FOCUS AND TRACKING SERVO SYSTEM OF OPTICAL DISK DRIVE

摘要

PURPOSE: A focus and tracking servo system of an optical disk drive is provided to secure a high gain in a low frequency area by maintaining a phase margin and positively offering feedback to a low frequency filter. CONSTITUTION: A feedback controller(C3(s)) receives a focus tracking error signal(e) for calculating the focus tracking error signal according to a set algorithm to be output to the next terminal. A DOB(Disturbance OBserver) control units adds an output signal(u) output from the feedback controller to a signal(v) given to a drive and passes a low band pass filter(Q(s)) to output the added signal to the current drive. An actuator processes the output signal(v) output from the DOB control unit with a set transfer function(P(s)).