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. 17, 2012
Filed:
Mar. 05, 2007
Naoki Fujii, Tokyo, JP;
Shuji Naka, Fuchu, JP;
Yoshiharu Takane, Iruma, JP;
Citizen Holdings Co., Ltd., Tokyo, JP;
Abstract
The present invention is directed to the provision of an optical pickup apparatus in which a liquid crystal optical element constructed by combining an aberration correcting liquid crystal panel and a λ/4 liquid crystal panel in an integral fashion is mounted in a tilted position. More particularly, the invention provides a liquid crystal optical element comprising a first liquid crystal layer for correcting aberration, a second liquid crystal layer functioning as an nλ/4 plate and combined in an integral fashion with the first liquid crystal layer, a transparent electrode for generating a potential difference on the second liquid crystal layer in order to control an amount of phase difference for the light beam passing through the second liquid crystal layer, and a driver for driving the transparent electrode so as to generate a potential difference that is the lowest among a plurality of potential differences that cause the second liquid crystal layer to function as an nλ/4 plate. The invention also provides an optical pickup apparatus incorporating such a liquid crystal optical element.