Digital Camera Image Sensor

A digital camera image sensor is a device that converts an optical image to an electric signal. It is used mostly in digital cameras and other imaging devices. It is a set of charge-coupled devices (CCD) or CMOS sensors such as active-pixel sensors. Both types of sensors accomplish the same task of capturing light and converting it into signals.

CCD Vs CMOS

A CCD is an analog device. When light strikes the chip it is held as a small electrical charge in each photo sensor. The charges are converted to voltage one pixel at a time as they are read from the chip. Additional circuitry in the camera converts the voltage into digital information.

A CMOS chip is a type of active pixel sensor made using the CMOS semiconductor process. Extra circuitry next to each photo sensor converts the light energy to a voltage. Additional circuitry on the chip converts the voltage to digital data.

CCDs use special manufacturing that allows a charge to transport without distortion! This means CCDs provide high quality sensors. On the other hand CMOS chips use the same process to make most microprocessors which is more traditional.

CCD digital camera image sensors provide high quality, low noise images where as CMOS sensors tend to come up a bit short. As a trade off CMOS ensors consume little power. CCDs use a process that consumes lots of power. CCDs consume as much as 100 times more power than an equivalent CMOS sensor.

CMOS chips can be created on most standard silicon production lines so they tend to be less costly compared to CCD sensors. CCD sensors have been mass produced for a longer period of time, so they are more mature. They tend to have higher quality and more pixels.