US4000503A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cold cathode for infrared image tube
Assignee: International Audio Visual Inc
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Filing: 1976-01-02
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Granted: 1976-12-28
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Expires: 1996-01-02
Abstract
Abstract A cold cathode for an image-type tube such as a vidicon. The cathode features a negative electron affinity surface and a field enhanced electron ejection method. The photons generate electron-hole pairs in a compound semi-conductor structure having Group III and Group V compounds to form a heterojunction.
Inventors
- 👤 Herbert F. Matare
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 04:12
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/34; H01J29/00; H01J29/02; H01J29/10; H01J29/36; H01J29/38; H01J2201/00; H01J2201/34; H01J2201/342; H01J2201/3421; H01J2201/3423
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
111 words
A cold cathode for an infrared image converter device, said cathode comprising: a. a body of semi-conductive material; b. said body consisting of a semi-conductor combination selected from Group III and Group V elements to provide a heterojunction having at least one P-type and one N-type region; c. means for biasing said body in the reverse direction; and d. a surface coating on said N-type region having a low work function, whereby infrared light impinging on the transparent region of the heterojunction will create electron-hole pairs, the electrons being carried across the depletion layer of said N-type region by the electric field and across the N-type region toward said surface coating.
Claim 2
Dependent Claim
111 words
A cold cathode for an infrared image converter device, said cathode comprising: a. a body of semi-conductive material; b. said body consisting of a semi-conductor combination selected from Group III and Group V elements to provide a heterojunction having at least one P-type and one N-type region; c. means for biasing said body in the reverse direction; and d. a surface coating on said N-type region having a low work function, whereby infrared light impinging on the transparent region of the heterojunction will create electron-hole pairs, the electrons being carried across the depletion layer of said N-type region by the electric field and across the N-type region toward said surface coating.
Claim 3
Dependent Claim
37 words
A cold cathode as defined in claim 1 wherein said N-type region is of reduced thickness at its center so that said bias means causes the depletion layer to extend into the neighborhood of said surface coating.
Claim 4
Dependent Claim
15 words
A cold cathode as defined in claim 1 wherein said surface coating consists of Cesium-oxide.
Claim 5
Dependent Claim
25 words
A cold cathode as defined in claim 1 wherein said heterojunction consists of Gallium-Aluminum-Arsenide for said P-type region on Gallium Arsenide forming said N-type region.
Claim 6
Dependent Claim
34 words
A cold cathode as defined in claim 4 wherein said P-type region consists of Ga x Al 1-x As, where x of a number smaller than 1, said Gallium Arsenide being doped with Silicon.
Claim 7
Dependent Claim
15 words
A cold cathode as defined in claim 5 wherein x is between 0.4 and 0.7.
Claim 8
Dependent Claim
22 words
A cold cathode as defined in claim 1 wherein said P-type region consists of GaAsP and said N-type region consists of GaAs.
Claim 9
Dependent Claim
22 words
A cold cathode as defined in claim 1 wherein said P-type region consists of InGaAs and said N-type region consists of GaAs.
Claim 10
Dependent Claim
53 words
A cold cathode as defined in claim 1 wherein an addition P-type layer is provided on said N-type layer and below said surface coating, whereby the P-N junction between said P-type region and said N-type region is biased in the reverse direction while the basic N-P junction is biased in the forward direction.
Claim 11
Dependent Claim
97 words
A cold cathode for an infrared converter tube comprising: a. a semi-conductive body; b. said body having an N-type region consisting of Gallium-Arsenide and a P-type region consisting of Gallium-Aluminum-Arsenide; c. a negative electron affinity surface layer disposed on top of said P-type region; and d. means for biasing said body so that the N-P junction is biased in the reverse direction, said N-type region being not transparent to infrared photons, whereby photons impinging upon said P-type region release hole-electron pairs, the electrons being accelerated by the electric field to said surface layer and ejected into vacuum.
Claim 12
Dependent Claim
97 words
A cold cathode for an infrared converter tube comprising: a. a semi-conductive body; b. said body having an N-type region consisting of Gallium-Arsenide and a P-type region consisting of Gallium-Aluminum-Arsenide; c. a negative electron affinity surface layer disposed on top of said P-type region; and d. means for biasing said body so that the N-P junction is biased in the reverse direction, said N-type region being not transparent to infrared photons, whereby photons impinging upon said P-type region release hole-electron pairs, the electrons being accelerated by the electric field to said surface layer and ejected into vacuum.
Claim 13
Dependent Claim
30 words
A cold cathode as defined in claim 10 wherein an additional N-type layer is provided on said P-type region and below said surface layer, thereby to form an N-P-N structure.
References Cited (Backward Citations)
US3408521A
Cited
US3874952A
Cited
US3900865A
Cited
US3696262A
Cited
US3667007A
Cited
US3699401A
Cited
US3932883A
Cited
US3914136A
Cited
US3953880A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-12-28 | 1980-06-28 | 1980-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-12-28 | 1984-06-28 | 1984-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-12-28 | 1988-06-28 | 1988-12-28 | $7700.00 | Window Closed / Lapsed |