Three-dimensional topometry with stereo microscopes

A stereo microscope arrangement used for visual quality in- spection is extended to a fast 3-D topometer using the fringe projection technique. With specially designed binary gratings, an ideal sinusoidal intensity distribution can be achieved for an optimized illumination. Using a two-grating technique, the unambiguity range can be increased signifi- cantly. Thus, various applications can be solved with this method as is discussed. The resolution that can be achieved depends on the field of view, which at a large magnification is below 0.2mm.