CCD implies Charged Coupled Device. They are devices used in digital cameras and video cameras to record moving and still images. The CCD captures light and changes it to digital information that is recorded by the camera. Hence, a CCD is considered the digital version of a film.
The CCD is a grand piece of technology in Digital Imaging. In a CCD sensor, pixels are characterized by p-doped MOS capacitors. These capacitors are biased above the frequency for inversion when image capture begins, allowing the transformation of incoming light rays into electrons charges at the semi-conductor oxide interface. The CCD is then used to interpret these charges.
A CCD is an integrated circuit imprinted onto a silicon surface to form a light sensitive element called Pixels. Photons (or light rays) incident on the surface creates charges that can be interpreted by electronics and converted into a digital copy of the photons falling on the device. CCDs are of different types and sizes and are used in many applications ranging from high-end scientific applications to camera phones.
The quality of photo produced by a CCD camera depends on the sensor’s resolution, and the resolution is measured in Megapixels. Hence, a 13MP digital camera produces a more detailed photo than an 8MP camera.
CCD in a video camera is measured by physical size. For example, most digital camera uses a CCD of about 1/5 or 1/6 of an inch in size. More sophisticated cameras may have CCDs 1/3 of an inch or larger size.
The larger the sensor, the bigger light it can capture or the better video it can produce in low light settings. Professional video cameras often have 3 sensors, called “3CCD,” which uses distinct CCDs for capturing blue, green and red hues.