Optical scanning of laser line sensors for 3D imaging

In scanning laser triangulation sensors for 3D imaging, the achievable throughput is strongly limited by the moving mass. By realizing an optical scanning approach rather than repositioning the entire sensor, this limitation could be reduced, leading to a reduced measurement time. This work presents sensor system geometries in which only the optical path of a line triangulation sensor is manipulated by a tip-tilt mirror. In the proposed rotational scanning systems, either the illumination path or both the illumination and the reflection path are manipulated. By using ray-tracing simulation, the performance of the scanning systems are optimized and possible disadvantages can be determined up front. Using geometric relations, the surface profile can be reconstructed from the measured sensor data, the mirror position, and the model parameters. Experimental results show that the image quality of the proposed rotational scanning systems is comparable to systems based on classical translational scanning motion.