Patent ID: 7980682

Claim:
A liquid droplet discharge apparatus which discharges liquid droplets of a liquid, the liquid droplet discharge apparatus comprising: a liquid droplet discharge head including: a cavity unit which has a plurality of pressure chambers arranged regularly in the cavity unit and a piezoelectric actuator which is joined to the cavity unit and which selectively discharges the liquid in each of the pressure chambers, the piezoelectric actuator having a piezoelectric material layer which covers the plurality of pressure chambers continuously; a plurality of individual electrodes which correspond to the pressure chambers respective; and first and second constant electric potential electrodes which correspond to each of the pressure chambers; and wherein the piezoelectric material layer includes: a first active portion, which is sandwiched by one of the individual electrodes and the first constant electric potential electrode, and which corresponds to a central portion of each of the pressure chambers; and a second active portion, which is sandwiched by one of the individual electrodes and the second constant electric potential electrode, and which corresponds to a portion, of each of the pressure chambers, located on an outer circumferential side with respect to the central portion of each of the pressure chambers; and a voltage-applying mechanism which applies a voltage to the piezoelectric actuator; wherein the first active portion is polarized in a predetermined direction along with a stacking direction of each of the individual electrodes and the first constant electric potential electrode; wherein the second active portion is polarized in a direction opposite to the predetermined direction along with the stacking direction of each of the individual electrodes and the second constant electric potential electrode; and wherein the voltage-applying mechanism selectively applies, to the individual electrodes, a first electric potential and a second electric potential different from the first electric potential, and the voltage-applying mechanism applies the first electric potential to the first and second constant electric potential electrodes.