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. 18, 2013
Filed:
Aug. 03, 2009
Fumitomo Yamasaki, Nara, JP;
Eishin Mori, Tokyo, JP;
Fumitomo Yamasaki, Nara, JP;
Eishin Mori, Tokyo, JP;
Panasonic Corporation, Osaka, JP;
Abstract
An object of the invention is to provide an optical disc device, an optical head, and an information processing device that enable to advantageously record or reproduce information with respect to an information recording medium having three or more information recording surfaces with light transmissive layers of different thicknesses from each other. Assuming that an aberration amount of third-order coma aberration resulting from tilting a multilayer optical disc () by a unit angle is CMD0 (unit: mλ/deg), an aberration amount of third-order coma aberration resulting from tilting an objective lens () by a unit angle is CML0 (unit: mλ/deg), a tilt angle of the multilayer optical disc () is θ, a coefficient is k0, and a tilt angle of the objective lens () by an objective lens actuator () is αin converging laser light on an information recording surface having a largest light transmissive layer thickness out of the information recording surfaces of the multilayer optical disc (), the objective lens actuator () tilts the objective lens () in such a manner that the tilt angle αof the objective lens () satisfies the following mathematical expression:α0=θ×0×0/0, where 0.5<k0<0.9.