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. 11, 1995
Filed:
Oct. 04, 1993
Applicant:
Inventors:
Assignee:
TDK Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
3692754 ; 369277 ;
Abstract
In a magneto-optical disk comprising a disk-shaped substrate including a grooved region in its surface and a recording layer covering the grooved region, the groove is defined by a pair of opposed side walls and a bottom in a radial cross section of the substrate and has a depth from the substrate surface to the groove bottom. The angle .theta. included between tangents to the side walls is at least 120 degrees, and the groove has a half-value width of 0.90 to 1.15 .mu.m and a depth of 600 to 900 .ANG.. The disk produces satisfactory values of push-pull signal level, radial contrast, and C/N ratio.