Research Of CMOS Image Sensor

With the development of manufacturing technology of Integrated Circuit and the improvement of IC design along with its advantages, CMOS Image Sensor using CMOS techniques have been widely used in many areas. Examples include digital electronic products, video electronic mail, medical equipment, security monitor systems, video communication, retina identification, industrial video monitors, video toys…etc. The market is wide open, especially in the area of digital products, therefore it is very useful and valuable to research and develop the CMOS Image Sensors.First, an overview on the research background, development history and the trend of technology are given. Then comparisons were done on advantages and disadvantages of CMOS and CCD image Sensors. In this thesis, the emphasis is to research circuit design and working flow of CMOS image sensors adopting 4T technology, then the paper analyzes the main source of noise and its model of CMOS Image Sensors and introduces the related noise elimination technologies.Finally, we will show the function of the Color Processing block at the end of imaging system based on CIS for better quality of graphics and lessen the influence of noise and emphasize on illuminating Automatic White Balance block for its function and algorithm. Then take one example from each algorithm to explain its concept and structure. From the analysis of their advantages and disadvantages, we present an improved algorithm.