Differential digital double sampling method and CMOS image sensor for performing same

摘要

A method for performing differential double sampling and a CMOS image sensing device for performing the same. In one example, the CMOS image sensing device includes a pixel array include a multitude of pixels with each pixel formed by a plurality of photodiodes, a floating diffusion point and a plurality of transistors electrically coupled the plurality of photodiodes. Moreover, a column readout circuit with four storage capacitors is selectively coupled to the pixel array by switches so that the storage capacitors can store sampled pixel values. A control circuit connected to the pixel array and the column readout circuit selectively activates the transistors to output to the column readout circuit sampled dark value and bright values of one photodiode and a sampled double bright value of the one photodiode and one additional photodiode.