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:
Aug. 10, 1999
Filed:
Aug. 14, 1996
Sakashi Ootaki, Tsurugashima, JP;
Masayuki Iwasaki, Tsurugashima, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
An optical pickup which is designed to correct coma aberration and spherical aberration as well as aberration caused by the relative positional deviation of an objective lens to an aberration correcting liquid crystal panel by using this liquid crystal panel and which is thus compatible to both DVDs and CDs. In the optical pickup having at least a laser light source and an objective lens, an aberration correcting liquid crystal panel is arranged on the optical axis of a laser beam and a transparent electrode of this liquid crystal panel is divided into segments in a predetermined pattern like the cross pattern of a chessboard, and voltages to be applied to the individual segments are variably controlled by a liquid crystal panel controller to alter the refractive index of each segment, thus correcting aberration.