A driving device including a signal controller which receives input image data corresponding to a plurality of frame periods, outputs the input image data during a first sub-frame period of one frame period among the plurality of frame periods, and outputs impulsive data having gray-scales, which are lower than those of the input image data, during a second sub-frame period of the one frame period. The impulsive data in the frame periods in which still images are displayed comprise first gray-scales, and the impulsive data in the frame periods in which moving images are displayed comprise second gray-scales, the second gray-scale being different from the first gray-scales. A data driver converts the input image data to pixel voltages during the first sub-frame period, and converts the impulsive data to impulsive voltages during the second sub-frame period.