— We have developed the first real-time 3-D image sensor with VGA pixel resolution using mixed-signal techniques to achieve high-speed and high-accuracy range calculation based on a light-section method. Our mixed-signal position detector, which consists of an adaptive threshold circuit and time-domain approximate ADCs, provides significant information for range finding quickly during high-speed analog-to-digital conversion. Moreover the position address and the intensity profile of a projected beam are selectively provided by the next digital stage to reduce data transmission. Our 3-D imager also has a standard analog readout circuit to get a 2-D image. Measurement results show that it achieves 65.1 range maps/sec with 0.87 mm range resolution at 1200 mm distance. I. I Recently we often see 3-D computer graphics in movies and televisions, and handle them interactively using personal computers and video game machines. Latest and future 3-D applica...