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LED Backlight Versus Traditional LCD Backlight

by Sean P. Aune | January 17, 2010January 17, 2010 10:04 am PDT

Have you ever looked at the back of your LCD high definition television and wondered why there is a whole lot of light coming out of the ventilation slits?  Well, there’s a reason for it, and someday it might be a whole lot more colorful.

While there are fans of both LCD (Liquid Crystal Display) and plasma HD TVs, one thing the latter has over the former is that the technology does not require any form of backlighting.  An LCD screen does not actually emit any light of its own, so for it to show the images on the screen properly, it needs to be backlit from some type of lighting source.  Currently the most common form of lighting in these television sets is Cold-Cathode Fluorescent Lamps (CCFL) that are laid horizontally running up the height of the screen.  However, if you are willing to shell out the extra money, you could go with an LCD TV that is running LEDs (light-emitting diodes), which are more than likely the wave of the future.

samsung-ledIgnoring the extra cost of the LEDs, there are even more choices you have to make once you decide that you want to go this route.  From the outside the TVs look no different (that is a Samsung LED set to the right), but on the inside you have at least two decisions to make about if you want the LEDs to be edge-mounted or direct.

As the name “edge-mounted” implies, the lights run along the exterior frame of the screen which allows them to be mounted in extra thin sets.  The issues are that if the light is not properly distributed you can end up with some shadowed areas, and you also lose some contrast because they are always on.

Direct LEDs are mounted in strips behind the screen and can be turned off in the darker areas of an image so that you get much better contrast in your picture.

The other debate with LEDs is whether you should be using white or RGB (Red Green Blue).  White is similar to the current CCFL set up, but RGB offers you a broader spectrum of color.  This will probably be decided for you by the manufacturers, but still handy to know about it.

In short, if you want the best LCD, you probably want direct RGB lighting for your set, but you also need to expect to pay quite a bit more at this time for the technology.  Eventually the price will drop and we will probably see all LCDs go this route, but it may be another year or two before it becomes mainstream technology.


Sean P. Aune

Sean P. Aune has been a professional technology blogger since July 2007, but his love of tech dates back to at least 1976 when his parents bought...

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