Patent US2881073A successfully refreshed from Google Patents.
US2881073A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming permanent data on magnetic recording media
Assignee: International Business Machines Corp
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Filing: 1955-12-29
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Granted: 1959-04-07
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Expires: 1975-12-29
Abstract
No abstract record available.
Inventors
- 👤 William R Maclay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:18
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/16; G11B11/00; G11B5/00; G11B5/84
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
143 words
THE METHOD OF PRODUCING A PERMANENT RECORD ON A MAGNETIZABLE RECORD MEDIUM, COMPRISING THE STEPS OF MAGNETIZING AREAS IN AT LEAST A SELECTED PORTION OF SAID RECORD MEDIUM IN A DESIRED PATTERN, COATING SAID SELECTED PORTION WITH A LIGHT SENSITIVE MEDIUM, EXPOSING SAID SELECTED PORTION TO A DISPERSION OF MINUTE PARTICLES OF MAGNETIZABLE MATERIAL WHICH ARE ATTRACTED TO SAID MAGNETIZED AREAS SO THAT SAID PARTICLES MASK THE THE LIGHT SENSITIVE MEDIUM OVER THE MAGNETIZED AREAS, EXPOSING SAID SELECTED PORTION TO A SOURCE OF LIGHT WHICH PRODUCES A DIFFERENTIATION INSOLUBILITY BETWEEN THOSE AREAS OF THE LIGHT SENSITIVE MEDIUM MASKED BY THE PARTICLES, DETICLES AND THOSE AREAS NOT MASKED BY THE PARTICLES, DEVELOPING SAID SELECTED PROTION, AND THEREAFTER PRODUCING A PLURALITY OF RELIEFS IN SAID SELECTED PORTION SEPARATED BY LANDS OF MAGNETIZABLE MATERIAL INCLUDING THE STEP OF SUBJECTING SAID SELECTED PORTION TO AN ETCHING OPERATION.
Claim 2
Independent Claim
143 words
THE METHOD OF PRODUCING A PERMANENT RECORD ON A MAGNETIZABLE RECORD MEDIUM, COMPRISING THE STEPS OF MAGNETIZING AREAS IN AT LEAST A SELECTED PORTION OF SAID RECORD MEDIUM IN A DESIRED PATTERN, COATING SAID SELECTED PORTION WITH A LIGHT SENSITIVE MEDIUM, EXPOSING SAID SELECTED PORTION TO A DISPERSION OF MINUTE PARTICLES OF MAGNETIZABLE MATERIAL WHICH ARE ATTRACTED TO SAID MAGNETIZED AREAS SO THAT SAID PARTICLES MASK THE THE LIGHT SENSITIVE MEDIUM OVER THE MAGNETIZED AREAS, EXPOSING SAID SELECTED PORTION TO A SOURCE OF LIGHT WHICH PRODUCES A DIFFERENTIATION INSOLUBILITY BETWEEN THOSE AREAS OF THE LIGHT SENSITIVE MEDIUM MASKED BY THE PARTICLES, DETICLES AND THOSE AREAS NOT MASKED BY THE PARTICLES, DEVELOPING SAID SELECTED PROTION, AND THEREAFTER PRODUCING A PLURALITY OF RELIEFS IN SAID SELECTED PORTION SEPARATED BY LANDS OF MAGNETIZABLE MATERIAL INCLUDING THE STEP OF SUBJECTING SAID SELECTED PORTION TO AN ETCHING OPERATION.
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) | 1962-04-06 | 1962-10-06 | 1963-04-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-04-06 | 1966-10-06 | 1967-04-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-04-06 | 1970-10-06 | 1971-04-07 | $7700.00 | Window Closed / Lapsed |