Patent ID: 6738327
Filing Date: 2004-05-18
Classification: G11B

Abstract:
A servo control apparatus of an optical pickup for reading recorded information from a recording medium to generate a read signal, comprising:an error signal extractor for extracting an error signal from said read signal, said error signal indicating a deviation from a servo target value of said optical pickup; a driver for changing the servo position of said optical pickup; an equalizer for equalizing said error signal to generate a drive signal for driving said driver; an integral value calculator for calculating an integral value of said error signal for each predetermined angular section of rotation of a track on said recording medium; a memory for storing each of the integral values for one rotation of said recording medium; a dropout detector to detect an occurrence of a dropout of said read signal; a variation calculator for calculating a variation by comparing said integral value for an angular section of rotation where said dropout occurred with a stored integral value for the identical angular section of rotation prior to the occurrence of the dropout; and a controller for changing an equalization characteristics of said equalizer in accordance with said variation.