US4113484A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrophotographic elements and processes
Assignee: Eastman Kodak Co
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Filing: 1977-08-12
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Granted: 1978-09-12
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Expires: 1997-08-12
Abstract
Abstract A positive image is formed by imagewise passing a current through a substantially uniform layer of physically developable catalyst having a coverage of 1 × 10 -6 to 1 × 10 -10 g/cm 2 . The catalytic ability of the catalyst layer is destroyed by subjecting the image areas to greater than 1 × 10 -8 coulombs/cm 2 . Physical development of the thus exposed catalyst layer produces the positive image. A photoconductive element which is useful in this process is also disclosed. This photographic element comprises: (1) a non-catalytic conductive support; (2) a substantially uniform first layer coated on the conductive support comprising a physically developable catalyst having a coverage of 1 × 10 -6 to 1 × 10 -10 g/cm 2 of support; (3) a photoconductive second layer separated from the first layer by an air gap of up to 20 microns; and (4) a conductive layer over the second layer wherein at least the conductive support (1) or the conductive layer (4) is transparent to the electromagnetic radiation to which the photoconductive second layer (3) is sensitive.
Inventors
- 👤 Mark Lelental
- 👤 William Andrew Light
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:50
CPC Classifications
G; G03; G03C; G03C5/00; G03C5/58; G03G; G03G5/00; G03G5/14; Y; Y10; Y10S; Y10S430/00; Y10S430/001; Y10S430/102
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
98 words
A photographic element comprising: (1) a non-catalytic conductive support; (2) a substantially uniform first layer coated on said support, said layer comprising a physically developable catalyst having a coverage of 1 × 10 -6 to 1 × 10 -10 g/cm 2 of support; (3) a photoconductive second layer separated from said first layer by an air gap of up to 20 microns; and (4) a conductive layer over said second layer wherein at least said conductive support (1) or said conductive layer (4) is transparent to the electromagnetic radiation to which said photoconductive second layer (3) is sensitive.
Claim 2
Dependent Claim
98 words
A photographic element comprising: (1) a non-catalytic conductive support; (2) a substantially uniform first layer coated on said support, said layer comprising a physically developable catalyst having a coverage of 1 × 10 -6 to 1 × 10 -10 g/cm 2 of support; (3) a photoconductive second layer separated from said first layer by an air gap of up to 20 microns; and (4) a conductive layer over said second layer wherein at least said conductive support (1) or said conductive layer (4) is transparent to the electromagnetic radiation to which said photoconductive second layer (3) is sensitive.
Claim 3
Dependent Claim
33 words
The element of claim 1 wherein said physically developable catalyst is selected from the group consisting of nuclei of metals from groups Ib and VIII of the periodic table and catalytic binary compounds.
Claim 4
Dependent Claim
27 words
The element of claim 1 wherein said physically developable catalyst is selected from the group consisting of nuclei of copper, silver, gold, palladium, platinum and copper phosphide.
Claim 5
Dependent Claim
45 words
The element of claim 1 wherein said photoconductive second layer is capable of passing a current of at least 1 × 10 -8 amp/cm 2 when a voltage gradient of 10 5 volts/cm is applied across said conductive support (1) and said conductive layer (4).
Claim 6
Dependent Claim
21 words
The element of claim 1 wherein said noncatalytic conductive support comprises a catalytic metal overcoated with a thin non-catalytic barrier layer.
Claim 7
Dependent Claim
21 words
The element of claim 1 wherein said layers (3) and (4) consist of a photoconductive layer coated on a conductive support.
Claim 8
Dependent Claim
25 words
The element of claim 1 wherein said non-catalytic conductive support is barium sulfate coated paper and said physically developable catalyst is vacuum evaporated palladium nuclei.
Claim 9
Dependent Claim
17 words
The element of claim 1 wherein said photoconductive second layer is a layer of tetragonal lead oxide.
Claim 10
Dependent Claim
68 words
A photographic element comprising (1) a non-catalytic conductive support; (2) a substantially uniform first layer coated on said support, said layer comprising palladium nuclei having a coverage of 1 × 10 -6 to 1 × 10 -10 g/cm 2 of support; (3) a second layer comprising tetragonal lead oxide separated from said first layer by an air gap of up to 20 microns; and (4) a nickel-coated support.
Claim 11
Dependent Claim
68 words
A photographic element comprising (1) a non-catalytic conductive support; (2) a substantially uniform first layer coated on said support, said layer comprising palladium nuclei having a coverage of 1 × 10 -6 to 1 × 10 -10 g/cm 2 of support; (3) a second layer comprising tetragonal lead oxide separated from said first layer by an air gap of up to 20 microns; and (4) a nickel-coated support.
Claim 12
Dependent Claim
79 words
A process of preparing an image in an element having a layer comprising a substantially uniform layer of physically developable catalyst having a coverage of 1 × 10 -6 to 1 × 10 -10 g/cm 2 comprising the steps of: (1) imagewise destroying the developability of said catalyst by subjecting the image areas of said catalyst layer to a charge exposure greater than 1 × 10 -8 coulombs/cm 2 ; and (2) developing said catalyst layer by physical development.
Claim 13
Dependent Claim
79 words
A process of preparing an image in an element having a layer comprising a substantially uniform layer of physically developable catalyst having a coverage of 1 × 10 -6 to 1 × 10 -10 g/cm 2 comprising the steps of: (1) imagewise destroying the developability of said catalyst by subjecting the image areas of said catalyst layer to a charge exposure greater than 1 × 10 -8 coulombs/cm 2 ; and (2) developing said catalyst layer by physical development.
Claim 14
Dependent Claim
147 words
A process of preparing an image in an element comprising a conductive support having coated thereon a substantially uniform first layer comprising a physically developable catalyst having a coverage of 1 × 10 -6 to 1 × 10 -10 g/cm 2 and a second photoconductive layer separated from said first layer by an air gap of up to 20 microns, said process comprising the steps of: (1) applying a voltage across said element of at least about 1 × 10 5 volts/cm up to the dielectric breakdown potential of said layers; (2) imagewise destroying the developability of said catalyst by imagewise exposing said second layer to electromagnetic radiation while said voltage is being applied so as to subject the image areas of said first layer to a charge exposure greater than 1 × 10 -8 coulombs/cm 2 ; and (3) developing said first layer by physical development.
Claim 15
Dependent Claim
147 words
A process of preparing an image in an element comprising a conductive support having coated thereon a substantially uniform first layer comprising a physically developable catalyst having a coverage of 1 × 10 -6 to 1 × 10 -10 g/cm 2 and a second photoconductive layer separated from said first layer by an air gap of up to 20 microns, said process comprising the steps of: (1) applying a voltage across said element of at least about 1 × 10 5 volts/cm up to the dielectric breakdown potential of said layers; (2) imagewise destroying the developability of said catalyst by imagewise exposing said second layer to electromagnetic radiation while said voltage is being applied so as to subject the image areas of said first layer to a charge exposure greater than 1 × 10 -8 coulombs/cm 2 ; and (3) developing said first layer by physical development.
Claim 16
Dependent Claim
27 words
The process of claim 11 wherein said photoconductive second layer is coated on a transparent conductive support and said photoconductive layer is imagewise exposed through said support.
Claim 17
Dependent Claim
26 words
The process of claim 11 wherein a voltage of between 3 × 10 5 volts/cm and 30 × 10 5 volts/cm is applied across said element.
Claim 18
Dependent Claim
25 words
The process of claim 11 wherein said second photoconductive layer is exposed to electromagnetic radiation while said voltage is applied for between 0.01and 60 seconds.
Claim 19
Dependent Claim
19 words
The process of claim 11 wherein the developing step comprises immersing said first layer in a physical developer solution.
Claim 20
Dependent Claim
31 words
The process of claim 11 wherein said first layer is coated with a dry-physical-developer after said imagewise exposure and wherein said developing step comprises heating said first layer and said dry-physical-developer.
Claim 21
Dependent Claim
24 words
The process of claim 16 wherein said dry-physical-developer comprises a silver salt oxidizing agent and a reducing agent and a source of silver ion.
Claim 22
Dependent Claim
31 words
The process of claim 15 wherein said physical developer solution comprises a salt of a heavy metal ion and a reducing agent and a complexing agent for said heavy metal ion.
Claim 23
Dependent Claim
24 words
The process of claim 15 wherein said physical developer solution comprises a reducible leucophthalocyanine dye or a reducible tetrazolium salt and a reducing agent.
References Cited (Backward Citations)
US3829317A
Cited
US3893854A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-09-11 | 1982-03-13 | 1982-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-09-11 | 1986-03-13 | 1986-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-09-11 | 1990-03-13 | 1990-09-12 | $7700.00 | Window Closed / Lapsed |