US4588995A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: Fujifilm Business Innovation Corp
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Filing: 1984-06-05
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Granted: 1986-05-13
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Expires: 2004-06-05
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
2026-10-27 09:11
CPC Classifications
G; G03; G03G; G03G19/00; G03G19/005; G03G5/00; G03G5/16
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
116 words
A method of forming a magnetic latent image, comprising: providing a recording medium having at least a high permeability layer possessing a low Curie temperature, and a magnetic recording layer; disposing a heat generating element in close contact with said recording layer; applying heating pulses modulated with image data to said element; disposing a magnetic recording head on a side of said recording medium opposite said element; and selectively heating said high permeability layer at least up to said Curie point according to said image data, to thereby temporarily render said high permeability layer non magnetic, whereby a magnetic recording signal from said head may be applied through said high permeability layer to said recording layer.
Claim 2
Independent Claim
116 words
A method of forming a magnetic latent image, comprising: providing a recording medium having at least a high permeability layer possessing a low Curie temperature, and a magnetic recording layer; disposing a heat generating element in close contact with said recording layer; applying heating pulses modulated with image data to said element; disposing a magnetic recording head on a side of said recording medium opposite said element; and selectively heating said high permeability layer at least up to said Curie point according to said image data, to thereby temporarily render said high permeability layer non magnetic, whereby a magnetic recording signal from said head may be applied through said high permeability layer to said recording layer.
Claim 3
Independent Claim
108 words
A method of forming a magnetic latent image, comprising: providing a recording medium having a first layer of high permeability with a Curie point on the order of 250° C., and having a magnetic layer formed on said first layer; applying a magnetic recording signal to said first layer; and selectively heating said first layer to control the formation of a magnetic latent image on said magnetic layer, said first layer preventing recording upon said magnetic layer when the temperature of said first layer is below said Curie point and allowing recording upon said magnetic layer when the temperature of said first layer is above said Curie point.
Claim 4
Independent Claim
108 words
A method of forming a magnetic latent image, comprising: providing a recording medium having a first layer of high permeability with a Curie point on the order of 250° C., and having a magnetic layer formed on said first layer; applying a magnetic recording signal to said first layer; and selectively heating said first layer to control the formation of a magnetic latent image on said magnetic layer, said first layer preventing recording upon said magnetic layer when the temperature of said first layer is below said Curie point and allowing recording upon said magnetic layer when the temperature of said first layer is above said Curie point.
Claim 5
Independent Claim
138 words
A method of thermomagnetic recording of image data, comprising: providing a recording medium having a magnetic recording layer for recording said image data and a high permeability recording control layer having a relatively low Curie point and having first and second sides, with said second side contacting said magnetic recording layer; applying a magnetic recording signal to said second side of said recording control layer; and selectively heating at least said recording control layer in accordance with image data to be recorded, said recording control layer preventing said image data from being recorded on said magnetic recording layer when said recording control layer is at a temperature below said Curie point and allowing said image data to be recorded on said magnetic recording layer when said recording control layer is heated to a temperature above said Curie point.
Claim 6
Independent Claim
138 words
A method of thermomagnetic recording of image data, comprising: providing a recording medium having a magnetic recording layer for recording said image data and a high permeability recording control layer having a relatively low Curie point and having first and second sides, with said second side contacting said magnetic recording layer; applying a magnetic recording signal to said second side of said recording control layer; and selectively heating at least said recording control layer in accordance with image data to be recorded, said recording control layer preventing said image data from being recorded on said magnetic recording layer when said recording control layer is at a temperature below said Curie point and allowing said image data to be recorded on said magnetic recording layer when said recording control layer is heated to a temperature above said Curie point.
Claim 7
Dependent Claim
30 words
A method as claimed in claim 1, wherein said high permeability layer, at temperatures below its Curie temperature, has a permeability higher than the permeability of said magnetic recording layer.
Claim 8
Dependent Claim
28 words
A method as claimed in claim 2, wherein said first layer, at temperatures below its Curie point, has a permeability higher than the permeability of said magnetic layer.
Claim 9
Dependent Claim
29 words
A method as claimed in claim 3, wherein said recording control layer, at temperatures below its Curie point, has a permeability higher than that of said magnetic recording layer.
Claim 10
Dependent Claim
34 words
A method as claimed in claim 1, wherein said high permeability layer, at temperatures below its Curie temperature, substantially blocks the passage of flux from said magnetic recording head to said magnetic recording layer.
Claim 11
Dependent Claim
30 words
A method as claimed in claim 2, wherein said first layer, at temperatures below its Curie point, substantially blocks the passage of said magnetic recording signal to said magnetic layer.
Claim 12
Dependent Claim
32 words
A method as claimed in claim 3, wherein said recording control layer, at temperatures below its Curie point, substantially blocks the passage of said magnetic recording signal to said magnetic recording layer.
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) | 1989-05-12 | 1989-11-11 | 1990-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-12 | 1993-11-11 | 1994-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-12 | 1997-11-11 | 1998-05-13 | $7700.00 | Window Closed / Lapsed |