what is the light source for lcd screens?

[supernova87a]

You know, for laptop screens or flat panel lcd's -- where does the light come from, and how is it generated? (does each pixel generate its own light?) I've always wondered about this.

Does anyone know? Thanks!

 

[RossGr]

I the ones I have dealt with there is a small flouresent tube behind the panel.

 

[AnthraX101]

The several I have seen have a flourescent light on the top, so it goes through the whole medium almost evenly.

Armani

 

[zephyrprime]

I asked the same question a few days ago in the general forum. I was told that they use cold cathode fluorescent tubes. Also, I was told that white leds would be used in the future.

I don't know how they'll overcome the cost associated with white LEDs which are expensive. In any case, LCD pixels can't generate light like CRT pixels can. LCD's are light filtering devices.

 

[Damascus]

<< Also, I was told that white leds would be used in the future. >>



Question: aren't white leds the things that are used to light devices like
the LCD screen on iPaq's? Even though I'd never buy one, I must admit that
the picture quality on those things is nice.