Determination of the vibrating phase by a time-averaged shadow moire method.

By the general time-averaged shadow moire method only amplitude distribution of an object vibration is recorded. In this paper determination by means of the time-averaged shadow moire method of the vibrating phase of an arbitrary position on the object is presented. In this method the illumination angle of the reference grating is periodically oscillated at the same frequency as the object vibration. Therefore, stationary contour fringes are shifted to a vibrating region that vibrates in-phase oscillation of the illumination angle. Accordingly it is possible to determine the vibration phase of each region on the object as the signal phase added to the illumination angle oscillator.