ストロボ位相シフト干渉法を用いた超音波モータの振動計測

Abstract

We evaluate performance of vibration type microdevices. Stroboscopic phase-shift interferometry is capable of imaging high speed (∿MHz) and small (∿10nm) vibration and is applied to displacement measurement of the microdevices. A laser diode, which is used as a light source of the inteferometry, is irradiated stroboscopically in order to observe an object vibrating at high frequency. Phase-shift algorithm is used to obtain high contrast images. The optical system is a Fizeau-type interferometer which eliminates optical noises. An ultrasonic motor, which consists of a rotor and a stator, is used as a test object. The vibration frequency of the stator is about 39.2kHz. In this paper, we measure the vibration of the stator surface of the ultrasonic motor. The vibration distributions are compared with each other. As a result, the change of the vibration distribution proves the movement of the surface of the stator. We examine vibration transmission of the stator surface.