A 960-fps Sub-sampling Object Extraction CMOS Image Sensor with 12-bit Column Parallel ADCs and ALUs

A CMOS image sensor with highly accurate object extraction pre-processing functions by 960-fps sub-sampling operation, 12-bit column parallel successive approximation ADCs and column parallel ALUs has been developed. The pixel is composed of four transistors type pixel which shares the source follower transistor and the pixel select transistor. The each ADC is composed of the noise and signal holding capacitance, the noise reduction circuit, the comparator and the small DAC that combined both the reference voltage ratios and capacitance ratios. In the ALU, the object categorization pre-processing is performed by the each macro block of 3 × 3 pixels which has a reference pixel and its neighboring eight pixels. The three image features which are the edge of object, the direction of edge-vector and the average of light-intensity of 3 × 3 pixels corresponded to each pixel are extracted by the ALUs. The image and the results of the object extraction pre-processing are outputted by every 60-fps. The image sensor was fabricated by 0.35-mm 2P3M technology. The pixel pitch is 5.3-mm, the number of pixels is 640H × 360V and the chip size is 4.9-mm square.