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Patent US3521294A successfully refreshed from Google Patents.
US3521294A
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US
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Magneto thermal recording process and apparatus
Assignee: Ampex Corp
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Filing: 1967-03-13
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Granted: 1970-07-21
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Expires: 1987-03-13
Abstract
No abstract record available.
Inventors
- 👤 David Treves
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:03
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G03; G03G; G03G19/00; G11B11/10582; G11B11/10586; G11B11/10589; G11B11/10591; H; H04; H04N; H04N5/00; H04N5/76; H04N5/78; H04N5/7805; G11B5/00; G11B2005/0002; G11B2005/0005; G11B2005/0021; G11B5/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3164816A
Cited
US3368209A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-07-20 | 1974-01-19 | 1974-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-07-20 | 1978-01-19 | 1978-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-07-20 | 1982-01-19 | 1982-07-21 | $7700.00 | Window Closed / Lapsed |