US4395447A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Medium for recording
Assignee: Individual
•
Filing: 1981-04-22
•
Granted: 1983-07-26
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Expires: 2001-04-22
Abstract
Abstract A video disc includes a magnetic material applied thereon in such a manner that the orientation of said magnetic material is gradually intensified from the outermost track of the video disc to the innermost track thereof, starting from zero orientation at the outermost track.
Inventors
- 👤 Yoshiro Nakamatsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:12
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/012; G11B5/016; G11B5/84; G11B5/842; G11B5/845; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/24; Y10T428/24479; Y10T428/24612
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
152 words
A recording medium comprising: (a) a recording disc, (b) a magnetic coating on said disc and with said coating having a thickness which decreases from a maximum to a minimum radially inwardly from the outer periphery toward the center of said disc to provide correspondingly increasing recording density from the outer periphery toward the center of said disc, said coating containing magnetic particles, (c) said magnetic particles being oriented relative to the surface of said disc generally inversely to the change in thickness of said coating and being essentially non-oriented at the periphery of said disc in the area of maximum coating thickness and increasing in orientation radially inwardly toward the center of said disc to a maximum uniform orientation in the area of minimum coating thickness, to thereby provide an essentially constant output for the recording medium from the disc periphery radially inwardly to the inner termination of said magnetic coating.
Claim 2
Dependent Claim
152 words
A recording medium comprising: (a) a recording disc, (b) a magnetic coating on said disc and with said coating having a thickness which decreases from a maximum to a minimum radially inwardly from the outer periphery toward the center of said disc to provide correspondingly increasing recording density from the outer periphery toward the center of said disc, said coating containing magnetic particles, (c) said magnetic particles being oriented relative to the surface of said disc generally inversely to the change in thickness of said coating and being essentially non-oriented at the periphery of said disc in the area of maximum coating thickness and increasing in orientation radially inwardly toward the center of said disc to a maximum uniform orientation in the area of minimum coating thickness, to thereby provide an essentially constant output for the recording medium from the disc periphery radially inwardly to the inner termination of said magnetic coating.
Claim 3
Dependent Claim
24 words
The recording medium of claim 1 wherein the resolution thereof adjacent the area of minimum coating thickness and maximum uniform orientation is about 90%.
Claim 4
Dependent Claim
178 words
In the manufacture of a recording medium comprising a recording disc provided with a magnetic coating on said disc and with said coating containing magnetic particles, the steps of: (a) coating said disc with said magnetic coating so that the latter has a thickness which decreases from a maximum to a minimum radially inwardly from the outer periphery toward the center of said disc to provide correspondingly increasing recording density from the outer periphery toward the center of said disc, (b) and causing said magnetic particles on said coated disc to be oriented relative to the surface of said disc generally inversely to the change in thickness of said coating so that said particles are essentially non-oriented at the periphery of said disc in the area of maximum coating thickness and increase in orientation radially inwardly toward the center of said disc to a maximum uniform orientation in the area of minimum coating thickness to provide a recording medium having an essentially constant output from the disc periphery radially inwardly to the inner termination of said magnetic coating.
Claim 5
Dependent Claim
178 words
In the manufacture of a recording medium comprising a recording disc provided with a magnetic coating on said disc and with said coating containing magnetic particles, the steps of: (a) coating said disc with said magnetic coating so that the latter has a thickness which decreases from a maximum to a minimum radially inwardly from the outer periphery toward the center of said disc to provide correspondingly increasing recording density from the outer periphery toward the center of said disc, (b) and causing said magnetic particles on said coated disc to be oriented relative to the surface of said disc generally inversely to the change in thickness of said coating so that said particles are essentially non-oriented at the periphery of said disc in the area of maximum coating thickness and increase in orientation radially inwardly toward the center of said disc to a maximum uniform orientation in the area of minimum coating thickness to provide a recording medium having an essentially constant output from the disc periphery radially inwardly to the inner termination of said magnetic coating.
References Cited (Backward Citations)
US4001463A
Cited
US4271782A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-07-25 | 1987-01-24 | 1987-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-25 | 1991-01-24 | 1991-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-25 | 1995-01-24 | 1995-07-26 | $7700.00 | Window Closed / Lapsed |