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:
Mar. 25, 1997
Filed:
Dec. 27, 1994
Applicant:
Inventors:
Assignee:
Teijin Limited, Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
428163 ; 428 643 ; 428 644 ; 428 647 ; 428212 ; 428216 ; 428336 ; 428412 ; 4286 / ; 4286 / ; 4286 / ; 4286 / ; 428900 ; 369 13 ;
Abstract
The reproduction characteristics, particularly the C/N ratio of a reproduced signal of an optical recording medium are deteriorated by an unevenness or deformation of an optical recording layer due to a convex or concave configuration of underlying guide means that are formed on the surface of the substrate. This deterioration can be prevented by disposing a leveling layer under the recording layer, but the leveling layer lowers the efficiency of the servo tracking. This lowering of servo tracking efficiency is prevented by insertion of a dielectric layer between the leveling layer and the guides.