Information
The first thing you need to know about LED (Light Emitting Diode) TVs is that they are not really LED TVs, as we would expect them to be. LED TVs are actually LCD (Liquid Crystal Display) screens, which are backlit, or sidelit by LEDs. So, they are more correctly called LED-Backlit, or LED-Edgelit TVs, or perhaps LED-Backlight or LED-Edgelight TVs.
The reason for this is that current technology limits how small LEDs can be made, so they cannot be made as small as a pixel on a TV screen, which is probably the way most of would have expected them to be.
However, they are still LED TVs, differentiating them from ordinary LCD TVs, as they are quite a lot better. The reason LED TVs are better than LCDs is that the picture quality is better, they are more environmentally friendly, can produce a better and clearer range of colours and they can be produced with very thin screens.
The LEDs replace the LCD-CCFL (Cold Cathode Fluorescent Lamp) lighting method which was previously used.
The most important feature must be the improved picture quality, which is immediately appreciated by the viewer. The image can be brighter than is possible with a traditional LCD, with higher contrast, purer whites, deeper blacks and a wider colour range, particularly when Edge-LED lighting is used.
Power consumption is typically about 40% less than a traditional LCD TV.
One of the striking features of an LED Television is just how thin they can be made. The terms Thin TV and Slim TV are being used to describe them. Current models can be as thin as about an inch, which is quite remarkable when you think of the size of the old fashioned CRT (Cathode Ray Tube), the traditional television, which is seen less and less these days.
There are two main methods of lighting a TV screen with LEDs, usually called LED-Backlit and Edge-LED. Backlighting, as you would expect, is achieved by positioning the LEDs behind the LCD display, by one of several methods, usually either white or RGB (red-green-blue) LED arrays.
Edge lighting is by LEDs positioned around the border of the screen, through diffusion panels in the screen.
Whether both forms will continue, or whether one of them will prevail remains to be seen. Backlighting has the advantages of lower cost and ease of manufacture, while the principal and very great advantage of edge lighting has to be the ability to produce thinner screens, although at the risk of some loss of image uniformity across the screen.
Technology of course continues to advance, although while true LED TVs can be manufactured for very large applications, such as the huge displays in sports grounds, it is difficult to see that they will ever be small enough to overtake the other developing technologies.
The most important developing technology in this field is probably the OLED (Organic Light Emitting Diode), which uses flat polymer technology, allowing even thinner screens and still lower power consumption!