Charge-Coupled Device (CCD)

Silicon chip containing an array of photosensitive sites. The imaging area consists of rows and columns of photosensitive pixels that accumulate and store electric charge. The term CCD refers to the way the photoelectron packets are moved around on the chip, the shift registers. Each column is separated by a shift register, to which pixel charge is transferred. Charge is read out from each pixel of the device through the shift register sequentially to an amplifier. The raw analog signal is either used directly, or quantized by an A/D converter.