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US5143797A
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Magneto-optic recording medium
Assignee: Mitsubishi Electric Corp
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Filing: 1989-08-15
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Granted: 1992-09-01
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Expires: 2009-08-15
Abstract
Abstract A magneto-optical recording medium comprises a dielectric film disposed on a substrate and formed, for example, of silicon nitride, of for example, 65 nm thickness, a magnetic film disposed on the dielectric film, and formed, for example, of, rare earth-transistion metal alloy thin film, of, for example, 35 thickness, and a reflective film disposed on the magnetic film, and formed of titanium nitride, by, for example, sputtering.
Inventors
- 👤 Kazuo Hashima
- 👤 Kazuhiko Tsutsumi
- 👤 Hiroshi Sugahara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:24
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10582; G11B11/10586; G11B11/10584
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
71 words
A magneto-optic recording medium comprising: a substrate; a dielectric film disposed on said substrate; a magnetic film disposed on said dielectric film; and a reflective film disposed on and in direct engagement with said magnetic film, on the side thereof opposite to said substrate, and formed of titanium nitride; and whereby said reflective film reflects light transmitted through said magnetic film and has a low thermal conductivity adjacent said magnetic film.
Claim 2
Dependent Claim
71 words
A magneto-optic recording medium comprising: a substrate; a dielectric film disposed on said substrate; a magnetic film disposed on said dielectric film; and a reflective film disposed on and in direct engagement with said magnetic film, on the side thereof opposite to said substrate, and formed of titanium nitride; and whereby said reflective film reflects light transmitted through said magnetic film and has a low thermal conductivity adjacent said magnetic film.
Claim 3
Dependent Claim
34 words
A medium according to claim 1, wherein said substrate, said dielectric film, and said magnetic film are transparent to a laser beam used for writing information in and reading information from said magnetic film.
Claim 4
Dependent Claim
15 words
A medium according to claim 1, wherein said dielectric film is formed of silicon nitride.
Claim 5
Dependent Claim
15 words
A medium according to claim 1, wherein said dielectric film is about 65 nm thick.
Claim 6
Dependent Claim
20 words
A medium according to claim 1, wherein said magnetic film is formed of a rare earth-transition metal alloy thin film.
Claim 7
Dependent Claim
15 words
A medium according to claim 1, wherein said magnetic film is about 35 nm thick.
Claim 8
Dependent Claim
14 words
A medium according to claim 1, wherein said reflective film is formed by sputtering.
Claim 9
Dependent Claim
124 words
A magneto-optic recording medium comprising: a substrate transparent to wavelengths of light emitted by a laser beam used for writing information onto and reading information out of said medium; a dielectric film disposed on said substrate and transparent to said wavelengths of light; a magnetic film disposed on said dielectric film, at least partially transparent to said wavelengths of light, and for storing information in the form of regions of differing magnetization; and a reflective film disposed on and in direct engagement with said magnetic film on the side thereof opposite to said substrate, said reflective film for reflecting light transmitted through said magnetic film and formed of titanium nitride, whereby said reflective film also has a low thermal conductivity adjacent said magnetic film.
Claim 10
Dependent Claim
124 words
A magneto-optic recording medium comprising: a substrate transparent to wavelengths of light emitted by a laser beam used for writing information onto and reading information out of said medium; a dielectric film disposed on said substrate and transparent to said wavelengths of light; a magnetic film disposed on said dielectric film, at least partially transparent to said wavelengths of light, and for storing information in the form of regions of differing magnetization; and a reflective film disposed on and in direct engagement with said magnetic film on the side thereof opposite to said substrate, said reflective film for reflecting light transmitted through said magnetic film and formed of titanium nitride, whereby said reflective film also has a low thermal conductivity adjacent said magnetic film.
Claim 11
Dependent Claim
29 words
A magneto optical recording medium as set forth in claim 1 without an additional dielectric film disposed on the same side of the magnetic film as said reflective film.
Claim 12
Dependent Claim
15 words
A medium according to claim 9 wherein said dielectric film is formed of silicon nitride.
Claim 13
Dependent Claim
15 words
A medium according to claim 9 wherein said dielectric film is about 65 nm thick.
Claim 14
Dependent Claim
31 words
A medium according to claim 9 wherein said magnetic film is formed of a thin film of an alloy of at least one rare earth and at least one transition metal.
Claim 15
Dependent Claim
15 words
A medium according to claim 9 wherein said magnetic film is about 35 nm thick.
Claim 16
Dependent Claim
14 words
A medium according to claim 9 wherein said reflective film is formed by sputtering.
Claim 17
Dependent Claim
29 words
A magneto optical recording medium as set forth in claim 9 without an additional dielectric film disposed on the same side of the magnetic film as said reflective film.
References Cited (Backward Citations)
DE291848C
Cited
GB195532A
Cited
JPS5766549A
Cited
JPS5952442A
Cited
US4569881A
Cited
US4675767A
Cited
JPS60171055A
Cited
JPS60179952A
Cited
US4801499A
Cited
US4737408A
Cited
US4792474A
Cited
US4897320A
Cited
US4800112A
Cited
US4849304A
Cited
JPH01202353A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-09-01 | 1996-03-02 | 1996-09-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-01 | 2000-03-02 | 2000-09-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-01 | 2004-03-02 | 2004-09-01 | $7700.00 | Window Closed / Lapsed |