INFORMATION APPARATUS AND OPTICAL PICKUP

摘要

PROBLEM TO BE SOLVED: To perform wavefront correction in which an effect of lens shift is reduced with high accuracy without necessitating a special exclusive member for aligning the optical axis of a light beam with that of an objective lens.

SOLUTION: An information apparatus for reading and/or writing data from/on an optical disk 7 with a light beam is provided. The information apparatus includes: a light source 1 for generating the light beam; an objective lens 6 for focusing the beam onto the optical disk 7; a wavefront sensor for detecting the wavefront of the beam; a lens shift sensor for sensing how much the optical axis of the objective lens has shifted from that of the beam; a wavefront corrector (variable mirror 5), in which correcting elements 5b are arranged as a two-dimensional array so as to locally correct the wavefront of the beam and to be driven independently of each other; a wavefront arithmetic means for making correspondence of each coordinate on a cross section of the beam to the wavefront phase of the beam according to the output of the wavefront sensor; a lens shift correction arithmetic means for changing the correspondence of the coordinate position to the wavefront phase according to the output of the lens shift sensor; and a controller for controlling the wavefront corrector (variable mirror 5) in accordance with the output of the lens shift correction arithmetic means.

COPYRIGHT: (C)2005,JPO&NCIPI