A drive method for a color CRT in which a pointsequential color video signal is produced to drive a modulation electrode of the CRT, in which an index signal (220) is generated consisting of pulses at a frequency identical to a frequency of scanning successive screen phosphor color trios of the CRT, multi-phase index signals (220A, 220B) are derived from that index signal, and respective time differences (t1,....) between scanning timings of each color trio in each scan line and a specific index signal phase are successively measured, stored in memory, and subsequently read out to produce timing control signals for gating the color components of the point-sequential video signal. Requirements for timing accuracy and assembly precision of the CRT can thereby be substantially relaxed by comparison with a prior art single-phase index signal method.
DRIVE METHOD FOR SYNCHRONIZING SCANNING AND MODULATION OF FLAT-CONFIGURATION COLOR CRT