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US3712700A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of making an electron emitter device

Assignee: RCA Corp
•
Filing: 1971-01-18
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Granted: 1973-01-23
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Expires: 1991-01-18
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Abstract

Abstract A method comprising coating an uncontaminated emitter surface of an emitter body with a non-contaminating protective layer and then mounting the body so that the coated surface is in the interior of an envelope. The envelope and body are then heated to a first temperature to drive contaminant gases from surfaces of the envelope interior while these gases are simultaneously pumped out. The first temperature is low enough that the protective layer remains. Then the body is heated to a second temperature, higher than the first, and the protective layer evaporated off the surface while the envelope is maintained at a temperature below the first temperature. Thereafter the emitter surface is activated by the application thereto of a material which lowers the work function.

Inventors

  • 👤 A Sommer

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 11:19
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/02; H01J9/12; H01J2201/00; H01J2201/32; H01J2201/34

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 14 words
The method defined in claim 1 wherein the protective layer is an alkali-halide compound.
Claim 2
Dependent Claim 29 words
The method defined in claim 1 wherein the protective layer is of potassium chloride, the first temperature is about 400*C, and the second temperature is about 450*C or higher.
Claim 3
Dependent Claim 29 words
The method defined in claim 1 wherein the protective layer is of cesium iodide, the first temperature is about 300*C, and the second temperature is about 350*C or higher.

References Cited (Backward Citations)

US2184323A Cited
US2441810A Cited
US2505909A Cited
US3390012A Cited
US3353890A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1976-01-23 1976-07-24 1977-01-23 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-01-23 1980-07-24 1981-01-23 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-01-23 1984-07-24 1985-01-23 $7700.00 Window Closed / Lapsed

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