Development of Projection Fringes Phase Shifting Technology Based Optical System for Small Object Surface Profile Fast Scanning

Abstract

During the decades, the application of fringe projection techniques for rebuilding the three-dimensional(3D) surface has become more useful. The fringe projection techniques can measures the 3D surface as small as MEMS components, and as large as large panel (2.5 m × 0.45 m). The technique can also be applied in versatile fields, such as 3D intra-oral dental measurements [1], non-invasive 3D imaging and monitoring of vascular wall deformations [2], industrial and scientific applications such as characterization of MEMS components [3, 4]. Aiming to measure the small size of object, we have designed a system which can measure the object minimized to 2.5 cm × 2.5 cm × 2.5 cm. The components in the system were the computer, mini protector and the camera which were used to generate different phases of fringe patterns, project the patterns on the object, and record the fringe patterns quickly. The data were processed by filtering, phase-shifting, and unwrapping algorithms. Finally, the object’s 3D surface profile has been rebuilt from the phase data. It’s no need to use extra device to produce shifted phase images; therefore, it can shorten the time of measurement.