A voltage with a predetermined pattern is applied to liquid crystals to drive the liquid crystals during a unit drive period of the liquid crystals and an application pattern according to the gradation data is set taking into account a value obtained by integrating the amount of transmitted light of liquid crystals at various points in time when each application pattern is applied to the liquid crystals. This allows a fine gradation display even if the liquid crystals are driven by only ON/OFF of a maximum rated voltage. As a result, it is possible to drive the liquid crystals at high speed and produce a multi-gradation display.