US3777209A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Non-thermionic electron emissive tube comprising a ceramic heater substrate
Assignee: RCA Corp
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Filing: 1972-05-17
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Granted: 1973-12-04
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Expires: 1992-05-17
Abstract
Abstract A non-thermionic electron emissive tube of the type comprising an evacuated envelope, an electron emissive cathode assembly in the envelope, and a collector anode for electrons emitted from the emissive layer. The cathode assembly comprises a thin ceramic substrate. On one face of the substrate is a non-thermionic cathode. On the opposite surface is a heater pattern of resistive metallizing.
Inventors
- 👤 A Mcdonie
- 👤 R Faulkner
- 👤 J Rhoads
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:38
CPC Classifications
H; H01; H01J; H01J40/00; H01J40/02; H01J40/04; H01J40/06; H01J43/00; H01J43/04; H01J43/06; H01J43/08
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
78 words
An electron emissive tube of the type comprising: an evacuated envelope; a non-thermionic, electron emissive cathode, having a photocathode layer and a work function reducing material on said photocathode layer, in the envelope, and a collector anode for electrons emitted from the electron emissive cathode, wherein the improvement comprises: a ceramic substrate on one surface of which the cathode is disposed, and a heater pattern of metallizing on the substrate in direct thermally conducting contact with the cathode.
Claim 2
Dependent Claim
78 words
An electron emissive tube of the type comprising: an evacuated envelope; a non-thermionic, electron emissive cathode, having a photocathode layer and a work function reducing material on said photocathode layer, in the envelope, and a collector anode for electrons emitted from the electron emissive cathode, wherein the improvement comprises: a ceramic substrate on one surface of which the cathode is disposed, and a heater pattern of metallizing on the substrate in direct thermally conducting contact with the cathode.
Claim 3
Dependent Claim
22 words
The tube defined in claim 1 wherein the heater pattern of metallizing is on the surface of the substrate opposite the cathode.
Claim 4
Dependent Claim
54 words
The tube defined in claim 1 wherein the emissive cathode comprises: a metal layer on the one surface of the substrate; a layer of semiconductor on the metal layer, and a work-function-reducing layer comprising at least one member of the group consisting of cesium, oxygen, and fluorine on the surface of the semiconductor layer.
Claim 5
Dependent Claim
23 words
The tube defined in claim 3 wherein the metal layer consists substantially of a metal from the group consisting of molybdenum and tungsten.
Claim 6
Dependent Claim
28 words
The tube defined in claim 4 wherein the semiconductor comprises at least one element from Groups IIIA, VA, IIB, and VIA of the Periodic Chart of the Elements.
Claim 7
Dependent Claim
24 words
The tube defined in claim 1 wherein the heater pattern metallizing consists substantially of a metal from the group consisting of molybdenum and tungsten.
Claim 8
Dependent Claim
36 words
An electron emissive tube in accordance with claim 1, characterized in that the ceramic substrate has a pair of spaced apertures therethrough and said heater pattern of metallizing extends over the ceramic substrate between the apertures.
Claim 9
Dependent Claim
51 words
An electron emissive tube in accordance with claim 7, characterized in that the heater pattern of metallization comprises an electrically resistive metal film of substantially uniform width extending in a zig-zag pattern between said apertures, said metal film having a portion of narrower width respectively adjacent to each of said apertures.
References Cited (Backward Citations)
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AU281761A
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US3307974A
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US3330991A
Cited
FR1432317A
Cited
US3408521A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-03 | 1977-06-04 | 1977-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-03 | 1981-06-04 | 1981-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-03 | 1985-06-04 | 1985-12-04 | $7700.00 | Window Closed / Lapsed |