EP0063439A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Optically readable record carriers
Assignee: Sony Corp
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Filing: 1982-04-02
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Granted: —
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Expires: 2002-04-02
Abstract
Abstract A record carrier has a spiral track (2) in which sound and/or video information is stored formed on a transparent substrate (1) and covered by a reflecting layer (8) of metallic material for reflecting a reading beam. The metallic layer (8) does not extend to the inner and/or the outer edge portion (4, 5) of the substrate (1) and is covered by a protective layer (12). The protective layer (12) is extended to the inner and/or the outer edge portion (4, 5) of the substrate (1) so as to seal the metallic layer (8) for preventing oxidation thereof.
Inventors
- 👤 Norio Ohga
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 09:39
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/2403; G11B7/24053; G11B7/24094
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
127 words
An optically readable carrier comprising a disc-like substrate (1) made of transparent material and having a central aperture (3), an information track (2) formed on one surface of said substrate (1) other than the outer edge portion (5) of said surface, a metallic layer (8) formed on said information track (2) for reflecting a reading beam, and a protective layer (12) formed on said metallic layer (8) to protect said metallic layer (8), wherein said metallic layer (8) is not formed on said outer edge portion (5) of said substrate (1), and said protective layer (12) covers said metallic layer (8) and said outer edge portion (5) of said substrate (1), so that said metallic layer (8) is not exposed to air and is protected from oxidation.
Claim 2
Dependent Claim
127 words
An optically readable carrier comprising a disc-like substrate (1) made of transparent material and having a central aperture (3), an information track (2) formed on one surface of said substrate (1) other than the outer edge portion (5) of said surface, a metallic layer (8) formed on said information track (2) for reflecting a reading beam, and a protective layer (12) formed on said metallic layer (8) to protect said metallic layer (8), wherein said metallic layer (8) is not formed on said outer edge portion (5) of said substrate (1), and said protective layer (12) covers said metallic layer (8) and said outer edge portion (5) of said substrate (1), so that said metallic layer (8) is not exposed to air and is protected from oxidation.
Claim 3
Dependent Claim
39 words
A record carrier according to claim 1 wherein said metallic layer (8) does not extend to an inner edge portion (4) adjacent to said central aperture (3) and said protective layer (12) extends over said inner edge portion (4).
Claim 4
Dependent Claim
22 words
A record carrier according to claim 1 or claim 2 wherein said protective layer (12) forms a label for the recored carrier.
Claim 5
Dependent Claim
38 words
A record carrier according to claim 1 or claim 2 wherein said protective layer (12) is formed by a resin cured by ultra-violet light, and a label is formed on said protective layer (12) by a printing technique.
Claim 6
Dependent Claim
27 words
A record carrier according to claim 3 wherein said protective layer (12) is made as a thin film and is fixed to said substrate by adhesive (10).
References Cited (Backward Citations)
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