Patent US2921121A successfully refreshed from Google Patents.
US2921121A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Notch filter in brightness channel of color television transmitter
Assignee: RCA Corp
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Filing: 1955-04-01
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Granted: 1960-01-12
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Expires: 1975-04-01
Abstract
No abstract record available.
Inventors
- 👤 Grundmann Gustave Louis
- 👤 Sonnenfeldt Richard Wolfgang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:17
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/64; H04N9/646
Claims Analysis
Total Claims: 0
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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) | 1963-01-11 | 1963-07-13 | 1964-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-01-11 | 1967-07-13 | 1968-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-01-11 | 1971-07-13 | 1972-01-12 | $7700.00 | Window Closed / Lapsed |