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. 02, 2013
Filed:
Sep. 23, 2011
Fumitomo Yamasaki, Nara, JP;
Kanji Wakabayashi, Kyoto, JP;
Yoshiaki Komma, Osaka, JP;
Toshiyasu Tanaka, Osaka, JP;
Fumitomo Yamasaki, Nara, JP;
Kanji Wakabayashi, Kyoto, JP;
Yoshiaki Komma, Osaka, JP;
Toshiyasu Tanaka, Osaka, JP;
Panasonic Corporation, Osaka, JP;
Abstract
An information recording medium includes a first information recording layer and a second information recording layer. The first information recording layer is formed at a laser beam entrance surface, and is configured so that information can be recorded thereupon and/or reproduced therefrom using a first objective lens having a numerical aperture NAand laser beam of a wavelength λ. The second information recording layer is formed so as to have a distance to the laser beam entrance surface of 0.05 mm to 1.2 mm and is configured so that information can be recorded thereupon and/or reproduced therefrom using a second objective lens having a numerical aperture NAand laser beam of a wavelength λ. When a diffraction limit δ, determined by numerical aperture NAand wavelength λ, is taken as δ0.61×λ/NA, a track pitch Tpof a track formed on the first information recording layer is Tp