US4403231A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Data recording medium
Assignee: Toshiba Corp
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Filing: 1982-01-29
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Granted: 1983-09-06
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Expires: 2002-01-29
Abstract
Abstract The invention provides a data recording medium comprising: a disc-shaped substrate; a radiation-sensitive recording layer formed on one surface of the substrate; an oxide layer formed by oxidizing a surface of the said recording layer; and a protective layer formed on the oxide layer. The data recording medium of the invention prevents formation of cracks in the recording layer and/or protective layer and is improved in the manufacturing yield.
Inventors
- 👤 Hideo Ando
- 👤 Toshiharu Nakagawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 03:47
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/26; G11B7/241; G11B7/252; G11B7/254; G11B7/2542; G11B7/242; G11B7/243; G11B2007/24302; G11B2007/2431; G11B2007/24314; G11B2007/24316; G11B7/257; G11B2007/25705; G11B2007/25706; G11B2007/25708; G11B2007/2571; G11B2007/25715; G11B2007/25718
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
40 words
A data recording medium comprising: a disc-shaped substrate; a radiation-sensitive recording layer formed on one surface of said substrate; an oxide layer formed by oxidizing a surface of said recording layer; and a protective layer formed on said oxide layer.
Claim 2
Dependent Claim
40 words
A data recording medium comprising: a disc-shaped substrate; a radiation-sensitive recording layer formed on one surface of said substrate; an oxide layer formed by oxidizing a surface of said recording layer; and a protective layer formed on said oxide layer.
Claim 3
Dependent Claim
20 words
A data recording medium according to claim 1, wherein said oxide layer has a thickness of 20 to 500 A.
Claim 4
Dependent Claim
25 words
A data recording medium according to claim 1, wherein said recording layer contains a metal selected from the group consisting of Te, Bi and Al.
Claim 5
Dependent Claim
40 words
A data recording medium according to claim 1, wherein said protective layer is made of an organic material selected from the group consisting of an epoxy resin, polystyrene resin, silicone resin, polycarbonate resin, vinyl chloride-acetate copolymer, and ethylenevinyl acetate copolymer.
Claim 6
Dependent Claim
61 words
A data recording medium according to claim 1, wherein said protective layer is made of an inorganic material selected from the group consisting of SiO 2 , SiO, In 2 O 3 , SnO 2 , MgO, ZnO, ZnO 2 , Al 2 O 3 , CeO 2 , TiO 2 , MgF 2 , CaF 2 and CeF 3 .
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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) | 1986-09-05 | 1987-03-07 | 1987-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-05 | 1991-03-07 | 1991-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-05 | 1995-03-07 | 1995-09-06 | $7700.00 | Window Closed / Lapsed |