Televisions are one of the primary media outlets by which people acquire information, entertainment and education. It is fascinating that a certain image and sound can be sent from distant regions of the globe and into your living room and that multiple people in different countries can watch the same exact footage at the same time, and there are many significant parts inside of a television that enable this to happen.
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Cathode Ray Tube
Most televisions used today utilize a cathode ray tube (CRT) inside of the TV to display images. The cathode is a heated filament similar to the filament in a typical light bulb, and it is placed within a vacuum inside a glass tube while a stream of electrons shoots from the heated cathode into the vacuum.
Between the cathode and the TV a set of anodes are installed to focus the stream of electrons into a tight beam and to accelerate the electron beam. Then the accelerated electron beam is sent by the anodes through the vacuum in the tube until it hits the screen of the TV on the other side.
Steering coils consist of copper winding coils that are capable of creating magnetic fields inside the tube to direct the electron beam. There are two sets of coils inside of a CTR that direct the beam as to which direction to go and where to hit the screen on the other side; one set of coils creates a magnetic field that directs the electron beam vertically and the other set moves the beam horizontally.
Phosphors pertain to any material that emits visible light when exposed to radiation caused by either ultraviolet light or by a beam of electrons. In a CTR, and thus in a TV, phosphor coats the inside of the screen, and when the electron beam strikes the phosphor, it makes the screen glow. To produce color for color TVs, three phosphors are arranged as dots that emit red, green and blue light, along with three electron beams that illuminate the three different colors together to generate and display any other colors on the light spectrum.