US4645703A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: Panasonic Holdings Corp
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Filing: 1985-10-10
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Granted: 1987-02-24
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Expires: 2005-10-10
Abstract
Abstract A magnetic recording medium comprises steep mountain-shaped protrusions having heights ranging 50-600 Å and distributed at a rate of 1×50 5 -1×10 8 protrusions/mm 2 on a surface of ferromagnetic metal layer and further thereon a lubricant layer; the magnetic recording medium is suitable for VTR tape which has a satisfactory durability for repeated use and eliminates head clogging and squealing.
Inventors
- 👤 Takashi Suzuki
- 👤 Kunio Hibino
- 👤 Mikio Murai
- 👤 Shigeki Kawase
- 👤 Koichi Shinohara
- 👤 Norimoto Nouchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:01
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/68; G11B5/70; G11B5/712; G11B5/72; G11B5/725; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/24; Y10T428/24355; Y10T428/24372; Y10T428/24413; Y10T428/24421; Y10T428/2443; Y10T428/24802; Y10T428/24851
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
60 words
A magnetic recording medium comprising: a substrate of non-ferromagnetic characteristic, and a ferromagnetic thin film, formed on said substrate, characterized by protrusions of mountain-shape having 50-600 Å heights and distributed with numbers of 1×10 5 -1×10 8 protrusions per 1 mm 2 on a surface of said ferromagnetic thin film, and a lubricant layer formed on said ferromagnetic thin film.
Claim 2
Dependent Claim
60 words
A magnetic recording medium comprising: a substrate of non-ferromagnetic characteristic, and a ferromagnetic thin film, formed on said substrate, characterized by protrusions of mountain-shape having 50-600 Å heights and distributed with numbers of 1×10 5 -1×10 8 protrusions per 1 mm 2 on a surface of said ferromagnetic thin film, and a lubricant layer formed on said ferromagnetic thin film.
Claim 3
Dependent Claim
75 words
A magnetic recording medium comprising: a substrate of non-ferromagnetic characteristic, and a ferromagnetic thin film, formed on said substrate, characterized by protrusions of mountain-shape having 50-600 Å heights and a ratio of average length of said protrusions to their heights being under 10, and distributed with numbers of 1×10 5 -1×10 8 protrusions per 1 mm 2 on a surface of said ferromagnetic thin film, and a lubricant layer formed on said ferromagnetic thin film.
Claim 4
Dependent Claim
75 words
A magnetic recording medium comprising: a substrate of non-ferromagnetic characteristic, and a ferromagnetic thin film, formed on said substrate, characterized by protrusions of mountain-shape having 50-600 Å heights and a ratio of average length of said protrusions to their heights being under 10, and distributed with numbers of 1×10 5 -1×10 8 protrusions per 1 mm 2 on a surface of said ferromagnetic thin film, and a lubricant layer formed on said ferromagnetic thin film.
Claim 5
Dependent Claim
26 words
A magnetic recording medium in accordance with claim 1 or claim 2, wherein said protrusions are formed by protrusions formed on a surface of said substrate.
Claim 6
Dependent Claim
35 words
A magnetic recording medium in accordance with claim 3, wherein said surface has a form of a moderate wave, and said protrusions are provided at recessed parts of said moderately waving surface of said surface.
Claim 7
Dependent Claim
23 words
A magnetic recording medium in accordance with claim 1 or claim 2, wherein said lubricant layer is formed partly with a minute pattern.
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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) | 1990-02-23 | 1990-08-25 | 1991-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-23 | 1994-08-25 | 1995-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-23 | 1998-08-25 | 1999-02-24 | $7700.00 | Window Closed / Lapsed |