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. 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.

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.

Comparison with CCFL-backlit LCDs

Compared to CCFL backlighting, LED backlighting offers:

• More colors (with certain LED types)
• 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

LED arrangements

LED backlights use either edge-lit or direct-lit LEDs:

• 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.

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

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. They also contain fewer toxic materials, like mercury, which is present in CCFLs, making LED displays safer for disposal and better for the environment.