EP0132410A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Information recording media
Assignee: Sony Corp
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Filing: 1984-07-25
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Granted: —
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Expires: 2004-07-25
Abstract
Abstract An information recording medium (1) for use with focused laser beams modulated with recorded information signals comprises a substrate (3) having a recording layer (6) composed of at least two layers (7, 8), the first layer (7) being formed on the substrate (3) and the second layer (8) being formed over the first layer (7). The substrate (3) and the first layer (7) have the property of high transmittance to laser beams and the second layer (8) is composed of a metal which is predominantly a low melting point metal capable of absorbing the laser beams and readily forming an alloy with the material of the first layer (7), the thickness of the first layer (7) being such that the reflectance of the laser beams entering from the substrate side is lowered by the interference effect caused by repetitive multiple reflections. The metal of the second layer (8) is thus alloyed to the first layer (7) due to the focused irradiation of a recording laser beam through the substrate (3) on the recording layer (6) changing the conditions for the multiple reflections and changing the reflectance in the recording layer (6) as viewed from the substrate (3), thereby carrying out the recording of the information signals.
Inventors
- 👤 Yasuaki C/O Sony Corporation Nakane
- 👤 Masataka C/O Sony Corporation Kitagawa
- 👤 Tadashi C/O Sony Corporation Kiyomiya
- 👤 Tetsunosuke C/O Sony Corporation Yanada
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 10:45
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/252; G11B7/258; G11B7/2403; G11B7/24035; G11B7/24038; G11B7/242; G11B7/243; G11B7/257; G11B2007/24302; G11B2007/24314; G11B2007/24316; G11B7/253; G11B7/2533; G11B7/2534; Y; Y10; Y10S; Y10S428/00; Y10S428/913; Y10S430/00; Y10S430/146; Y10S430/165; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551; Y10T428/31598; Y10T428/31601; Y10T428/31605; Y10T428/31609
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
206 words
An information recording medium (1) for use with focused laser beams modulated with information signals to be recorded, the medium (1) comprising: a substrate (3) carrying a recording layer (6) comprising a first layer (7) formed on said substrate (3), and a second layer (8) formed on said first layer (7); said substrate (3) and said -first layer (7) having the property of high transmittance to laser beams; characterised in that: said second layer (8) is composed of a metal at least predominantly composed of a low melting metal which absorbs said laser beams and readily forms an alloy with the material of said first layer (7); the thickness of said first layer (7) is such that the reflectance to said laser beams entering from the substrate side is lowered by the interference effect caused by repetitive multiple reflections; and the metal of said second layer (8) is alloyed to that of said first layer (7) due to the focused'irradiation of a laser beam passing through said substrate (3) to said recording layer (6) thereby changing the conditions for said repetitive multiple reflections and changing the reflectance in said recording layer (6) as viewed from said substrate side, thereby effecting the recording of said information signals.
Claim 2
Dependent Claim
206 words
An information recording medium (1) for use with focused laser beams modulated with information signals to be recorded, the medium (1) comprising: a substrate (3) carrying a recording layer (6) comprising a first layer (7) formed on said substrate (3), and a second layer (8) formed on said first layer (7); said substrate (3) and said -first layer (7) having the property of high transmittance to laser beams; characterised in that: said second layer (8) is composed of a metal at least predominantly composed of a low melting metal which absorbs said laser beams and readily forms an alloy with the material of said first layer (7); the thickness of said first layer (7) is such that the reflectance to said laser beams entering from the substrate side is lowered by the interference effect caused by repetitive multiple reflections; and the metal of said second layer (8) is alloyed to that of said first layer (7) due to the focused'irradiation of a laser beam passing through said substrate (3) to said recording layer (6) thereby changing the conditions for said repetitive multiple reflections and changing the reflectance in said recording layer (6) as viewed from said substrate side, thereby effecting the recording of said information signals.
Claim 3
Dependent Claim
25 words
A recording medium (1) according to claim 1 comprising a pair of individual recording elements (2) in inverted relation and secured together at their interface.
Claim 4
Dependent Claim
20 words
A recording medium according to claim 1 or claim 2 wherein said first layer (7) is composed of chalcogenide glass.
Claim 5
Dependent Claim
33 words
A recording medium according to claim 1, claim 2 or claim 3 wherein said second layer (8) is composed of Te, Bi, Sb, In or a low melting point compound of these. metals.
Claim 6
Dependent Claim
22 words
A recording medium according to any one of the preceding claims wherein the thickness of said first layer (7) is 440 angstroms.
Claim 7
Dependent Claim
28 words
A recording medium according to any one of the preceding claims wherein the thickness of said second layer (8) is in the range of 100 to 500 angstroms.
Claim 8
Dependent Claim
25 words
A recording medium according to any one of the preceding claims which also includes a light permeable layer (9) disposed on said second layer (8).
Claim 9
Dependent Claim
18 words
A recording medium according to claim 7 wherein said light permeable layer (9) is composed of chalcogenide glass.
Claim 10
Dependent Claim
25 words
A recording medium according to claim 7 wherein the thickness of said light permeable layer (9) is in the range of 1200 to 1400 angstroms.
Claim 11
Dependent Claim
19 words
A recording medium according to claim 7 which includes a reflective layer (10) on said light permeable layer (9).
Claim 12
Dependent Claim
37 words
A recording medium according to claim 10 wherein said reflective layer (10) is AI, Sn, Ag or Au, and has a refractive index and an absorption coefficient greatly different from those of the light permeable layer (9).
Claim 13
Dependent Claim
40 words
A recording medium according to claim 10 wherein said reflective layer (10) is Ni, Cr, W, Mo or Ti, thus preventing the metal of said second layer (8) from scattering or evaporating upon heating caused by irradiation from laser beams.
References Cited (Backward Citations)
No citation records indexed.
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