Patent US3881923A successfully refreshed from Google Patents.
US3881923A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrophotographic sensitive plate
Assignee: Minolta Co Ltd
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Filing: 1973-06-12
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Granted: 1975-05-06
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Expires: 1993-06-12
Abstract
Abstract An electrophotographic sensitive plate is formed by depositing first and second photoconductive layers on a conductive substrate in which the first photoconductive layer provides a rectifying barrier for preventing the injection of charges from the substrate and the second photoconductive layer is formed in a reticulated pattern. The second photoconductive layer may comprise a mixture of selenium with an element selected from the group consisting of Te, As and Sb. One of the photoconductive layers has a greater sensitivity than the other so as to improve the fidelity of half tone image reproduction. A transparent organic semiconductor layer is formed on the second photoconductive layer to maintain electric charges on its surface and for transporting photo-charge carriers generated within the first and second photoconductive layers. In an alternative embodiment the second photoconductive layer comprises a mixture in which the amount of the selected element is less than the amount of the selected element in the first photoconductive layer.
Inventors
- 👤 Susumu Tanaka
- 👤 Katsutoshi Konishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:33
CPC Classifications
G; G03; G03G; G03G5/00; G03G5/005
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
135 words
AN ELECTROPHOTOGRAPHIC SENSITIVE PLAT FOR IMPROVING THE FIDELITY OF HALF-TONE IMAGE REPRODUCTION, COMPRISING: A CONDUCTIVE SUBSTRATE, A FIRST PHOTOCONDUCTIVE SELENIUM LAYER HAVING A THICKNESS OF LESS THAN 1 MICRON DEPOSITED ON SAID SUBSTRATE FOR FORMING A RECTIFYING BARRIER PREVENTING THE INJECTION OF CHARGES FROM SAID SUBSTRATE, A SECOND PHOTOCONDUCTIVE LAYER FORMED ON SAID FIRST PHOTOCONDUCTIVE LAYER IN A RETICULATED PATTERN HAVING A THICKNESS NO GREATER THAN 1 TO MICORN ACID COMPRISING A MIXTURE OF SELENIUM WITH AN ELEMENT SELECTED FROM THE GROUP CONSISTING OF TE, AS AND SB AND CONTAINING BETWEEN 10 AND 30 PERCENT OF SAID ELEMENT BY WEIGHT, A TRANSPARENT ORGANIC SEMICONDUCTOR LAYER FORMED ON SAID SECOND PHOTOCONDUCTIVE LAYER AND COMPRISING POLYVINYL CARBAZOLE FOR MAINTAINING ELECTRIC CHARGES ON ITS SURFACE AND FOR TRANSPORTIRE PHOTO-CHARGE CARRIERS GENERATED WITHIN SAID FIRST AND SECOND PHOTOCONDUCTIVE LAYERS.
Claim 2
Dependent Claim
135 words
AN ELECTROPHOTOGRAPHIC SENSITIVE PLAT FOR IMPROVING THE FIDELITY OF HALF-TONE IMAGE REPRODUCTION, COMPRISING: A CONDUCTIVE SUBSTRATE, A FIRST PHOTOCONDUCTIVE SELENIUM LAYER HAVING A THICKNESS OF LESS THAN 1 MICRON DEPOSITED ON SAID SUBSTRATE FOR FORMING A RECTIFYING BARRIER PREVENTING THE INJECTION OF CHARGES FROM SAID SUBSTRATE, A SECOND PHOTOCONDUCTIVE LAYER FORMED ON SAID FIRST PHOTOCONDUCTIVE LAYER IN A RETICULATED PATTERN HAVING A THICKNESS NO GREATER THAN 1 TO MICORN ACID COMPRISING A MIXTURE OF SELENIUM WITH AN ELEMENT SELECTED FROM THE GROUP CONSISTING OF TE, AS AND SB AND CONTAINING BETWEEN 10 AND 30 PERCENT OF SAID ELEMENT BY WEIGHT, A TRANSPARENT ORGANIC SEMICONDUCTOR LAYER FORMED ON SAID SECOND PHOTOCONDUCTIVE LAYER AND COMPRISING POLYVINYL CARBAZOLE FOR MAINTAINING ELECTRIC CHARGES ON ITS SURFACE AND FOR TRANSPORTIRE PHOTO-CHARGE CARRIERS GENERATED WITHIN SAID FIRST AND SECOND PHOTOCONDUCTIVE LAYERS.
Claim 3
Dependent Claim
176 words
An electrophotographic sensitive plate for improving the fidelity of half-tone image reproduction, comprising: a conductive substrate including a semiconductor layer of selenium deposited thereon having a thickness of less than 1 micron to provide a rectifying barrier preventing the injection of charges from said substrate; a first photoconductive layer having a thickness of no greater than 1 micron formed on said semiconductor layer and comprising a mixture of selenium and an element selected from the group consisting of Te, As and Sb and containing between 10 and 30 percent of said element by weight; a second photoconductive layer having a thickness of no greater than 1 micron formed on said first photoconductive layer in a reticulated pattern and comprising a mixture of selenium and an element selected from the group consisting of Te, As and Sb with the amount of the selected element in said second photoconductive layer less than the amount of the selected element in said first photoconductive layer; a transparent organic semiconductor layer formed on said second photoconductive layer and comprising polyvinyl carbazole.
Claim 4
Dependent Claim
176 words
An electrophotographic sensitive plate for improving the fidelity of half-tone image reproduction, comprising: a conductive substrate including a semiconductor layer of selenium deposited thereon having a thickness of less than 1 micron to provide a rectifying barrier preventing the injection of charges from said substrate; a first photoconductive layer having a thickness of no greater than 1 micron formed on said semiconductor layer and comprising a mixture of selenium and an element selected from the group consisting of Te, As and Sb and containing between 10 and 30 percent of said element by weight; a second photoconductive layer having a thickness of no greater than 1 micron formed on said first photoconductive layer in a reticulated pattern and comprising a mixture of selenium and an element selected from the group consisting of Te, As and Sb with the amount of the selected element in said second photoconductive layer less than the amount of the selected element in said first photoconductive layer; a transparent organic semiconductor layer formed on said second photoconductive layer and comprising polyvinyl carbazole.
Claim 5
Dependent Claim
29 words
An electrophotographic sensitive plate as defined in claim 1, wherein said second photoconductive layer comprises a mixture of selenium and tellurium and containing approximately 20% of tellurium by weight.
Claim 6
Dependent Claim
28 words
An electrophotographic sensitive plate as defined in claim 1 wherein a 200 - 400 mesh screen is used for forming said second photoconductive layer in a reticulated pattern.
Claim 7
Dependent Claim
117 words
An electrographic sensitive plate for improving the fidelity of half-tone image reproduction, comprising: a conductive substrate; a first photoconductive layer having a thickness of no greater than 1 micron and comprising a mixture of selenium with an element selected from the group consisting of Te, AS and Sb and containing between 10 and 30 percent of said element by weight; a second photoconductive selenium layer having a thickness of less than 1 micron deposited on said first photoconductive layer in a reticulated pattern; a transparent organic semiconductor layer formed on said second photoconductive layer and comprising pOlyvinyl-carbazole for maintaining electric charges on its surface and for transporting photo-charge carriers generated within said first and second photoconductive layers.
Claim 8
Dependent Claim
117 words
An electrographic sensitive plate for improving the fidelity of half-tone image reproduction, comprising: a conductive substrate; a first photoconductive layer having a thickness of no greater than 1 micron and comprising a mixture of selenium with an element selected from the group consisting of Te, AS and Sb and containing between 10 and 30 percent of said element by weight; a second photoconductive selenium layer having a thickness of less than 1 micron deposited on said first photoconductive layer in a reticulated pattern; a transparent organic semiconductor layer formed on said second photoconductive layer and comprising pOlyvinyl-carbazole for maintaining electric charges on its surface and for transporting photo-charge carriers generated within said first and second photoconductive layers.
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) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |