1. A display device comprising: a display panel comprising pixels connected to gate lines and data lines; and an image display control unit configured to convert an image signal input from an external source into a data signal and drive the gate lines and the data lines so as to display an image corresponding to the data signal on the display panel, wherein the image display control unit is configured to output the data signal such that a position of the image on the display panel is changed when the input image signal is the same for a preselected period of time, and is configured to set a next position change time period of the image according to a distance between an original position of the image and a changed position of the image.