What is LCD and how does it work?

Answer

LCD stands for Liquid Crystal Display.

LCD technology has been around for a long time but it is now becoming very popular for flat-screen computer monitors and televisions. It can provide a much better, brighter image than the old CRT (Cathode Ray Tube) monitors and TVs.

Here is a very basic summary of how LCD works. (Maybe someone can expand on this.)

There is a set of two transparent panels with a liquid crystal solution between them. Light is shined from behind the panels. Each crystal either allows light to pass through or blocks the light. The configuration of the crystals forms the image.

There's a little more to it than that...

The two transparent panels are polarised, which means they will only pass light waves in one plane. These two polarised panels at 90� to each other so that light filtered from one plane cannot get through the other panel because it only lets light through in a plane at 90� to the first plane. So the panel appears to be "black" (or at least very dark). However, when electricity is applied to one of the segments of liquid crystals (segments are switched on and off to form the images you see on the screen). The crystals line up in such a way as to make the light turn through 90� in between the two panels. So now the light "TWISTS" through the panels and is visible on the other side. Does having a "Super-Twist" display mean more to you now?

Actually, LCD images are inferior to CRT images, colour uniformity, image sharpness and viewing angle are poor compared to a CRT and fast moving images appear blurred because the crystals can't quite keep up and react quickly enough. They are getting better, but will never beat the image quality of a CRT. But obviously are smaller and lighter, so it's worthing having one anyway.

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