Patent ID: 7722165

Claim:
A liquid-droplet jetting apparatus which jets liquid droplets of a liquid from a plurality of nozzles, the apparatus comprising: a cavity unit which has the nozzles and a plurality of pressure chambers corresponding to the nozzles respectively and extending on a predetermined plane; and a piezoelectric actuator which has a plurality of active portions extending corresponding to the pressure chambers respectively, and which is formed on the cavity unit so as to cover the plane; wherein a length in a longitudinal direction of each of the active portions is not more than 1.5 mm; wherein a height of each of the pressure chambers is 40 μm to 60 μm; wherein a thickness of a member which defines surfaces, of the pressure chambers, on a side facing the piezoelectric actuator is 100 μm to 150 μm; wherein volume of the pressure chambers in which liquid is filled is changed by displacement of the active portions so as to jet the liquid-droplets from the nozzles; and wherein the piezoelectric actuator has a plurality of individual electrode layers in each of which a plurality of individual electrodes extending corresponding to the pressure chambers respectively are formed.