Television

Television is often abbreviated as TV. It is a telecommunication medium for receiving and transmitting images, either color or monochromatic, which usually associated with sound. Television is also referred as a television transmission, television programming, and television set.

History of Television

Television was invented in 1920 by deploying a combination of electronic, mechanical, and optical technologies to trap, display, and transmits images.

Types of Televisions

There are four types of televisions; they are, Direct View – Tube, Digital Light Processing (DLP), Liquid Crystal Display (LCD), and Plasma Display Panels (PDP). Let us take a better look at each of them.

Direct View – Tube

This is a tube television constructed using a cathode ray tube, and a vacuum tube. Usually, CRTs come in different sizes, but the common size is 40-inches. Price of this TV is significantly lower, but it provides good picture quality. However, it is bulkier and has longer lifespan. These TVs can produce a good quality picture for decades.

Digital Light Processing (DLP)

This process was found in 1987 by Texas Instruments. It processes light with the help of a Micromirror Device or DMD chip, which is an optical semiconductor. This chip consists of more than one million mirrors. Size of every mirror is lesser than 1/5 inch width of an individual hair.

Liquid Crystal Display (LCD)

A Liquid Crystal Display is used in this type of televisions. Actually, this LCD is used as screen of the TV. It has light weight construction and the same screen is also used as computer display also. Advantages of LCD screens are good picture quality, resolution, and low emission of radiation. Its screen is very sensible and it is not as hard as DLPs.

Plasma Display Panels (PDP)

A plasma TV is bigger in size and it just like LCD TVs. Generally, high class people use this plasma TVs, since their pricing is always on the higher side. Usually, these TVs are suitable for big houses and these are not for congested rooms. A plasma TV gives good looks to a living room. In market, plasma TVs are available in variable sizes ranging from 40-49-inches. However, lifetime of Plasma Display Panels (PDP) is lower than other TVs; still they last for up to 20 years.

Working of Television

The working of television is completely based on a cathode ray tube. To know the working of TV, first you have to know the working principle of cathode ray tube. Pictures of the CRT are included in this post for better understanding.

Taking a look at the figure, starting from the left hand side of CRT; it has an electron gun to emit electrons. This electron gun is connected to positive and negative electrodes.

After these terminals are switched on, the electron gun receives electric supply. After some time, it gets heated and emits electrons. At the extreme right of figure, you can see an oval shaped semi circle called CRT. All emitted electrons go and fall on this screen to form picture. Movement of electrons is controlled by some electric and magnetic mechanism.