Patent ID: 7264339

Claim:
A droplet ejecting apparatus comprising: a channel unit having a plurality of pressure chambers which communicate, at respective first ends thereof, with a liquid supply manifold so as to be supplied with a liquid by the liquid supply manifold and, at respective second ends thereof, with respective nozzles so as to eject respective droplets of the liquid through the respective nozzles; and an actuator unit fixed to the channel unit; wherein the actuator unit has a plurality of groups of active portions each group of which includes two active portions which are opposed in a first direction to a corresponding one of the plurality of pressure chambers, at respective different positions in a second direction perpendicular to the first direction; wherein each of the two active portions of said each group includes a piezoelectric sheet, and a first electrode and a second electrode which are opposed to each other in a direction of thickness of the piezoelectric sheet that is parallel to the first direction, such that the first and second electrodes cooperate with each other to sandwich the piezoelectric sheet; wherein when an electric voltage is applied across the first and second electrodes of said each of the two active portions of said each group, the two active portions are deformed to change a volume of said corresponding pressure chamber; wherein the respective piezoelectric sheets of the two active portions of said each group comprise respective portions of a common piezoelectric sheet which additionally includes an intermediate portion continuous with said respective portions in a direction in which the two active portions are distant from each other, and the respective portions of the common piezoelectric sheet are polarized in a direction of thickness of the common piezoelectric sheet, and wherein when an electric field is applied to the respective portions of the common piezoelectric sheet in a same direction as the direction of polarization thereof, the two active portions are elongated in the direction of thickness of the common piezoelectric sheet; and wherein a distance between the two active portions of said each group is selected at a value which assures that, when the two active portions are elongated in the direction of thickness of the common piezoelectric sheet, the intermediate portion of the common piezoelectric sheet that is located between the two active portions is elongated in a same direction as the direction of elongation of the two active portions.