US2947912A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electro-luminescent display devices
Assignee: National Research Development Corp UK
•
Filing: 1958-04-07
•
Granted: 1960-08-02
•
Expires: 1978-04-07
Abstract
No abstract record available.
Inventors
- 👤 Hoffman George Richard
- 👤 Cheltenham Roy Ernest Hayes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 11:04
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/10; H01J29/18
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2818531A
Cited
US2796584A
Cited
US2877371A
Cited
US2774813A
Cited
US2883582A
Cited
US2892968A
Cited
US2881360A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-08-02 | 1964-02-01 | 1964-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-08-02 | 1968-02-01 | 1968-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-08-02 | 1972-02-01 | 1972-08-02 | $7700.00 | Window Closed / Lapsed |