A high S/N ratio object extraction CMOS image sensor with column parallel signal processing

A new complementary metal oxide semiconductor (CMOS) image sensor with a capability for noise reduction, column-parallel analog to digital (A/D) converters, a capacity for signal processing for object extraction every approximately 1 ms and a high-quality frame signal output every 1/60 s has been developed. The sensor pixel circuit is composed of a photodiode, a signal readout circuit with noise reduction and sample-hold functions. The sensor is equipped with column-parallel A/D converters and arithmetic logic units (ALU). Three feature values for object extraction, such as color difference, color intensity and texture, are first calculated, and motion is detected using the inter frame differences of these feature values. The calculations of these feature values are simplified so as to be implemented by compact ALU. The size of pixel, A/D converter and ALU are small enough to be able to incorporate them into practical sensor chip.