What is CCD? What is it used for?

CCD is a charge-coupled device, which is a kind of detection element that uses the amount of charge to represent the signal size and transmits the signal through coupling. It has a series of advantages, such as self-scanning, wide sensing spectrum range, small distortion, small volume, light weight, low system noise, low power consumption, long service life and high reliability, and can be made into highly integrated components.

CCD is widely used in digital photography and astronomy, especially in optical telemetry, optical and spectral telescopes and high-speed photography, such as lucky imaging. CCD is widely used in video cameras, digital cameras and scanners, except that the camera adopts dot matrix CCD, that is, it includes X and Y directions for shooting plane images, while the scanner adopts linear CCD, and the scanning in X direction is only completed by the mechanical device of the scanner.

Extended data

Generally, a Bayer filter is added to the CCD for color digital cameras. Every four pixels form a unit, one for red, one for blue and two for green (because human eyes are sensitive to green). Therefore, each pixel receives a photosensitive signal, but the color resolution is not as good as the photosensitive resolution.

The 3CCD system composed of three ccds and a beam splitting prism can better divide colors. The beam-splitting prism can analyze the incident light into three colors: red, blue and green, and three CCDs are responsible for the image presentation of one color. All professional digital cameras and some semi-professional digital cameras adopt 3CCD technology.

As of 2005, ultra-high resolution CCD chips are still quite expensive, and the price of still cameras equipped with 3CCD often exceeds the budget of many professional photographers. Therefore, some high-end cameras use rotating color filters. This multi-imaging camera can only be used to shoot static objects.

References:

Baidu encyclopedia -CCD