PURPOSE: To switch independently color information contained in electron beams by scanning an index strip with the aid of a pilot signal and two electron beams, and extracting frequency components of the electron beams through a filter and a frequency converter.

CONSTITUTION: Chrominance signals from input terminals 1R, 1G and 1B are introduced to amplifiers 31 and 32 through switch circuits 21 and 22. Signal waves modulated by using pilot signals of pilot signal generators 121 and 122 of frequencies f1 and f2 as carrier waves are supplied to a CRT. Assuming that frequencies of signals formed by scanning an index strip with the aid of the pilot signals of the frequencies f1 and f2 and two electron beams are fp1 and fp2, frequency converters 141 and 142 convert the frequencies f1 and f2, after which filters 151 and 152 extract frequency components of the fp1 and fp2. After these signals are phase-corrected by a delay amount of the circuit in phase shifters 161 and 162, they are transmitted to limiters 171 and 172, and only frequency information is fetched. Its output is transmitted to a two-multiplying circuits 71 and 72 consisting of PLLs. Finally the circuits 21 and 22 are sequentially switched through three-frequency divider circuits 81 and 82.