CRT MONITORS

A monitor is a receiver, such as a screen or speaker, that is used to observe or review the quality or content of an electronic transmission. Television sets, computers, automated teller machines, video game machines, video cameras, monitors, oscilloscopes and radar displays all a contain cathode-ray tube monitors.

A CRT monitor is a cathode ray tube, a specialized vacuum tube in which images are produced. {A vacuum tube is an electron tube consisting of a sealed glass or metal enclosure from which the air has been withdrawn.)

A cathode is a terminal or electrode at which electrons enter a system, such as an electrolytic cell or an electron tube.

A cathode ray is a stream of electrons leaving the negative electrode, or cathode, in a discharge tube (an electron tube that contains gas or vapor at low pressure), or emitted by a heated filament in certain electron tubes.

A cathode ray tube is a vacuum tube that produces images when the phosphorescent surface, a screen,is struck by electron beams.
* Phosphor screens using multiple beams of electrons allow CRT monitors to display millions of colors.

History

The first cathode ray tube scanning device was invented by the German scientist Karl Ferdinand Braun in 1897. Braun introduced a CRT with a fluorescent screen, known as the cathode ray oscilloscope. The screen would emit a visible light when struck by a beam of electrons.

In 1907, the Russian scientist Boris Rosing used a CRT in the receiver of a television system that, at the camera end, made use of mirror-drum scanning. Rosing transmitted crude geometrical patterns, the first inventor to do so using a CRT monitor.

With the development of the "Iconoscope" by Vladimir Zworykin in 1932 it was possible to imitate the conditions under which the human eye functions. He created a sheet with millions of light sensitive elemental capacitors that should have a function comparable to the receptors of the human eye.

During the representation of an image on the sheet of capacitors the elemental capacitors are charged dependent on the brilliance. So a charge image is developed which can be converted into a picture signal on the monitor. The way was free for the development of modern image converter tubes.