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US4489139A
Expired / Lapsed
US
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Magneto-optic memory medium
Assignee: Sharp Corp
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Filing: 1983-03-17
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Granted: 1984-12-18
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Expires: 2003-03-17
Abstract
Abstract A magneto-optic memory medium is disclosed which is made up by an acryl resin substrate having strip-like grooves, a magneto-optic magnetization film disposed on the substrate and having an axis of easy magnetization perpendicular to its surface. The magnetization film is made of amorphous ferromagnetic material such as GdTbFe, GdTbDyFe, SmTbFe, GdDyFe, TbCo or the like. A reflective film is provided overlying the magneto-optic magnetization film.
Inventors
- 👤 Kenji Ohta
- 👤 Akira Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:01
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10582; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10S428/922; Y10S428/9265; Y10S428/928; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12771; Y10T428/24; Y10T428/24479; Y10T428/24521; Y10T428/24545; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
51 words
A magneto-optic memory medium consisting essentially of: a substrate having strip-like grooves; a magnetic film comprising a magneto-optic magnetization film having an axis of easy magnetization perpendicular to its surface disposed on said substrate, said magnetic film having an uneven surface which corresponds to the strip-like grooves formed in said substrate.
Claim 2
Dependent Claim
51 words
A magneto-optic memory medium consisting essentially of: a substrate having strip-like grooves; a magnetic film comprising a magneto-optic magnetization film having an axis of easy magnetization perpendicular to its surface disposed on said substrate, said magnetic film having an uneven surface which corresponds to the strip-like grooves formed in said substrate.
Claim 3
Dependent Claim
22 words
The magneto-optic memory medium of claim 1, wherein said substrate is selected from either an acryl resin substrate or a glass substrate.
Claim 4
Dependent Claim
70 words
A magneto-optic medium comprising: a substrate having strip-like grooves; a magnetic film disposed on said substrate, said magnetic film comprising a magneto-optic magnetization film having an axis of easy magnetization perpendicular to its surface, said film having an uneven surface which corresponds to the strip-like grooves formed in said substrate; a reflective film overlying said magnetic film, and a dielectric layer disposed between said magnetic film and said reflective film.
Claim 5
Dependent Claim
70 words
A magneto-optic medium comprising: a substrate having strip-like grooves; a magnetic film disposed on said substrate, said magnetic film comprising a magneto-optic magnetization film having an axis of easy magnetization perpendicular to its surface, said film having an uneven surface which corresponds to the strip-like grooves formed in said substrate; a reflective film overlying said magnetic film, and a dielectric layer disposed between said magnetic film and said reflective film.
Claim 6
Dependent Claim
63 words
A magneto-optic memory medium comprising: a substrate having strip-like grooves; a magnetic film disposed on said substrate, said magnetic film comprising a magneto-optic magnetization film having an axis of easy magnetization perpendicular to its surface, said film having an uneven surface which corresponds to the strip-like grooves formed in said substrate, wherein said magnetic film is selected from at least GdTbFe or TbDyFe.
Claim 7
Dependent Claim
63 words
A magneto-optic memory medium comprising: a substrate having strip-like grooves; a magnetic film disposed on said substrate, said magnetic film comprising a magneto-optic magnetization film having an axis of easy magnetization perpendicular to its surface, said film having an uneven surface which corresponds to the strip-like grooves formed in said substrate, wherein said magnetic film is selected from at least GdTbFe or TbDyFe.
Claim 8
Dependent Claim
71 words
A magneto-optic memory medium comprising: a glass substrate having strip-like grooves, a magnetic film disposed on said substrate, said magnetic film comprising a magneto-optic magnetization film having an axis of easy magnetization perpendicular to its surface, said film having an uneven surface which corresponds to the strip-like grooves formed in said glass substrate wherein said magnetic film comprises GdTbFe, a dielectric layer, and an aluminum reflection layer overlying said dielectric layer.
Claim 9
Dependent Claim
71 words
A magneto-optic memory medium comprising: a glass substrate having strip-like grooves, a magnetic film disposed on said substrate, said magnetic film comprising a magneto-optic magnetization film having an axis of easy magnetization perpendicular to its surface, said film having an uneven surface which corresponds to the strip-like grooves formed in said glass substrate wherein said magnetic film comprises GdTbFe, a dielectric layer, and an aluminum reflection layer overlying said dielectric 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) | 1987-12-18 | 1988-06-18 | 1988-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-18 | 1992-06-18 | 1992-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-18 | 1996-06-18 | 1996-12-18 | $7700.00 | Window Closed / Lapsed |