Patent ID: 8777382

Claim:
An inkjet head comprising: plural individual liquid chambers formed with partition walls, each of the individual liquid chambers having a liquid droplet discharging hole; an oscillation plate attached to surfaces of plural of the individual liquid chambers, the surfaces of plural of the individual liquid chambers being different from surfaces where the liquid droplet discharging holes are provided; plural piezoelectric elements arranged at positions corresponding to the plural of the individual liquid chambers on the oscillation plate, each of the piezoelectric elements being formed by laminating a lower electrode, a piezoelectric material, and an upper electrode, in this order on the oscillation plate, wherein the lower electrode is a common electrode and the upper electrode is an individual electrode; a common electrode wiring connected to the lower electrode; and individual electrode wirings individually and conductively connected to the corresponding upper electrodes of plural of the piezoelectric elements, wherein driving signals are individually input to the corresponding individual electrode wirings, wherein the inkjet head further includes an upper layer insulator film that coats at least the common electrode wiring and surfaces of the individual electrode wirings; an intermediate layer insulator film that is provided between the individual electrode wirings and the lower electrode, at least, at areas where the individual electrode wirings and the lower electrode overlap, the intermediate layer insulator film being a lower layer of the upper layer insulator film; and a lower layer insulator film that coats, at least, surfaces of the piezoelectric elements, the lower layer insulator film being a lower layer of the intermediate layer insulator film, wherein the intermediate layer insulator film and the upper layer insulator film have openings therein for exposing the piezoelectric elements, wherein widths of the openings are greater than width of each of the piezoelectric elements, and the widths of the openings are less than width of each of the individual liquid chambers, and wherein, in a width direction of the piezoelectric elements, each of the piezoelectric elements is disposed inside the corresponding opening.