LED-backlit LCD
An LED-backlit LCD is a liquid-crystal display that uses LEDs for backlighting instead of traditional cold cathode fluorescent (CCFL) backlighting.[1] LED-backlit displays use the same TFT LCD (thin-film-transistor liquid-crystal display) technologies as CCFL-backlit LCDs, but offer a variety of advantages over them.
"LED TV" redirects here. For true LED displays, see LED display.
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.[1][2]
Backlit LCDs cannot achieve true blacks for pixels, unlike 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.[3]
LED backlights replace CCFL (fluorescent) lamps with a few to several hundred white, RGB or blue LEDs. An LCD with LED-Backlight may be edge- or direct-lit:[9]
Additionally a special diffusion panel (light guide plate, LGP) is often used to spread the light evenly behind the screen.
The local dimming method of backlighting allows to dynamically control the level of light intensity of specific areas of darkness on the screen, resulting in much higher dynamic-contrast ratios, though at the cost of less detail in small, bright objects on a dark background, such as star fields or shadow details.[10]
A 2016 study by the University of California (Berkeley) suggests that the subjectively perceived visual enhancement with common contrast source material levels off at about 60 LCD local dimming zones.[11]
