Patent US3776722A successfully refreshed from Google Patents.
US3776722A
Expired / Lapsed
US
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Electrophotographic method of imagewise particle transfer employing alternating modulated field
Assignee: Individual
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Filing: 1971-06-14
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Granted: 1973-12-04
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Expires: 1991-06-14
Abstract
Abstract A process and a device for electrophotographic reproduction using a photoconductive layer placed in contact with a uniform layer of developer between two electrodes. An alternatively modulated voltage is applied to the electrodes.
Inventors
- 👤 M Cantarano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:02
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/22; G03G15/34; G03G15/344; G03G2215/00; G03G2215/04; G03G2215/0497; G03G2217/00; G03G2217/0091; Y; Y10; Y10S; Y10S430/00; Y10S430/001; Y10S430/102
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
44 words
The method of claim 1 wherein said photo-conductive layer is located between an insulating backing and said layer of electrically chargeable particles and said alternatively modulated electric field is generated across said layer of electrically chargeable particles, said photoconductive layer and said insulating backing.
Claim 2
Dependent Claim
44 words
The method of claim 1 wherein said layer of electrically chargeable particles is located between said photoconductive layer and an insulating Layer, and said alternatively modulated electric field is generated across said insulating layer, said layer of electrically chargeable particles and said photoconductive layer.
Claim 3
Dependent Claim
60 words
The method of claim 3 wherein said insulating layer is formed from a fluid layer interposed between said photoconductive layer and a grid-shaped electrode, and said alternatively modulated electric field is generated between said photoconductive layer and said grid-electrode, whereby said removed part of the particles is definitively attracted across said fluid and said grid-electrode away from said electric field.
Claim 4
Dependent Claim
41 words
The method of claim 1 wherein said layer of electrically chargeable particles is located between said photoconductive layer and an image carrier whereby a second stable electrographic image is developed on said image carrier by said removed part of said particles.
Claim 5
Independent Claim
171 words
A method for producing an electrographic image comprising the steps of placing a layer of electrically chargeable particles against a photoconductive layer, exposing said photoconductive layer to a pattern of radiation to form in said photoconductive layer a conductivity pattern including maximum and minimum electric conductivities, sandwiching said layer of electrically chargeable particles between said photoconductive layer and an image carrier having a uniform electric conductivity between the maximum and minimum conductivities which are included in said conductivity pattern, generating across said image carrier, said layer of electrically chargeable particles and said photoconductive layer an alternatively modulated electric field charging said layer of electrically chargeable particles from said conductivity pattern and said image carrier simultaneously, said layer of electrically chargeable particles thereby receiving electric charges attracting a part of said particles away from said image carrier to develop a first stable electrographic image on said photoconductive layer and opposite electric charges attracting the remaining particles away from said photoconductive layer to develop a second stable electrographic image on said image carrier.
Claim 6
Dependent Claim
45 words
The method of claim 6 wherein said photoconductive layer is located between an insulating backing and said layer of electrically chargeable particles and said electric field is generated across said image carrier, said layer of electrically chargeable particles, said photoconductive layer and said insulating backing.
Claim 7
Dependent Claim
45 words
The method of claim 6 wherein said image carrier is located bewteen said layer of electrically chargeable particles and an insulating layer, and said electric field is generated across said insulating layer, said image carrier, said layer of electrically chargeable particles and said photoconductive layer.
Claim 8
Dependent Claim
55 words
The method of claim 6 wherein the sandwich, formed by said layer of electrically chargeable particles disposed between said photoconductive layer and said image carrier, is located between two insulating layers, and said electric field is generated across said two insulating layers, said image carrier, said layer of electrically chargeable particles and said photoconductive layer.
Claim 9
Independent Claim
173 words
A method for producing an electrographic image comprising the steps of coating a conductive image carrier with a layer of loosely-adhering electrically chargeable particles, placing said coated image carrier against a photo-conductive layer so that said layer of electrically chargeable particles is sandwiched between said photoconductive layer and said conductive image carrier, exposing said photoconductive layer to a pattern of radiation to form a conductivity pattern in said photoconductive layer, generating across said conductive image carrier, said layer of electrically chargeable particles and said photoconductive layer an alternatively modulated electric field so as to charge said layer of electrically chargeable particles from said photoconductive layer and said conductive image carrier simultaneously, said layer of electrically chargeable partIcles thereby receiving a pattern of greater and lesser alternating charges, said greater alternating charges attracting a part of said particles away from said image carrier to develop a first stable electrographic image on said photoconductive layer while said lesser alternating charges maintain the remaining particles on said image carrier thereby developing thereon second stable electrographic image.
Claim 10
Dependent Claim
48 words
The method of claim 10 wherein said photoconductive layer is located between said layer of electrically chargeable particles and an insulating backing, and said alternatively modulated electric field is generated across said conductive image carrier, said layer of electrically chargeable particles, said photoconductive layer and said insulating backing.
Claim 11
Dependent Claim
49 words
The method of claim 10, wherein said conductive image carrier is located between said layer of electrically chargeable particles and an insulating layer, and said alternatively modulated electric field is generated across said insulating layer, said conductive image carrier, said layer of electrically chargeable particles and said photoconductive layer.
Claim 12
Dependent Claim
57 words
The method of claim 10, wherein the sandwich, formed by said layer of electrically chargeable particles disposed between said image carrier and said photoconductive layer, is located between two insulating layers, and said alternatively modulated electric field is generated across said two insulating layers, said image carrier, said layer of electrically chargeable particles and said photoconductive layer.
Claim 13
Independent Claim
148 words
A method for producing an electrographic image comprising the steps of affixing a photoconductive layer on an insulating backing material, coating said photoconductive layer with a layer of electrically chargeable particles, disposing said layer of electrically chargeable particles between said photoconductive layer and an insulating layer, exposing said photoconductive layer to a pattern of radiation to form a conductivity pattern in said photoconductive layer, generating across said insulating layer, said layer of electrically chargeable particles, said photoconductive layer and said insulating backing material an alternatively modulated electric field thereby transferring alternating electric charges from said conductivity pattern to said layer of electrically chargeable particles whereby said layer of particles receives a pattern of greater and lesser alternating charges, said greater alternating charges removing a part of said particles while said lesser alternating charges maintain the remaining particles in said layer of particles thereby developing a stable electrographic image.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-03 | 1977-06-04 | 1977-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-03 | 1981-06-04 | 1981-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-03 | 1985-06-04 | 1985-12-04 | $7700.00 | Window Closed / Lapsed |