CMOS Image Sensors

Advent of CMOS technology in eighties led to the phenomenal growth in semiconductor industry. Transistors have become smaller, faster, consume less power, and are cheaper to manufacture. It is CMOS technology which has enabled very high integration on the chips leading to modern high performance, miniaturized integrated circuits.

 

Apart from the valuable contribution in miniaturization of integrated circuits, CMOS technology found applications in sensing applications. CMOS technology has been adopted to design sensors, especially in the field of imaging. Due to the wide usage of CMOS based image sensors, CMOS sensors are often considered to be a synonym of CMOS based image sensors and have emerged as a competitor to CCD based image sensors.

 

Until recently, Charge Coupled Devices (CCDs) dominated most of the image sensing systems, i.e., cameras, camcorders, etc. CCDs have been in use in astronomical cameras, video camcorders and scanners. However of late, CMOS Imaging have emerged as an alternative to CCD imagers and it also offers better features.

 

Subsequent sections will discuss both CCD and CMOS sensor based imagers, their pros and cons, and also their applications. Further, other applications of CMOS technology in the field of sensing will be discussed.