A display panel driving method that can reduce power consumption in a
sustain step is provided. Output terminals of a column electrode drive
circuit connected to column electrodes of a display panel sustain a state
of high impedance during the period of the sustain step. An X sustain
signal is set as a bipolar pulse signal, in each half-cycle of which the
commencement time of the rise of the negative pulse is set longer than
the completion time of the rise of the positive pulse, and the
commencement time of the fall of the positive pulse is set longer the
completion time of fall of the negative pulse. Furthermore, a Y sustain
signal is displaced by a half cycle from the phase of the X sustain
signal. It should be noted that the polarity of these pulses may be
reversed.