US5292592A
Expired / Lapsed
US
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Optical information recording medium in which a protective layer comprises a Ni-Cr alloy layer
Assignee: NEC Corp
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Filing: 1992-05-08
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Granted: 1994-03-08
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Expires: 2012-05-08
Abstract
Abstract In an optical information recording medium comprising a substrate (11) of polycarbonate, a recording layer, and a reflecting layer (14) covering the reflecting layer and containing Al, an alloy layer (17) of a Ni-Cr alloy is deposited on the reflecting layer to sufficiently protect transmission of moisture into the reflecting layer. A covering layer (18) of ultraviolet curable resin may be deposited on the alloy layer. The recording layer is formed on the substrate and includes a magneto-optical layer (13) sandwiched between first and second interference layers (15, 16). For protecting transmission of moisture into the substrate, it is preferable that an additional layer (21) of SiO 2 is deposited on the substrate opposite to the recording layer.
Inventors
- 👤 Masaki Itoh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 06:50
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/252; G11B11/00; G11B11/10; G11B11/105; G11B11/10582; G11B11/10584; G11B11/10586; G11B7/258; G11B7/242; G11B7/243; G11B2007/24302; G11B2007/24306; G11B7/253; G11B7/2533; G11B7/2534; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10S428/922; Y10S428/9265; Y10S428/928; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12556; Y10T428/12569; Y10T428/12736; Y10T428/1275; Y10T428/12771; Y10T428/12861; Y10T428/12931
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
62 words
An optical information recording medium comprising a substrate, a protective layer, a recording layer between said substrate and said protective layer, and a reflecting layer between said protective layer and said recording layer, said reflecting layer containing Al, said protective layer comprising an alloy layer of a Ni-Cr alloy on said reflecting layer, said Ni-Cr alloy containing 20% by weight of Cr.
Claim 2
Dependent Claim
62 words
An optical information recording medium comprising a substrate, a protective layer, a recording layer between said substrate and said protective layer, and a reflecting layer between said protective layer and said recording layer, said reflecting layer containing Al, said protective layer comprising an alloy layer of a Ni-Cr alloy on said reflecting layer, said Ni-Cr alloy containing 20% by weight of Cr.
Claim 3
Dependent Claim
35 words
An optical information recording medium as claimed in claim 1, wherein said protective layer further comprises a covering layer covering said alloy layer, said alloy layer being between said covering layer and said reflecting layer.
Claim 4
Dependent Claim
20 words
An optical information recording medium as claimed in claim 2, wherein said covering layer is made of ultraviolet curable resin.
Claim 5
Dependent Claim
29 words
An optical information recording medium as claimed in claim 1, further comprising an additional layer of Si dioxide, said substrate being between said recording layer and said additional layer.
Claim 6
Dependent Claim
36 words
An optical information recording medium as claimed in claim 1, further comprising: a first interference layer between said substrate and said recording layer; and a second interference layer between said recording layer and said reflecting layer.
Claim 7
Dependent Claim
18 words
An optical information recording medium as claimed in claim 1, wherein said recording layer comprises a magneto-optical layer.
Claim 8
Dependent Claim
26 words
An optical information recording medium as claimed in claim 6, wherein said recording layer further comprises an interference layer between said substrate and said magneto-optical layer.
Claim 9
Dependent Claim
28 words
An optical information recording medium as claimed in claim 6, wherein said recording layer further comprises an additional interference layer between said reflecting layer and said magneto-optical layer.
Claim 10
Dependent Claim
60 words
An optical information recording medium as claimed in claim 1, wherein said recording layer is composed of at least one material selected from a group consisting of TbFe, TbFeTi, TbFeCr, TbFeNi, TbFeNiCr, TbFeTa, TbFeNb, TbFePt, TbFeCo, TbFeCoTi, TbFeCoCr, TbFeCoNi, TbFeCoNiCr, TbFeCoTa, TbFeCoNb, TbFeCoPt, TbDyFeCo, TbDyFeCoTi, TbDyFeCoCr, TbDyFeCoNi, TbDyFeCoNiCr, TbDyFeCoTa, TbDyFeCoNb, TbDyFeCoPt, TbNdFeCo, TbNdFeCoTi, TbNdFeCoCr, TbNdFeCoNi, TbNdFeCoNiCr, TbNdFeCoTa, TbNdFeCoNb, and TbNdFeCoPt.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-03-07 | 1997-09-06 | 1998-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-03-07 | 2001-09-06 | 2002-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-03-07 | 2005-09-06 | 2006-03-08 | $7700.00 | Window Closed / Lapsed |