Disc replay and record device with tracking control disc drive

摘要

The tracking control and synchronisation system for an optical disc system has a scanner device for the recording medium, which provides an output signal for connection to a synchronisation circuit. The synchroniser has a variable middle frequency signal output generator (12,13), and may be a digital device. An input signal BS compared with the measured tracking signal NS in a phase comparator 10. The comparator output is fed to a low pass filter 11 coupled to a processor 12 that determines filter coefficients based upon the phase signal. The output is fed to a tracking oscillator 13 providing the output from the loop