Grating projection methods have been often used for non- contacting shape measurement. An image of equal-height contours of an object can be obtained in real-time using moire topography. We have developed the phase-shifting scanning moire method for real-time shape measurement with high resolution. But there is a problem that the measuring error becomes larger when the object is moving speedily because several images are captured while shifting the grating phase. In this paper, we propose a phase- shifting scanning moire method using a DMD, which can obtain an image of equal-height contours within a frame time. The direction of a ray reflected at each mirror of a DMD can be selected quickly. For this purpose, we developed a DMD reflection-type CCD camera called as 'DMD camera'. The camera works as a camera whose each pixel has a shutter. The structure and an experimental result to confirm the algorithm to obtain a contour image using het DMD camera are shown.

Date Published: 29 May 2002
PDF: 4 pages
Proc. SPIE 4537, Third International Conference on Experimental Mechanics, (29 May 2002); doi: 10.1117/12.468865

Published in SPIE Proceedings Vol. 4537:
Third International Conference on Experimental Mechanics
Xiaoping Wu; Yuwen Qin; Jing Fang; Jingtang Ke, Editor(s)