US4390600A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magneto-optic memory medium
Assignee: Sharp Corp
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Filing: 1982-01-05
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Granted: 1983-06-28
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Expires: 2002-01-05
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
2026-10-23 20:11
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
38 words
A magneto-optic memory medium comprising: a substrate having strip-like grooves, a magneto-optic magnetization film disposed on said substrate and having an axis of easy magnetization perpendicular to its surface; and a reflective film overlying said magneto-optic magnetization film.
Claim 2
Dependent Claim
38 words
A magneto-optic memory medium comprising: a substrate having strip-like grooves, a magneto-optic magnetization film disposed on said substrate and having an axis of easy magnetization perpendicular to its surface; and a reflective film overlying said magneto-optic magnetization film.
Claim 3
Dependent Claim
53 words
A magneto-optic memory medium comprising: a substrate having strip-like grooves and made of an acryl resin, said grooves being formed during molding of said substrate; a magneto-optic magnetization film disposed on said substrate and having an axis of easy magnetization perpendicular to its surface; and a reflective film overlying said magneto-optic magnetization film.
Claim 4
Dependent Claim
53 words
A magneto-optic memory medium comprising: a substrate having strip-like grooves and made of an acryl resin, said grooves being formed during molding of said substrate; a magneto-optic magnetization film disposed on said substrate and having an axis of easy magnetization perpendicular to its surface; and a reflective film overlying said magneto-optic magnetization film.
Claim 5
Dependent Claim
21 words
A magneto-optic memory medium as set forth in claim 1 wherein said grooves are used for the formation of guide tracks.
Claim 6
Dependent Claim
21 words
A magneto-optic memory medium as set forth in claim 1 wherein said magnetization film is made of an amorphous ferrimagnetic material.
Claim 7
Dependent Claim
29 words
The magneto-optic memory medium as set forth in claim 4 wherein said magnetization is made of a ferrimagnetic material, which includes a rare earth metal and a transition metal.
Claim 8
Dependent Claim
31 words
The magneto-optic memory medium as set forth in claim 1 wherein said reflective film is made of a member selected from the group consisting of Al, Cu, Au, Zn and Sn.
Claim 9
Dependent Claim
18 words
The magneto-optic memory medium as set forth in claim 5 wherein said magnetization film is made of TbDyFe.
References Cited (Backward Citations)
US4239835A
Cited
US4272348A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-06-27 | 1986-12-27 | 1987-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-27 | 1990-12-27 | 1991-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-27 | 1994-12-27 | 1995-06-28 | $7700.00 | Window Closed / Lapsed |