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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
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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 11:29
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)

JPS6124040A Cited
US4717628A Cited
JPS6438109A Cited
EP0406569A2 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
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

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