3D micro-inspection goes DMD

Digital image-projection and video-projection are the classical applications of Digital Micromirror Devices (DMD) but further applications in the field of optical metrology are also possible. Operated with certain patterns, a DMD can function. for instance, as an array of pinholes that may substitute the Nipkow disk presently used for lateral scanning in confocal microscopes. The various process parameters that influence the measurement (e.g. pinhole size, pinhole shape. lateral step-size and the number of pinholes used simultaneously, etc.) can be configured easily for individual measurements by simply programming the DMD. Furthermore. price-drops for metrological precision instruments may be achieved by implementation of the mass article DMD. The paper explains the basics of DMD technology, illustrates the principle setup of a newly designed instrument, shows results achieved with it and gives examples for its application. (C) 2001 Elsevier Science Ltd. All rights reserved.