LCD vs plasma TVs LED TV
What is LED technology in TVs?
LEDs (light-emitting diodes) have been around for decades, but their introduction into HD TV design and availability on the high street is a fairly recent development.
LED televisions are basically LCD TVs with one crucial difference – the handful of traditional back light lamps that illuminate the screen have been replaced by hundreds of smaller LEDs.
To give an LED TV its full name is more of a mouthful – LED lit LCD. LED TVs still employ standard LCD TV technology; Light from behind the screen is shone through the television screen's matrix of tiny coloured liquid crystal cells. Signals control each cell, letting varying amounts of colour through, and a picture is built up.
Keep an eye on our LCD and plasma TV reviews to read full reviews of new LED TVs as we test them
Who makes LED TVs?
Following on from Sony and Samsung in 2008 and 2009, all the major television manufacturers have now launched an LED TV range.
The downside at the moment is common to any new technology – a hefty price tag. The majority of new LED TVs tend to be higher end fare, though there are now some budget options available.
Do LED TV pictures look better?
In theory the use of LED back lighting should deliver an improved contrast between bright and dark elements of a picture.
On many of the LED TVs we've tested, we found the pictures vibrant, sharp, detailed and oozing with depth, though the viewing angle tends to be poor (a common problem on LCD TVs that the new back lighting doesn't appear to have resolved).
Whether this picture quality success can be set purely at the door of LED back lighting is debatable. The higher end (and very expensive) models tend to perform well, but it is not the case across the board. Picture quality varies by brand and budget, just as it does with LCD and plasma technologies.
What are the benefit of LED TVs?
The benefits are twofold: LED TVs are slimmer and typically more energy efficient than both regular LCD TVs and plasma TVs.
What makes LED TVs so slim?
There are basically two types of LED TVs - Edge LED TVs and backlit LED TVs. Edge models are simply those with the LED lighting placed around the the edge of the screen. Without the traditional bulky lamps at the back of the TV, Edge LED models can be designed to be incredibly slim.
Some early Edge TVs suffered from an uneven backlighting effect, especially in the corners of the screen. This is a problem Samsung seems to have cracked with its models thanks to some clever light diffusion technology.
Thicker LED panels, are typically illuminated by LEDs dotted over the rear of the panel, but many backlit models (such as the LG LX9900) are slimmer than regular TVs too.
Energy efficient LED TVs
LEDs are also more energy efficient than traditional bulbs and require less power to illuminate the screen. The effect on power consumption can be dramatic, especially when compared to the LCD and plasma TVs we've already tested.
Some of the most dramatic examples include the (right) and Panasonic Viera TX-L42D25. The Samsung is a huge 55-inch screen but consumes only 114 watts when switched on (nearer to a typical the 40-inch LCD screen.
The Panasonic uses about a third of the power of an equivalent-sized Panasonic plasma TV - just under 94W in normal viewing mode.
Both are fine examples of how LED TV technology is pushing the boundaries of energy efficiency.
- Buying a new TV? Take a look at our best TV brands video
- Thinking about a HD TV? Take a look at our expert guide
- Read our guide to buying the best smart TV
