PURPOSE: To enable to store the three primary color signals to one analog memory element, by sequential sampling of the three primary color signals of color video signal to convert them into time serial signals.

CONSTITUTION: The gate signal generator 5 feeds the gate pulse to the input gate circuits 1, 2, 3, sequentially in response to the clock pulse for write-in. Further, the R signal S1, G signal S2, and B signal S3 of the color video signal are sequentially gated at the gate circuits 1, 2, 3, and this gated signal is converted into the time serial signal, i.e., serial signal at the mixing circuit 10 and fed to the analog memory 4. Next, the signal read out from the memory 4 is sequentially responded to the gate pulse from the gate signal unit 9, and gated at the output gates 11, 12 and 13 and outputted as the R signal S1, G signal S2 and B signal S3. Thus, the three primary color signals can be stored by using one analog memory.