To suppress the flickering of display, which occurs because a frequency at which a display element is driven is changed at the moment when switched to the control signal of a display controller.
A second image display storage circuit device which is actuated by a detection circuit which detects changes in images displayed by a first image display storage circuit device stores, from the first image display storage circuit device, images for a single or plural frames corresponding to one screen, in response to detection signals of the detection circuit, and then self-travels to continue to drive a display image signal generating circuit device, and if a signal indicating image changes is generated in the detection circuit, a correcting circuit device 522 for correcting the frequency of signals transmitted to the display image signal generating circuit device is actuated. Thereafter the second image display storage circuit device is stopped to switch to a display image signal generating circuit drive signal which is output from the first image display storage circuit device.