Patent ID: 7387372

Claim:
A liquid delivery apparatus comprising: a pressure chamber accommodating a liquid and communicated with an opening; and a piezoelectric actuator plate which is disposed to close the pressure chamber and is deflected to deliver the liquid accommodated in the pressure chamber through the opening, and which has a laminated structure including: a piezoelectric layer including a deformable area which is provided over a central part of the pressure chamber and is deformable at least in a planar direction thereof by an application of an electric field to the deformable area; and a planar diaphragm which has a recess in one surface of opposite surfaces thereof such that the recess is defined by a thinner portion thereof located over the central part of the pressure chamber, and which is laminated at the one surface thereof to the piezoelectric layer, the one surface comprising a fixed portion which is fixed to the piezoelectric layer around the recess.