Image display device and image display method

An image display device comprising:

• an image display unit;
• a target value calculating unit configured to calculate a target value of a ratio of black which corresponds to a ratio of black display period occupied in one frame period of an input image;
• a change amount calculating unit configured to obtain an amount of change per unit period of an output value of the ratio of black within a range in which occurrence of flicker in the unit period can be restrained on the basis of
• (1) the difference between the target value and a output value of a previous frame or
• (2) the difference between the target value and the target value obtained in the past;
• an output value calculating unit configured to obtain a output value of the ratio of black for displaying a current frame by adding the amount of change to the output value of the previous frame;
• and
• a control unit configured to divide the one frame period into two periods of
• (1) a first period which corresponds to the output value of the current frame and
• (2) a second period which corresponds to a remaining period of the first period and
• making a control to cause the image display unit to display a black image during the first period and to cause the image display unit to display an image on the basis of the input image during the second period.