Revision Method of Track Deviation for Optical Disk

摘要

PURPOSE: A method for correcting track deviation of an optical disk is provided to accurately transfer a pickup assembly for reading data of a wanted position on the optical disk. CONSTITUTION: A focus servo is turned on in transferring a pickup assembly for following a disk to generate a signal while a tracking servo is turned off for following tracks on the disk(S11). If the disk rotates while the pickup is transferred, the rotating disk cross the tracks between an inner periphery and an outer periphery for generating a traverse signal due to a difference in intensity of light between the tracks and other parts(S12). The number of pulses of the traverse signal is counted after fixing the shape of the traverse signal(S13). The rotary frequency of the disk is measured and stored while the pickup assembly is being transferred to measure pitch(S14-S15). Track pitch of the rotating disk is calculated by using the number of pulses and a physical distance moving the pickup assembly(S16). A target track is calculated by using the calculated track pitch and seek operation is executed(S17).