US3944866A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermionic emitter of lanthanum strontium vanadates
Assignee: Queen's University
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Filing: 1974-04-08
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Granted: 1976-03-16
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Expires: 1994-04-08
Abstract
Abstract A thermionic emitter for apparatus such as electron microscopes, scanning electron microscopes, and high power vacuum tubes which require a source of electrons formed from lanthanum strontium vanadate which is prepared from the compounds La.sub.(1 -x ) Sr.sub.(x) VO 3 , where x is the fraction of strontium (Sr) incorporated into LaVO 3 . The value of x lies between 0.1 and 0.4.
Inventors
- 👤 Michael Sayer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:39
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/13; H01J1/14; H01J1/144
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
73 words
A thermionic emitter for electron beam apparatus comprising a metallic, electrically conducting support structure and a shaped piece of electron emitting material mounted on and in electrical contact with the said support structure, said material being the compound lanthanun strontium vanadate having the formula La.sub.(1 -x ) Sr x VO 3 where x is the fraction of strontium (Sr) incorporated in the La VO 3 and with x lying between 0.01 and 0.4.
Claim 2
Dependent Claim
73 words
A thermionic emitter for electron beam apparatus comprising a metallic, electrically conducting support structure and a shaped piece of electron emitting material mounted on and in electrical contact with the said support structure, said material being the compound lanthanun strontium vanadate having the formula La.sub.(1 -x ) Sr x VO 3 where x is the fraction of strontium (Sr) incorporated in the La VO 3 and with x lying between 0.01 and 0.4.
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) | 1979-03-16 | 1979-09-15 | 1980-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-16 | 1983-09-15 | 1984-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-16 | 1987-09-15 | 1988-03-16 | $7700.00 | Window Closed / Lapsed |