A device used to trace out an object and build up an image. One of the most common of these types is video scanning. The scanning takes place inside the television tube as electrons, guided by electron optics, sweep linearly across a tube face coated on the inside with a phosphorescent material. A scanner can convert a paper drawing or photograph into pixels on a display screen. Scanners are also used to relay information in optical data processing. 2.
A device that automatically measures or checks a process or condition and may initiate a desired corrective action by means of switching. 3.
A device for sensing recorded data, such as a supermarket bar code.