Phase-shifting fringe projection system based on a tailored free-form mirror

Phase-shifting fringe projection is a very effective method for 3D-shape measurements. Conventional fringe projection systems are based on a digital projector that images fringes into the measurement plane. Such systems are limited to the visible spectral range, as most projectors suffer from technical problems in UV or IR spectral ranges. We propose a novel fringe projector that is based on a single tailored free-form mirror. The free-form mirror generates fringes in the measurement plane by redistribution of light comparable to illumination purposes. Therefore no classical imaging is performed. Due to the application of a single free-form mirror, the projector is wavelength independent and therefore applicable in UV and IR spectral ranges. We present the design and realization of a prototype and a characterization of the generated intensity distribution in the measurement plane.