LED-backlit LCD
An LED-backlit LCD is a liquid-crystal display that uses LEDs for backlighting instead of traditional cold cathode fluorescent backlighting. LED-backlit displays use the same TFT LCD technologies as CCFL-backlit LCDs, but offer a variety of advantages over them.
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.
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.
Comparison with CCFL-backlit LCDs
Advantages
When compared with earlier CCFL backlights, using LEDs for backlighting offers:- Wider color gamut and dimming range
- Greater contrast ratio
- Very slim
- Significantly lighter and cooler, as much as half the total chassis and system weight of a comparable CCFL
- Typically 20–30% lower power consumption and longer lifespan
- Greater reliability
LED arrangements
- edge-lit : LEDs form a line around the rim of the screen. May additionally support:
- *frame dimming: adjusts the brightness of the entire backlight based on the content displayed, as if local dimming was supported but only with a single zone
- *local dimming: multiple vertical or horizontal zones are individually controlled
- direct-lit or full-array: LEDs form an array directly behind the screen at equally spaced intervals. May additionally support:
- *frame dimming: adjusts the brightness of the entire backlight based on the content displayed, as if local dimming was supported but only with a single zone
- *local dimming: multiple direct-lit LED clusters are individually controlled. Commonly referred to as Full Array Local Dimming.
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.
A 2016 study by the University of California suggests that the subjectively perceived visual enhancement with common contrast source material levels off at about 60 LCD local dimming zones.
In 2025 RTINGS.com found in accelerated longevity tests a that edge-lit TVs where more prone to quicker failure than direct-lit panels due the heat of the LEDs being more concentrated and intense than direct-lit panels making them more prone panel cracking and warping and thus LED burnouts and failures.
Technology
LED-backlit LCDs are not self-illuminating. There are several methods of backlighting an LCD panel using LEDs, including the use of either white or RGB LED arrays behind the panel and edge-LED lighting. Variations in LED backlighting offer different benefits. The first commercial full-array LED-backlit LCD TV was the Sony Qualia 005, which used RGB LED arrays to produce a color gamut about twice that of a conventional CCFL LCD television. This was possible because red, green and blue LEDs have sharp spectral peaks which result in significantly less bleed-through to adjacent color channels. Unwanted bleed-through channels do not "whiten" the desired color as much, resulting in a larger gamut. RGB LED technology continues to be used on Sony BRAVIA LCD models. LED backlighting using white LEDs produces a broader spectrum source feeding the individual LCD panel filters, resulting in a more limited display gamut than RGB LEDs at lower cost.Television sets described as "LED TVs" are LCD-based, with the LEDs dynamically controlled using the video information, energy consumption categories are enforced for television sets. Standards for power ratings for TV sets have been introduced, e.g., in the US, EU, Australia, and China. A 2008 study showed that among European countries power consumption is one of the most important criteria for consumers when they choose a television, as important as the screen size.
Using PWM, a technology where the intensity of the LEDs are kept constant but the brightness adjustment is achieved by varying a time interval of flashing these constant light intensity light sources, the backlight is dimmed to the brightest color that appears on the screen while simultaneously boosting the LCD contrast to the maximum achievable levels, drastically increasing the perceived contrast ratio, increasing the dynamic range, improving the viewing angle dependency of the LCD and drastically reducing power consumption.
The combination of LED dynamic backlight control in combination with reflective polarizers and prismatic films televisions far more efficient than the previous CRT-based sets, leading to a worldwide energy saving of 600 TWh in 2017, equal to 10% of the electricity consumption of all households worldwide, or twice the energy production of all solar cells in the world.
The prismatic and reflective polarization films are generally achieved using so called DBEF films manufactured and supplied by 3M. These reflective polarization films using uniaxial oriented polymerized liquid crystals were invented in 1989 by Philips researchers Dirk Broer, Adrianus de Vaan and Joerg Brambring.
A first dynamic "local dimming" LED backlight was public demonstrated by BrightSide Technologies in 2003, and later commercially introduced for professional markets. Edge LED lighting was first introduced by Sony in September 2008 on the BRAVIA KLV-40ZX1M. Edge-LED lighting for LCDs allows thinner housing; the Sony BRAVIA KLV-40ZX1M is 1 cm thick, and others are also extremely thin.
LED-backlit LCDs have longer life and better energy efficiency than plasma and CCFL LCD TVs. Unlike CCFL backlights, LEDs do not use mercury in their manufacture, which is an environmental pollutant. However, other elements are used in the manufacture of the LED emitters; there is debate over whether they are a better long-term solution to the problem of screen disposal.
Because LEDs can be switched on and off more quickly than CCFLs and can offer a higher light output, it is theoretically possible to offer very high contrast ratios. They can produce deep blacks and high brightness. However, measurements made from pure-black and pure-white outputs are complicated by edge-LED lighting not allowing these outputs to be reproduced simultaneously on screen.
Full-array mini-LED backlights, consisting of several thousand WLEDs, were being researched for TVs and mobile devices in 2017.
The white LEDs in LED backlights may use special silicate phosphors, which are brighter but degrade faster. The size of the LEDs is one of the factors that determines the size of the bezel of LED-backlit LCDs.
Quantum dot enhancement film (QDEF)
Quantum dots are photoluminescent; they are useful in displays because they emit light in specific, narrow normal distributions of wavelengths. To generate white light best suited as an LCD backlight, parts of the light of a blue-emitting LED are transformed by quantum dots into small-bandwidth green and red light such that the combined white light allows a nearly ideal color gamut to be generated by the RGB color filters of the LCD panel. The quantum dots may be in a separate layer as a quantum dot enhancement film, or replace pigment-based green and red resists normally used in LCD color filters. In addition, efficiency is improved, as intermediate colors are no longer present and do not have to be filtered out by the color filters of the LCD screen. This can result in a display that more accurately renders colors in the visible spectrum. Companies developing quantum dot solutions for displays include Nanosys, 3M as a licensee of Nanosys, QD Vision of Lexington, Massachusetts, US and Avantama of Switzerland. This type of backlighting was demonstrated by various TV manufacturers at the Consumer Electronics Show 2015. Samsung introduced their first 'QLED' quantum dot displays at CES 2017 and later formed the 'QLED Alliance' with Hisense and TCL to market the technology.Mini LED
Mini LED displays are LED-backlit LCDs that use thousands of miniature light-emitting diodes as the backlight source, enabling hundreds to thousands of full-array local dimming zones. This offers improved contrast and deeper blacks compared with conventional LED-backlit LCDs.Compared with OLED displays, Mini-LED LCDs can achieve higher sustained brightness and avoid burn-in, although they may still display slight blooming around bright highlights due to limited zone granularity.
The technology was first commercialized in high end televisions in 2019, notably by TCL Technology, followed by other manufacturers including Samsung and LG. It has since been used in tablets and laptops: for example, the Apple 12.9-inch iPad Pro featured a “Liquid Retina XDR” Mini-LED panel with over 10,000 LEDs divided into 2,596 dimming zones.
Despite these advantages, Mini-LED displays remain more complex and expensive to manufacture than traditional LCDs, and uniform illumination across thousands of backlight segments presents ongoing manufacturing challenges.
RGB mini-LED
Unlike conventional white or blue LED backlights, RGB backlights generate spectrally pure light with separate RGB LEDs with narrow band red, green, and blue spectrum, allowing the LCD to produce a wider color gamut and more accurate colors. This technology allows LCDs to provide increases brightness and 100% coverage of BT.2020 color gamut, without relying on the QD film layer required by blue backlights.TVs using an "Micro RGB" backlight have been released by Samsung, whereas Hisense employs a larger variant called RGB Mini-LED. At CES 2026, TVs and computer monitors using RGB Mini-LED backlights were announced by LG, TCL, Hisense, and HKC.
Despite the name, RGB Mini-LED and "Micro RGB" are not a self-emissive display technologies like MicroLED. These displays still rely on liquid crystal layers and do not offer pixel-level light control, as the light is modulated through the LCD matrix rather than emitted directly from each pixel. Although “Micro” is not defined by a specific industry standard, the term is commonly used to refer to LEDs that are smaller in size compared to those used in Mini-LED technology.