Patent US5080946A successfully refreshed from Google Patents.
US5080946A
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Optical information recording medium and recording method
Assignee: Taiyo Yuden Co Ltd
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Filing: 1990-07-06
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Granted: 1992-01-14
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Expires: 2010-07-06
Abstract
Abstract An optical information recording medium comprising a light transmitting substrate having a spiral pregroove formed on its surface, a light absorptive layer of a coloring matter formed on the substrate directly or with other layer interposed therebetween, and a light reflective layer made of a metal film formed on the light absorptive layer directly or with other layer interposed therebetween, wherein ΔS≦0.3 wherein ΔS is the optical phase difference represented by ΔS=2d sub {n sub -n abs (1-d abs /d sub )}/λ wherein d sub is the depth of the layer boundary on the substrate side of the light absorptive layer at the portion corresponding to the pregroove, d abs is the depth of the layer boundary on the light absorptive layer side of the light reflective layer at the portion corresponding to the pregroove, n sub is the real part of the complex refractive index of the substrate and any layer present on the substrate side of the light absorptive layer, n abs is the real part of the complex refractive index of the light absorptive layer, and λ is the wavelength of a laser beam.
Inventors
- 👤 Yosikazu Takagisi
- 👤 Kunihiko Ootaguro
- 👤 Emiko Hamada
- 👤 Toru Fujii
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:47
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/24018; G11B7/24027; G11B7/004; G11B7/0045; Y; Y10; Y10S; Y10S428/00; Y10S428/913; Y10S430/00; Y10S430/146; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24851; Y10T428/24868; Y10T428/24876; Y10T428/24893
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
238 words
An optical information recording medium comprising: a light transmitting substrate having a pregroove formed on a surface thereof, a land being provided at at least one side of the pregroove, a light absorptive layer of a coloring matter formed on the substrate directly or with another layer interposed therebetween, and a light reflective layer, separate from the light absorptive layer made of a metal film formed on the light absorptive layer directly or with other layer interposed therebetween, wherein ΔS≦0.3, ΔS being the optical phase difference between light reflected by the light reflective layer at the pregroove and at the land and being represented by ΔS=2d sub {n sub -n abs (1-d abs /d sub )}/λ, and wherein d sub is the depth of a first layer boundary at a substrate side of the light absorptive layer from the land to a bottom of the pregroove, d abs is the depth of a second layer boundary at a light absorptive layer side of the light reflective layer from a portion thereof at the land to a portion thereof at eh pregroove, n sub is the real part of the complex refractive index of the substrate and any layer present on the substrate side of the light absorptive layer, n abs is the real part of the complex refractive index of the light absorptive layer, and λ is the wavelength of a laser beam reflected from the recording medium.
Claim 2
Dependent Claim
238 words
An optical information recording medium comprising: a light transmitting substrate having a pregroove formed on a surface thereof, a land being provided at at least one side of the pregroove, a light absorptive layer of a coloring matter formed on the substrate directly or with another layer interposed therebetween, and a light reflective layer, separate from the light absorptive layer made of a metal film formed on the light absorptive layer directly or with other layer interposed therebetween, wherein ΔS≦0.3, ΔS being the optical phase difference between light reflected by the light reflective layer at the pregroove and at the land and being represented by ΔS=2d sub {n sub -n abs (1-d abs /d sub )}/λ, and wherein d sub is the depth of a first layer boundary at a substrate side of the light absorptive layer from the land to a bottom of the pregroove, d abs is the depth of a second layer boundary at a light absorptive layer side of the light reflective layer from a portion thereof at the land to a portion thereof at eh pregroove, n sub is the real part of the complex refractive index of the substrate and any layer present on the substrate side of the light absorptive layer, n abs is the real part of the complex refractive index of the light absorptive layer, and λ is the wavelength of a laser beam reflected from the recording medium.
Claim 3
Dependent Claim
18 words
The optical information recording medium according to claim 1, wherein d sub is d sub ≧ 50 nm.
Claim 4
Dependent Claim
48 words
The optical information recording medium according to claim 1, wherein the light absorptive layer is formed on a part of the light transmitting substrate and a ROM area wherein pits for read-out signals are already formed, is provided at the region where the light absorptive layer is absent.
Claim 5
Dependent Claim
271 words
An optical information recording medium comprising: a light transmitting substrate having a pregroove formed on a surface thereof, a land being provided at each side of the pregroove, a light absorptive layer of a coloring matter formed on the substrate, and a light reflective layer, separate from the light absorptive layer, made of a metal film formed on the light absorptive layer, wherein 0.3≦ΔS≦0.3, ΔS being the optical phase difference between a reading laser beam reflected from the light reflective layer at a portion thereof corresponding to the pregroove and the reading laser beam reflected from the light reflective layer at a portion thereof corresponding to the land located on each side of the pregroove, wherein ΔS=2d sub {n sub -n abs (1-d abs /d sub )}/λ, and wherein d sub is the depth of a first layer boundary at a substrate side of the light absorptive layer from the land to a bottom of the pregroove, d abs is the depth of a second layer boundary at a light absorptive layer side of the light reflective layer from a portion thereof at the land to a portion thereof at the pregroove, n sub is the real part of the complex refractive index of the substrate and any layer present on the substrate side of the light absorptive layer, n abs is the real part of the complex refractive index of the light absorptive layer, and λ is the wavelength of the reading laser beam; and 90 nm ≦d gr ≦ 350 nm wherein d gr is a thickness of the light absorptive layer at a portion corresponding to the pregroove.
Claim 6
Dependent Claim
271 words
An optical information recording medium comprising: a light transmitting substrate having a pregroove formed on a surface thereof, a land being provided at each side of the pregroove, a light absorptive layer of a coloring matter formed on the substrate, and a light reflective layer, separate from the light absorptive layer, made of a metal film formed on the light absorptive layer, wherein 0.3≦ΔS≦0.3, ΔS being the optical phase difference between a reading laser beam reflected from the light reflective layer at a portion thereof corresponding to the pregroove and the reading laser beam reflected from the light reflective layer at a portion thereof corresponding to the land located on each side of the pregroove, wherein ΔS=2d sub {n sub -n abs (1-d abs /d sub )}/λ, and wherein d sub is the depth of a first layer boundary at a substrate side of the light absorptive layer from the land to a bottom of the pregroove, d abs is the depth of a second layer boundary at a light absorptive layer side of the light reflective layer from a portion thereof at the land to a portion thereof at the pregroove, n sub is the real part of the complex refractive index of the substrate and any layer present on the substrate side of the light absorptive layer, n abs is the real part of the complex refractive index of the light absorptive layer, and λ is the wavelength of the reading laser beam; and 90 nm ≦d gr ≦ 350 nm wherein d gr is a thickness of the light absorptive layer at a portion corresponding to the pregroove.
Claim 7
Dependent Claim
29 words
The optical information recording medium according to claim 4, wherein 0.05≦ρ≦1.6, wherein ρ=n abs ·d av /λ, wherein d av is the average thickness of the light absorptive layer.
Claim 8
Dependent Claim
31 words
The optical information recording medium according to claim 5, wherein k abs ≦ 0.3 wherein k abs is the imaginary part of the complex refractive index of the light absorptive layer.
Claim 9
Dependent Claim
271 words
An optical information recording medium comprising: a light transmitting substrate having a pregroove formed on a surface thereof, a land being positioned on each side of the pregroove, a light absorptive layer of a coloring matter formed on the substrate, and a light reflective layer, separate from the light absorptive layer, made of a metal film formed on the light absorptive layer, wherein -0.4≦ΔS≦-0.04, ΔS being the optical phase difference between a reading laser beam reflected from the light reflective layer at a portion thereof corresponding to the pregroove and the reading laser beam reflected from the light reflective layer at a portion thereof corresponding to the land located on each side of the pregroove, wherein ΔS=2d sub {n sub -n abs (1-d abs /d sub )}/λ, and wherein d sub is the depth of a first layer boundary at a substrate side of the light absorptive layer from the land to a bottom of the pregroove, d abs is the depth of a second layer boundary at a light absorptive layer side of the light reflective layer from a portion thereof at the land to a portion thereof at the pregroove, n sub is the real part of the complex refractive index of the substrate and any layer present on the substrate side of the light absorptive layer, n abs is the real part of the complex refractive index of the light absorptive layer, and λ is the wavelength of the reading laser beam; and 90 nm ≦d 1n ≦ 350 nm wherein d 1n is a thickness of the light absorptive layer at a portion corresponding to the land.
Claim 10
Dependent Claim
271 words
An optical information recording medium comprising: a light transmitting substrate having a pregroove formed on a surface thereof, a land being positioned on each side of the pregroove, a light absorptive layer of a coloring matter formed on the substrate, and a light reflective layer, separate from the light absorptive layer, made of a metal film formed on the light absorptive layer, wherein -0.4≦ΔS≦-0.04, ΔS being the optical phase difference between a reading laser beam reflected from the light reflective layer at a portion thereof corresponding to the pregroove and the reading laser beam reflected from the light reflective layer at a portion thereof corresponding to the land located on each side of the pregroove, wherein ΔS=2d sub {n sub -n abs (1-d abs /d sub )}/λ, and wherein d sub is the depth of a first layer boundary at a substrate side of the light absorptive layer from the land to a bottom of the pregroove, d abs is the depth of a second layer boundary at a light absorptive layer side of the light reflective layer from a portion thereof at the land to a portion thereof at the pregroove, n sub is the real part of the complex refractive index of the substrate and any layer present on the substrate side of the light absorptive layer, n abs is the real part of the complex refractive index of the light absorptive layer, and λ is the wavelength of the reading laser beam; and 90 nm ≦d 1n ≦ 350 nm wherein d 1n is a thickness of the light absorptive layer at a portion corresponding to the land.
Claim 11
Dependent Claim
29 words
The optical information recording medium according to claim 7, wherein 0.05≦ρ≦1.6 wherein ρ=n abs ·d av /λ wherein d av is the average thickness of the light absorptive layer.
Claim 12
Dependent Claim
31 words
The optical information recording medium according to claim 8, wherein k abs ≦ 0.3 wherein k abs is the imaginary part of the complex refractive index of the light absorptive layer.
Claim 13
Dependent Claim
275 words
An optical information recording medium comprising: a light transmitting substrate having a pregroove formed on a surface thereof, a land being positioned on each side of the pregroove, a light absorptive layer of a coloring matter formed on the substrate, and a light reflective layer, separate from the light absorptive layer, made of a metal film formed on the light absorptive layer, wherein 0.03≦ΔS≦0.3, ΔS being the optical phase difference between a reading laser beam reflected from the light reflective layer at a portion thereof corresponding to the pregroove and the reading laser beam reflected from the light reflective layer at a portion thereof corresponding to the land located on each side of the pregroove, wherein ΔS=2d sub {n sub -n abs (1-d abs /d sub )}/λ, and wherein d sub is the depth of a first layer boundary on a substrate side of the light absorptive layer from the land to a bottom of the pregroove, d abs is the depth of a second layer boundary at a light absorptive layer side of the light reflective layer from a portion thereof at the land to a portion thereof at the pregroove, n sub is the real part of the complex refractive index of the substrate and any layer present on the substrate side of the light absorptive layer, n abs is the real part of the complex refractive index of the light absorptive layer, and λ is the wavelength of the reading laser beam; and 90 nm ≦d gr ≦ 350 nm wherein d gr is the thickness of the light absorptive layer at a portion corresponding to the pregroove; and d sub ≦nm.
Claim 14
Dependent Claim
275 words
An optical information recording medium comprising: a light transmitting substrate having a pregroove formed on a surface thereof, a land being positioned on each side of the pregroove, a light absorptive layer of a coloring matter formed on the substrate, and a light reflective layer, separate from the light absorptive layer, made of a metal film formed on the light absorptive layer, wherein 0.03≦ΔS≦0.3, ΔS being the optical phase difference between a reading laser beam reflected from the light reflective layer at a portion thereof corresponding to the pregroove and the reading laser beam reflected from the light reflective layer at a portion thereof corresponding to the land located on each side of the pregroove, wherein ΔS=2d sub {n sub -n abs (1-d abs /d sub )}/λ, and wherein d sub is the depth of a first layer boundary on a substrate side of the light absorptive layer from the land to a bottom of the pregroove, d abs is the depth of a second layer boundary at a light absorptive layer side of the light reflective layer from a portion thereof at the land to a portion thereof at the pregroove, n sub is the real part of the complex refractive index of the substrate and any layer present on the substrate side of the light absorptive layer, n abs is the real part of the complex refractive index of the light absorptive layer, and λ is the wavelength of the reading laser beam; and 90 nm ≦d gr ≦ 350 nm wherein d gr is the thickness of the light absorptive layer at a portion corresponding to the pregroove; and d sub ≦nm.
Claim 15
Dependent Claim
29 words
The optical information recording medium according to claim 10, wherein 0.05≦ρ≦1.6, wherein ρ=n abs ·d av /λ wherein d av is the average thickness of the light absorptive layer.
Claim 16
Dependent Claim
31 words
The optical information recording medium according to claim 11, wherein k abs ≦ 0.3 wherein k abs is the imaginary part of the complex refractive index of the light absorptive layer.
Claim 17
Dependent Claim
275 words
An optical information recording medium comprising: a light transmitting substrate having a pregroove formed on a surface thereof, a land being positioned on each side of the pregroove, a light absorptive layer of a coloring matter formed on the substrate, and a light reflective layer, separate from the light absorptive layer, made of a metal film formed on the light absorptive layer, wherein -0.4≦ΔS≦0.04, ΔS being the optical phase difference between a reading laser beam reflected from the light reflective layer at a portion thereof corresponding to the pregroove and the reading laser beam reflected from the light reflective layer at a portion thereof corresponding to the land located on each side of the pregroove, wherein ΔS=2d sub {n sub -n abs (1-d abs /d sub )}/λ, and wherein d sub is the depth of a first layer boundary on a substrate side of the light absorptive layer to a bottom of the pregroove, d abs is the depth of a second layer boundary on a light absorptive layer side of the light reflective layer at the portion thereof at the land to a portion thereof at the pregroove, n sub is the real part of the complex refractive index of the substrate and any layer present on the substrate side of the light absorptive layer, n abs is the real part of the complex refractive index of the light absorptive layer, and λ is the wavelength of the reading laser beam; and 90 nm ≦d 1n ≦ 350 nm wherein d 1n is the thickness of the light absorptive layer at a portion thereof corresponding to the land; and d sub ≦ 40 nm.
Claim 18
Dependent Claim
275 words
An optical information recording medium comprising: a light transmitting substrate having a pregroove formed on a surface thereof, a land being positioned on each side of the pregroove, a light absorptive layer of a coloring matter formed on the substrate, and a light reflective layer, separate from the light absorptive layer, made of a metal film formed on the light absorptive layer, wherein -0.4≦ΔS≦0.04, ΔS being the optical phase difference between a reading laser beam reflected from the light reflective layer at a portion thereof corresponding to the pregroove and the reading laser beam reflected from the light reflective layer at a portion thereof corresponding to the land located on each side of the pregroove, wherein ΔS=2d sub {n sub -n abs (1-d abs /d sub )}/λ, and wherein d sub is the depth of a first layer boundary on a substrate side of the light absorptive layer to a bottom of the pregroove, d abs is the depth of a second layer boundary on a light absorptive layer side of the light reflective layer at the portion thereof at the land to a portion thereof at the pregroove, n sub is the real part of the complex refractive index of the substrate and any layer present on the substrate side of the light absorptive layer, n abs is the real part of the complex refractive index of the light absorptive layer, and λ is the wavelength of the reading laser beam; and 90 nm ≦d 1n ≦ 350 nm wherein d 1n is the thickness of the light absorptive layer at a portion thereof corresponding to the land; and d sub ≦ 40 nm.
Claim 19
Dependent Claim
29 words
The optical information recording medium according to claim 13, wherein 0.05≦ρ≦1.6 wherein ρ=n abs ·d av /λ wherein d av is the average thickness of the light absorptive layer.
Claim 20
Dependent Claim
31 words
The optical information recording medium according to claim 14, wherein k abs ≦ 0.3 wherein k abs is the imaginary part of the complex refractive index of the light absorptive layer.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1995-01-13 | 1995-07-15 | 1996-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-01-13 | 1999-07-15 | 2000-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-01-13 | 2003-07-15 | 2004-01-14 | $7700.00 | Window Closed / Lapsed |