Method of driving piezoelectric ink jet head

Abstract

The present invention is directed to a method for driving a piezoelectric ink jet head comprising a piezoelectric actuator AC that includes two piezoelectric ceramic layershaving such a size that covers the plurality of pressure chambers, wherein an electric field of opposite sense to the polarizing direction is applied to the second piezoelectric ceramic layerby using the common electrodesand, (1) for the pressure chambersfrom which the ink is discharged, an electric field of the same sense as the polarizing direction of the layer is applied to the first piezoelectric ceramic layerby using the individual electrodeand the first common electrode, thereby causing the region of the piezoelectric actuator AC to deflect toward the pressure chamber, while (2) for the pressure chambersfrom which the ink should not be discharged, an electric field of the opposite sense to the polarizing direction is applied to the first piezoelectric ceramic layerby using the electrodes, thereby to maintain the region of the piezoelectric actuator AC in the initial state, so as to discharge an ink droplet selectively through the nozzlethat communicates with the pressure chamberdescribed in (1) and form a dot.