In a display device capable of low power and multi-color displaying without raising
a frame rate due to increase of display gradations in number by combining a gradation
representation through a FRC and a gradation representation system using a pulse
width modulation or pulse height modulation method, the gradation representation
is executed by a method of pulse width or pulse height modulation in one frame
using lower significant N bits to a video signal of M bits, and the display of
the gradations is performed by the FRC of the present invention using more significant
M-N bits and further using 2M-N-1 frames, and thus the number of the
frames required for FRC is reduced to decrease a frame frequency to thereby realize
a gradation display with reduction of electric power and suppression of flickers.
