A digital scan converter having an oscillator providing a clock signal used to scan-convert an input video signal to thereby produce a scan-converted output video signal, an automatic frequency control for controlling the oscillator in synchronism with a synchronizing signal separated from the input video signal and a counter for frequency-dividing the clock signal from the oscillator to thereby form a control signal used for controlling blanking of the input video signal. The counter also provides an address signal for a memory in which the video signal is temporarily stored during the scan converting operation. Since a composite blanking pulse for the input video signal is formed in synchronism with the address signal for the memory, it is possible to prevent appearance of a jitter of the composite blanking pulse on a display screen.
