In an electro-optical device for performing image display using an n-bit (where
n is a natural number, n2) digital image signal, nm (where m is a
natural number) volatile memory circuits, and nk (where k is a natural number)
non-volatile memory circuits are contained in every one pixel. The electro-optical
device has a function for storing m frame portions of the digital image signal
in the volatile memory circuits, and k frame portions of the digital image signal
in the non-volatile memory circuits. By performing display of a static image in
accordance with repeatedly reading out, for each frame, the digital image signal
stored once in the memory circuits and performing display, drive of a source signal
line driver circuit can be stopped during that period. Further, a digital image
signal stored in the non-volatile memory circuits is stored even after a power
source is cut off, and therefore display is possible immediately when the power
source is next turned on.