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:
Aug. 30, 1994
Filed:
Dec. 21, 1992
Tatsunori Ide, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
The optical data recording media is provided on a substrate with a recording layer changing its optical characteristic dependent upon difference in the heat history, or processes of temperature elevation due to laser beam irradiation and the following cooling. The media is composed of layered structure not only varying its own reflectance or transmittance as an integrated media, but also changing the optical phase of the reflected light or transmitted light, when the optical characteristic of the recording layer is changed. In the method of recording, erasing and reproducing data using this optical data recording media, when the variations of the reflectance is to be detected, recording and erasing are effected after temporarily setting the recording layer in a state having a higher reflectance. On the other hand, when the variations of the transmittance is to be detected, recording and erasing are effected after temporarily setting the recording layer in a state having a higher transmittance. The substrate has such guide grooves that the width of either the convex portion between the guide grooves or the concave portion of the guide grooves is smaller than the diameter of the laser beam spot for reproduction.