US3681225A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a magnetic disc
Assignee: Victor Company of Japan Ltd
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Filing: 1970-11-23
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Granted: 1972-08-01
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Expires: 1990-11-23
Abstract
Abstract A METHOD OF MAKING MAGNETIC DISC WHEREIN AN ELECTRICALLY CONDUCTING MATERIAL LAYER IS FORMED ON THE SUFACES OF A BASE PLATE MADE BY SHAPING A SYNTHETIC RESINOUS MATERIAL, THEN A MAGNETIC MATERIAL IS APPLIED TO THE COAT BY ELECTRODEPOSITION AND FINALLY THE SURFACES ARE POLISHED BY A POLISHING MATERIAL OF VERY SMALL GRAIN SIZE. THE LAYER OF MAGNETIC MATERIAL FORMED BY ELECTRODEPOSITION HAS ITS SURFACES RENDERED SMOOTH BY THE POLISHING OPERATION BECAUSE MINUTE FISSURES IN THE SURFACES ARE REMOVED AND AT THE SAME TIME THE MAGNETIC MATERIAL LAYER ITSELF IS ANNEALED BY THE HEAT OF FRICTION.
Inventors
- 👤 Susumu Genma
- 👤 Akio Kuroda
- 👤 Toshio Kato
- 👤 Fusao Kishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:36
CPC Classifications
H; H01; H01F; H01F10/00; H01F10/06; G; G11; G11B; G11B5/00; G11B5/84; G11B5/8404; Y; Y10; Y10S; Y10S205/00; Y10S205/917; Y10S205/922; Y10S428/00; Y10S428/922; Y10S428/9265; Y10S428/928; Y10S428/9335; Y10S428/934; Y10S428/935; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12771; Y10T428/12861; Y10T428/12944; Y10T428/12993
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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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) | 1975-08-01 | 1976-01-31 | 1976-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-01 | 1980-01-31 | 1980-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-01 | 1984-01-31 | 1984-08-01 | $7700.00 | Window Closed / Lapsed |