Inexpensive range camera operating at video speed

An optoelectronic device has been developed and built that acquires and displays the range data of an object surface in space in video real time. The recovery of depth is performed with active triangulation. A galvanometer scanner system sweeps a sheet of light across the object at a video field rate of 50 Hz. High-speed signal processing is achieved through the use of a special optical sensor and hardware implementation of the simple electronic-processing steps. Fifty range maps are generated per second and converted into a European standard video signal where the depth is encoded in gray levels or color. The image resolution currently is 128 x 500 pixels with a depth accuracy of 1.5% of the depth range. The present setup uses a 500-mW diode laser for the generation of the light sheet. A 45-mm imaging lens covers a measurement volume of 93 mm x 61 mm x 63 mm at a medium distance of 250 mm from the camera, but this can easily be adapted to other dimensions.