Patent ID: 8054732
Filing Date: 2011-11-08
Classification: G02F,G11B

Abstract:
1. An optical recording and reproducing apparatus equipped with an optical pickup having a light source for emitting a light beam, a liquid crystal correcting element which includes a liquid crystal layer arranged between two electrode layers which face each other and modulates a phase of said light beam, an objective lens for converging said modulated light beam onto a signal recording surface of an optical recording medium, and an optical system for guiding said light beam to said liquid crystal correcting element, comprising: a memory for storing a plurality of correction data sets respectively corresponding to a plurality of refractive index distribution to be formed by said liquid crystal correcting element; an operation mode control unit for designating an operation mode of said optical pickup; a liquid crystal element control unit for selectively reading out the correction data set corresponding to the operation mode designated by said operation mode control unit from said memory and applying a driving voltage according to said read-out correction data set to said electrode layers; a signal detecting unit for forming a servo signal on the basis of the return light beam reflected by said signal recording surface; and a servo control unit for controlling an operation of said optical pickup on the basis of said servo signal in the operation mode designated by said operation mode control unit, wherein when said operation mode control unit designates a seek operation mode, said liquid crystal element control unit selectively reads out, from said memory, the correction data set which has been set so that the refractive index distribution which minimizes a generation amount of a noise component contained in a focusing error signal at the time of the seeking operation of said optical pickup is formed in said liquid crystal layer.