Patent US4664976A successfully refreshed from Google Patents.
US4664976A
Expired / Lapsed
US
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Magnetic recording medium comprising a protective carbon nitride layer on the surface thereof
Assignee: Victor Company of Japan Ltd
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Filing: 1985-05-29
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Granted: 1987-05-12
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Expires: 2005-05-29
Abstract
Abstract A magnetic recording medium of the type which comprises a non-magnetic support, and a thin magnetic metal layer formed on at least one surface of the support is described. The magnetic metal layer is protected with a carbon nitride layer.
Inventors
- 👤 Akihiro Kimura
- 👤 Toshio Ando
- 👤 Toshikazu Nishihara
- 👤 Toshio Kato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:30
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/72; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
43 words
In a magnetic recording medium which comprises a non-magnetic support, and a thin magnetic metal layer formed on at least one surface of the support, the improvement comprising a protective layer formed on said magnetic metal layer and consisting essentially of carbon nitride.
Claim 2
Dependent Claim
43 words
In a magnetic recording medium which comprises a non-magnetic support, and a thin magnetic metal layer formed on at least one surface of the support, the improvement comprising a protective layer formed on said magnetic metal layer and consisting essentially of carbon nitride.
Claim 3
Dependent Claim
24 words
A magnetic recording medium according to claim 1, wherein said protective layer has an atomic ratio of carbon to nitrogen of 4:1 to 3:2.
Claim 4
Dependent Claim
21 words
A magnetic recording medium according to claim 1, wherein said protective layer has a thickness of from 0.02 to 0.15 μm.
Claim 5
Dependent Claim
26 words
A magnetic recording medium according to claim 1, further comprising an undercoat layer provided between said non-magnetic support and said at least one magnetic metal layer.
Claim 6
Dependent Claim
15 words
A magnetic recording medium according to claim 1, wherein said medium is a magnetic disk.
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) | 1990-05-11 | 1990-11-10 | 1991-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-11 | 1994-11-10 | 1995-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-11 | 1998-11-10 | 1999-05-12 | $7700.00 | Window Closed / Lapsed |