US3919938A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Permanent electrostatic master
Assignee: Xerox Corp
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Filing: 1974-09-20
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Granted: 1975-11-18
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Expires: 1994-09-20
Abstract
Abstract A method of producing multiple copies from a permanent master containing a latent image produced by aligning anisotropic particles in the presence of an image electrostatic field. The permanent master so formed may be utilized to produce multiple copies of the original document by merely charging the master without the necessity of repeated exposure steps.
Inventors
- 👤 Eugene P Goldberg
- 👤 Donald A Seanor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:37
CPC Classifications
G; G03; G03G; G03G13/00; G03G13/22; G03G5/00; G03G5/02; G03G5/022
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
141 words
A method of storing images in a matrix having electrically anisotropic particles dispersed therein and reproducing said images comprising the steps of: charging said matrix to establish image-charge regions on the surface thereof and a corresponding electric field in the interior of said matrix, softening said matrix in the presence of said surface imagecharge regions thereby reducing the viscosity of the matrix and aligning the anisotropic particles in accordance with said surface image-charge regions, cooling said matrix to fix the position of said aligned anisotropic particles whereby the matrix contains electrical image regions corresponding to said surface image-charge regions, subsequently producing a visual image by the steps of: charging said matrix, allowing image-charge regions to form on the surface of said matrix by selective discharge through said electrical image regions in said matrix, and developing said image-charge regions of said master.
Claim 2
Independent Claim
141 words
A method of storing images in a matrix having electrically anisotropic particles dispersed therein and reproducing said images comprising the steps of: charging said matrix to establish image-charge regions on the surface thereof and a corresponding electric field in the interior of said matrix, softening said matrix in the presence of said surface imagecharge regions thereby reducing the viscosity of the matrix and aligning the anisotropic particles in accordance with said surface image-charge regions, cooling said matrix to fix the position of said aligned anisotropic particles whereby the matrix contains electrical image regions corresponding to said surface image-charge regions, subsequently producing a visual image by the steps of: charging said matrix, allowing image-charge regions to form on the surface of said matrix by selective discharge through said electrical image regions in said matrix, and developing said image-charge regions of said master.
Claim 3
Dependent Claim
17 words
A method as recited in claim 1 wherein said second charging step is a non-image charging step.
Claim 4
Dependent Claim
23 words
A method as recited in claim 1 wherein said developing step comprises applying toner particles to said master to form toner image regions.
Claim 5
Dependent Claim
12 words
A method as recited in claIm 1 wherein said matrix is photoconductive.
Claim 6
Dependent Claim
16 words
A method as recited in claim 1 wherein said first charging step is an image-charging step.
Claim 7
Independent Claim
121 words
A method of forming regions of different RC decay time constants within a material and forming surface image charge regions corresponding thereto comprising the steps of: image-charging said material to establish image-charge regions on the surface of said material, aligning filler particles within said material in accordance with said image charge regions, said aligned filler particles have an RC decay constant smaller than the RC decay constant of non-aligned regions, subsequently producing a surface image charge on said material by: non-image charging said material; allowing the formation of a surface image charge on said material by charge decay through said material whereby surface charge is dissipated at a higher rate by said aligned filler particles than by said non-aligned filler particles.
Claim 8
Independent Claim
121 words
A method of forming regions of different RC decay time constants within a material and forming surface image charge regions corresponding thereto comprising the steps of: image-charging said material to establish image-charge regions on the surface of said material, aligning filler particles within said material in accordance with said image charge regions, said aligned filler particles have an RC decay constant smaller than the RC decay constant of non-aligned regions, subsequently producing a surface image charge on said material by: non-image charging said material; allowing the formation of a surface image charge on said material by charge decay through said material whereby surface charge is dissipated at a higher rate by said aligned filler particles than by said non-aligned filler particles.
Claim 9
Dependent Claim
34 words
A method as recited in claim 6 wherein said RC decay time constant may be determined by: selecting the electrical resistivity of said material/filler composition and selecting the dielectric constant of said material/filler composition.
Claim 10
Dependent Claim
43 words
A method as recited in claim 7 wherein said electrical resistivity is selected within the range 1011 < or = Rho < or = 1013, and said dielectric constant is selected within the range 2 < or = epsilon < or = 10.
Claim 11
Dependent Claim
38 words
A method as recited in claim 6 wherein aligning said filler particles comprises the steps of: reducing the viscosity of said material to allow filler particle alignment, and increasing the viscosity of said material to fix said alignment.
Claim 12
Dependent Claim
22 words
A method as recited in claim 9 wherein said reducing and increasing said material viscosity comprises respectively heating and cooling said material.
Claim 13
Dependent Claim
19 words
A method as recited in claim 6 wherein said material is silicone rubber and said filler is barium titanate.
Claim 14
Dependent Claim
12 words
A method as recited in claim 6 wherein said material is photoconductive.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-17 | 1979-05-19 | 1979-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-17 | 1983-05-19 | 1983-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-17 | 1987-05-19 | 1987-11-18 | $7700.00 | Window Closed / Lapsed |