LCD and LED televisions image display.
LCD technology uses two major components to display, namely Cold Cathode Florescent Lamps or CCFLs and molecules of liquid crystals. The CCFLs are used to illuminate the liquid molecules with white light, and as the light passes through, an image is created. This is basically an advanced model of a LCD TV, which uses Light Emitting Diodes instead of the traditional Cold Cathode Florescent Lamps for its back light. The major advantage of using an LED TV is that it eliminated the numerous black spots that were as a result of using fluorescent lights. A LED TV has the best color levels and contrast ratio, hence superb picture quality that is viewable from wider angles.
An edge-mounted, white LED module. An RGB backlight
(Credit: Ty Pendlebury / CNET Australia) (Credit: Samsung)
LCD panels create dark tones by blocking the backlight passing through the panel; this method of displaying black has been a problem inherent in the technology. Local dimming LED back lighting presents a solution to this problem by dimming the back light in areas where the screen should be dark. Edge lit LED will have brighter whites than most fluorescent back lit LCDs but do not have the control over the backlighting like local dimming TVs do.
This comparison has become muddied lately with some LCD TVs showing very concentrated black levels. Local dimming LED TVs have been the best in the past. With white LED backlights the difference between the two technologies isn't very significant, but with RGB colored lights or a color wheel to affect the backlight color the LED TVs have an advantage in displaying realistic color. White backlight LED TVs and LCD TVs with fluorescent backlight are nearly equal in color accuracy. Colored backlight LED TVs trump both.