US3613102A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Copying magnetic signals by thermoremanent transfer
Assignee: EIDP Inc
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Filing: 1969-11-06
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Granted: 1971-10-12
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Expires: 1989-11-06
Abstract
Abstract Signals on magnetic recording members, such as signals recorded on magnetic tape, can be copied by placing the recording in contact with a copying member and transiently heating the magnetic material of the copy member in the vicinity of or above the Curie transition with a pulse of radiant energy, particularly visible or infrared energy.
Inventors
- 👤 Nelson B Daly
- 👤 Walter W Gilbert
- 👤 George R Nacci
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:57
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/86; G11B5/865; G03; G03G; G03G5/00; G03G5/16
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
195 words
Method of transferring a signal recorded on an original magnetic recording member to a copy magnetic recording member, said copy member and said original member each comprising a stratum of hard magnetic material on a support, which comprises: i. placing the copy member to expose the stratum of hard magnetic material of the copy member to the magnetic field of the signals recorded on the original recording member, ii. exposing the magnetic material of the copy member to at least one pulse of exposing radiation having a duration of less than 100 milliseconds while screening the magnetic material of the original recording member from said pulse of radiation, said radiation being capable of heating the hard magnetic material of the copy member, the intensity of said pulse of radiation being sufficient to heat the magnetic material of the copy member to a temperature at least in the vicinity of the Curie temperature, and whereby the support of the copy member and the original member are not substantially heated and iii. permitting the magnetic material of the copy member to cool substantially below the Curie temperature while in stationary relationship to the original magnetic recording member.
Claim 2
Dependent Claim
195 words
Method of transferring a signal recorded on an original magnetic recording member to a copy magnetic recording member, said copy member and said original member each comprising a stratum of hard magnetic material on a support, which comprises: i. placing the copy member to expose the stratum of hard magnetic material of the copy member to the magnetic field of the signals recorded on the original recording member, ii. exposing the magnetic material of the copy member to at least one pulse of exposing radiation having a duration of less than 100 milliseconds while screening the magnetic material of the original recording member from said pulse of radiation, said radiation being capable of heating the hard magnetic material of the copy member, the intensity of said pulse of radiation being sufficient to heat the magnetic material of the copy member to a temperature at least in the vicinity of the Curie temperature, and whereby the support of the copy member and the original member are not substantially heated and iii. permitting the magnetic material of the copy member to cool substantially below the Curie temperature while in stationary relationship to the original magnetic recording member.
Claim 3
Dependent Claim
29 words
Process of claim 1 in which the magnetic material of the copy magnetic recording member is heated to a temperature above the Curie temperature by said pulse of radiation.
Claim 4
Dependent Claim
58 words
Process of claim 2 in which the stratum of magnetic material of the copy member is a substantially continuous film on the surface of the substrate, and is exposed to said pulse of radiation through said substrate, whereby the magnetic material of the copy member screens the magnetic material of the original member from said pulse of radiation.
Claim 5
Dependent Claim
18 words
Process of claim 3 in which the magnetic material of the copy member is finely particulate magnetic material.
Claim 6
Dependent Claim
16 words
Process Of claim 4 in which said pulse of radiation comprises visible and infrared electromagnetic radiation.
Claim 7
Dependent Claim
14 words
Process of claim 4 in which said finely particulate magnetic material is chromium dioxide.
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) | 1974-10-11 | 1975-04-12 | 1975-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-11 | 1979-04-12 | 1979-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-11 | 1983-04-12 | 1983-10-12 | $7700.00 | Window Closed / Lapsed |