PURPOSE: To accurately perform positioning of an optical head by compensating disturbance of a tracking signal caused by a preformat section of an optical disk at the time of access control.
CONSTITUTION: A binarization circuit 7 forms a tracking error signal 101 to a pulse state. A pulse width discriminating circuit 8 eliminates pulses in which pulse generation interval is the prescribed value or less out of binarization signals 102. An error count compensating circuit 9 measures pulse generation interval of a discriminated binarization signal 105, judges that next generated pulse is missing or not based on the measured value, when the pulse is missing, a supplemental pulse is generated. An aimed speed detecting circuit 18 counts the number of pulses of a compensating track cross signal 111, finds the number of remaining moving tracks to an aimed track, and generates a control aimed speed.
SUZUKI YOSHIO
SUZUKI MOTOYUKI
HITACHI VIDEO & INF SYST