US2774646A
Expired / Lapsed
US
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Magnetic recording method
Assignee: International Business Machines Corp
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Filing: 1951-12-31
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Granted: 1956-12-18
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Expires: 1971-12-31
Abstract
No abstract record available.
Inventors
- 👤 Byron E Phelps
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:23
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/02; G06; G06K; G06K7/00; G06K7/08; G11B5/008; H; H04; H04N; H04N5/00; H04N5/76; H04N5/78; H04N5/782
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) | 1959-12-18 | 1960-06-18 | 1960-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-12-18 | 1964-06-18 | 1964-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-12-18 | 1968-06-18 | 1968-12-18 | $7700.00 | Window Closed / Lapsed |