Patent ID: 9614463
Date: 2017-04-04
CPC Classifications: B06B,H01L,H02N

Claim:
1. A piezoelectric device comprising: a piezoelectric element including a piezoelectric layer and electrode layers configured to sandwich the piezoelectric layer; and a drive circuit that applies an alternating current drive electric field to the piezoelectric layer through the electrode layers, wherein a polarizability γ of the piezoelectric layer in the case where an electric field is applied until polarization is saturated is smaller than 1×10 the drive circuit sets a minimum value of the drive electric field to become larger than a positive coercive electric field of the piezoelectric layer and sets a maximum value of the drive electric field to become smaller than ( Pm ′(maximum value of polarization)− Pr ′(quasi-remanent polarization))/(1×10 −9 ) (C/(V·m)) where polarizability γ=(Pm (saturation polarization)−Pr (remanent polarization))/Ed (maximum value of applied electric field).