SEEK SYSTEM FOR OPTICAL DISK

PURPOSE:To allow positioning with high accuracy by driving only the rough moving mechanism to move the greater part of a seek operation and simultaneously driving both the fine moving mechanism and simultaneously driving both the fine moving mechanism and rough moving mechanisms upon attainment of the speed at which a light spot decelerates and movement can be made by a two-stage servo system. CONSTITUTION:Mode selecting switches 10, 12 are held connected to a C side before a seek error 106 attains a preset value N and, therefore, a linear motor driver 20 drives a linear motor 14 at a relative speed by a signal 116 and a linear motor control signal 118. The mode selecting switches 10, 12 are selected to the D side when the light spot moves and the seek error 106 falls to the preset value N or below. The relative speed error 114 is then made into a galvanomirror control signal 120 and a galvanomirror driver 22 begins to drive a galvanomirror 16. The seek operation is thus executed at the high speed with the high accuracy.