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. 20, 2004
Filed:
Jan. 31, 2002
Masataka Yamaguchi, Tsurugashima, JP;
Takahiro Togashi, Tsurugashima, JP;
Yoichi Okumura, Tsurugashima, JP;
Pioneer Corporation, Tokyo-to, JP;
Abstract
An information recording medium has a light transmissive layer, a first information recording layer, a transparent layer, and a second information recording layer sequentially stacked to reproduce information signals upon exposure of the light transmissive layer to laser light, wherein the first information recording layer comprises a first protective layer, a phase change recording film, and a second protective layer sequentially from the light transmissive layer, and the rate of power fluctuation between a reproducing light passing through a recorded region of the first information recording layer and that passing through an unrecorded region of the first information recording layer during reproduction of the information signals from the second information recording layer, are within 10%, whereby the information signals can be recorded/reproduced on/from the second information recording layer through the first information recording layer satisfactorily.