SIGNAL SYNCHRONIZATION CIRCUIT AND COLOR SIGNAL REPRODUCTION CIRCUIT USING THE SAME

PROBLEM TO BE SOLVED: To speed up pull in of a color synchronization signal and to improve coloring of a reproduced signal of a PAL broadcast system by using a prescribed phase difference signal and comparing the level of the signal with a preset threshold level and inverting an output signal from an oscillation circuit depending on the comparison result. SOLUTION: A phase comparator 101 compares the phase of a subcarrier signal SC with a burst signal SB and outputs a phase difference signal SD in response to the comparison result and a VCO 104 generates an oscillation signal with a prescribed frequency and a prescribed phase in response to the phase difference signal SD. A phase inversion control circuit 105 compares the phase of the subcarrier signal SC with that of the burst signal SB and outputs a phase inversion control signal ST when the phase difference exceeds a preset threshold level SPO as a result of comparison and inverts an oscillated signal of the VCO 104 in response to the phase inversion control signal ST. In the case of reproducing a signal of the PAL system, a prescribed phased difference addition signal is added to a detected phase difference signal and the adjusted phase difference signal is compared with a threshold level.