US4664963A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium and production processes thereof
Assignee: Fujitsu Ltd
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Filing: 1984-06-21
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Granted: 1987-05-12
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Expires: 2004-06-21
Abstract
Abstract A magnetic recording medium having an excellent resistance to wear and CSS strength and showing a satisfactory lubricant retention, and processes for production thereof. The magnetic recording medium includes a substrate having formed thereon, in sequence, a magnetic recording layer, a protective coating, and a lubricant coating, the protective coating including a plane portion and a plurality of fine projections and recesses formed on the plane portion.
Inventors
- 👤 Yusaku Sakai
- 👤 Yoshito Kitamoto
- 👤 Shinji Ohtaki
- 👤 Yasushi Tamaki
- 👤 Hikaru Nagai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:22
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/72; G11B5/726; G11B5/7262; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/24; Y10T428/24479; Y10T428/24612; Y10T428/24628; Y10T428/24669
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
55 words
A magnetic recording medium comprising a substrate having formed thereon, in sequence, a magnetic recording layer, a protective coating, and a lubricant coating, said protective coating being one material and comprising a plane portion which occupies a substantial area of the coating, and a plurality of fine projections and recesses formed on said plane portion.
Claim 2
Dependent Claim
55 words
A magnetic recording medium comprising a substrate having formed thereon, in sequence, a magnetic recording layer, a protective coating, and a lubricant coating, said protective coating being one material and comprising a plane portion which occupies a substantial area of the coating, and a plurality of fine projections and recesses formed on said plane portion.
Claim 3
Dependent Claim
21 words
A magnetic recording medium as in claim 1, in which said projections and/or recesses are regularly distributed on said plane portion.
Claim 4
Dependent Claim
21 words
A magnetic recording medium as in claim 1, in which said projections and/or recesses are randomly distributed on said plane portion.
Claim 5
Dependent Claim
24 words
A magnetic recording medium as in any of claims 1 through 3, in which said projections and/or recesses have the same size and configuration.
Claim 6
Dependent Claim
23 words
A magnetic recording medium as in any of claims 1 through 3, in which said projections and/or recesses have different sizes and configuration.
Claim 7
Dependent Claim
19 words
A magnetic recording medium as in claim 1, in which said projections and/or recesses are partially or entirely stepped.
Claim 8
Dependent Claim
31 words
A magnetic recording medium as in claim 1, in which said projections and recesses are combined with each other and are in the form of craters having different sizes and configurations.
Claim 9
Dependent Claim
19 words
A magnetic recording medium as in claim 7, in which said craters are randomly distributed on said plane portion.
Claim 10
Dependent Claim
20 words
A magnetic recording medium as in claim 1, wherein said projections are friction-reducing projections and said recesses are lubricant-retaining recesses.
Claim 11
Dependent Claim
67 words
A magnetic recording medium comprising a substrate having formed thereon, in sequence, a magnetic recording layer, a protective coating means for reducing friction and retaining lubricant, and a lubricant coating, said protective coating means being made of one material and comprising a plane portion which occupies a substantial area of the coating, and a plurality of fine friction-reducing productions and lubricant-retaining recesses formed on said plane portion.
Claim 12
Dependent Claim
67 words
A magnetic recording medium comprising a substrate having formed thereon, in sequence, a magnetic recording layer, a protective coating means for reducing friction and retaining lubricant, and a lubricant coating, said protective coating means being made of one material and comprising a plane portion which occupies a substantial area of the coating, and a plurality of fine friction-reducing productions and lubricant-retaining recesses formed on said plane portion.
References Cited (Backward Citations)
US4154875A
Cited
US4069360A
Cited
US4152487A
Cited
US4307156A
Cited
US4326229A
Cited
US4425404A
Cited
US4540618A
Cited
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 |