US5862121A
Expired / Lapsed
US
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Double-layered information recording medium having information recording layers
Assignee: Toshiba Corp
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Filing: 1997-03-20
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Granted: 1999-01-19
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Expires: 2017-03-20
Abstract
Abstract In a double-layered optical disk capable of reading two-layer information from one face, the substrates constituting this optical disk can hardly peel even with a dropping shock or a change over time. The double-layered optical disk is constituted by a transparent first substrate, a first information recording layer, and a second substrate adhered to the first substrate through the first information recording layer. The first substrate has information pits to be read with a read laser beam and is transparent to this read laser beam. The first information recording layer is formed on the information pit formation surface of the first substrate and is made of an inorganic dielectric having a higher refractive index than that of the first substrate.
Inventors
- 👤 Katsumi Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:22
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/26; G11B7/2403; G11B7/24035; G11B7/24038; G11B7/24047; G11B7/2407; G11B7/24085; G11B7/241; G11B7/242; G11B7/243; G11B7/252; G11B7/257; G11B7/258; G11B2007/24302; G11B2007/2431; G11B2007/24312; G11B2007/25705; G11B2007/25706; G11B2007/2571; G11B2007/25715; G11B7/253; G11B7/2533; G11B7/2534; G11B7/256; G11B7/2585
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
76 words
An information medium comprising: a first substrate having an information pit arranged to be read with a predetermined light beam and being transparent to the predetermined light beam; a first information recording layer formed on an information pit formation face of said first substrate and made of an inorganic dielectric having a higher refractive index than that of said first substrate; and a second substrate adhered to said first substrate through said first information recording layer.
Claim 2
Dependent Claim
76 words
An information medium comprising: a first substrate having an information pit arranged to be read with a predetermined light beam and being transparent to the predetermined light beam; a first information recording layer formed on an information pit formation face of said first substrate and made of an inorganic dielectric having a higher refractive index than that of said first substrate; and a second substrate adhered to said first substrate through said first information recording layer.
Claim 3
Dependent Claim
132 words
An information recording medium comprising: a first substrate having a first information pit arranged to be read with a predetermined light beam and being transparent to the predetermined light beam; a first information recording layer formed on an information pit formation face of said first substrate and made of an inorganic dielectric having a higher refractive index than that of said first substrate; a second substrate having a second information pit arranged to be read with the light beam; a second information recording layer formed on an information pit formation face of said second substrate and made of a reflection material which reflects the light beam; and an adhesive layer for adhering said first substrate and said second substrate so that said first information recording layer faces said second information recording layer.
Claim 4
Dependent Claim
132 words
An information recording medium comprising: a first substrate having a first information pit arranged to be read with a predetermined light beam and being transparent to the predetermined light beam; a first information recording layer formed on an information pit formation face of said first substrate and made of an inorganic dielectric having a higher refractive index than that of said first substrate; a second substrate having a second information pit arranged to be read with the light beam; a second information recording layer formed on an information pit formation face of said second substrate and made of a reflection material which reflects the light beam; and an adhesive layer for adhering said first substrate and said second substrate so that said first information recording layer faces said second information recording layer.
Claim 5
Dependent Claim
25 words
A medium according to claim 1 or 2, wherein said inorganic dielectric contains a material selected from the group consisting of silicon and titanium oxide.
Claim 6
Dependent Claim
27 words
A medium according to claim 1 or 2, wherein said inorganic dielectric has a thickness falling within a range of about 20 nm to about 1,000 nm.
Claim 7
Dependent Claim
31 words
A medium according to claim 1 or 2, wherein said second substrate has a reflection material which contains one material selected from the group consisting of aluminum and an aluminum-molybdenum alloy.
Claim 8
Dependent Claim
14 words
A medium according to claim 1 or 2, wherein said first substrate contains polycarbonate.
Claim 9
Dependent Claim
28 words
A medium according to claim 1 or 2, wherein said first substrate and said second substrate are made of polycarbonate disks each having a thickness of 0.6 mm.
Claim 10
Dependent Claim
35 words
A medium according to claim 1 or 2, wherein a thickness of said inorganic dielectric is selected on the basis of a 1/4 wavelength of a wavelength of the light beam in said inorganic dielectric.
Claim 11
Dependent Claim
26 words
A medium according to claim 2, wherein said adhesive layer contains an ultraviolet curing resin having a thickness larger than the thickness of said inorganic dielectric.
Claim 12
Dependent Claim
95 words
A medium according to claim 2, wherein each of said first substrate and said second substrate has a disk-like shape having a hole and a predetermined outer diameter, a predetermined inner diameter, and a predetermined thickness, said medium further comprises a spacer having a specific outer diameter, a specific inner diameter, and a specific thickness and concentrically sandwiched between said first substrate and said second substrate, and said adhesive layer is present between said first substrate and said second substrate except a position of said spacer, and has a predetermined thickness defined by said spacer.
Claim 13
Dependent Claim
87 words
An information recording medium comprising: a transparent disk-like first substrate on which information is recorded as an embossed pit, said first substrate having a predetermined shape; an inorganic dielectric film formed on an embossed pit side of said first substrate and having a higher refractive index than that of said first substrate; a second substrate having generally the same shape as said first substrate; and an adhesive portion for adhering said first substrate and said second substrate so that said inorganic dielectric film faces said second substrate.
Claim 14
Dependent Claim
87 words
An information recording medium comprising: a transparent disk-like first substrate on which information is recorded as an embossed pit, said first substrate having a predetermined shape; an inorganic dielectric film formed on an embossed pit side of said first substrate and having a higher refractive index than that of said first substrate; a second substrate having generally the same shape as said first substrate; and an adhesive portion for adhering said first substrate and said second substrate so that said inorganic dielectric film faces said second substrate.
Claim 15
Dependent Claim
102 words
An information recording medium comprising: a transparent disk-like first substrate on which first information is recorded as an embossed pit; an inorganic dielectric film formed on an embossed pit side of said first substrate and having a higher refractive index than that of said first substrate; a disk-like second substrate on which second information is recorded as an embossed pit; a reflection film formed on an embossed pit side of said second substrate; and an adhesive portion constituted by a transparent organic material to adhere said first substrate and said second substrate so that said inorganic dielectric film faces said reflection film.
Claim 16
Dependent Claim
102 words
An information recording medium comprising: a transparent disk-like first substrate on which first information is recorded as an embossed pit; an inorganic dielectric film formed on an embossed pit side of said first substrate and having a higher refractive index than that of said first substrate; a disk-like second substrate on which second information is recorded as an embossed pit; a reflection film formed on an embossed pit side of said second substrate; and an adhesive portion constituted by a transparent organic material to adhere said first substrate and said second substrate so that said inorganic dielectric film faces said reflection film.
Claim 17
Dependent Claim
25 words
A medium according to claim 11 or 12, wherein said inorganic dielectric contains a material selected from the group consisting of silicon and titanium oxide.
Claim 18
Dependent Claim
27 words
A medium according to claim 11 or 12, wherein said inorganic dielectric has a thickness falling within a range of about 20 nm to about 1,000 nm.
Claim 19
Dependent Claim
102 words
An information recording medium comprising: a transparent disk-like first substrate on which first information is recorded as an embossed pit; an inorganic dielectric film formed on an embossed pit side of said first substrate and having a higher refractive index than that of said first substrate; a disk-like second substrate on which second information is recorded as an embossed pit; a recording film formed on an embossed pit side of said second substrate; and an adhesive portion made of a transparent organic material to adhere said first substrate and said second substrate so that said inorganic dielectric film faces said recording film.
Claim 20
Dependent Claim
102 words
An information recording medium comprising: a transparent disk-like first substrate on which first information is recorded as an embossed pit; an inorganic dielectric film formed on an embossed pit side of said first substrate and having a higher refractive index than that of said first substrate; a disk-like second substrate on which second information is recorded as an embossed pit; a recording film formed on an embossed pit side of said second substrate; and an adhesive portion made of a transparent organic material to adhere said first substrate and said second substrate so that said inorganic dielectric film faces said recording film.
Claim 21
Dependent Claim
19 words
A medium according to claim 15, wherein said inorganic dielectric contains a mixture of zinc sulfide and silicon oxide.
Claim 22
Dependent Claim
75 words
An information medium comprising: a first substrate having an information pit arranged to be read with a predetermined light beam and being transparent to the predetermined light beam; a first information recording layer formed on an information pit formation face of said first substrate and made of a material having a higher refractive index than that of said first substrate; and a second substrate adhered to said first substrate through said first information recording layer.
Claim 23
Dependent Claim
75 words
An information medium comprising: a first substrate having an information pit arranged to be read with a predetermined light beam and being transparent to the predetermined light beam; a first information recording layer formed on an information pit formation face of said first substrate and made of a material having a higher refractive index than that of said first substrate; and a second substrate adhered to said first substrate through said first information recording layer.
Claim 24
Dependent Claim
100 words
An information recording medium comprising: a transparent disk-like first substrate on which first information is recorded as an embossed pit; a transparent film formed on an embossed pit side of said first substrate and having a higher refractive index than that of said first substrate; a disk-like second substrate on which second information is recorded as an embossed pit; a recording film formed on an embossed pit side of said second substrate; and an adhesive portion made of a transparent organic material to adhere said first substrate and said second substrate so that said transparent film faces said recording film.
Claim 25
Dependent Claim
100 words
An information recording medium comprising: a transparent disk-like first substrate on which first information is recorded as an embossed pit; a transparent film formed on an embossed pit side of said first substrate and having a higher refractive index than that of said first substrate; a disk-like second substrate on which second information is recorded as an embossed pit; a recording film formed on an embossed pit side of said second substrate; and an adhesive portion made of a transparent organic material to adhere said first substrate and said second substrate so that said transparent film faces said recording film.
Claim 26
Dependent Claim
23 words
A medium according to claim 4, wherein said inorganic dielectric has a thickness falling within a range of 20 nm to 280 nm.
Claim 27
Dependent Claim
23 words
A medium according to claim 14, wherein said inorganic dielectric has a thickness falling within a range of 20 nm to 280 nm.
Claim 28
Dependent Claim
15 words
A medium according to claim 15, wherein said recording film is a write/read recording film.
Claim 29
Dependent Claim
15 words
A medium according to claim 15, wherein said recording film is a write/read/erase recording film.
Claim 30
Dependent Claim
16 words
A medium according to claim 15, wherein said recording film is an overwrite enable recording film.
Claim 31
Dependent Claim
15 words
A medium according to claim 18, wherein said recording film is a write/read recording film.
Claim 32
Dependent Claim
15 words
A medium according to claim 18, wherein said recording film is a write/read/erase recording film.
Claim 33
Dependent Claim
16 words
A medium according to claim 18, wherein said recording film is an overwrite enable recording film.
References Cited (Backward Citations)
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