Integrated image sensors: an introduction to their functioning principles, structures and characteristics

Abstract

The importance of imaging techniques has encouraged the development of image sensors in general. These sensors have found many applications in robotics, pattern recognition, information detection, etc. The need for reliable, compact, high-performance image sensors led naturally to research in integrated sensors combining all image sensing functions. Solid state imagers, which first appeared in the early 1970s, make up the rapidly evolving forefront of image sensing. This being the case, a description of specific products is of limited relevance. Our aim in this article is rather to present the general functioning principles, structures and characteristics of integrated image sensors. We describe the various approaches to fulfilling the two basic functions of an image sensor: the conversion of light quanta into electric charges (optoelectronic conversion) and readout (multiplexing). The numerious parameters used in characterizing these complex imagers are then examined, with special emphasis on the need to know the specific application.