Motion detection with an intelligent optical sensor with on-chip analogue memory

A 64 × 64-pixel image sènsor with full-frame analogue memory and on-chip motion processor is presented. The processor, consisting of a charge amplifier and an analogue subtractor realised with a switched capacitor technique, calculates the difference between the values of the signal on each pixel in successive frames at a rate of up to 60 frames/s with limited area and power overhead. Fabricated in a 1.2 μm standard CMOS process with an added metal 3 light-shielding layer, the circuit is fully functional and requires a total core area of 13 mm
²
.