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. 21, 1995
Filed:
Aug. 15, 1991
Shuichi Igarashi, Miyagi, JP;
Sony Corporation, Tokyo, JP;
Abstract
A magnetic optical disc comprising a magnetic optical recording layer on a transparent substrate. The disc measures less than 80 millimeters in outer diameter and is capable of recording at least 130 megabytes of compressed digital signals. The extreme storage density of the disk is achieved by the suppression of double refraction characteristics near the center area of the disk, whereby the minimum diameter of the recording area can be made smaller. This allows a small-diameter magnetic optical disc to provide a recording area of sufficient storage capacity. In combination with a novel magnetic optical recording system, the disc may illustrative accommodate at least 60 minutes of the user's audio signals while measuring smaller than any other conventional discs of comparable storage capacity.