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. 28, 2013
Filed:
Feb. 16, 2007
Shuji Naka, Huchu, JP;
Shinya Sato, Koganei, JP;
Shuji Naka, Huchu, JP;
Shinya Sato, Koganei, 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 an nλ/4 liquid crystal panel in an integral fashion is mounted in a tilted position. More specifically, the invention provides a liquid crystal optical element includes a first liquid crystal layer having a first rubbing direction and for correcting aberration, a second liquid crystal layer having a second rubbing direction and combined with the first liquid crystal layer in an integral fashion, and a transparent electrode for generating a potential difference across 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 wherein the angle (ψ) that the second rubbing direction makes with the first rubbing direction is determined in accordance with the tilt angle (α) so that the second liquid crystal layer functions as an nλ/4 plate. The invention also provides an optical pickup apparatus incorporating such a liquid crystal optical element.