US4789606A
Expired / Lapsed
US
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Magneto-optical recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1987-04-13
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Granted: 1988-12-06
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Expires: 2007-04-13
Abstract
Abstract A magneto-optical recording medium comprises a transparent substrate, a magneto-optical recording layer formed on the transparent substrate and containing a rare earth metal-transition metal alloy, and a thin film containing at least either one of platinum and palladium and formed at least on one surface of the magneto-optical recording layer. Or, the magneto-optical recording medium comprises the transparent substrate, and a magneto-optical recording layer formed on the transparent substrate by alternately overlaying a plurality of thin layers containing a rare earth metal-transition metal alloy, and a plurality of thin layers containing at least either one of platinum and palladium.
Inventors
- 👤 Takashi Yamada
- 👤 Masaaki Nomura
- 👤 Ryoichi Yamamoto
- 👤 Akira Nahara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 03:58
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10582; G11B11/10586; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10S428/922; Y10S428/9265; Y10S428/928
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
59 words
A magneto-optical recording medium comprising a transparent substrate, and a magneto-optical recording layer formed on said transparent substrate, said magneto-optical recording layer including a plurality of alternating thin first and second layers, each of said first layers containing a rare earth metal-transition metal alloy, and each of said second layers containing at least either one of platinum and palladium.
Claim 2
Dependent Claim
59 words
A magneto-optical recording medium comprising a transparent substrate, and a magneto-optical recording layer formed on said transparent substrate, said magneto-optical recording layer including a plurality of alternating thin first and second layers, each of said first layers containing a rare earth metal-transition metal alloy, and each of said second layers containing at least either one of platinum and palladium.
Claim 3
Dependent Claim
26 words
A magneto-optical recording medium as defined in claim 1 wherein said magneto-optical recording layer has a thickness within the range of 100 Å to 5,000 Å.
Claim 4
Dependent Claim
21 words
A magneto-optical recording medium as defined in claim 2 wherein said magneto-optical recording layer has a thickness of approximately 1,000 Å.
Claim 5
Dependent Claim
36 words
A magneto-optical recording medium as defined in claim 1 wherein each of said second layers containing at least either one of platinum and palladium has a thickness within the range of 2 Å to 20 Å.
Claim 6
Dependent Claim
36 words
A magneto-optical recording medium as defined in claim 4 wherein each of said second layers containing at least either one of platinum and palladium has a thickness within the range of 5 Å to 10 Å.
Claim 7
Dependent Claim
34 words
A magneto-optical recording medium as defined in claim 1 wherein the content of platinum and/or palladium is within the range of 1 to 20 atomic percent with respect to the whole magneto-optical recording layer.
Claim 8
Dependent Claim
29 words
A magneto-optical recording medium as defined in claim 6 wherein the content of platinum and/or palladium is approximately 10 atomic percent with respect to the whole magneto-optical recording layer.
Claim 9
Dependent Claim
29 words
A mageto-optical recording medium as defined in claim 1, wherein each of said second layers is a passivity film further containing at least either one of oxygen and hydrogen.
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) | 1991-12-06 | 1992-06-06 | 1992-12-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-12-06 | 1996-06-06 | 1996-12-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-12-06 | 2000-06-06 | 2000-12-06 | $7700.00 | Window Closed / Lapsed |