Method and device for measuring the shape of a three dimensional object

摘要

A 3D shape measurement method and a device using the method eliminate harmful influences of periodic inconstancy in the phase shift method. Optical intensity patterns following periodic functions of sine waves are irradiated on an object while shifting the phases thereof. Based on the image picked up from the object, the 3D shape of the object is measured. In this method, a plurality of optical intensity patterns following periodic functions with varying wavelengths are projected onto the object so as not to interfere with each other. The least common multiple of the wavelengths of the periodic functions is larger than the extent having periodic inconstancy within the image pickup area.