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:
Jan. 13, 2009
Filed:
Dec. 05, 2005
Toshihiro Sugaya, Moriya, JP;
Naomasa Nakamura, Yokohama, JP;
Nobuhisa Yoshida, Kamakura, JP;
Masato Otsuka, Tokyo, JP;
Toshihiro Sugaya, Moriya, JP;
Naomasa Nakamura, Yokohama, JP;
Nobuhisa Yoshida, Kamakura, JP;
Masato Otsuka, Tokyo, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Memory-Tech Corporation, Chikuse, Ibaraki, JP;
Abstract
An optical disc of this invention is configured to be capable of dealing with both information in HD DVD and information in DVD. The optical disc is basically specified by the following items (1) to (7): (1) the optical disc is a single-sided dual layer optical disc where a light transmission layer, a first recording layer accessed with a first laser beam, an space layer, and a second recording layer accessed with a second laser beam are arranged in that order in the direction in which the laser beam enters, (2) the areal recoding density of the second recording layer is three times or more as high as that of the first recording layer, (3) identifying information which indicates that the first recording layer has been formed is formed in the second recording layer, (4) the distance in the light transmission layer from the incidence plane to the first recording layer is 550 μm or more, (5) the distance in the light transmission layer from the incidence plane to the second recording layer is 622 μm or less, (6) the reflectivity of the first recording layer with respect to the first laser beam is 45% to 65%, and (7) the reflectivity of the second recording layer with respect to the second laser beam is 15% to 29%.