Patent ID: 7517062

Claim:
A liquid discharge device comprising a piezoelectric actuator in which a plurality of piezoelectric displacement elements with a plurality of driving electrodes formed on a common piezoelectric ceramic layer are longitudinally and laterally disposed with regularity; and a flow passage member in which a plurality of liquid compressing chambers with liquid outlet orifices are formed, and on which the piezoelectric actuator is placed to cover said liquid compressing chambers, so that the driving electrodes correspond in position to the liquid compressing chambers, wherein the piezoelectric displacement elements are disposed longitudinally in N lines (N≧4), having dot density of not less than 300 dpi in the lateral direction, showing 0.95 to 1.5 in the ratio (B/A) of arrangement interval B between the driving electrodes in the longitudinal direction to arrangement interval A between the driving electrodes in the lateral direction, and showing D≧0.15 A in the minimum distance D between the neighboring driving electrodes.