US4371590A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium with stepwise orientation of deposited metallic particles
Assignee: TDK Corp
•
Filing: 1980-12-05
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Granted: 1983-02-01
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Expires: 2000-12-05
Abstract
Abstract A magnetic recording medium having multi-layer structure of two or more thin metallic layers on a substrate. The orientations of metallic particles are different for each of said thin metallic layers.
Inventors
- 👤 Toshiaki Izumi
- 👤 Seitoku Saito
- 👤 Fumio Maruta
- 👤 Minoru Kameya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 01:51
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/66; G11B5/674; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/9265; Y10S428/928; Y10T; Y10T428/00; Y10T428/12; Y10T428/12014; Y10T428/12028; Y10T428/12049; Y10T428/12063; Y10T428/12069; Y10T428/12076; Y10T428/12465
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
53 words
A magnetic recording medium comprising two or more thin metallic layers on a substrate, said layers having deposited thereon metallic particles whose angle of orientation varies stepwise between said layers to provide a substantially constant coercive force while residual magnetic flux increases in substantial proportion to the number of said thin metallic layers.
Claim 2
Dependent Claim
53 words
A magnetic recording medium comprising two or more thin metallic layers on a substrate, said layers having deposited thereon metallic particles whose angle of orientation varies stepwise between said layers to provide a substantially constant coercive force while residual magnetic flux increases in substantial proportion to the number of said thin metallic layers.
Claim 3
Dependent Claim
35 words
The magnetic recording medium according to claim 1 wherein the angles of orientations of said metallic particles to the normal line of said substrate are progressively smaller as the layers are away from said substrate.
Claim 4
Dependent Claim
27 words
The magnetic recording medium according to claim 1 or 2 wherein said metallic layers are formed by depositions of metallic particles from different direction for each layer.
Claim 5
Dependent Claim
30 words
The magnetic recording medium according to claim 1 wherein said metallic layer is made of a metal or alloy of the iron group element with or without a third element.
Claim 6
Dependent Claim
69 words
The magnetic recording medium according to claim 1 or 2 wherein the angle of orientation of said metallic particles to the normal line of said substrate for the first layer is different by at least 3 degrees from the angle of orientation of said metallic particles for the adjacent layer and by at least 5 degrees from the angle of orientation of said metallic particles for the outermost layer.
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) | 1986-01-31 | 1986-08-02 | 1987-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-01-31 | 1990-08-02 | 1991-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-01-31 | 1994-08-02 | 1995-02-01 | $7700.00 | Window Closed / Lapsed |