US4389010A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic tape guide means
Assignee: Fujifilm Holdings Corp
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Filing: 1981-03-10
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Granted: 1983-06-21
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Expires: 2001-03-10
Abstract
Abstract A magnetic tape guide means is disclosed having formed on the surface thereof for contact with a moving tape substantially hemispherical projections having diameters or major axis of from 0.5 to 5 mu m and a distribution density of from 10,000 to 100,000 projections per square millimeter.
Inventors
- 👤 Kengo Oishi
- 👤 Masayoshi Moriwaki
- 👤 Osamu Suzuki
- 👤 Kouji Kamiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:46
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/60; G11B15/605
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
48 words
A magnetic tape guide means of cylindrical configuration having formed on the peripheral surface thereof for contact with a moving tape substantially hemispherical projections having diameters or major axis of from 0.5 to 5 μm and a distribution density of from 10,000 to 100,000 projections per square millimeter.
Claim 2
Dependent Claim
48 words
A magnetic tape guide means of cylindrical configuration having formed on the peripheral surface thereof for contact with a moving tape substantially hemispherical projections having diameters or major axis of from 0.5 to 5 μm and a distribution density of from 10,000 to 100,000 projections per square millimeter.
Claim 3
Dependent Claim
29 words
A magnetic tape guide means as in claim 1 wherein the material forming the hemispherical projections is selected from the group consisting of a metal and a metal oxide.
Claim 4
Dependent Claim
24 words
A magnetic tape guide means as in claim 2 wherein said metal is selected from the group consisting of chromium, nickel, tungsten, and titanium.
Claim 5
Dependent Claim
41 words
A magnetic tape guide means as in claim 2 wherein said metal oxide is selected from the group consisting of Al 2 O 3 , ZrO 2 , Cr 2 O 3 , α-Fe 2 O 3 and TiO 2 .
Claim 6
Dependent Claim
25 words
A magnetic tape guide means as in claim 1 wherein the material comprising said hemispherical projections is an electrically conductive scaly carbon having high hardness.
Claim 7
Dependent Claim
31 words
A magnetic tape guide means as in claim 1, 2, 3, 4, or 5 wherein said hemispherical projections are formed on a base member selected from aluminum, brass, ceramic, and glass.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-06-20 | 1986-12-20 | 1987-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-20 | 1990-12-20 | 1991-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-20 | 1994-12-20 | 1995-06-21 | $7700.00 | Window Closed / Lapsed |