Patent US1870710A successfully refreshed from Google Patents.
Patent EP0424809A2 successfully refreshed from Google Patents.
EP0424809A2
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Magneto-optical recording medium
Assignee: Sony Corp
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Filing: 1990-10-18
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Granted: —
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Expires: 2010-10-18
Abstract
Abstract A magnetooptical recording medium is disclosed which is fabricated by a so-called 2P method wherein a pattern of a guide groove (2a) or grooves or signal pits is formed by transfer to a photopolymerizable resin layer (3) formed on a substrate (1), wherein there are formed on the substrate (1) a high magnetic permeability layer (2), a photopolymerizable resin layer (3), an magnetooptical recording layer (4) and a transparent protective plate (6) in this order. By this arrangement, it becomes possible to improve an efficiency of a vertical magnetic field wherein an application of a magnetic field from the transparent protective plate (6) is possible and to form a precise pattern in the magnetooptical recording layer (4). Moreover, it is also possible to provide a double-sided magnetooptical recording medium by which a magnetic field-modulating recording is enabled.
Inventors
- 👤 Tetsu Watanabe
- 👤 Hidetoshi Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 06:27
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10582; G11B11/10584
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
89 words
A magnetooptical recording medium comprising; a substrate (1), a high magnetic permeability layer (2) formed on a surface of said substrate (1), a photopolymerizable resin layer (3) formed on said high magnetic permeability layer (2) having a guide groove (3a) and/or signal pits formed on a surface remote from said high magnetic permeability layer (2), a magnetooptical recording layer (4) formed on said photopolymerizable resin layer over (3) over said guide groove (3a) and/or signal pits, and a transparent protective layer (6) formed on said magnetooptical recording layer (4).
Claim 2
Dependent Claim
89 words
A magnetooptical recording medium comprising; a substrate (1), a high magnetic permeability layer (2) formed on a surface of said substrate (1), a photopolymerizable resin layer (3) formed on said high magnetic permeability layer (2) having a guide groove (3a) and/or signal pits formed on a surface remote from said high magnetic permeability layer (2), a magnetooptical recording layer (4) formed on said photopolymerizable resin layer over (3) over said guide groove (3a) and/or signal pits, and a transparent protective layer (6) formed on said magnetooptical recording layer (4).
Claim 3
Dependent Claim
35 words
A magnetooptical recording medium according to claim 1, said high magnetic permeability layer (2) has an initial permeability of not less than 500, and a saturation magnetic flux density of not less than 5000 gauss.
Claim 4
Dependent Claim
36 words
A magnetooptical recording medium according to claim 1, said magnetooptical recording layer (4) is formed of a reflective layer, a dielectric layer a magnetic layer having perpendicular anisotropy and a dielectric layer formed in this order.
Claim 5
Dependent Claim
26 words
A magnetooptical recording medium according to claim 3, said magnetic layer (4) is formed of an amorphous alloy of rare earth element and transition metal element.
Claim 6
Dependent Claim
23 words
A magnetooptical recording medium according to claim 1, said transparent protective layer (6) is a thin glass plate bonded by an adhesive (5).
Claim 7
Dependent Claim
33 words
A magnetooptical recording medium according to claim 1, further comprises another set of said high magnetic permeability layer (12) through said transparent protective layer (16) formed on another surface of said substrate (11).
Claim 8
Independent Claim
132 words
A method for manufacturing a magnetooptical recording medium comprising the steps of, a) providing a first substrate (21), b) forming a photopolymerizable resin (22) on said first substrate (21) having a guide groove (22a) and/or signal pits on a surface remote from said substrate (21), c) forming a magnetooptical recording layer (23) over said guide groove (22a) and/or signal pits, d) forming a protective layer (24) on said magnetooptical recording layer (23) thus forming a first unit, e) providing a second substrate (25), f) forming a high magnetic permeability layer (26) on a surface of said second substrate (25), thus forming a second unit, and g) bonding said first unit and said second unit so that said protective layer (24) and said high magnetic permeability layer (26) are facing to each other.
Claim 9
Independent Claim
132 words
A method for manufacturing a magnetooptical recording medium comprising the steps of, a) providing a first substrate (21), b) forming a photopolymerizable resin (22) on said first substrate (21) having a guide groove (22a) and/or signal pits on a surface remote from said substrate (21), c) forming a magnetooptical recording layer (23) over said guide groove (22a) and/or signal pits, d) forming a protective layer (24) on said magnetooptical recording layer (23) thus forming a first unit, e) providing a second substrate (25), f) forming a high magnetic permeability layer (26) on a surface of said second substrate (25), thus forming a second unit, and g) bonding said first unit and said second unit so that said protective layer (24) and said high magnetic permeability layer (26) are facing to each other.
Claim 10
Independent Claim
135 words
A method for manufacturing a magnetooptical recording medium comprising the steps of, a) providing a first substrate (31), b) forming a photopolymerizable resin (22) on said first substrate (31) having a guide groove (22a) and/or signal pits on a surface remote from said substrate (31), c) forming a magnetooptical recording layer (23) over said guide groove (22a) and/or signal pits, d) forming a protective layer (24) on said magnetooptical recording layer (23) thus forming a first unit, e) providing a second substrate (35), f) forming a high magnetic permeability layers (26) on both surfaces of said second substrate (35), thus forming a second unit, and g) bonding a pair of said first unit and said second unit so that said protective layers (24,24) and said high magnetic permeability layers (26,26) are facing to each other.
Claim 11
Independent Claim
135 words
A method for manufacturing a magnetooptical recording medium comprising the steps of, a) providing a first substrate (31), b) forming a photopolymerizable resin (22) on said first substrate (31) having a guide groove (22a) and/or signal pits on a surface remote from said substrate (31), c) forming a magnetooptical recording layer (23) over said guide groove (22a) and/or signal pits, d) forming a protective layer (24) on said magnetooptical recording layer (23) thus forming a first unit, e) providing a second substrate (35), f) forming a high magnetic permeability layers (26) on both surfaces of said second substrate (35), thus forming a second unit, and g) bonding a pair of said first unit and said second unit so that said protective layers (24,24) and said high magnetic permeability layers (26,26) are facing to each other.
References Cited (Backward Citations)
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