It was not too long ago that people had to make do with black and white images on their TVs. These days, the images on flat-panel televisions are not only colorful and in high-definition, they operate on different types of technologies, including LCD, LED and plasma TVs. The choices can be a bit confusing for someone in the market for a TV.
LCD stands for Liquid Crystal Display. This type of TV allows light to pass through molecules of liquid crystals, also known as pixels, that twist to improve viewing objects. These pixels are illuminated by cold cathode fluorescent lamps (CCFLs) to produce pictures. The color pixels in LCD use three sub-pixels of green, red and blue color filters. Not only are LCD TVs light and flat, they produce very sharp and clear pictures, which is why they are widely used in the production of other display screens, such as those for cell phones and laptops. One of the advantages of LCD TVs is that they do not consume much power. Most LCD TVs can be lit by a single fluorescent back-light, unlike plasma TVs which require every sub pixel to be lit individually.
Plasma TVs, or plasma display panels (PDPs), are used in large TV displays and are also display flat-panel screens. Plasma TVs generate images by using a small sheet of individual plasma cells which create a picture when an electrical charge is applied. Generally, LCDs have a better color generation than plasma, and they have wider viewing angles. LCD's do not have the kind of picture distortion which occurs in plasmaTVs. Plasma screens are made from glass and reflect more light than LCD screens. The glass can cause glare from reflected objects in the viewing area.
LED stands for light emitting diode. LED TV is simply a type of LCD TV which uses LEDs for back-lighting, as opposed to the LCDs which use fluorescent lights. The reason for this is to eliminate the black spots created by fluorescent back-lights. LED TVs are not cheap because they typically cost more than the average plasma or LCD TV. LED TVs may be edge lit or backlit. Edge lit LEDs consume less power than either the LED or plasma TVs, while backlit LEDs will consume more power. LED TVs have better contrast ratio and picture quality that LCDs, if they are backlit and have RGB (red-green-blue) LEDs.