Crt and Lcd

CGMB 113: Multimedia Technologies Chapter 12 What is a Cathode ray tube?  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 vapour at low pressure), or emitted by a heated filament in certain electron tubes.  A vacuum tube is an electron tube consisting of a sealed glass or metal enclosure from which the air has been withdrawn.  A cathode ray tube or CRT is a specialized vacuum tube in which images are produced when an electron beam strikes a phosphorescent surface.  Besides television sets, cathode ray tubes are used in computer monitors, automated teller machines, video game machines, video cameras, oscilloscopes and radar displays. How cathode ray tube works in television?  Almost all TVs in use today rely on a device known as the cathode ray tube, or CRT, to display their images.  LCDs and plasma displays are sometimes seen, but they are still rare when compared to CRTs.  It is even possible to make a television screen out of thousands of ordinary 60-watt light bulbs

 The terms anode and cathode are used in electronics as synonyms for positive and negative terminals.  For example, you could refer to the positive terminal of a battery as the anode and the negative terminal as the cathode.  In a cathode ray tube, the "cathode" is a heated filament (not unlike the filament in a normal light bulb).

By: Tony Kennedy

CGMB 113: Multimedia Technologies Chapter 12  The heated filament is in a vacuum created inside a glass "tube."  The "ray" is a stream of electrons that naturally pour off a heated cathode into the vacuum.  Electrons are negative. The anode is positive, so it attracts the electrons pouring off the cathode.  In a TV's cathode ray tube, the stream of electrons is focused by a focusing anode into a tight beam and then...