Patent ID: 7919904

Claim:
A piezoelectric actuator, comprising: a substrate having a plurality of deformable portion rows each having deformable portions arranged in a row and restricted portions defining the deformable portions; and a plurality of thin film layers which are disposed on the substrate and which include a piezoelectric material layer and driving electrodes arranged on one surface of the piezoelectric material layer, each of the driving electrodes overlapping at least partially with one of the deformable portions; wherein at least one thin film layer among the thin film layers has a plurality of areas adjacent to each other, each of the areas overlaps with at least one of the deformable portion rows, and a boundary portion of the adjacent areas is positioned outside each of the deformable portions; and wherein each of the areas and the boundary portion continuously extends in one direction, each of the areas having uniform thickness in the one direction and having thickness distribution in a direction orthogonal to the one direction.