Ink-jet head with piezoelectric actuator

Abstract

An ink jet including a head body including plural pressure chamber concaves each having a supply port for supplying ink and a discharge port for discharging ink, and a piezoelectric actuator including mutually electrically connected vibration plates that cover the concaves of the head body in order to form pressure chambers together with the concaves and are separately provided correspondingly to one or plural pressure chambers, piezoelectric device respectively provided on surfaces of the vibration plates opposite to the pressure chambers correspondingly to the pressure chambers and individual electrodes respectively provided on surfaces of said piezoelectric devices opposite to said vibration plates for applying a voltage to said piezoelectric devices together with said vibration plates. The vibration plates are deformed in a manner that volumes of the pressure chambers are decreased by applying a voltage to the piezoelectric devices through the vibration plates and the individual electrodes, whereby ink contained in the pressure chambers is discharged through the discharge ports. Additionally, a portion of each of the vibration plates corresponding to each of the pressure chambers is bent into a convex projecting toward an opposite direction to the corresponding pressure chamber due to a compressive internal stress action of each of the piezoelectric devices.