US5636201A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical disk memory for recording reproducible information
Assignee: Nikon Corp
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Filing: 1995-11-16
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Granted: 1997-06-03
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Expires: 2015-11-16
Abstract
Abstract This optical disk comprises neighboring land tracks and a groove track laid therebetween. Light modulating regions are formed in said land tracks and each of the light modulating regions extends in the groove track.
Inventors
- 👤 Hiroshi Ooki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 04:45
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/252; G11B7/258; G11B11/00; G11B11/10; G11B11/105; G11B11/10502; G11B11/10515; G11B11/10582; G11B11/10584; G11B7/004; G11B7/005; G11B7/0051; G11B7/242; G11B7/243; G11B7/257; G11B2007/24302; G11B2007/2431; G11B2007/24314; G11B2007/24316; G11B7/0045; G11B7/2585; G11B7/2595
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
134 words
An optical disk, comprising: (a) neighboring land tracks, wherein light modulating regions are formed on said land tracks, wherein information is read out by irradiating a light beam onto said land tracks, and wherein the light beam is focused on the light modulating region by a lens; and (b) a grove track separating said land tracks, wherein each of the light modulating regions extends into said groove track, wherein said optical disk satisfies the following expressions: H=(2n-1)×λ/4, and r<0.61λ/NA; where, H is the step height between a top surface of one of said land tracks and a bottom surface of said groove track, n is a natural number, λ is the wavelength of the light beam, r is the interval between said neighboring land tracks, and NA is the numerical aperture of the lens.
Claim 2
Dependent Claim
134 words
An optical disk, comprising: (a) neighboring land tracks, wherein light modulating regions are formed on said land tracks, wherein information is read out by irradiating a light beam onto said land tracks, and wherein the light beam is focused on the light modulating region by a lens; and (b) a grove track separating said land tracks, wherein each of the light modulating regions extends into said groove track, wherein said optical disk satisfies the following expressions: H=(2n-1)×λ/4, and r<0.61λ/NA; where, H is the step height between a top surface of one of said land tracks and a bottom surface of said groove track, n is a natural number, λ is the wavelength of the light beam, r is the interval between said neighboring land tracks, and NA is the numerical aperture of the lens.
Claim 3
Dependent Claim
55 words
An optical disk according to claim 1, wherein each of the land track has an intensity modulation layer including: first and second dielectric protection films; a recording layer of GaSbTe; and a metal reflection film, wherein both said recording layer and said metal reflection film are sandwiched between said first and second dielectric protection films.
Claim 4
Dependent Claim
19 words
An optical disk according to claim 2, wherein said first and second dielectric protection films are comprised of ZnS.
Claim 5
Dependent Claim
20 words
An optical disk according to claim 2, wherein said first and second dielectric protection films are comprised of phospho-silicate glass.
Claim 6
Dependent Claim
19 words
An optical disk according to claim 2, wherein said first and second dielectric protection films are comprised of SiN.
Claim 7
Dependent Claim
16 words
An optical disk according to claim 2, wherein said metal reflection film is comprised of Al.
Claim 8
Dependent Claim
16 words
An optical disk according to claim 2, wherein said metal reflection film is comprised of Ni.
Claim 9
Dependent Claim
16 words
An optical disk according to claim 2, wherein said metal reflection film is comprised of Au.
Claim 10
Dependent Claim
21 words
An optical disk according to claim 1, wherein the wavelength λ is larger than 400 nm and small than 900 nm.
Claim 11
Dependent Claim
44 words
An optical disk according to claim 1, wherein phase difference ψ between light components reflected respectively by a top surface of one of said land tracks and a bottom surface of said groove track satisfies following equation: ψ=(2n-1)×π, where, n is a natural number.
Claim 12
Dependent Claim
126 words
An optical disk comprising first and second track groups which form a hill and valley structure, wherein light modulating regions are formed on one of said track groups, and a width of one of said light modulating region is greater than a width of said track, wherein a light beam is focused on said light modulating regions by a lens, and said optical disk satisfied the following expressions: H=(2n-1)×λ/4, and r<0.61λ/NA; where, H is the step height between a top surface of one of said land tracks and a bottom surface of said groove track, n is a natural number, λ is the wavelength of the light beam, r is the interval between said neighboring land tracks, and NA is the numerical aperture of the lens.
Claim 13
Dependent Claim
126 words
An optical disk comprising first and second track groups which form a hill and valley structure, wherein light modulating regions are formed on one of said track groups, and a width of one of said light modulating region is greater than a width of said track, wherein a light beam is focused on said light modulating regions by a lens, and said optical disk satisfied the following expressions: H=(2n-1)×λ/4, and r<0.61λ/NA; where, H is the step height between a top surface of one of said land tracks and a bottom surface of said groove track, n is a natural number, λ is the wavelength of the light beam, r is the interval between said neighboring land tracks, and NA is the numerical aperture of the lens.
Claim 14
Dependent Claim
21 words
An optical disk according to claim 11, wherein each of said light modulating regions differs in reflectance from its surrounding region.
Claim 15
Dependent Claim
22 words
An optical disk according to claim 11, wherein each of said light modulating regions differs in magnetic susceptibility from its surrounding region.
Claim 16
Independent Claim
154 words
A method for reproducing an information from an optical disk having land tracks and a groove track separating said land tracks, said method comprising: irradiating a light beam onto an light modulating region extending from said land track to said groove track, wherein the light beam is reflected by the light modulating region and the intensity of the light beam is changed by the reflection; and detecting the reflected light beam with a photodetector, wherein the light beam is focused on said light modulating regions by a lens, and said optical disk satisfies the following expressions: H=(2n-1)×λ/4, and r<0.61λ/NA; where, H is the step height between a top surface of one of said land tracks and a bottom surface of said groove track, n is a natural number, λ is the wavelength of the light beam, r is the interval between said neighboring land tracks, and NA is the numerical aperture of the lens.
Claim 17
Independent Claim
154 words
A method for reproducing an information from an optical disk having land tracks and a groove track separating said land tracks, said method comprising: irradiating a light beam onto an light modulating region extending from said land track to said groove track, wherein the light beam is reflected by the light modulating region and the intensity of the light beam is changed by the reflection; and detecting the reflected light beam with a photodetector, wherein the light beam is focused on said light modulating regions by a lens, and said optical disk satisfies the following expressions: H=(2n-1)×λ/4, and r<0.61λ/NA; where, H is the step height between a top surface of one of said land tracks and a bottom surface of said groove track, n is a natural number, λ is the wavelength of the light beam, r is the interval between said neighboring land tracks, and NA is the numerical aperture of the lens.
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