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:
Jun. 28, 1994
Filed:
Jun. 28, 1993
Applicant:
Inventors:
Koji Sasaki, Miyagi, JP;
Takashi Kishi, Miyagi, JP;
Assignee:
Sony Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
3692752 ; 3692751 ; 3692755 ; 369279 ;
Abstract
An optical recording medium formed of a pre-grooved substrate provided with a recording layer formed on the groove, in which the groove has a shape to satisfy the condition I.sub.Gr /I.sub.0 .gtoreq.0.85, where I.sub.0 represents the reflected light quantity from the mirror surface and I.sub.Gr represents the reflected light quantity from the groove surface when the laser beam is concentrated to a spot size of approximately 1 .mu.m on the surface of the medium, and to enable three-spot tracking to be performed. According to this invention, the CN ratio as the measure of noise in an optical recording medium can be improved.