US4388368A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording media
Assignee: Fujifilm Holdings Corp
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Filing: 1981-07-27
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Granted: 1983-06-14
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Expires: 2001-07-27
Abstract
Abstract The increased occurrence of jitter, wow, flutter, folding, and tendency to crumple of a magnetic recording medium when reducing the thickness of the support of the magnetic recording medium is effectively prevented by forming a thin glass layer on the base film for the magnetic recording medium.
Inventors
- 👤 Noburo Hibino
- 👤 Goro Akashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:08
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/73; G11B5/739; G11B5/73923; G11B5/73927; G11B5/73931; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/31504; Y10T428/31511; Y10T428/31515; Y10T428/31518; Y10T428/31551; Y10T428/31616
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
52 words
In a magnetic recording tape comprising a base film having coated thereon a magnetic recording layer, the improvement wherein said base film comprises a plastic film having a thin glass layer laminated on at least one surface thereof, wherein the thickness of the glass layer is about 0.1 to about 5 μm.
Claim 2
Dependent Claim
52 words
In a magnetic recording tape comprising a base film having coated thereon a magnetic recording layer, the improvement wherein said base film comprises a plastic film having a thin glass layer laminated on at least one surface thereof, wherein the thickness of the glass layer is about 0.1 to about 5 μm.
Claim 3
Dependent Claim
25 words
A base film for a magnetic recording medium as in claim 1, wherein the glass layer is adhered to the plastic film using an adhesive.
Claim 4
Dependent Claim
23 words
A base film for a magnetic recording medium as in claim 1, wherein said magnetic recording medium is a magnetic video recording tape.
Claim 5
Dependent Claim
30 words
A base film for a magnetic recording medium as in claim 1 or 2, wherein the plastic film has a tear strength of more than about 10 kg/mm 2 .
Claim 6
Dependent Claim
23 words
A base film for a magnetic recording medium as in claim 1 or 2, wherein the plastic film is a polyethylene terephthalate film.
Claim 7
Dependent Claim
31 words
A base film for a magnetic recording medium as in claim 1 or 2, wherein the glass layer is formed from lime glass, soda lime glass, borosilicate glass, or high-silica glass.
Claim 8
Dependent Claim
24 words
A base film for a magnetic recording medium as in claim 1, wherein the thickness of the glass layer is 0.5 to 3 μm.
Claim 9
Dependent Claim
19 words
A base film for a magnetic recording medium as in claim 1, wherein the thin glass layer is homogeneous.
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) | 1986-06-13 | 1986-12-13 | 1987-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-13 | 1990-12-13 | 1991-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-13 | 1994-12-13 | 1995-06-14 | $7700.00 | Window Closed / Lapsed |