A fast CMOS optical position sensor with high subpixel resolution

Abstract

This paper describes a novel architecture for an optical position sensor which has been implemented on a single chip using standard digital CMOS technology. The prototype device consists of 20 × 20 active pixels and two row and column parallel processing units with corresponding digital decoding logic. Image contour is extracted by means of distributed peak-detection, implemented at pixel level, followed by a digital extraction of the beam centroid position executed at row and column level. The sensor chip achieves up to 3000 frames/s with a position accuracy of 0.013 pixel and a total power consumption of 15 mW @ 5 V.