US3885187A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photodiode controlled electron velocity selector image tube
Assignee: United States Department of the Army
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Filing: 1973-10-11
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Granted: 1975-05-20
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Expires: 1993-10-11
Abstract
Abstract An electronic imaging device of the multigrid type having a novel photo-cathode that is uniformly flooded with a bias light on the front surface, or grid side, and is adapted to emit a flow of electrons from the front surface in direct proportion to a pattern of infrared light incident on the back surface of the photocathode. The photocathode comprises a mosaic of discrete electrically isolated photodiode-photoemitter islands with external grids adjacent to and separated from the photoemitter islands and an antireflection coating on the back surface of a Ptype substrate portion of the photodiode. A mosaic of evenly spaced N-type islands are contiguous with the P-type material with a layer of insulation deposited on the front side of the Ptype substrate surrounding the N-type islands. Discrete photoemitter islands are contiguous with the N-type islands, or are contiguous with a metallic layer deposited directly on the Ntype islands, with each of the discrete photodiode-photoemitter islands being discrete and electrically isolated on the photoemitter side of the substrate.
Inventors
- 👤 Alvin D Schnitzler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:59
CPC Classifications
H; H01; H01J; H01J31/00; H01J31/08; H01J31/50; H01J29/00; H01J29/02; H01J29/10; H01J29/36; H10; H10D; H10D99/00; H01J2231/00; H01J2231/50; H01J2231/50005; H01J2231/5001; H01J2231/50015; H01J2231/50026; H01J2231/50057; H01J2231/50063
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
384 words
A photodiode controlled electron velocity selector image tube in a vacuum envelope comprising: a P-type material substrate having a plurality of electrically isolated photosensitive junctions comprising a plurality of evenly spaced N-type material islands on a front side of said P-type material substrate and a layer of electrical insulation contiguous with the entire front side of said P-type material substrate but only around the periphery of said N-type material islands; a solid antireflection coating contiguous with a back side of said P-type material substrate; a plurality of discrete thin metal islands contiguous with said N-type material islands and said layer of electrical insulation wherein said thin metal islands are spread over said layer of electrical insulaTion in close proximity to but electrically isolated from each other; a plurality of discrete electrically isolated photoemitters contiguous with and covering the entire lateral surface of said plurality of discrete thin metal islands wherein said plurality of electrically isolated photoemitters are serially connected to said plurality of electrically isolated photosensitive junctions through said plurality of thin metal islands with each related photosensitive junction and photoemitter forming a plurality of discrete photocathode elements; an electroluminescent screen; a plurality of fine mesh grids positioned between said plurality of discrete electrically isolated photoemitters and said electroluminescent screen; a voltage divider source having voltage taps therefrom connected in step up voltage from said antireflection coating through said plurality of fine mesh grids to said electroluminescent screen for velocity controlling the electrons emitted from said discrete electrically isolated photoemitters to said electroluminescent screen; a bias light source for uniform illumination of the front surface of said plurality of discrete electrically isolated photoemitters for producing electron current saturation therefrom; and an infrared image radiation source for projecting an image on said antireflection coating such that the resistance across each of said plurality of electrically isolated photosensitive junctions is in direct relation to the intensity of said radiation source image to cause a change in velocity of electrons emitted from each of said plurality of photoemitters with relation to the fixed voltages on said plurality of fine mesh grids, and wherein said plurality of discrete thin metal islands inhibits said bias light illumination from entering said plurality of N-type material islands yet allows easy movement of electrons from said N-type material islands into said photoemitters.
Claim 2
Dependent Claim
384 words
A photodiode controlled electron velocity selector image tube in a vacuum envelope comprising: a P-type material substrate having a plurality of electrically isolated photosensitive junctions comprising a plurality of evenly spaced N-type material islands on a front side of said P-type material substrate and a layer of electrical insulation contiguous with the entire front side of said P-type material substrate but only around the periphery of said N-type material islands; a solid antireflection coating contiguous with a back side of said P-type material substrate; a plurality of discrete thin metal islands contiguous with said N-type material islands and said layer of electrical insulation wherein said thin metal islands are spread over said layer of electrical insulaTion in close proximity to but electrically isolated from each other; a plurality of discrete electrically isolated photoemitters contiguous with and covering the entire lateral surface of said plurality of discrete thin metal islands wherein said plurality of electrically isolated photoemitters are serially connected to said plurality of electrically isolated photosensitive junctions through said plurality of thin metal islands with each related photosensitive junction and photoemitter forming a plurality of discrete photocathode elements; an electroluminescent screen; a plurality of fine mesh grids positioned between said plurality of discrete electrically isolated photoemitters and said electroluminescent screen; a voltage divider source having voltage taps therefrom connected in step up voltage from said antireflection coating through said plurality of fine mesh grids to said electroluminescent screen for velocity controlling the electrons emitted from said discrete electrically isolated photoemitters to said electroluminescent screen; a bias light source for uniform illumination of the front surface of said plurality of discrete electrically isolated photoemitters for producing electron current saturation therefrom; and an infrared image radiation source for projecting an image on said antireflection coating such that the resistance across each of said plurality of electrically isolated photosensitive junctions is in direct relation to the intensity of said radiation source image to cause a change in velocity of electrons emitted from each of said plurality of photoemitters with relation to the fixed voltages on said plurality of fine mesh grids, and wherein said plurality of discrete thin metal islands inhibits said bias light illumination from entering said plurality of N-type material islands yet allows easy movement of electrons from said N-type material islands into said photoemitters.
Claim 3
Dependent Claim
27 words
A photodiode controlled electron velocity selector image tube as set forth in claim 1 wherein said plurality of discrete electrically isolated photoemitters are made of cesium antimonide.
Claim 4
Dependent Claim
27 words
A photodiode controled electron velocity selector image tube as set forth in claim 1 wherein said plurality of discrete electrically isolated photoemitters are made of cesiated silicon.
Claim 5
Dependent Claim
20 words
A photodiode controlled electron velocity selector image tube as set forth in claim 1 wherein said electroluminescent screen is phosphor.
Claim 6
Dependent Claim
25 words
A photodiode controlled electron velocity selector image tube as set forth in claim 4 wherein said both N-type material and said P-type material is silicon.
Claim 7
Dependent Claim
25 words
A photodiode controlled electron velocity selector image tube as set forth in claim 4 wherein said both N-type material and said P-type material is germanium.
Claim 8
Dependent Claim
26 words
A photodiode controlled electron velocity selector image tube as set forth in claim 4 wherein said P-type material is indium and said N-type material is arsenide.
Claim 9
Dependent Claim
26 words
A photodiode controlled electron velocity selector image tube as set forth in claim 4 wherein said P-type material is indium and said N-type material is antimony.
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) | 1978-05-19 | 1978-11-18 | 1979-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-19 | 1982-11-18 | 1983-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-19 | 1986-11-18 | 1987-05-20 | $7700.00 | Window Closed / Lapsed |