LED backlit and Full LED are two famous jargons you would have heard when you go to buy a Television set. When you see an advertisement proclaiming a TV to be LED, do not be fooled. TV manufacturers use a lot of jargon to confuse people and to sell their TV’s. When they say LED, it definitely refers to an LCD with just LED backlighting. The real difference lies in what type of LED used and how configured that makes all the difference.
All LCD’s depend upon some kind of backlight to light up the liquid crystal panel. Most make use of fluorescent lights known as CCFL but these days there is a trend to make use of LED backlighting. These LED lights consume less power and provide better color contrast and give manufacturers excuse to charge more prices. But make no mistake, LED TV’s are just LCD’s with different kinds of backlights.
There are two methods of backlighting LCD’s and these are known as edge-lit and full array backlighting.
Full Array backlighting
This refers to arrangement of lights in the shape of a matrix behind LCD and the diffuser. The diffuser makes sure that this matrix of backlights gets spread across the back of LCD. This arrangement of LED’s with diffuser gives far superior results in terms of uniformity as compared to edge-lit LED’s.
Local dimming is a technique that is made use of for dimming of backlighting in some areas of display where there are darker elements of a scene. This technique tremendously increases the contrast ratio in LCD’s making them comparable to HD plasma TV’s. This technique makes blacks blacker and contrast levels far more than can be achieved by using edge-lit LED. One variation of Full Array backlighting is where white LED’s are replaced by a cluster of color LED’s which produces a purer white light. This pure white light allows for more vivid and true to life colors.
Edge Lit backlighting
The arrangement of LED’s along the edges of an LCD is known as Edge Lighting. A reflective light plate is mounted at the back of LCD that reflects light at an angle of and is able to pass through LCD panel. This plate produces uniform backlighting in such a manner that a diffuser is not required. Dimming of lights was not possible individually and could be achieved in groups till recently. Samsung has achieved individual dimming of light thus retaining 30-40% cost advantage over full array backlighting.
Summary
Though full array backlighting is superior to edge-lit backlighting on any given day, recent innovations by market leaders have ensured that edge-lit backlight TV’s are much closer in performance to full array backlighting than ever before.