OS01W0414 High-speed phase-shifting method for shape measurement using digital micro-mirror device

Abstract

In the case of phase-shifted grating projection method, there is a problem that the measurement error becomes larger when the object is moving more speedily. In order to solve this problem, we developed a DMD reflection-type CCD camera that we call a DMD camera. In this paper, we develop an algorithm to apply the phase-shifting method using correlation to the shape measurement using the DMD camera and high-speed phase-shifting method using the DMD camera. The four step phase-shift can be performed within 1/7,500 seconds because the pattern on the DMD can be changed theoretically 30,000 times in a second. The principle and the experimental result are shown.