Patent ID: 7527362

Claim:
An ink-jet head, comprising: a passage unit in which a plurality of pressure chambers each connected to a corresponding nozzle are arranged adjacent to each other along a plane; and an actuator unit that is fixed to the passage unit to change the volume of the pressure chambers, wherein the actuator unit includes: a piezoelectric element that spans a plurality of pressure chambers, a plurality of individual electrodes that have been sintered on a surface of the piezoelectric element at positions corresponding to the respective pressure chambers, and that are arranged in two intersecting arrangement directions, and a plurality of dummy electrodes of the same residual stress characteristics as the individual electrodes at positions other than positions corresponding to the pressure chambers and that are, on the surface of the piezoelectric element provided with the plurality of individual electrodes, the dummy electrodes being spaced from an outermost one of the individual electrodes and positioned along each of the two intersecting arrangement directions, in a respective outward direction from the plurality of individual electrodes.