Patent ID: 9375923
Filing Date: 2016-06-28
CPC Classification: B41J,H01L,Y10T

Claim Text:
1. A piezoelectric element comprising: a vibration plate; a lower electrode; a piezoelectric film; and an upper electrode, wherein the vibration plate, the lower electrode, the piezoelectric film, and the upper electrode are laminated in the stated order, an electric field is applied to the piezoelectric film by the lower electrode and the upper electrode, a shape of the piezoelectric film near a boundary face between the piezoelectric film and the upper electrode as viewed from a lamination direction of the piezoelectric film and the upper electrode, is substantially the same as a shape of the upper electrode, a width of the piezoelectric film extends from an end of the boundary face, and edge portions of the upper electrode have a concavely curved shape such that a thickness of the upper electrode tapers outwardly along the edge portions.