US4695510A
Expired / Lapsed
US
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Opto-magnetic recording medium
Assignee: Canon Inc
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Filing: 1985-08-21
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Granted: 1987-09-22
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Expires: 2005-08-21
Abstract
Abstract In an opto-magnetic recording medium having on a substrate at least a recording layer consisting of an amorphous magnetic material, there is provided between the substrate and the recording layer an undercoated layer comprising a silicon oxide film, a metal film and a nitride film laminated in succession from the substrate side.
Inventors
- 👤 Mitsuharu Sawamura
- 👤 Kazuoki Honguu
- 👤 Kazuhiko Kikuchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:54
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/252; G11B7/258; G11B7/2585; G11B11/00; G11B11/10; G11B11/105; G11B11/10582; G11B7/253; G11B7/2533; G11B7/257; G11B7/2578; G11B2007/25705; G11B2007/25713; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
80 words
An opto-magnetic recording medium comprising: a plastic substrate at least substantially transparent to light; a recording layer consisting of an amorphous magnetic material; an under-coated layer comprising a silicon oxide film, a metal film at least substantially transparent to light and a nitride film laminated in succession from the substrate side between said substrate and said recording layer; and a protective overcoat formed on the side of said recording layer opposite the side on which said under-coated layer is formed.
Claim 2
Dependent Claim
80 words
An opto-magnetic recording medium comprising: a plastic substrate at least substantially transparent to light; a recording layer consisting of an amorphous magnetic material; an under-coated layer comprising a silicon oxide film, a metal film at least substantially transparent to light and a nitride film laminated in succession from the substrate side between said substrate and said recording layer; and a protective overcoat formed on the side of said recording layer opposite the side on which said under-coated layer is formed.
Claim 3
Dependent Claim
18 words
An opto-magnetic recording medium according to claim 1, wherein said recording layer is formed of GdTbFe or GdTbFeCo.
Claim 4
Dependent Claim
41 words
An opto-magnetic recording medium according to claim 1 wherein said protective overcoat is formed from a spacer layer, a reflecting film, a protective layer, an adhesive layer and a protective substrate which are laminated in succession from the recording layer side.
Claim 5
Dependent Claim
20 words
An opto-magnetic recording medium according to claim 1, wherein said silicon oxide film is formed of SiO 2 or SiO.
Claim 6
Dependent Claim
21 words
An opto-magnetic recording medium according to claim 1, wherein said metal film is formed of Si, Cr, Ni, Ti or Al.
Claim 7
Dependent Claim
23 words
An opto-magnetic recording medium according to claim 1, wherein said nitride film is formed of Si 3 N 4 , AlN or BN.
Claim 8
Dependent Claim
20 words
An opto-magnetic recording medium according to claim 4, wherein the thickness of said silicon oxide film is 500Å to 1000Å.
Claim 9
Dependent Claim
19 words
An opto-magnetic recording medium according to claim 5, wherein the thickness of said metal film is 20Å to 40Å.
Claim 10
Dependent Claim
19 words
An opto-magnetic recording medium according to claim 6, wherein the thickness of said nitride film is 200Å to 400Å.
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) | 1990-09-21 | 1991-03-23 | 1991-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-09-21 | 1995-03-23 | 1995-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-09-21 | 1999-03-23 | 1999-09-22 | $7700.00 | Window Closed / Lapsed |