NEC LCD2180WG-LED-BK - MultiSync - 21" LCD Monitor, Reference Manual

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Light from Red, Green and Blue LEDs is combined in the folded light guide. White light is filtered back into Red, Green and Blue sub-pixels. The modified blue filter further enhances blue spectrum. Resulting spectrums are very pure which gives a very wide color gamut.
LED Backlight
Typical CCFL Backlight
Resulting spectrums contain unwanted colors such as yellow, cyan and orange which reduces the color gamut.
Comparison of LED and CCFL Backlight Color Gamuts
White light from CCFL is filtered back into Red, Green and Blue sub-pixels.
Why not use white LEDs?
White LEDs typically emit white light by using either a blue LED
with
a
yellow
phosphor
coating,
or
an
ultra-violet
LED
with
a mix of red, green and blue phosphor coatings. The spectrum of the white light has many of the drawbacks of using a CCFL backlight and does not produce a wide color gamut. Additionally, the white point, or color temperature, of the white LED output is fixed. Therefore the advantage of being able to adjust the white point by varying the individual red, green and blue LED intensities would be lost.
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