Patent attributes
An ink-jet head includes a channel unit in which a plurality of pressure chambers are formed; and a piezoelectric actuator which includes a vibration plate, a piezoelectric layer formed on an upper surface of the vibration plate, and an electroconductive layer formed on an upper surface of the piezoelectric layer. On an upper surface of the piezoelectric actuator, there are formed outer grooves each extended along an area overlapping with the periphery of each of the pressure chambers, and inner grooves each extended along one of the outer grooves at a portion inside of one of the outer grooves. Further, recesses deeper than the thickness of the electroconductive layer is formed in the piezoelectric actuator at portions each located inside of the one of the inner grooves. Accordingly, it is possible to improve a drive efficiency of the piezoelectric actuator.