1. An image display apparatus for displaying an image by driving a passive light modulation device based on a video signal compressed in the time axis direction, the passive modulation device modulating light from a light source in a pixel-by-pixel manner based on an electric signal, the apparatus comprising: motion detection means for detecting the amount of motion of a display image based on the video signal; modulation pulse generation means for generating modulation pulses different in period, phase or pulse width according to the detection result from the motion detection means; and light source driving means for enabling the light source to emit light at optimum timing corresponding to the motion amount by intermittently driving the light source according to the modulation pulses generated by the modulation pulse generation means.