DEVICE FOR DETECTING A TRACKING ERROR OF AN OPTICAL SPOT OBTAINED BY RADIATING A LIGHT ON AN OPTICAL RECORDING MEDIUM

摘要

PURPOSE: A device for detecting a tracking error is provided to detect an exact tracking error signal even though a disk is played at CAV(Constant Angular Velocity) or the disk is damaged, thereby performing exact tracking control. CONSTITUTION: A phase difference detecting circuit(31) has 2-series of digital signals as input, compares phases by using a distance between zero cross points of the inputted digital signals, and outputs the compared results. An LPF(108) generates a tracking error signal from the compared results. The phase difference detecting circuit(31) does not compare the phases in an improper position, and outputs the compared results as a pulse with one sampling clock.