Patent US3826770A successfully refreshed from Google Patents.
US2921990A
Expired / Lapsed
US
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Magnetic tape system and method
Assignee: Ampex Corp
•
Filing: 1955-12-13
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Granted: 1960-01-19
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Expires: 1975-12-13
Abstract
No abstract record available.
Inventors
- 👤 Charles P Ginsburg
- 👤 Jr Shelby F Henderson
- 👤 Ray M Dolby
- 👤 Charles E Anderson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 01:13
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/02; G11B15/12; G11B15/14; H; H04; H04N; H04N5/00; H04N5/76; H04N5/91; H04N5/93; H04N5/95
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2038216A
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US2245286A
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US2583983A
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US2648589A
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US2685079A
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US2612566A
Cited
US2694748A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-01-18 | 1963-07-20 | 1964-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-01-18 | 1967-07-20 | 1968-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-01-18 | 1971-07-20 | 1972-01-19 | $7700.00 | Window Closed / Lapsed |