Patent ID: 9702698
Date: 2017-07-11
CPC Classifications: G01C,G01P

Claim:
1. An angular velocity sensor comprising: a flexible diaphragm part including a laminated structure, the laminated structure of the diaphragm part including an upper electrode, a piezoelectric layer, a lower electrode, and one or more vibration plate layers, the upper electrode including a driving electrode part and a detection electrode part, the driving electrode part and the detection electrode part being pattern-arranged; a pedestal section configured to support an outer circumference of the diaphragm part; and a weight section joined to a central part of the diaphragm part, the angular velocity sensor being configured to cause the weight section to vibrate using an inverse piezoelectric effect of a piezoelectric body by applying an electric field to the piezoelectric layer via the driving electrode part, and detect a displacement generated in the weight section based on a Coriolis force, the displacement being detected by a piezoelectric effect from the detection electrode part, the vibration plate layer being formed by a thin film forming technique, and when a resonance frequency in a resonance vibration mode calculated from dimensions of a structural body of the angular velocity sensor and an elastic parameter of a material of the structural body is f kilohertz, a mass of the weight section is M milligrams, a circumferential length of the diaphragm part is r meters, a stress acting on the piezoelectric layer is σ satisfies: