Tv Physics Essays

Submitted By kmcdo50
Words: 1906
Pages: 8

Today the television has become an integral part of our lives and it would be hard to imagine a world without it. The invention of the television was invented by various people who were performing different expressions in the field of electricity and radio. This led to the development of the basic foundation of the television. A student in Germany called Paul Gottlieb developed the very first mechanical module of television. He was able to send images through wires with the help of a rotating metal disk. This system was called the electric telescope which consisted of 18 lines of resolution. In 1907, A.A. Campbell Swinton and Boris Rosing used the cathode ray tube along with the mechanical scanner system to create a new system of 1927 Philo Taylor Farnsworth invented a working model of the television that developed on the ideas from Swinton. Later televisions began to create coloured images.
Today televisions are different to the televisions compared to the televisions of a half century ago. Today you have a chose between a variety of different types of televisions compared to the half a century ago when all you get acquire where cathode ray tube televisions.
In today’s world there are mainly three types of televisions. They are LCD Televisions, LED Televisions and Plasma Televisions. Plasma Televisions are said to be the best televisions out of all of these but are they? That Plasma Televisions are an all-round better television than a LCD television and LED Television for the price.
LCD Televisions: LCD stands for Liquid Crystal Display. The Liquid Crystal display produces the image on LCD Television with a Fluorescent Light or more commonly now LED lights behind the LCD panel. Liquid Crystal Display is a state that exhibits both the properties of a liquid and a solid. The Liquid Crystal molecules arrange themselves in such a way that they all point in the same specific direction. Depending on the temperature and nature of a Liquid Crystal, it can have one of several distinct phases. The first phase is called the Nematic Stage and is basically when there is no spatial ordering of the molecules.
A feature with liquid crystal is that electrical current affects them. They use the Liquid crystal in LCD TVs because they are controllable and predictable when an electric current is passing through. The Nematic Liquid (or twisted Nematic) is naturally twisted, but applying an electric current will untwist them, depending on the current of electricity that passes through will also vary the degrees at which the nematic crystal will turn. All this helps to control how much light from the fluorescent light passes through thus creating images.
Along with the Liquid Crystal Display there are many other parts of the Television that help contribute to the picture. In the picture below it shows parts of a simple LCD television and A being the back of the television and F being the Front of the Television. A) A mirror which helps to reflect the fluorescent light through the following. B) A glass panel with polarised filter running on a horizontal axis to block or pass light through. C) A common Electrode Plane that covers the complete area of the Liquid Crystal Display. At the top of the Electrode Plane it is made of Indium-tin oxide. D) Next is the LCD panel or Liquid Crystal Display Panel. E) Is another pane of glass but with a rectangular shape electrode at the top and bottom. F) A polarising filter film with a vertical axis to polarise light as it enters.
The electrode in section E is connected to a power source which in this case is the power grid. When the TV is off and there is no current, any light that enters through the front of TV will simply reflect off the mirror in the back of the TV. When an electric current is provided to the electrodes, the liquid crystals that are between the two electrode planes untwist and block the light trying to pass through that region.
At the Back of the LCD television there is a…