A display image of a frame is input in time series. An inverse colored
image to cancel the display image is generated. The display image is
divided into a plurality of subfields, and the inverse colored image is
also divided into a plurality of subfields. A time divisional image is
generated by disposing a display time of a subfield of the inverse
colored image before and after a display time of a corresponding subfield
of the display image. While displaying the time divisional image on a
screen, a light from the screen is transmitted in synchronization with
display timing of the display image in a display time of the time
divisional image, and the light is cut off in synchronization with
display timing of the inverse colored image in the display time of the
time divisional image.