Patent US3258754A successfully refreshed from Google Patents.
US3258754A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Block markers
Assignee: —
•
Filing: —
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Granted: 1966-06-28
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Expires: 1983-06-28
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 01:17
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/12; G11B20/1201; G11B20/1202; G11B20/1205
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
88 words
IN AN INFORMATION STORAGE AND RETRIEVAL SYSTEM, A MAGNETIC STORAGE MEDIUM, FIRST MEANS INCLUDING A TRANSDUCER FOR RECORDING A MAGNETIZED REGION OF ONE CHARACTERISTIC ON EACH MEDIUM AT THE BEGINNING OF AN INFORMATION BLOCK AND A MAGNETIZED REGION OF A DIFFERENT CHARACTERISTIC AT THE END OF AN INFORMATION BLOCK, AND SECOND MEANS COUPLED TO SAID TRANSDUCER FOR DETECTING THE MAGNETIZED REGIONS MARKING THE BEGINNING OF A PREVIOUSLY WRITTEN BLOCK OF INFORMATION, WHEREBY THE POSITION OF THE BEGINNING OF A BLOCK IS DETERMINED ACCURATELY WHEN REWRITING THE SAME BLOCK.
Claim 2
Dependent Claim
88 words
IN AN INFORMATION STORAGE AND RETRIEVAL SYSTEM, A MAGNETIC STORAGE MEDIUM, FIRST MEANS INCLUDING A TRANSDUCER FOR RECORDING A MAGNETIZED REGION OF ONE CHARACTERISTIC ON EACH MEDIUM AT THE BEGINNING OF AN INFORMATION BLOCK AND A MAGNETIZED REGION OF A DIFFERENT CHARACTERISTIC AT THE END OF AN INFORMATION BLOCK, AND SECOND MEANS COUPLED TO SAID TRANSDUCER FOR DETECTING THE MAGNETIZED REGIONS MARKING THE BEGINNING OF A PREVIOUSLY WRITTEN BLOCK OF INFORMATION, WHEREBY THE POSITION OF THE BEGINNING OF A BLOCK IS DETERMINED ACCURATELY WHEN REWRITING THE SAME BLOCK.
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) | 1969-06-27 | 1969-12-27 | 1970-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-06-27 | 1973-12-27 | 1974-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $7700.00 | Window Closed / Lapsed |