US5118564A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Longitudinal magnetic recording media with fine grain crystal magnetic layer
Assignee: Proterial Ltd
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Filing: 1990-04-17
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Granted: 1992-06-02
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Expires: 2010-04-17
Abstract
Abstract The invention discloses a magnetic recording medium used for recording and reproducing information in combination with a magnetic head. The magnetic recording medium in accordance with the present invention comprises a substrate made of a non-magnetic material, an underlayer which is formed on the substrate and has a thickness of 300 to 1000 ANGSTROM and which consists of a chromium metal or a chromium alloy, and a magnetic recording layer which is formed on the underlayer by vacuum evaporation, which consists essentially of 5 to 15 at% of Cr, 1 to 8 at% of Ta and the balance substantially being Co, and which has a direction of easy magnetization within the surface parallel to the surface of the substrate.
Inventors
- 👤 Tadashi Shinohara
- 👤 Koji Ichikawa
- 👤 Shigeo Fujii
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:09
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/65; G11B5/656; G11B5/73; G11B5/7368; G11B5/7373; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/12; Y10T428/12465; Y10T428/12493; Y10T428/12771; Y10T428/12861; Y10T428/12931; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
104 words
A magnetic recording medium comprising: a substrate made of a non-magnetic material; an underlayer which is formed on said substrate and has a thickness of 300 to 1000 Å and which consists of a chromium metal or a chromium alloy; and a magnetic recording layer which is grown on said underlayer by deposition, which consists essentially of 5 to 15 at % of Cr, 1 to 8 at % of Ta and the balance substantially being Co, which has an average crystal grain side of 100-300 Å, and which has a direction of easy magnetization in the plane of the surface of said substrate.
Claim 2
Dependent Claim
104 words
A magnetic recording medium comprising: a substrate made of a non-magnetic material; an underlayer which is formed on said substrate and has a thickness of 300 to 1000 Å and which consists of a chromium metal or a chromium alloy; and a magnetic recording layer which is grown on said underlayer by deposition, which consists essentially of 5 to 15 at % of Cr, 1 to 8 at % of Ta and the balance substantially being Co, which has an average crystal grain side of 100-300 Å, and which has a direction of easy magnetization in the plane of the surface of said substrate.
Claim 3
Dependent Claim
107 words
A magnetic recording medium comprising: a substrate made of a non-magnetic material; an underlayer which is formed on said substrate and has a thickness of 300 to 1000 Å and which consists of a chromium metal or a chromium alloy; and a magnetic recording layer which is epitaxially grown on said underlayer by deposition, which consists essentially of 5 to 15 at % of Cr, 1 to 8 at % of Ta and the balance substantially being Co, which has an average crystal grain size of 100 to 300 Å, and which has a direction of easy magnetization in the plane of the surface of said substrate.
Claim 4
Dependent Claim
107 words
A magnetic recording medium comprising: a substrate made of a non-magnetic material; an underlayer which is formed on said substrate and has a thickness of 300 to 1000 Å and which consists of a chromium metal or a chromium alloy; and a magnetic recording layer which is epitaxially grown on said underlayer by deposition, which consists essentially of 5 to 15 at % of Cr, 1 to 8 at % of Ta and the balance substantially being Co, which has an average crystal grain size of 100 to 300 Å, and which has a direction of easy magnetization in the plane of the surface of said substrate.
Claim 5
Dependent Claim
98 words
A magnetic recording medium comprising: a substrate made of a non-magnetic material; an underlayer which is formed on said substrate and has a thickness of 300 to 1000 Å and which consists of a chromium metal or a chromium alloy; and a magnetic recording layer which consists of 5-15 at % of Cr, 1-8 at % of Ta, and the balance being Co, grown on said underlayer by deposition and having an average crystal grain size of 100 to 300 Å and which has a direction of easy magnetization in the plane of the surface of said substrate.
Claim 6
Dependent Claim
98 words
A magnetic recording medium comprising: a substrate made of a non-magnetic material; an underlayer which is formed on said substrate and has a thickness of 300 to 1000 Å and which consists of a chromium metal or a chromium alloy; and a magnetic recording layer which consists of 5-15 at % of Cr, 1-8 at % of Ta, and the balance being Co, grown on said underlayer by deposition and having an average crystal grain size of 100 to 300 Å and which has a direction of easy magnetization in the plane of the surface of said substrate.
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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) | 1995-06-02 | 1995-12-02 | 1996-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-06-02 | 1999-12-02 | 2000-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-06-02 | 2003-12-02 | 2004-06-02 | $7700.00 | Window Closed / Lapsed |