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:
Jun. 20, 2006
Filed:
Jul. 01, 2005
Katsuhiko Yasuda, Neyagawa, JP;
Kousei Sano, Osaka, JP;
Daisuke Ogata, Amagasaki, JP;
Yuuichi Kuze, Settsu, JP;
Katsuhiko Yasuda, Neyagawa, JP;
Kousei Sano, Osaka, JP;
Daisuke Ogata, Amagasaki, JP;
Yuuichi Kuze, Settsu, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
The quantity of spherical aberration correction is predetermined for each recording plane of an optical disk on which focusing control is performed. Before operating the focusing control, the quantity of spherical aberration to be corrected by an aberration correcting system is set based on an output signal from an aberration correction quantity switching device that corresponds to the type of the optical disk and the recording plane to be subjected to the focusing control. This makes it possible to perform stable focusing control on each recording plane of a multi-layer optical disk with high density by using an objecting lens having a large NA after spherical aberration has been corrected properly.