A light-emitting diode (LED) television (TV) is a liquid crystal display (LCD) television that is backlit by LEDs rather then standard fluorescent tubing. An LED TV should not be confused with the organic light emitting diode (OLED) variety, which is a TV that features an actual electroluminescent layer comprised of a film of organic compounds. Unlike an LED TV, an OLED TV is a self-illuminating display that does not require a backlight – in fact, the very term LED TV is something of a misnomer as it is technically considered to be a backlit LCD TV. The advantage LED backlighting is thought to have over fluorescent lighting is that the latter typically reduces the TV's ability to display black effectively due to light leakage that results in a fuzzier image. Fluorescent-tubing LCD televisions have limited color saturation, and because of these overall disadvantages with fluorescent lighting, manufacturers introduced LEDs to replace the fluorescent lighting.
There are two varieties of LED TV on the market: Edge LED and Dynamic RGB LED. In Edge LEDs, the edge of the television is lined with LEDs, allowing for an extremely thin television casing – generally around 1 inch (about 2.54 cm) thick. RGB Dynamic LED televisions have LEDs interspersed throughout the entire panel and are thought to provide a clearer differentiation between dark and light areas than similar fluorescent models. As both plasma and LED models provide the user with flat-screen technology, the primary differences come down to aesthetics, price, and sustainability. Plasma TVs are far cheaper than their LED counterparts and remain at the forefront of flat-panel sales, whereas LED TVs are more energy efficient than plasma and conventionally lit fluorescent LCD counterparts.
The Sony® Qualia was the first LED TV offered for sale to the public in 2004 and featured the RGB LED lighting scheme. Its design was quite popular and has since been incorporated into several Sony® BRAVIA models. LED TV technology has significantly advanced and now features plans to incorporate quantum dot technology, which has been recently developed for use in LED displays. Quantum dots are semiconductors whose shape closely matches that of the individual crystal in LCD displays, which allows for a more Gaussian distribution of light. This results in a far superior picture than has previously been available in LED TVs and will eventually rival plasma, if not OLED, for picture quality and clarity.