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Q & A: LCD Displays

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Most recent answer: 10/22/2007
How does a LCD screen works and who maded one first?
- Tom Nijns (age 18)
Karel De Grote hogeschool, Belgium
The first liquid crystal display was made by RCA in 1968. But now, you can find them almost everywhere.

The liquid crystal in the display is a special material that changes its structure when you apply electricity to it. One of the things that changes about the material is whether it reflects or absorbs light. When the material has and electric potential on it, it changes it structure and absorbs light. That means the spot looks black. When it reflects light, it will appear white. When you carefully adjust the potential, the material will change to different chaged of grey (a mix of black and white).

Now comes the really cool part. If you put a little red filter in front of the liquid crystal, then you have a dot that changes from black to red and all the shades of red you want. If you put that next to a green one and a blue one, you can make all the colors of the rainbow by mixing different amounts of each color. It you mix red+blue+green, you get white. If you mix red+green, you get yellow.

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(published on 10/22/2007)

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