1, wherein said particles comprise a core material of light transmitting property coated by a first layer containing said sublimable substance, said first layer being further coated by a second layer containing said electrically conductive material.
Claim 9
Dependent Claim
21 words
Image forming particles as claimed in claim 7, wherein said second layer containing said electrically conductive material has permeability to gases.
Claim 10
Dependent Claim
24 words
Image forming particles as claimed in claim 1, wherein said sublimable substance has a subliming temperature in the range from 80° to 220° C.
Claim 11
Dependent Claim
15 words
Image forming particles as claimed in claim 1, wherein said sublimable substance is sublimable dye.
Claim 12
Dependent Claim
32 words
Image forming particles as claimed in claim 10, wherein said sublimable dye is subliming colorless dye which is colorless in the normal state and develops color upon reaction with a developing agent.
Claim 13
Dependent Claim
24 words
Image forming particles as claimed in claim 1, wherein said sublimable substance is sublimable developing agent which develops color upon reaction with colorless dye.
Claim 14
Dependent Claim
16 words
Image forming particles as claimed in claim 1, wherein said particles exhibit selective spectral light transmission.
Claim 15
Dependent Claim
34 words
Image forming particles as claimed in claim 13, wherein said selective spectral light transmitting property of said particles is capable of transmitting one color selected from three primary colors of the additive color process.
Claim 16
Dependent Claim
28 words
Image forming particles as claimed in claim 13, wherein said sublimable substance is capable of developing one color selected from three primary colors of the subtractive color process.
Claim 17
Dependent Claim
27 words
Image forming particles as claimed in claim 1, wherein said electrically conductive contained in said particles for imparting electrically conductive property thereto is capable of light transmission.
Claim 18
Dependent Claim
19 words
Image forming particles as claimed in claim 1, wherein the each of said particles has an approximately spherical shape.
Claim 19
Dependent Claim
21 words
Image forming particles as claimed in claim 1, wherein said particles have diameters in the range from 1 to 80 microns.
Claim 20
Dependent Claim
279 words
An electrostatic image formation process which comprises the steps of: (1) providing a photoconductive support member and image forming particles; (2) imparting to said photoconductive support an electrostatic charge, whereby said image forming particles are caused to adhere to the surface of said photoconductive support by electrostatic induction; (3) exposing the charged photoconductive support member of (2) having said particles adhered thereto by electrostatic force, to a light image, the charge of the photoconductive support member at portions thereof being exposed to the light through the particles being attenuated, whereby the image of said particles is formed on said support by utilizing the difference in electrostatic attraction between the photoconductive support member and said image forming particles, said image on said support corresponding to said light image; (4) heating the particles on the photoconductive support member obtained by the step (3) to cause a sublimable substance contained in said particles to be sublimed, whereby the colored image is obtained by causing said sublimable substance to adhere to said photoconductive support member or image receptor containing therein developing color agent which forms the colored image through reaction with said sublimable substance; said particles comprising a sublimable substance selected from the group consisting of a colored subliming dye, a subliming colorless dye which is colorless in its normal state and develops color upon reaction with developing agent and a subliming developing agent which is colorless in its normal state and develops color upon reaction with a colorless dye and an electrically conductive substance which facilitates the electrostatic induction of said particles, and said particles being capable of transmitting light and having a specific resistance of less than 10 10 ohms cm.
Claim 21
Dependent Claim
279 words
An electrostatic image formation process which comprises the steps of: (1) providing a photoconductive support member and image forming particles; (2) imparting to said photoconductive support an electrostatic charge, whereby said image forming particles are caused to adhere to the surface of said photoconductive support by electrostatic induction; (3) exposing the charged photoconductive support member of (2) having said particles adhered thereto by electrostatic force, to a light image, the charge of the photoconductive support member at portions thereof being exposed to the light through the particles being attenuated, whereby the image of said particles is formed on said support by utilizing the difference in electrostatic attraction between the photoconductive support member and said image forming particles, said image on said support corresponding to said light image; (4) heating the particles on the photoconductive support member obtained by the step (3) to cause a sublimable substance contained in said particles to be sublimed, whereby the colored image is obtained by causing said sublimable substance to adhere to said photoconductive support member or image receptor containing therein developing color agent which forms the colored image through reaction with said sublimable substance; said particles comprising a sublimable substance selected from the group consisting of a colored subliming dye, a subliming colorless dye which is colorless in its normal state and develops color upon reaction with developing agent and a subliming developing agent which is colorless in its normal state and develops color upon reaction with a colorless dye and an electrically conductive substance which facilitates the electrostatic induction of said particles, and said particles being capable of transmitting light and having a specific resistance of less than 10 10 ohms cm.
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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) | 1983-10-28 | 1984-04-28 | 1984-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-28 | 1988-04-28 | 1988-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-28 | 1992-04-28 | 1992-10-28 | $7700.00 | Window Closed / Lapsed |