DMD Camera and Its Applications To Fringe Pattern Analysis

Digital micromirror device (DMD) is an array of microscopic mirrors fabricated with the microelectromechanical systems (MEMS) technologies. In this paper, a pixilated programmable imaging system-- DMD camera-- based on the MEMS technology is developed. The DMD camera comprises a DMD, an image sensor and two imaging lenses. Individual DMD mirrors correspond to CCD pixels by moiré methodology. In the DMD camera optics, individual DMD mirrors operate as controllable high-speed shutters for corresponding CCD pixels by changing binary on-off pattern. Furthermore, the exposure time of each CCD pixel can be adjusted by displaying DMD pattern as grayscale. As a result, all phase-shifting images can be obtained within one frame time of a conventional CCD camera, and each pixel can be exposed to be the optimum time for phase analysis. Several applications to fringe pattern analysis using the DMD camera are reported. Experimental results demonstrated the effectiveness of the DMD camera as a novel image acquisition device for fringe pattern analysis