The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 19, 1994
Filed:
May. 22, 1992
Applicant:
Inventor:
Norio Ohga, Tokyo, JP;
Assignee:
Sony Corporation, Tokyo, JP;
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
3692753 ; 369283 ; 369286 ; 3461351 ;
Abstract
A record carrier has a spiral track in which sound and/or video information is stored formed on a transparent substrate and covered by a reflecting layer of metallic material for reflecting a reading beam. The metallic layer does not extend to the inner and/or the outer edge portion of the substrate and is covered by a protective layer. The protective layer is extended to the inner and/or the outer edge portion of the substrate so as to seal the metallic layer for preventing oxidation thereof.