What we often refer to as LED television is actually a LED-backlit LCD television, which is one of the two types of LCD televisions available today. While the first type uses cold-cathode fluorescent lamps (CCFLs) to illuminate the screen, LED-backlit LCD TVs use light-emitting diodes (LEDs) for the same.
The popularity of the term 'LED TV' can be attributed to marketing of LED-backlit LCD TVs as LED TVs―a practice which is followed by some of the major firms in the field of consumer electronics.
Within LED-backlit LCD televisions there are two types: Full-array LEDs, which are also known as backlit LEDs―albeit informally, and Edge-LEDs, which are also known as edge-lit LEDs.
Difference Between Edge-Lit and Backlit LED Televisions
As we mentioned earlier, LED TVs are LCD TVs which use light-emitting diodes (LEDs) to illuminate the display. There are two methods by which these light-emitting diodes (LEDs) can be used to illuminate the screen. Based on the method used, LED-backlit LCD TVs are grouped into two categories.
In the first method, light-emitting diodes (LEDs) are placed in such a manner that the entire back portion of the display is covered―this is the Full-array LED TV (aka backlit LED TV). In the second method, light-emitting diodes (LEDs) are placed around the perimeter or the edges of the display―this is the edge-lit LED TV.
In case of full-array backlit LED TVs, a diffuser is used to ensure that the backlighting is spread evenly behind the entire LCD panel. It is this uniform backlighting that helps these television sets produce the exceptional contrast ratio that they boast of.
In case of edge-lit LED TVs, a reflective light plate is mounted directly behind the display. This light plate reflects the light emitted by LED at an angle of 90°, which makes it pass through the LCD panel. Irrespective of the method used, LED-backlit LCD televisions consume less power compared to their LCD counterparts with CCFLs and Plasma TVs.
Which is Better?
There is no questioning the fact that LED-backlit LCD TVs have an edge over their counterparts when it comes to power consumption. What needs to be looked into, is how the two types of LED-backlit LCD TVs fare when pitched head-to-head against each other. Frankly speaking, both have their own advantages and disadvantages.
In terms of appearance, edge-lit LED TVs are thinner than their backlit counterparts as the light-emitting diodes used in them are placed at the edges and not at the back.
Even though backlit LED TVs are a bit bulky compared to edge-lit LEDs, they are not as bulky as LCDs with CCFLs. Though negligible, the uniformity problem wherein edges appear brighter than the center portion of the screen does surface as a drawback of edge-lit LEDs.
Backlit LED TVs do boast of a technique referred to as 'local dimming' which facilitates sharp deep black images. If you watch a scene wherein a part of the screen is black on both these televisions, you will realize that the black portion is much more prominent in the backlit LED TV.
This difference in picture is attributed to the 'local dimming' technique wherein light-emitting diodes (LEDs) are completely put off for that particular region which has to depict the color black. The effect of this technique is at its best when the light emitting diodes are not grouped, but instead, every single LED has a different source of power.
If they are grouped, it can result in dimming of surrounding portion which has to be bright. Full array with local dimming technology can be a little expensive though, which explains why the best LED TV is also one of the most expensive.
Add to it the fact that edge-lit LED TVs are less expensive as compared to backlit LEDs, and they surely get an upper hand in the comparison. As far as the difference in contrast ratio is concerned, it has lessened significantly with the introduction of edge-lit LEDs with local dimming feature.
If you are not facing a financial crunch, a backlit LED with local dimming is what you need to go for. On the other hand, if price has an important role to play, you should go for new edge-lit LED TVs with local dimming.