CMOS image sensor

A CMOS-based chip that records the intensities of light as variable charges similar to a CCD chip. Although initially used in less expensive digital cameras, the quality of CMOS sensors has improved steadily.

CMOS sensors have advantages over CCDs. They can be made like other CMOS chips on standard CMOS fabrication lines, which makes development less costly, and auxiliary circuitry, such as analog-to-digital conversion, can be combined on the same chip. In addition, CMOS chips use less power than CCDs.

No Charge Coupling
Unlike CCD sensors, CMOS image sensors do not use charge coupling, which transfers charges to a second bank of photosites before sending them out for analog-to-digital conversion. Because they are standard CMOS chips, CMOS image sensors have amplifiers and output circuitry connected to each photosite. Contrast with CCD. See CMOS camera and digital camera.