How Your Phone Screen Works

A basic guide to LCD screens

YouTube.com

white+smartphone+near+laptop

By: Desmond Kraft, Journalist

(Note: this article explains the display part of a phone screen, not the touchscreen.)

Have you ever wondered how you phone screen displays such detailed images? You probably already know about pixels, and how each pixel is made up of red, green, and blue light, but how does the phone turn each light on and off at will? There is not enough space for hundreds of thousands of wires or lightbulbs in there. So what is going on?

Phones, and many other screens such as TVs and monitors, use something called a Liquid Crystal Display (LCD). “Liquid crystal” sounds like a contradiction, because how can something be liquid and solid at the same time, and why does liquid in your device screen not short-circuit it? The liquid crystal is a substance that is halfway between liquid and solid. It is specifically designed so that when an electric current passes through it, the molecules twist and turn in a predictable way to only let certain amounts of light through. This controls the brightness of each red, blue and green subpixel for every pixel. There is a web of transistors through out, which apply electricity to the crystals in specific ways to make them let only the right amounts of light through. transistors are the smallest electric component, and are so small that you can easily fit many in the space between pixels. The whole thing is powered from a light in the back, so the liquid crystals aren’t creating light, only altering it.

Of course it is more complicated than this. There are some aspects not covered here, such as polarizers, which make the light passing through more well defined. Check out the related stories for more info.

RELATED STORIES:

https://www.techtarget.com/whatis/definition/LCD-liquid-crystal-display#:~:text=In%20short%2C%20LCDs%20are%20lit,is%20placed%20at%2090%20degrees.

https://nelson-miller.com/lcd-displays-work/

https://electronics.howstuffworks.com/lcd.htm

https://en.wikipedia.org/wiki/Liquid-crystal_display

https://www.xenarc.com/lcd-technology.html

TAKE ACTION: