3-DIMENSIONAL SHAPE RECONSTRUCTION BY PHASE-SHIFTING SHADOW MOIRE

Shadow moire shows contour lines of an object with respect to a master grating plane; they result from the interference between the lines of the master grid and their shadow projected by a point source of light. In best cases the sensitivity of this procedure is a few tenths of a millimeter. The introduction of a phase-shifting procedure gives a better resolution, but the problem in practice is how can we shift the phase of the interferogram into shadow moire? A complete study is presented showing the influence of different parameters. It is shown that only possibility is available. Some applications to three-dimensional shape reconstructions are presented with an accuracy of 0.01 mm, showing that the potentiality of shadow moire is greatly improved.