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USRE27685E Expired / Lapsed US ⏱️ 0.0 years remaining

Double transfer curie-point and magnetic bias tape copy system

Assignee: —
•
Filing: 1971-11-01
•
Granted: 1973-06-26
•
Expires: 1991-11-01
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Abstract

Abstract METHOD AND SYSTEM IS DISCLOSED FOR COPYING MAGNETIC RECORDING, FOR EXAMPLE, ON A REGULAR MAGNETIC TAPE ONTO ANOTHER TAPE, FOR EXAMPLE, OF THE SAME TYPE, BY USING AN INTERMEDIARY CARRIER HAVING A RELATIVELY LOW CURIE POINT, PREFERABLY A LOWER CURIE POINT THAN THE MASTER TAPE, AND HAVING A ROOM TEMPERATURE COERCIVITY ABOVE THE COERCIVITY OF THE COPY TAPE. THE CONTENT OF THE MASTER TAPE IS PROGRESSIVELY COPIED ONTO THE INTERMEDIARY BY THERMOMAGNETIC TECHNIQUE AND AFTER COOLING, THE INFORMATION IS TRANSFERRED FROM THE INTERMEDIARY AGAIN PROGRESSIVELY TO THE COPY TAPE BY MAGNETIC HIGH-FREQUENCY BIAS SLOWLY DECAYING AS THE RESPECTIVE TAPE INCREMENT RECEDES FROM THE BIAS SOURCE.

Inventors

No inventors recorded.

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 10:20
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/86; G11B5/865

Claims Analysis

Total Claims: 0
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References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1976-06-25 1976-12-25 1977-06-26 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-06-25 1980-12-25 1981-06-26 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-06-25 1984-12-25 1985-06-26 $7700.00 Window Closed / Lapsed

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