US2159774A
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Secondary electron emitter and method of making it
Assignee: Koninklijke Philips NV
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Filing: 1938-03-15
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Granted: 1939-05-23
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Expires: 1958-03-15
Abstract
No abstract record available.
Inventors
- 👤 Veenemans Cornelis Frederik
- 👤 Lopp Edmund Heinrich
- 👤 Bruining Hajo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:29
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/02; H01J9/12; H01J9/125; H01J1/00; H01J1/02; H01J1/32; H01J2201/00; H01J2201/32
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1942-05-22 | 1942-11-21 | 1943-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1946-05-22 | 1946-11-21 | 1947-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1950-05-22 | 1950-11-21 | 1951-05-23 | $7700.00 | Window Closed / Lapsed |