Changes

'''Cathode ray tube''' or CRT is a vacuum tube device used to display graphic information on a screen (as opposed to performing purely electronic operations such as amplifying, oscillating, or switching). It is distantly descended from the [[Crooke's tube]].

'''Cathode ray tube''' or CRT is a vacuum tube device used to display graphic information on a screen (as opposed to performing purely electronic operations such as amplifying, oscillating, or switching). It is distantly descended from the [[Crooke's tube]].

In a cathode ray tube, a series of electrodes produces a narrow, tightly focussed beam of electrons. This beam is then deflected horizontally or vertically, either by other electrodes or by external magnetic fields. The beam travels a distance, typically on the order of one or two feet, and strikes a flat screen covered with phosphors. The phosphors glow where the beam strikes, causing a bright dot of light.

In a cathode ray tube, a series of electrodes produces a narrow, tightly focussed beam of electrons. This beam is then deflected horizontally and vertically, either by other electrodes or by external magnetic fields. The beam travels a distance, typically on the order of one or two feet, and strikes a flat screen covered with phosphors. The phosphors glow where the beam strikes, causing a bright dot of light.

Cathode-ray tubes were very important electronic devices throughout most of the twentieth century. They found application in the early part of the century in oscilloscopes, a piece of technical equipment used in scientific research and electrical engineering. During the Second World War, they were used as radar screens. After the war, they became ubiquitous as television "picture tubes."  

Cathode-ray tubes were very important electronic devices throughout most of the twentieth century. They found application in the early part of the century in oscilloscopes, a piece of technical equipment used in scientific research and electrical engineering. During the Second World War, they were used as radar screens. After the war, they became ubiquitous as television "picture tubes."