In one embodiment of the present invention, when an image is displayed in an
image display device which has a frequency of 50 to 70 Hz in one frame period, a control LSI is set so that, in the case where the frame average luminance of a pixel is in the range of 150 [cd / m2] to 350 [cd / m2], the
contrast ratio between
subframe periods is set to: a range of not greater than 50 and not smaller than 1.5 when the luminance is 150 [cd / m2]; a range of not greater than 3.5 and not smaller than 1.5 when the luminance is 200 [cd / m2]; a range of not greater than 2.2 and not smaller than 1.5 when the luminance is 250 [cd / m2]; a range of not greater than 1.8 and not smaller than 1.5 when the luminance is 300 [cd / m2]; 1.5 when the luminance is 350 [cd / m2], and, for a frame average luminance other than the frame average luminance in the range, the
contrast ratio is set so as to be monotonously changed between the contrast ratios corresponding to the respective frame average luminance. As a result,
flicker visibility can be prevented and moving image blur can be suppressed, thereby realizing an
image display device that can display a moving image with high quality.