Patent ID: 7870787

Claim:
A method of measuring an angular velocity by an angular velocity sensor, comprising: preparing the angular velocity sensor including a substrate having a vibration part and a piezoelectric thin film bonded to the vibration part, wherein, the piezoelectric thin film includes: a piezoelectric layer; first and second electrodes that sandwich the piezoelectric layer therebetween; and an interface layer sandwiched between the first electrode and the piezoelectric layer, the first electrode is formed of a metal electrode film having a plane orientation of (100), the interface layer consisting of a (Bi,Na)TiO 3 film, the piezoelectric layer consisting of a (Bi,Na,Ba)TiO 3 film having a plane orientation of (001), and one of the first and second electrodes selected therefrom is constituted of an electrode group including a drive electrode and a sense electrode; applying a driving voltage to the piezoelectric layer through the drive electrode and the other of the first and second electrodes selected therefrom to oscillate the vibration part; and measuring, through the other electrode and the sense electrode, a deformation of the vibration part caused by an angular velocity applied to the oscillating vibration part to obtain a value of the applied angular velocity.