US4480258A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: Fujifilm Business Innovation Corp
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Filing: 1982-05-11
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Granted: 1984-10-30
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Expires: 2002-05-11
Abstract
Abstract A magnetic recording medium for use in recording a magnetic latent image includes a high permeability layer having a low Curie point and a magnetic recording layer formed thereover. In use, the high permeability layer is selectively heated to the Curie point, so as to allow a magnetic signal to pass therethrough and be recorded on the recording layer.
Inventors
- 👤 Nobuo Nishimura
- 👤 Teruhiko Itami
- 👤 Toshifumi Kimoto
- 👤 Koichi Saitoh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:37
CPC Classifications
G; G03; G03G; G03G19/00; G03G19/005; G03G5/00; G03G5/16
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
179 words
A magnetic recording medium, having a magnetic transformation point, for use in a thermomagnetic recording apparatus of the type comprising a heat generating part which operates in close contact with said recording medium wherein a current signal is applied to said heat generating part according to image data to be recorded in order to heat said magnetic recording medium to a temperature higher than said magnetic transformation point, and a magnetic head for recording said image data onto said magnetic recording medium; said magnetic recording medium comprising: a magnetic recording layer for recording said image data; and a high permeability recording control layer formed of NiO.79FE alloy, having a relatively low Curie point and having first and second sides, said recording head being disposed adjacent said first side and said magnetic recording layer contacting said second side, for preventing said image data from being recorded when said high permeability recording control layer is below said Curie point and for allowing said image data to be recorded when said high permeability recording control layer is heated above said Curie point.
Claim 2
Dependent Claim
179 words
A magnetic recording medium, having a magnetic transformation point, for use in a thermomagnetic recording apparatus of the type comprising a heat generating part which operates in close contact with said recording medium wherein a current signal is applied to said heat generating part according to image data to be recorded in order to heat said magnetic recording medium to a temperature higher than said magnetic transformation point, and a magnetic head for recording said image data onto said magnetic recording medium; said magnetic recording medium comprising: a magnetic recording layer for recording said image data; and a high permeability recording control layer formed of NiO.79FE alloy, having a relatively low Curie point and having first and second sides, said recording head being disposed adjacent said first side and said magnetic recording layer contacting said second side, for preventing said image data from being recorded when said high permeability recording control layer is below said Curie point and for allowing said image data to be recorded when said high permeability recording control layer is heated above said Curie point.
Claim 3
Dependent Claim
178 words
A magnetic medium, having a magnetic transformation point, for use in a thermomagnetic recording apparatus of the type comprising a heat generating part which operates in close contact with said recording medium wherein a current signal is applied to said heat generating part according to image data to be recorded in order to heat said magnetic recording medium to a temperature higher than said magnetic transformation point, and a magnetic head for recording said image data onto said magnetic recording medium, said magnetic recording medium comprising: a magnetic recording layer for recording said image data; and a high permeability recording control layer formed of NiZn ferrite, having a relatively low Curie point and having first and second sides, said recording head being disposed adjacent said first side and said magnetic recording layer contacting said second side, for preventing said image data from being recorded when said high permeability recording control layer is below said Curie point and for allowing said image data to be recorded when said high permeability recording control layer is heated above said Curie point.
Claim 4
Dependent Claim
178 words
A magnetic medium, having a magnetic transformation point, for use in a thermomagnetic recording apparatus of the type comprising a heat generating part which operates in close contact with said recording medium wherein a current signal is applied to said heat generating part according to image data to be recorded in order to heat said magnetic recording medium to a temperature higher than said magnetic transformation point, and a magnetic head for recording said image data onto said magnetic recording medium, said magnetic recording medium comprising: a magnetic recording layer for recording said image data; and a high permeability recording control layer formed of NiZn ferrite, having a relatively low Curie point and having first and second sides, said recording head being disposed adjacent said first side and said magnetic recording layer contacting said second side, for preventing said image data from being recorded when said high permeability recording control layer is below said Curie point and for allowing said image data to be recorded when said high permeability recording control layer is heated above said Curie point.
References Cited (Backward Citations)
US3562760A
Cited
US4314257A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-30 | 1988-04-30 | 1988-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-30 | 1992-04-30 | 1992-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-30 | 1996-04-30 | 1996-10-30 | $7700.00 | Window Closed / Lapsed |