In one embodiment of the present application, a memory stores a lookup table storing, in accordance with a combination of a value of a video signal of a current frame and a value of a video signal of a previous frame, each of correction values, the correction values in each of which a temporal change of a video signal is enhanced. A correcting circuit carries out, with respect to a correction value selected from the lookup table, a predetermined correcting operation in accordance with a polarity of a voltage to be applied to each of data signal lines S1 through Sm, with the use of a correction coefficient which is set based on properties of liquid crystal. Thus found is a corrected video signal in accordance with a positive or negative polarity. This makes it possible to find, with less memory capacity, an optimum corrected video signal in accordance with a polarity of a voltage to be applied to a data signal line.