Intensity transfer function of DMD and its application in PMP

摘要

Phase measuring profilometry using structured illumination with a digital micro-mirror device(DMD) has been extensively studied because of its advantage of the programmable projection. In this paper we discussed the effect of intensity transfer function of the commercial projector with DMD, analyzed the influence of the intensity transfer function and the nonlinear of detector on the quantity of projected sinusoidal fringe and the accuracy of phase measurement, and proposed the correction method for intensity transfer function of DMD. A DMD based phase measuring profilometry system includes a commercial projector with DMD, a CCD camera and a fringe pattern analysis and processing unit. The experiments show that with the correction of the intensity transfer function of the projector the phase measurement accuracy has been improved obviously.