PURPOSE: To surely execute the DC reproducing of a MUSE signal with a comparatively simple configuration by generating a clamp pulse in response to a delayed frame pulse detection signal and applying the generated pulse to a clamp circuit.

CONSTITUTION: A MUSE signal through the clamp circuit 1 is inputted to a frame pulse detecting circuit 3. The circuit 3 shapes the inputted analog MUSE signal to a square wave, enters the shaped MUSE signal synchronously with an inputted clock pulse CK, collates whether or not the MUSE signal coincides with the pattern of a previously set frame pulse signal, and outputs a detection signal S1 to a counter 6. At the input of the signal S2, the counter 6 starts the count of pulses CK, and when its count value reaches n1 or n2, outputs a countup signal S2. A clock pulse generating circuit 7 generates a cclamp pulse S0 in response to the signal S and outputs the clamp pulse S0 to the clamp circuit 1.