US4743502A
Expired / Lapsed
US
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Magneto-optical medium
Assignee: Mitsubishi Chemical Corp
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Filing: 1986-07-09
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Granted: 1988-05-10
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Expires: 2006-07-09
Abstract
Abstract Disclosed herein is a magneto-optical medium comprising a magnetic layer, a protective layer of a complex oxide containing oxides of aluminum and a base plate.
Inventors
- 👤 Toshihiko Yoshitomi
- 👤 Yoshimitsu Kobayashi
- 👤 Jun Sasaki
- 👤 Yukio Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:12
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10582; G11B11/10586; G11B5/00; G11B5/62; G11B5/72; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
87 words
A magneto-optical medium comprising a magnetic layer, a protective layer of a binary mixed oxide comprising aluminum oxide and one oxide selected from the group consisting of tantalum oxide, niobium oxide, titanium oxide, zirconium oxide and tungsten oxide, and a base plate, wherein the respective content of tantalum oxide and niobium oxide is 3 to 80 mol%, the respective content of titanium oxide and zirconium oxide is 20 to 95 mol% and the contents of tungsten oxide is 5 to 80 mol% based on said mixed oxide.
Claim 2
Dependent Claim
87 words
A magneto-optical medium comprising a magnetic layer, a protective layer of a binary mixed oxide comprising aluminum oxide and one oxide selected from the group consisting of tantalum oxide, niobium oxide, titanium oxide, zirconium oxide and tungsten oxide, and a base plate, wherein the respective content of tantalum oxide and niobium oxide is 3 to 80 mol%, the respective content of titanium oxide and zirconium oxide is 20 to 95 mol% and the contents of tungsten oxide is 5 to 80 mol% based on said mixed oxide.
Claim 3
Dependent Claim
19 words
A magneto-optical medium according to claim 1, wherein the thickness of said protective layer is 10 to 5000 Å.
Claim 4
Dependent Claim
21 words
A magneto-optical medium according to claim 1, wherein said protective layer is disposed between the magnetic layer and the base plate.
Claim 5
Dependent Claim
32 words
A magneto-optical medium according to claim 1, wherein said mixed oxide comprises aluminum oxide and one oxide selected from the group consisting of tantalum oxide, tungsten oxide, niobium oxide and zirconium oxide.
Claim 6
Dependent Claim
17 words
A magneto-optical medium according to claim 4, wherein said mixed oxide comprises aluminum oxide and tantalum oxide.
Claim 7
Dependent Claim
21 words
A magneto-optical medium according to claim 1, wherein said magnetic layer is disposed between the protective layer and the base plate.
Claim 8
Dependent Claim
22 words
A magneto-optical medium according to claim 6, wherein a protective layer is further disposed between the base layer and the magnetic layer.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-10 | 1991-11-09 | 1992-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-10 | 1995-11-09 | 1996-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-10 | 1999-11-09 | 2000-05-10 | $7700.00 | Window Closed / Lapsed |