The present invention has an object to provide a video signal control technique capable of suppressing deterioration in display quality of a display device in which FRC is employed. A video signal control method for display device according to the present invention includes: (a) acquiring coordinate information and time information in a display screen of a display device; (b) selecting, with reference to an LUT storing a plurality of FRC parameters, a FRC parameter corresponding to the coordinate information and the time information; and (c) outputting the selected FRC parameter as a FRC parameter for controlling red and blue pixels and a FRC parameter for controlling green pixels opposite in phase to the FRC parameter for controlling red and blue pixels.