TRACKING ERROR SIGNAL FORMING METHOD AND OPTICAL DISK DEVICE USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a tracking error signal forming method which is the tracking error signal forming system by a phase difference detection system to lessen the occurrence of an offset in shifting of an objective lens and is suitable for a small-scale circuit and lower electric power consumption. SOLUTION: This tracking system is provided with only one system of a circuit for executing phase difference detection and is constituted to divide the signal from a photodetector to plural signal pairs and to execute phase difference detection while selecting the signal pair in time division. As a result, the phase difference detection is substantially equal to the phase difference detection to which the respective signal pairs are independently subjected without increasing the circuit scale. The tracking error signal having the lesser amount of the occurrence of the offset is thus formed.