EP0360466A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Optical information recording medium and information recording and reproducing method therefor
Assignee: Panasonic Holdings Corp
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Filing: 1989-09-08
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Granted: —
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Expires: 2009-09-08
Abstract
Abstract An optical information recording medium according to the present invention has a thin film material (3) formed on a substrate (1), the optical constant of which film material (3) is changed with application of a light beam so that the optical phase of reflected or transmitted light of incident light is changed between before and after the change of the optical constant, thereby reproducing signal by detecting a change in the overall quantity of the reflected or transmitted light due to this optical phase change. It is preferable that the optical information recording medium has a structure which causes no change or a small change in the amplitude of the reflected or transmitted light between before and after that change. It is also possible to perform the signal reproduction equivalent to concave/convex pits without being accompanied with deformation, thereby improving the recording density. It is easy to make interchange with optical recording medium of write once type and read only type and, furthermore, it is possible to erase and rewrite.
Inventors
- 👤 Nobuo Akahira
- 👤 Kenichi Nishiuchi
- 👤 Kenichi Nagata
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 05:43
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/004; G11B7/005; G11B7/0051; G11B7/0045; G11B7/00455; G11B7/24
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
72 words
An optical information recording medium having a recording layer (3) of a material making a change which is optically detectable with application of a light beam formed on a substrate (1), wherein an optical constant of the material of the recording layer (3) is changed with application of the light beam so that the detectable change is caused mainly due to a change in an optical phase of reflected or transmitted light.
Claim 2
Dependent Claim
72 words
An optical information recording medium having a recording layer (3) of a material making a change which is optically detectable with application of a light beam formed on a substrate (1), wherein an optical constant of the material of the recording layer (3) is changed with application of the light beam so that the detectable change is caused mainly due to a change in an optical phase of reflected or transmitted light.
Claim 3
Dependent Claim
37 words
An optical information recording medium according to Claim 1, wherein a change in an amplitude of the transmitted or reflected light of the incident light is small between before and after the change of the optical constant.
Claim 4
Dependent Claim
38 words
An optical information recording medium according to Claim 1 or 2, wherein a transparent layer (2, 4) having a different refractive index from the substrate (1) is formed on at least one of surfaces of the recording later.
Claim 5
Dependent Claim
97 words
An optical information recording medium according to Claim 1 or 2, wherein the substrate is formed thereon with a first transparent layer (2) having a different refractive index from the substrate (1), the recording layer (3), a second transparent layer (4) and a reflective layer (5) in the mentioned order, thicknesses of said first transparent layer (2), recording layer (3), second transparent layer (4) and reflective layer (5) being selected such as to make the optical phase of the transmitted or reflected light change in response to the change in the material of the recording layer (3).
Claim 6
Dependent Claim
25 words
An optical information recording medium according to Claim 1 or 2, wherein the optical phase change is substantially (1 ± 2n)π, n being an integer.
Claim 7
Dependent Claim
32 words
An optical information recording medium according to Claim 1, wherein the shape of the recording layer (3) is not changed at the time of making change with application of the light beam.
Claim 8
Dependent Claim
32 words
An optical information recording medium according to Claim 1, wherein the change in the recording layer (3) due to application of the light beam is reversible and the recorded signal is erasable.
Claim 9
Dependent Claim
109 words
An optical information recording medium having a recording layer of a material making a change which is optically detectable with application of a light beam formed on a substrate (1), wherein the substrate (1) is formed beforehand with concave and/or convex serving to change an optical phase of reflected or transmitted light of a light incident on a surface thereof on which the recording layer is formed, and an optical constant of the material of the recording layer (3) is changed with application of the light beam so that the detectable change is caused mainly due to a change in the optical phase of the reflected or transmitted light.
Claim 10
Dependent Claim
109 words
An optical information recording medium having a recording layer of a material making a change which is optically detectable with application of a light beam formed on a substrate (1), wherein the substrate (1) is formed beforehand with concave and/or convex serving to change an optical phase of reflected or transmitted light of a light incident on a surface thereof on which the recording layer is formed, and an optical constant of the material of the recording layer (3) is changed with application of the light beam so that the detectable change is caused mainly due to a change in the optical phase of the reflected or transmitted light.
Claim 11
Dependent Claim
38 words
An optical information recording medium according to Claim 8, wherein a change in an amplitude of the transmitted or reflected light of the incident light is small between before and after the change of the recording layer (3).
Claim 12
Dependent Claim
99 words
An optical information recording medium according to Claim 8 or 9, wherein the substrate is formed thereon with a first transparent layer (2) having a different refractive index from the substrate (1), the recording layer (3), a second transparent layer (4) and a reflective layer (5) in the mentioned order, thicknesses of said first transparent layer (2), recording film layer (3), second transparent layer (4) and reflective layer (5) being selected such as to make the optical phase of the reflected light of the incident light change in response to the change in the material of the recording layer.
Claim 13
Dependent Claim
25 words
An optical information recording medium according to Claim 8 or 9, wherein the optical phase change is substantially (1 ± 2n)π, n being an integer.
Claim 14
Dependent Claim
25 words
An optical information recording medium according to Claim 8 or 9, wherein the optical phase change is substantially (-1/2 ± 2n)π, n being an integer.
Claim 15
Dependent Claim
25 words
An optical information recording medium according to Claim 8 or 9, wherein the optical phase change is substantially (+1/2 ± 2n)π, n being an integer.
Claim 16
Dependent Claim
113 words
An optical information recording medium having a recording layer of a material making a change which is optically detectable with application of a light beam formed on a portion of a substrate (1), wherein the substrate (1) is formed beforehand with concave and/or convex serving to change an optical phase of reflected or transmitted light of incident light in a portion thereof except the portion on which the recording layer is formed, and an optical constant of the material of the recording layer is changed with application of the light beam so that the detectable change is caused mainly due to a change in the optical phase of the reflected or transmitted light.
Claim 17
Dependent Claim
113 words
An optical information recording medium having a recording layer of a material making a change which is optically detectable with application of a light beam formed on a portion of a substrate (1), wherein the substrate (1) is formed beforehand with concave and/or convex serving to change an optical phase of reflected or transmitted light of incident light in a portion thereof except the portion on which the recording layer is formed, and an optical constant of the material of the recording layer is changed with application of the light beam so that the detectable change is caused mainly due to a change in the optical phase of the reflected or transmitted light.
Claim 18
Dependent Claim
23 words
An optical information recording medium according to Claim 14, wherein the optical phase change is substantially (1 ± 2n)π, n being an integer.
Claim 19
Dependent Claim
167 words
An information recording and reproducing method for an optical information recording medium having a recording layer of a material making a change which is optically detectable with application of a light beam formed on a substrate, wherein the substrate (1) is formed beforehand with concave and/or convex serving to change an optical phase of reflected or transmitted light of a light incident on a surface thereof on which the recording layer (3) is formed, and an optical constant of the material of the recording layer (3) is changed with application of the light beam so that the detectable change is caused mainly due to a change in the optical phase of the reflected or transmitted light, said method comprising the step of: recording and reproducing information by making use of the concave and/or convex formed beforehand in the surface of the substrate (1) on which the recording layer (3) is formed for changing the optical phase of the reflected light of the incident light while executing tracking.
Claim 20
Dependent Claim
167 words
An information recording and reproducing method for an optical information recording medium having a recording layer of a material making a change which is optically detectable with application of a light beam formed on a substrate, wherein the substrate (1) is formed beforehand with concave and/or convex serving to change an optical phase of reflected or transmitted light of a light incident on a surface thereof on which the recording layer (3) is formed, and an optical constant of the material of the recording layer (3) is changed with application of the light beam so that the detectable change is caused mainly due to a change in the optical phase of the reflected or transmitted light, said method comprising the step of: recording and reproducing information by making use of the concave and/or convex formed beforehand in the surface of the substrate (1) on which the recording layer (3) is formed for changing the optical phase of the reflected light of the incident light while executing tracking.
Claim 21
Dependent Claim
169 words
An information recording and reproducing method for an optical information recording medium having a recording layer of a material making a change which is optically detectable with application of a light beam formed on a substrate, wherein the substrate (1) is formed beforehand with concave and/or convex serving to change an optical phase of reflected or transmitted light of a light incident on a surface thereof on which the recording layer is formed, and an optical constant of the material of the recording layer (3) is changed with application of the light beam so that the detectable change is caused mainly due to a change in the optical phase of the reflected or transmitted light, said method comprising the step of: applying a reproducing light beam onto the concave and/or convex formed beforehand in the surface of the substrate(1) on which the recording layer is formed through modulation in accordance with some information signal for changing the optical phase of the reflected light, so as to reproduce said information.
Claim 22
Dependent Claim
169 words
An information recording and reproducing method for an optical information recording medium having a recording layer of a material making a change which is optically detectable with application of a light beam formed on a substrate, wherein the substrate (1) is formed beforehand with concave and/or convex serving to change an optical phase of reflected or transmitted light of a light incident on a surface thereof on which the recording layer is formed, and an optical constant of the material of the recording layer (3) is changed with application of the light beam so that the detectable change is caused mainly due to a change in the optical phase of the reflected or transmitted light, said method comprising the step of: applying a reproducing light beam onto the concave and/or convex formed beforehand in the surface of the substrate(1) on which the recording layer is formed through modulation in accordance with some information signal for changing the optical phase of the reflected light, so as to reproduce said information.
Claim 23
Dependent Claim
174 words
An information recording and reproducing method for an optical information recording medium having a recording layer of a material making a change which is optically detectable with application of a light beam formed on a portion of a substrate, wherein the substrate is formed beforehand with concave and/or convex serving to change an optical phase of reflected or transmitted light of incident light in a portion thereof except the portion on which the recording layer is formed, and an optical constant of the material of the recording layer is changed with application of the light beam so that the detectable change is caused mainly due to a change in the optical phase of the reflected or transmitted light, said method comprising the step of: applying a reproducing light beam onto the concave and/or convex formed beforehand in the surface of the substrate (1) on which the recording layer (3) is formed through modulation in accordance with some information signal for changing the optical phase of the reflected light, so as to reproduce said information.
Claim 24
Dependent Claim
174 words
An information recording and reproducing method for an optical information recording medium having a recording layer of a material making a change which is optically detectable with application of a light beam formed on a portion of a substrate, wherein the substrate is formed beforehand with concave and/or convex serving to change an optical phase of reflected or transmitted light of incident light in a portion thereof except the portion on which the recording layer is formed, and an optical constant of the material of the recording layer is changed with application of the light beam so that the detectable change is caused mainly due to a change in the optical phase of the reflected or transmitted light, said method comprising the step of: applying a reproducing light beam onto the concave and/or convex formed beforehand in the surface of the substrate (1) on which the recording layer (3) is formed through modulation in accordance with some information signal for changing the optical phase of the reflected light, so as to reproduce said information.
References Cited (Backward Citations)
US4664977A
Cited
WO1988009549A1
Cited
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