US3885960A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of development of liquid electrostatic images using an hydrophobic barrier liquid
Assignee: Bankers Trust Co
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Filing: 1972-12-11
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Granted: 1975-05-27
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Expires: 1992-12-11
Abstract
Abstract An improved method of developing a latent electrostatic image disposed on a surface comprises depositing a barrier liquid and an aqueous liquid developer on said surface, holding said barrier liquid and developer on said surface until the developer displaces the barrier liquid from the latent electrostatic imagebearing areas of said surface to form a visible image and thereafter fixing the visible image on a receptor sheet, which may be the said surface or one or more separate sheets placed in contact therewith. The barrier liquid is hydrophobic, and the developer carries a coloring agent which can be an organic dye, inorganic pigment, or the like. Fixing can be accomplished merely by drying the coloring agent in place. The surface tension of the developer is lowered sufficiently by the electric field surrounding the latent electrostatic image to effect the desired physical displacement of the barrier liquid.
Inventors
- 👤 Terry G Anderson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:45
CPC Classifications
G; G03; G03G; G03G13/00; G03G13/06; G03G13/10; Y; Y10; Y10S; Y10S101/00; Y10S101/37
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
139 words
A METHOD OF DEVELOPMENT OF ELECTROSTATIC IMAGES, WHICH METHOD COMPRISES: DEPOSITING A LAYER OF HYDROPHOBIC BARRIER LIQUID ON A SURFACE BEARING A LATENT ELECTROSTATIC IMAGE, SAID BARRIER LIQUID WETTING SAID SURFACE; DEPOSITING A LAYER OF AQUEOUS DEVELOPER LIQUID, CONTAINING A MAJOR PROPORTION BY WEIGHT OF WATER AND A MINOR PROPORTION BY WEIGHT OF A SURFACE TENSION-LOWERING AGENT, ON SAID LAYER OF BARRIER LIQUID, SAID LIQUID DEVELOPER BEING IMMISCIBLE WITH SAID BARRIER LIQUID ANB BEARING A COLORING AGENT DISSOLVED OR DISPERSED THEREIN HAVING NO OR LOW SOLUBILITY IN SAID BARRIER LIQUID; HOLDING SAID BARRIER LIQUID AND DEVELOPER LIQUID ON SAID SURFACE UNTIL SAID DEVELOPER LIQUID DISPLACES SAID BARRIER LIQUID FROM THE AREAS OF SAID SURFACE BEARING SAID IMAGE; AND WETS SAID SURFACE AREAS SO AS TO FORM A VISIBLE IMAGE; AND THEREAFTER FIXING SAID VISIBLE IMAGE ON A RECEPTOR SHEET.
Claim 2
Independent Claim
139 words
A METHOD OF DEVELOPMENT OF ELECTROSTATIC IMAGES, WHICH METHOD COMPRISES: DEPOSITING A LAYER OF HYDROPHOBIC BARRIER LIQUID ON A SURFACE BEARING A LATENT ELECTROSTATIC IMAGE, SAID BARRIER LIQUID WETTING SAID SURFACE; DEPOSITING A LAYER OF AQUEOUS DEVELOPER LIQUID, CONTAINING A MAJOR PROPORTION BY WEIGHT OF WATER AND A MINOR PROPORTION BY WEIGHT OF A SURFACE TENSION-LOWERING AGENT, ON SAID LAYER OF BARRIER LIQUID, SAID LIQUID DEVELOPER BEING IMMISCIBLE WITH SAID BARRIER LIQUID ANB BEARING A COLORING AGENT DISSOLVED OR DISPERSED THEREIN HAVING NO OR LOW SOLUBILITY IN SAID BARRIER LIQUID; HOLDING SAID BARRIER LIQUID AND DEVELOPER LIQUID ON SAID SURFACE UNTIL SAID DEVELOPER LIQUID DISPLACES SAID BARRIER LIQUID FROM THE AREAS OF SAID SURFACE BEARING SAID IMAGE; AND WETS SAID SURFACE AREAS SO AS TO FORM A VISIBLE IMAGE; AND THEREAFTER FIXING SAID VISIBLE IMAGE ON A RECEPTOR SHEET.
Claim 3
Dependent Claim
53 words
The method of claim 1 wherein said liquid developer has an initial surface tension higher than that of said barrier liquid and wherein said surface tension of said developer is lowered sufficiently by the electric field accompanying said latent electrostatic image to enable said developer to displace said barrier liquid in said areas.
Claim 4
Dependent Claim
18 words
The method of claim 2 wherein said coloring agent of said developer is devoid of electrically charged particles.
Claim 5
Dependent Claim
24 words
The method of claim 3 wherein said coloring dye is selected from the group consisting of inorganic pigment and organic dye and mixtures thereof.
Claim 6
Dependent Claim
13 words
The method of claim 2 wherein said barrier liquid comprises non-polar organic liquid.
Claim 7
Dependent Claim
13 words
The method of claim 5 wherein said non-polar organic liquid comprises a hydrocarbon.
Claim 8
Dependent Claim
13 words
The method of claim 6 wherein said hydrocarbon comprises a liquid paraffinic hydrocarbon.
Claim 9
Dependent Claim
28 words
The method of claim 1 wherein said coloring agent comprises an organic dye and wherein said developer also includes a minor proportion of a solvent for said dye.
Claim 10
Dependent Claim
46 words
The method of claim 8 wherein said developer comprises at least about 60 percent by weight of water, about 10-15 percent by weight of surface tension-lowering agent, up to about 15 percent by weight of dyestuff solvent, and about 3-10 percent by weight of dye stock.
Claim 11
Dependent Claim
23 words
The method of claim 9 wherein said surface tension-lowering agent comprises isopropyl alcohol, said dyestuff solvent comprises dimethylformamide and said dye comprises chlorophyll.
Claim 12
Dependent Claim
16 words
The method of claim 10 wherein said developer is deposited on said surface by a roller.
Claim 13
Dependent Claim
11 words
The method of claim 11 wherein said roller is electrically conductive.
Claim 14
Dependent Claim
38 words
The method of claim 12 wherein said surface is photoconductive and disposed on an electrically grounded metallic substrate and wherein said roller is electrically connected to a power supply of polarity to induce negative development of said images.
Claim 15
Dependent Claim
27 words
The method of claim 1 wherein said visible image is fixed by allowing it to dry on said surface, and wherein said surface is said receptor sheet.
Claim 16
Dependent Claim
30 words
The method of claim 1 wherein said visible image is transferred from said surface to a separate receptor sheet by contact therewith and is then fixed on said separate sheet.
Claim 17
Dependent Claim
34 words
The method of claim 15 wherein said visible image is printed off on a plurality of separate receptor sheets without redevelopment and said printed off images are fixed by drying on said receptor sheets.
Claim 18
Dependent Claim
21 words
The method of claim 15 wherein said surface is photoconductive zinc oxide paper and said separate receptor sheet is ordinary paper.
Claim 19
Dependent Claim
31 words
The method of claim 1 wherein at least one of said developer and barrier liquid is deposited on said surface by release from a pod during crushing thereof by a roller.
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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) | 1978-05-26 | 1978-11-25 | 1979-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-26 | 1982-11-25 | 1983-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-26 | 1986-11-25 | 1987-05-27 | $7700.00 | Window Closed / Lapsed |