Patent US3740266A successfully refreshed from Google Patents.
US3740266A
Expired / Lapsed
US
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Magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1970-11-25
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Granted: 1973-06-19
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Expires: 1990-11-25
Abstract
Abstract A MAGNETIC RECORDING MEDIUM COMPRISING A SUPPORT AND A MEGNETIC RECORDING LAYER THEREON, THE LAYER COMPRISING A MIXTURE OF AN ACICULAR MAGNETIC POWDER SUCH MAY BE A FE-CO-NI ALLOY, A FE-CO ALLOY, A CO-NI ALLOY, OR A FE-NI ALLOY, AND AN ACICULAR MAGNETIC POWDER SUCH AS Y-FE2O3, CO-CONTAINING Y-FE2O3, CRO2, OR FE3O4. EITHER THE MAGNETIC ALLOY OR THE MAGNETIC POWDER MAY CONTAIN EITHER CU, SB, TE, MG, B OR BE. THE USE OF THE MIXTURE PREVENTS THE AGGREGATION OF THE MAGNETIC ALLOY PARTICLES AND MINIMIZES THE REDUCTION IN MAGNETIC FLUX DENSITY CAUSED BY THE ADDITION OF OTHER MATERIALS.
Inventors
- 👤 G Akashi
- 👤 M Fujiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:25
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/706; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/25; Y10T428/256; Y10T428/257
Claims Analysis
Total Claims: 0
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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) | 1976-06-18 | 1976-12-18 | 1977-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-18 | 1980-12-18 | 1981-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-18 | 1984-12-18 | 1985-06-19 | $7700.00 | Window Closed / Lapsed |