17-9 A CMOS image sensor with the function for counting the number of saturation times in each photo-diode

Abstract

A dynamic range expansion method for a CMOS image sensor is proposed. The image with column parallel read-out consists of a 90×120 array of pixels, signal comparators, counter-memories and an adder. Counter-memories store the number of times when the signal accumulated in each PD reaches to the threshold level. The test device included 2 bit counter-memories for each pixel realized to extend the dynamic range.