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:
Sep. 28, 1992
Applicant:
Inventors:
Assignee:
Sony Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
430 21 ; 430 13 ; 430495 ; 430945 ;
Abstract
An optical disk having a greatly improved recording density. The disk has a transparent substrate provided with phase pits. A layer of a phase changeable material is formed on the substrate. This phase changeable material is a chalcogen or chalcogenide such as Sb.sub.2 Se.sub.3 or Sb.sub.2 Te.sub.3. When reading light is directed onto the disk, a part of the layer of the phase changeable material is melted within the spot of the reading light beam, and the reflectivity changes and a phase pit is read through the melted part. After the reading, the melted portion recrystallizes.