PURPOSE: To obtain a carrier signal which is coincident with the initial value of a color discriminating signal that is intermittently supplied, by shifting the phase of a signal by means of plural multipliers, oscillators, phase shifters, sample holding circuits, adders and switch circuits.

CONSTITUTION: A multiplier 13 compares phases between an output carrier wave SC of an oscillator 11 and a color discriminating signal SHID. A multiplier 15 compares phases between a signal SC' obtained by giving a 90° phase shift to the wave SC and the signal SHID. These output signals SV1 and SV2 are led to multipliers 21 and 22 through LPF16 and 17 and then sample holding circuits 18 and 19 respectively. Output signals SL1 and SL2 of circuits 18 and 19 are compared with the wave SC through multipliers 21 and 22 in terms of their phases to obtain signals SM1 and SM2. These signals are added together 23. An output signal Sa of addition and the signal SHID are supplied to a switch circuit 24, and a switch is controlled by a signal PC which is synchronous with a horizontal synchronizing signal. Then a signal S0 is delivered through a terminal 27 via a BPF26.