Image display device and driving method thereof

An image display device, comprising:

• a display screen for displaying an input image;
• a moving speed calculator configured to detect an amount of data change of an input image and calculates a moving speed of the input image;
• a moving speed determiner configured to determine whether the image moving speed is within a preset reference range, the preset reference range having a lower limit and an upper limit higher than the lower limit;
• and
• a frame frequency modulator configured to:
• whenever the image moving speed is determined to be within the preset reference range, drive the display screen according to an input frame frequency synchronized to the input image;
• whenever the image moving speed is determined to exceed the upper limit, down-modulate a frame frequency for displaying the input image to a first modulated frame frequency lower than the input frame frequency and drive the display screen according to the first modulated frame frequency;
• and
• whenever the image moving speed is determined to be less than the lower limit, down-modulate a frame frequency for displaying the input image to a second modulated frame frequency lower than the input frame frequency and drive the display screen according to the second modulated frame frequency,
• wherein the frame frequency for displaying the input image is down-modulated only to the first modulated frame frequency or the second modulation frame frequency in all image moving speed ranges excluding the preset reference range,
• wherein the first modulated frame frequency and the second modulated frame frequency are equal to each other, and
• wherein the frame frequency modulator is further configured to delete some of the frames of the input image according to the first modulated frame frequency whenever the image moving speed is determined to exceed the upper limit.