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:
Sep. 30, 2003
Filed:
Mar. 26, 2001
Masayuki Iwasaki, Tsurugashima, JP;
Masakazu Ogasawara, Tsurugashima, JP;
Pioneer Corporation, Tokyo, JP;
Abstract
An apparatus and a method are provided for compensating an aberration occurring in a reflected light beam from a recording medium. The apparatus includes a liquid crystal unit including a first electrode layer having divisional electrodes and a second electrode layer, and a liquid crystal element which provides a light beam with a phase change when an electric field is applied; a detector for receiving the reflected light beam through the liquid crystal unit to generate a detection signal; a voltage generator for generating voltages to be applied to the divisional electrodes; and a controller for performing aberration compensation control by changing the applied voltages to each of the divisional electrodes with reference to an applied reference voltage to a predetermined divisional electrode. The controller determines the applied reference voltage based on an amplitude change of the detection signal when the applied voltages to the divisional electrodes are changed.