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:
Sep. 09, 2008
Filed:
Aug. 06, 2004
Hideo Kusada, Osaka, JP;
Ken'ichi Nagata, Nishinomiya, JP;
Hideki Kitaura, Souraku-gun, JP;
Kenichi Nishiuchi, Hirakata, JP;
Noboru Yamada, Hirakata, JP;
Rie Kojima, Kadoma, JP;
Hideo Kusada, Osaka, JP;
Ken'ichi Nagata, Nishinomiya, JP;
Hideki Kitaura, Souraku-gun, JP;
Kenichi Nishiuchi, Hirakata, JP;
Noboru Yamada, Hirakata, JP;
Rie Kojima, Kadoma, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
The present invention provides an optical information recording medium of excellent signal quality in high density recording onto a semitransparent information layer, its manufacturing method and a manufacturing apparatus. The optical information recording medium of the present invention includes at least a semitransparent information layer disposed between a circular transparent substrate and a protective substrate, in which the information layer has spiral grooves for guiding a light beam, and also includes a recording film capable of recording/reproducing information thereon/therefrom by changing at least in two states detectable optically by irradiation of the light beam from the transparent substrate side, and the difference in film thickness of slope portions of the inner circumferential side and outer circumferential side of the groove is within ±10% in the entire region for recording/reproducing information.