A type of vacuum tube and its related electronics that converts variations of voltage into patterns of images on a surface coated with phosphorous, generating light. The CRT is the basis of most television sets, computer monitors, and some scanners (see CRT Flying Spot Scanner).
A monochrome monitor (or black-and-white TV set) has a single electron gun which fires a continuous stream of electrons at the back of the display screen. Focusing lenses and deflection plates constantly control the position of the electron beam, ensuring the image quality. A color CRT uses three electron guns to produce red, green, and blue dot patterns.
When used to describe computer video terminals, CRT has on occasion been used to refer to the entire device, including a keyboard, rather than simply the mechanism that generates the images.