EP0265204A2
Expired / Lapsed
EP
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Protective layer for optical information recording medium
Assignee: Panasonic Holdings Corp
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Filing: 1987-10-19
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Granted: —
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Expires: 2007-10-19
Abstract
Abstract A protective layer which is applied to rewritable optical information recording medium comprising a substrate and a photosensitive thin film. When exposed to optical energy, the thin layer is capable of undergoing a reversible phase change by which an optical reflectivity is changed between two states. The protective layer is inhibiting the thermal damages of the substrate during light irradiation and also controlling thermal and optical boundary conditions. The protective layer is made of the mixture of mutually solid insoluble materials. The typical choice of the mixture of small crystalline grains (2) of ZnS and noncrystalline SiO₂ (1).
Inventors
- 👤 Masatoshi Takao
- 👤 Kunio Kimura
- 👤 Toshimitsu Kurumizawa
- 👤 Kenichi Nagata
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 21:44
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/252; G11B7/254; G11B7/257; G11B7/2578; G11B7/242; G11B7/243; G11B2007/24302; G11B2007/24312; G11B2007/24316; G11B2007/24318; G11B2007/2432; G11B2007/25705; G11B2007/25706; G11B2007/25708; G11B2007/2571; G11B2007/25713; G11B2007/25715; G11B2007/25716; G11B7/253; G11B7/2533; G11B7/2534; G11B7/256; Y; Y10; Y10S; Y10S428/00; Y10S428/913; Y10T; Y10T428/00; Y10T428/24; Y10T428/24273; Y10T428/24322; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/24975; Y10T428/25; Y10T428/259
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
58 words
An optical information recording medium which comprises a substrate, optically active layer provided on said substrate, and a heat-resistant protective layer between said optically active layer and said substrate and/or on said optically active layer, said heat-resistant protective layer consisting of a mixture of a plurality of compounds, at least two of which compounds are mutually solid insoluble.
Claim 2
Dependent Claim
58 words
An optical information recording medium which comprises a substrate, optically active layer provided on said substrate, and a heat-resistant protective layer between said optically active layer and said substrate and/or on said optically active layer, said heat-resistant protective layer consisting of a mixture of a plurality of compounds, at least two of which compounds are mutually solid insoluble.
Claim 3
Dependent Claim
20 words
The optical information recording medium according to claim 1, wherein at least one of said compounds is a glassy one.
Claim 4
Dependent Claim
30 words
The optical information recording medium according to claim 1, wherein at least one of said compounds is a metal chalcogenide and at least one of said compounds is an oxide.
Claim 5
Dependent Claim
32 words
The optical information recording medium according to claim 3, wherein at least one of said metal chalcogenides is a zinc chalcogenide and at least one of said oxides is a glassy one.
Claim 6
Dependent Claim
39 words
The optical information recording medium according to claim 4, wherein said zinc chalcogenide is at least one selected from ZnS, ZnSe and ZnTe, and said glassy oxide is at least one selected from SiO₂, GeO₂, SnO₂, In₂O₃ and TeO₂.
Claim 7
Dependent Claim
26 words
The optical information recording medium according to claim 3, wherein at least one of said metal chalcogenides is a lead chalcogenide and said oxide is glassy.
Claim 8
Dependent Claim
39 words
The optical information recording medium according to claim 6, wherein said lead chalcogenide is at least one selected from PbS, PbSe and PbTe, and said glassy oxide is at least one selected from SiO₂, GeO₂, SnO₂, In₂O₃ and TeO₂.
Claim 9
Dependent Claim
30 words
The optical information recording medium according to claim 1, wherein at least one of said compounds is a metal chalcogenide and at least one of said compounds is a nitride.
Claim 10
Dependent Claim
32 words
The optical information recording medium according to claim 8, wherein at least one of said metal chalcogenides is a zinc chalcogenide and at least one of said nitrides is a glassy nitride.
Claim 11
Dependent Claim
28 words
The optical information recording medium according to claim 9, wherein said zinc chalcogenide is at least one selected from ZnS, ZnSe and ZnTe, and said nitride is Si₃N₄.
Claim 12
Dependent Claim
30 words
The optical information recording medium according to claim 1, wherein at least one of said compounds is a metal chalcogenide and at least one of said compounds is a carbide.
Claim 13
Dependent Claim
26 words
The optical information recording medium according to claim 11, wherein at least one of said metal chalcogenides is a zinc chalcogenide and said carbide is glassy.
Claim 14
Dependent Claim
26 words
The optical information recording medium according to claim 12, wherein said zinc chalcogenide is selected from ZnS, ZnSe and ZnTe and said glassy carbide is SiC.
Claim 15
Dependent Claim
30 words
The optical information recording medium according to claim 1, wherein at least one of said compounds is a metal chalcogenide, and at least one of said compounds is an oxynitride.
Claim 16
Dependent Claim
47 words
The optical information recording medium according to claim 1, wherein the size of the microstructural unit (grain) of said protective layer is smaller than that of the microstructural unit of each of the compounds constituting said protective layer when said layer was made of said compound only.
Claim 17
Dependent Claim
30 words
The optical information recording medium according to claim 15, wherein at least one of said compounds is a metal chalcogenide, and at least one of said compounds is an oxide.
Claim 18
Dependent Claim
30 words
The optical information recording medium according to claim 16, wherein at least one of said metal chalcogenides is a zinc chalcogenide and at least one of said oxides is glassy.
Claim 19
Dependent Claim
39 words
The optical information recording medium according to claim 17, wherein said zinc chalcogenide is at least one selected from ZnS, ZnSe and ZnTe and said glassy oxide is at least one selected from SiO₂, GeO₂, SnO₂, In₂O₃ and TeO₂.
Claim 20
Dependent Claim
24 words
The optical information recording medium according to claim 15, wherein said microstructural unit (grain) has an average grain size of 10 nm or less.
Claim 21
Dependent Claim
25 words
The optical information recording medium according to claim 19, wherein said microstructural unit is constituted by at least one selected from ZnS, ZnSe and ZnTe.
References Cited (Backward Citations)
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