In an image display system, when a sequence of frames α, α+1, α+2, α+3, . . . , with a frame rate of m is given as an input video signal S1, a controller controls a frame memory to output a sequence of frames α, α+2, . . . , as an output video signal S2 at a frame rate of m/2 and a sequence of frames α+1, α+3, . . . , as an output video signal S3 at a frame rate of m/2 such that the timing of outputting each of frames α+1, α+3, . . . , of the output video signal S3 is delayed by 1/m with respect of the timing of outputting each of frames α, α+2, . . . , of the output video signal S2. By displaying the output video signals S3 and S2 in the above-described manner, a resultant motion image formed by a combination of the output video signals S3 and S2 is refreshed at an effective frame rate of m.