Patent US3595694A successfully refreshed from Google Patents.
US3595694A
Expired / Lapsed
US
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Magnetic recording tape
Assignee: Maxell Ltd
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Filing: 1968-09-17
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Granted: 1971-07-27
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Expires: 1988-09-17
Abstract
Abstract IN A MAGNETIC RECORDING TAPE COMPRISING A BASE FILM AND A MAGNETIC LAYER PROVIDED THEREON, THE IMPROVEMENT WHEREIN THE THICKNESS OF THE BASE FILM AND OF THE MAGNETIC LAYER ARE RESPECTIVELY 38 TO 42 MICRONS AND 12 TO 8 MICRONS, THE MAGNETIC MATERIAL IN THE MAGNETIC LAYER BEING NEEDLE-SHAPE Y-FE2O3 OF 270 TO 350 OERSTEDS IN COERSIVE FORCE, 0.1 TO 0.3 MIRCRON INMAJOR AXIS LENGTH AND 5 TO 7 IN MAJOR AXIS/MINOR AXIS RATIO AND THE PACKING DENSITY OF THE MAGNETIC MATERIAL BEING NOT LESS THAN 1.7 G./CM.3. THE NOISE AND THE PRINT EFFECT IN THE MAGNETIC RECORDING TAPE ARE MUCH REDUCED.
Inventors
- 👤 Norio Akai
- 👤 Tomizo Taniguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:38
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/706; G11B5/70626; G11B5/70642; G11B5/70652; G11B5/70647
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) | 1974-07-26 | 1975-01-25 | 1975-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-26 | 1979-01-25 | 1979-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-26 | 1983-01-25 | 1983-07-27 | $7700.00 | Window Closed / Lapsed |