US4775603A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical-magnetic recording medium
Assignee: Pioneer Corp
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Filing: 1987-06-29
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Granted: 1988-10-04
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Expires: 2007-06-29
Abstract
Abstract An optical-magnetic recording medium utilizing a recording layer of an amorphous rare-earth-transition metal alloy so as to rely on the Kerr effect. An enhancing layer of ZnS and a fluoride of an alkaline-earth metal (preferably CaF 2 ) is deposited on a grooved substrate and the recording layer deposited thereover to both enhance the Kerr effect and prevent peeling.
Inventors
- 👤 Seiro Fujii
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:45
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10582; G11B11/10586; G11B11/10589; G11B11/10593; Y; Y10; Y10S; Y10S428/00; Y10S428/90
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
56 words
An optical-magnetic recording medium, comprising: a recording layer comprising an amorphous alloy having a single axis anisotropy perpendicular to the surface of said recording layer, said amorphous alloy including a rare-earth metal-transition metal alloy; a support; and an enhancing layer between said recording layer and said support comprising ZnS and a fluoride of an alkaline-earth metal.
Claim 2
Dependent Claim
56 words
An optical-magnetic recording medium, comprising: a recording layer comprising an amorphous alloy having a single axis anisotropy perpendicular to the surface of said recording layer, said amorphous alloy including a rare-earth metal-transition metal alloy; a support; and an enhancing layer between said recording layer and said support comprising ZnS and a fluoride of an alkaline-earth metal.
Claim 3
Dependent Claim
15 words
An optical-magnetic recording medium claimed in claim 1, wherein said enhancing layer is vapor deposited.
Claim 4
Dependent Claim
14 words
An optical-magnetic recording medium claimed in claim 1, wherein said enhancing layer is sputtered.
Claim 5
Dependent Claim
19 words
An optical-magnetic recording medium claimed in claim 1, wherein said fluoride of said alkaline-earth metal is MgF 2 .
Claim 6
Dependent Claim
33 words
An optical-magnetic recording medium claimed in claim 1, further comprising a protective layer comprising ZnS and a fluoride of an alkaline-earth metal adjacent a side of said recording layer opposite said enhancing layer.
Claim 7
Dependent Claim
20 words
An optical-magnetic recording medium claimed in claim 1, wherein said support is grooved on a side of said enhancing layer.
Claim 8
Dependent Claim
19 words
An optical-magnetic recording medium claimed in claim 1, wherein said fluoride of said alkaline-earth metal is CaF 2 .
Claim 9
Dependent Claim
22 words
An optical-magnetic recording medium claimed in claim 4, wherein said ZnS and CaF 2 are in an atomic ratio of approximately 3:1.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-10-04 | 1992-04-04 | 1992-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-10-04 | 1996-04-04 | 1996-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-10-04 | 2000-04-04 | 2000-10-04 | $7700.00 | Window Closed / Lapsed |