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. 28, 1998
Filed:
Jun. 27, 1997
Eiji Ohno, Hirakata, JP;
Kenichi Nishiuchi, Moriguchi, JP;
Yoshitaka Sakaue, Nara, JP;
Kazuhisa Ide, Osaka, JP;
Naoyasu Miyagawa, Suita, JP;
Nobuo Akahira, Yawata, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An optical information recording medium includes: a substrate including a groove having a concave shape and a land having a convex shape adjacent to the groove; and a recording layer on the substrate, wherein the recording layer consists of a material which changes between a first state and a second state whose optical property is different from that of the first state, a first portion of the optical information recording medium including a portion in the first state of the recording layer having a first reflectance, and a second portion of the optical information recording medium including a region in the second state of the recording layer having a second reflectance which is different from the first reflectance, whereby information is recorded onto the groove and the land, and wherein a ratio of the first reflectance to the second reflectance, a phase of reflected light from the first portion and a phase of reflected light from the second portion are set such that at least one of an amplitude and a carrier to noise ratio (CNR) of a signal obtained by reproducing information from the groove is approximately identical to that from the land.