US3694261A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cobalt ferrite magnetic recording tape
Assignee: HIDETAKA HIGUCHI
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Filing: 1971-02-11
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Granted: 1972-09-26
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Expires: 1991-02-11
Abstract
Abstract MAGNETIC RECORDING TAPE HAVING IMPROVED STABILITY TOWARD STORAGE AND ELEVATED TEPERATURES, COMPRISING MAGNETIC POWDER WHICH GIVES THE TAPE ITS IMPROVED PROPERTIES, THE POWDER BEING A COBALT FERRITE WHICH IS SUBSTITUTED BY MEANS OF ZINC, MAGNESIUM, CADMIUM, CALCIUM, A MIXTURE OF ZINC AND MAGNESIUM, OR A MIXTURE OF CADMIUM AND CALCIUM.
Inventors
- 👤 Yoshimi Makino
- 👤 Higetaka Higuchi
- 👤 Iwao Kamiya
- 👤 Yoshikazu Masuya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:27
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/706; G11B5/70626; G11B5/70642; G11B5/70678; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551; Y10T428/31558; Y10T428/31591; Y10T428/31605; Y10T428/31609; Y10T428/31678; Y10T428/31681; Y10T428/31692; Y10T428/31699; Y10T428/31703; Y10T428/31725; Y10T428/31765; Y10T428/31768; Y10T428/31786; Y10T428/3179; Y10T428/31797; Y10T428/31855; Y10T428/3188; Y10T428/31884; Y10T428/31891; Y10T428/31895; Y10T428/31906
Claims Analysis
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-26 | 1976-03-27 | 1976-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-26 | 1980-03-27 | 1980-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-26 | 1984-03-27 | 1984-09-26 | $7700.00 | Window Closed / Lapsed |