LED-backlit LCD

LED-backlit LCD is a type of liquid-crystal display (LCD) that uses LED lights for its backlight instead of older cold cathode fluorescent (CCFL) backlighting.^[1] LED-backlit displays are similar to CCFL-backlit LCDs in technology, but have several advantages.

Some LED-backlit televisions are called LED TVs, though they are not true LED displays.^[1][2]

Limitations

LED-backlit LCDs cannot produce true black colors as well as OLED or microLED displays can. Even in dark areas, a small amount of light may come through. Some LED-backlit LCDs use "local dimming," which darkens certain parts of the screen to improve contrast, though this may create a "halo" effect around bright parts of the display.^[3]

Comparison with CCFL-backlit LCDs

Compared to CCFL backlighting, LED backlighting offers:

• More colors (with certain LED types)^[4][5]
• Greater contrast ratio
• Slimmer, with some screens less than 0.5 inches (13 mm) thick
• Lighter and cooler, sometimes half the weight of a CCFL display
• 20–30% less power use and longer lifespan
• Greater reliability^[6]

LED arrangements

LED backlights use either edge-lit or direct-lit LEDs:^[7]

• Edge-lit (ELED): LEDs are around the edges of the screen, often with frame dimming or basic local dimming.
• Direct-lit (DLED) or Full Array: LEDs are directly behind the screen. Some models support local dimming for better contrast.

Technology

LED-backlit LCDs do not light up by themselves; they need backlighting. Different ways to use LEDs include white LEDs and RGB (Red, Green, and Blue) LEDs. RGB LEDs can show more colors than white LEDs. The first full-array LED-backlit TV was the Sony Qualia 005, released in 2004, using RGB LEDs.^[8][9][10]

Many "LED TVs" are LCDs with LEDs controlled to match video details (dynamic backlight control or local dimming).^[11][12]

Energy standards for TVs now require lower power use, pushing companies to make more energy-efficient screens.

Energy efficiency and environment

LED-backlit LCDs generally use less power than older plasma displays or CRTs, and they are more energy-efficient than CCFL-backlit displays.^[13] They also contain fewer toxic materials, like mercury, which is present in CCFLs, making LED displays safer for disposal and better for the environment.^[14]