Liquid Crystal Displays

Or LCD. These are the most commonly found and inexpensive flat screen TV sets and computer monitors.

They work with a glass screen that contains liquid controlled by transistors and colored filters. As the transistor activates polarization occurs to let more light through the liquid crystal and create a pixel image.

This is one of the oldest displays, going back to the 1970s and one of the most fragile. Drop it, bend it or press on it and you break it!

Itís liquid inside of glass! Easy to fracture!

The downside of LCDs include limited viewing angle (those off to the side see a darker image or no image at all) and lag time. When something moves it takes a while for the transistors or change the liquid inside the display, as a result you see a staggered image when there is great motion. A traditional CRT (Cathode Ray Tube) TV set has a 1 millisecond (ms) refresh rate while LCD screens vary from12 to 20 ms.

Different companies, such as Toshiba and Samsung, have been working on improving this process over the years and each has their own system with their own problems.

LCD screens offer very good color saturation as compared to DLP, but they have lower contrast and a smaller viewing area.

TFT (Thin Film Technologies) screens are the most widely used for LCD televisions.

Because of the way that LCD screens work using a pixel by pixel operation, it is easy to make multi-national TV sets capable of picking up NTSC, PAL, SECAM, ATSC Digital, DVB Digital and even computer digital signals. Thus many LCD screen TV sets can be designed for world wide use quite easily.



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