Topic summary

LED-backlit LCD

LED-backlit LCD

An LED-backlit LCD is a liquid-crystal display that uses light-emitting diodes (LED) for backlighting instead of cold cathode fluorescent lamps (CCFL). LED-backlit displays use the same TFT (thin-film transistor) LCD technologies as CCFL-backlit LCDs, but offer a variety of advantages over them. The LED bulbs are typically blue or white, but more recently RGB ones have been developed. There are four types of LED-backlit LCDs: Edge-Lit, Direct-Lit, Full-Array Local Dimming (FALD) and Mini-LED, each describing how the LED bulbs are arranged behind the liquid-crystal display for illumination. A variant is QLED, a type of LED-backlit LCD that uses an extra layer film of quantum dots for improved color gamut.

Televisions that use a combination of an LED backlight with an LCD panel are sometimes advertised as LED TVs, although they are not truly LED displays. They largely replaced CCFL-backlit LCD TVs in sales and manufacture by the early 2010s.

Backlit LCDs of any type cannot achieve true blacks for pixels, unlike the totally self-emissive OLED and MicroLED displays. This is because even in the "off" state, black pixels still allow some light from the backlight through. Some LED-backlit LCDs use local dimming zones to increase contrast between bright and dim areas of the display, but this can result in a "blooming" or "halo" effect on dark pixels in or adjacent to an illuminated zone.