Patent US3870921A successfully refreshed from Google Patents.
US3870921A
Expired / Lapsed
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Image intensifier tube with improved photoemitter surface
Assignee: Xerox Corp
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Filing: 1973-09-24
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Granted: 1975-03-11
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Expires: 1993-09-24
Abstract
Abstract An image intensifier tube in which the efficiency and wavelength span of the photoemitter are increased by providing on a light transmissive surface a thin film of a Group II-VI compound intermediate the amorphous screen of the tube and the photoemitter surface. The thin transparent film is preferably zinc selenide or zinc sulfide with the photoemitter being a layer of gallium arsenide or another compound or alloy prepared from the elements of Group III and Group V of the period table of elements. The thickness of the film is preferably about 1.0 micrometers, and the film is heat treated at 400*C - 500*C in an inert gas for a selected period of time.
Inventors
- 👤 James W Burns
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:55
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/20; H01J29/00; H01J29/02; H01J29/10; H01J29/36; H01J29/38; H01J31/00; H01J31/08; H01J31/50; H01J31/501
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
77 words
IN AN IMAGE INTENSIFER TUBE HAVING AN AMORPHOUS OPTICAL SURFACE, A PHOTOCATHODE COMPRISING: A THIN FILM OF A FIRST COMPOUND PREPARED FROM THE ELEMENTS OF GROUP II AND GROUP VI OF THE PERIODIC TABLE DEPOSITED DIRECTLY ON SAID AMORPJOUS OPTICAL SURFACE, AND A LAYER OF A SECOND COMPOUND PREPARED FROM THE ELEMENTS OF GROUP III AND GROUP V OF THE PERIODIC TABLE DEPOSITED ON SAID FILM, SAID FIRST AND SECOND COMPOUNDS HAVING CLOSELY MACTHED CRYSTALLOGRAPHIC LATTICE CONSTANTS.
Claim 2
Dependent Claim
77 words
IN AN IMAGE INTENSIFER TUBE HAVING AN AMORPHOUS OPTICAL SURFACE, A PHOTOCATHODE COMPRISING: A THIN FILM OF A FIRST COMPOUND PREPARED FROM THE ELEMENTS OF GROUP II AND GROUP VI OF THE PERIODIC TABLE DEPOSITED DIRECTLY ON SAID AMORPJOUS OPTICAL SURFACE, AND A LAYER OF A SECOND COMPOUND PREPARED FROM THE ELEMENTS OF GROUP III AND GROUP V OF THE PERIODIC TABLE DEPOSITED ON SAID FILM, SAID FIRST AND SECOND COMPOUNDS HAVING CLOSELY MACTHED CRYSTALLOGRAPHIC LATTICE CONSTANTS.
Claim 3
Dependent Claim
77 words
In an image intensifier tube having an amorphous optical surface, a photocathode comprising: a thin film of a first compound prepared from the elements of Group II and Group VI of the periodic table deposited directly on said amorphous optical surface, and a layer of a second compound prepared from the elements of Group III and Group V of the periodic table deposited on said film, said first and second compounds having closely matched crystallographic lattice constants.
Claim 4
Dependent Claim
77 words
In an image intensifier tube having an amorphous optical surface, a photocathode comprising: a thin film of a first compound prepared from the elements of Group II and Group VI of the periodic table deposited directly on said amorphous optical surface, and a layer of a second compound prepared from the elements of Group III and Group V of the periodic table deposited on said film, said first and second compounds having closely matched crystallographic lattice constants.
Claim 5
Dependent Claim
28 words
The tube of claim 1 wherein said film is selected from the group consisting of zinc selenide, zinc sulphide, and cadmium sulphide, and said layer is gallium arsenide.
Claim 6
Dependent Claim
19 words
The tube of claim 1 wherein said layer is treated with an alkali metal to lower its work function.
Claim 7
Dependent Claim
72 words
A photocathode formed on an amorphous optical surface and comprising: a thin film of a compound prepared from the elements of Group II and Group VI of the periodic table deposited directly on said amorphous optical surface, and a layer of a compound prepared from the elements of Group III and Group V of the periodic table Deposited on said film, said film and said layer having closely matched crystallographic lattice constants.
Claim 8
Dependent Claim
72 words
A photocathode formed on an amorphous optical surface and comprising: a thin film of a compound prepared from the elements of Group II and Group VI of the periodic table deposited directly on said amorphous optical surface, and a layer of a compound prepared from the elements of Group III and Group V of the periodic table Deposited on said film, said film and said layer having closely matched crystallographic lattice constants.
Claim 9
Dependent Claim
28 words
The photocathode of claim 4 wherein said film is selected from the group consisting of zinc selenide, zinc sulphide, and cadmium sulphide, and said layer is gallium arsenide.
Claim 10
Dependent Claim
19 words
The photocathode of claim 4 wherein said layer is treated with an alkali metal to lower its work function.
Claim 11
Dependent Claim
81 words
A process for forming a photocathode on an amorphous surface comprising the steps of: depositing directly on said surface a thin film of a compound formed from the elements of Group II and Group VI of the periodic table of elements, heat treating said thin film to increase the crystal grain size of said film, and depositing on said film a layer of a compound formed from the elements of Group III and Group V of the periodic table of elements.
Claim 12
Dependent Claim
81 words
A process for forming a photocathode on an amorphous surface comprising the steps of: depositing directly on said surface a thin film of a compound formed from the elements of Group II and Group VI of the periodic table of elements, heat treating said thin film to increase the crystal grain size of said film, and depositing on said film a layer of a compound formed from the elements of Group III and Group V of the periodic table of elements.
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) | 1978-03-10 | 1978-09-09 | 1979-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-10 | 1982-09-09 | 1983-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-10 | 1986-09-09 | 1987-03-11 | $7700.00 | Window Closed / Lapsed |