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:
May. 07, 2013
Filed:
Dec. 15, 2010
Yusuke Kanatake, Tokyo, JP;
Tomo Kishigami, Tokyo, JP;
Toshiya Matozaki, Tokyo, JP;
Nobuo Takeshita, Tokyo, JP;
Yusuke Kanatake, Tokyo, JP;
Tomo Kishigami, Tokyo, JP;
Toshiya Matozaki, Tokyo, JP;
Nobuo Takeshita, Tokyo, JP;
Mitsubishi Electric Corporation, Tokyo, JP;
Abstract
An optical recording/reproduction method and device that can perform control for optimizing the amount of spherical aberration in a multilayered optical disc in a short period of time. When the objective lens is displaced in the focusing direction, the amplitude value of the focusing error signal detected just after leaving the focal position of a given first recording layer and the amplitude value of the focusing error signal detected just before passing through the focal position of a given second recording layer other than the first recording layer are measured with a particular spherical aberration, the amplitude ratio of amplitude values is calculated, the difference between spherical aberration and the optimal spherical aberration for the second recording layer is approximated as a function of the amplitude ratio, the optimal spherical aberration is calculated on the basis of this approximation, and the spherical aberration is set.