LCDs Explained Part-2

After the invention of the CRT TV everything was great everybody liked it, And in a short period of time it replaced the mechanical televisions, but later people started having problems with it. taking too much space, rising electricity bill. and many more. To read more about the CRT tv's click on this
 link-http://shekhar087tech.blogspot.in/2014/07/get-to-know-displays.html
So to get rid of all those problems in the year 1964 first Liquid Crystal Display or LCD was made, by a man named George H. Heilmeier.

George H. Heilmeier

Friedrich Reintzer

Liquid Crystal is another state of matter other than Liquid, Solid and Gas, discovered by an Australian scientist Friedrich Reintzer, yes there are more than three states of matter you have been misled by your school. but that's not the point, the point is what are Liquid Crystals ?

Liquid Crystals have the properties of both liquid and crystals it has molecular structure of crystals but it's molecules can flow over each other as a liquid. But the main reason why they are used to make electronic displays, it's because of their tendency of bending light. there are many types of liquid crystals but the one we use in displays are Twisted Nematics (TN) and the reason for that is down there some where..



LCD's play a major role in the world of technology conquering every field from desktops to smartphones from tablets to laptop LCD's are used in almost every electronic devices.
so let's see how LCD's works?

Liquid Crystal Display

LCDs consist of two polarizers right angled to each other what polarizers do is that they let only one phase of light pass through so what ever light passes through the first polarizer cannot go through the second. To let the light pass we use Liquid  Crystals and especially Twisted Nematics because TN can turn the angle of light by 90 degrees and change it's phase.

Liquid Crystals have predictable effects of electricity, when we apply current they untwist a certain degrees depending on the intensity of the current. so when liquid crystals untwist they block the light and when they are in rest mode they turn light and change it's phase. that  is how light is controlled in an LCD and speaking of light LCDs cannot produce light of their own so they need backlight. which are placed generally  at the bottom and layers of different kinds of transparent sheets spread it evenly on the screen.

On top of every thing there are different layers of  three fundamental colors Red, Blue and green are placed, yes these are the little red, blue and green dots you see when you come really close to any screen and these are called the subpixel and together they make one complete pixel.

all the colors are made by using the three subpixels.

Pros and Cons

• Pros

1. LCD's are slim, light weight and making a 50 inch LCD display doesn't take up much space.
2. Uses way less power than CRT's 

• Cons

1. Expensive.
2. Small viewing angles if you move out of the viewing angle you can even see the negative of the image.
3. Because they use back light they cannot show deep black it's always Grey and shades of Grey.

To remove the cons or inabilities of the LCDs many different types of LCDs were invented, and even changing the circuit of the display can create a big effect so the next article is all about that types of LCD's

I have already made a video Get To Know- Displays. be sure to check that to link is
 here-https://www.youtube.com/watch?v=aHVEBThfC_U&list=PLari93Sljmzi6ZTgcNdVnwGU32xbVYOnD&index=2

Be sure to share it on facebook or twitter if you like it and to follow me

Facebook-https://www.facebook.com/shekhar087tech
Twitter-https://twitter.com/Shekhar087tech
YouTube-https://www.youtube.com/user/startechvidoes