Fact-checked by Grok 2 weeks ago

Backlight

A backlight is an illumination system integral to displays (LCDs), providing a source from behind or the sides of the to enable image visibility, as LCDs themselves do not emit and rely on modulating transmitted through liquid crystals, polarizers, and color filters. This technology is essential for such as televisions, computer monitors, laptops, smartphones, and tablets, where it directly influences , , color accuracy, and power efficiency. The development of backlight technology traces back to early LCD innovations in the 1960s and 1970s, initially using panels or incandescent lamps for basic illumination, but these were limited by low and high use. By the , cold cathode fluorescent lamps (CCFLs) became the standard, offering brighter and more uniform but containing mercury, consuming significant , and contributing to thicker designs. The transition to backlights began in the early 2000s, accelerating around 2009–2010 with white LED (WLED) adoption, which provided mercury-free operation, reduced energy consumption by 20–30%, thinner profiles, and longer lifespans exceeding 50,000 hours. This shift enabled the proliferation of high-definition and HDR-capable , with further advancements like quantum dot-enhanced LEDs in the improving color coverage to over 95% of DCI-P3. Modern backlight configurations vary by design and performance needs, primarily categorized as edge-lit and direct-lit (or full-array). Edge-lit backlights position LEDs along the 's edges, diffusing inward via light guides for slim, cost-effective builds, though they offer limited dimming zones (often 8–16), leading to potential light blooming and reduced in dark scenes. In , direct-lit systems place LED arrays across the rear of the , supporting dimming in hundreds of zones for deeper blacks, higher peak (up to 1,000 nits or more), and better performance, at the expense of increased thickness and cost. Mini-LED backlights, commercially introduced around 2019, have become widespread in high-end displays by 2025, employing thousands of tiny LEDs (under 200 microns) for precise control, minimizing halo effects and achieving contrasts rivaling displays while maintaining LCD's advantages in and burn-in resistance. These technologies continue to evolve, with ongoing research into and micro-LED backlights and 2025 advancements like RGB mini-LED systems for even greater efficiency and color fidelity.

Fundamentals

Definition and Purpose

A backlight is a light source positioned behind transmissive display panels, such as those in displays (LCDs), to provide uniform illumination that passes through the panel's layers for image visibility. In LCD systems, the backlight serves as the primary illumination mechanism since themselves do not emit but instead modulate transmitted to form images. The widespread adoption of backlights began in the early with their integration into early LCD-based devices to enhance readability in low-light environments. In 1972, North American Rockwell Microelectronics Corp incorporated backlights into dynamic scattering mode (DSM) LCDs for calculators marketed by Lloyds Electronics, addressing visibility limitations of initial reflective LCDs. By 1973, introduced pocket-sized calculators using DSM LCDs with orientation layers to improve display performance in varied lighting conditions. The primary purposes of a backlight include compensating for the inherent opacity of materials by directing light through individual , which are selectively blocked or allowed to create patterns and shades. This transmitted light also interacts with color filters on subpixels to enable full-color reproduction, a process essential for vibrant imagery in transmissive displays. Unlike emissive displays such as organic light-emitting diode () panels, which generate light directly at each without needing external illumination, backlights are indispensable for LCDs to produce any visible output. Key benefits of backlights in portable devices include enhanced by overpowering ambient interference, thereby maintaining clear indoors or in dim settings, and broader viewing angles through uniform illumination across the panel. These attributes make backlights critical for applications like smartphones and laptops, where consistent readability in diverse environments is paramount. Various light source technologies, including fluorescent lamps and , fulfill this role while optimizing for efficiency and brightness.

Basic Operating Principles

In backlight systems for liquid crystal displays (LCDs), light originates from the source and propagates through a series of optical layers to produce visible images. The process begins as from the backlight passes through a rear , which aligns the light waves into a single . This polarized light then enters the (LC) layer, where an applied voltage modulates the orientation of LC molecules, twisting or aligning them to control the polarization rotation of the light. Subsequently, the light encounters color filters that separate it into red, green, and blue components for color reproduction, before reaching the front , which determines whether the modulated light is transmitted or blocked to form the desired image pattern. A key requirement for effective backlight performance is uniformity of illumination across the surface, ensuring consistent without hotspots or dark spots that could distort image quality. Uniformity is achieved by distributing evenly, typically evaluated through metrics such as , measured in candelas per square meter (cd/m²), which quantifies the emitted from the surface. Additionally, backlights are designed to maintain a specific , such as 6500 K, which simulates neutral daylight illumination and supports accurate color rendering in standard viewing conditions. Polarization forms the core mechanism enabling image formation in these systems, relying on the interaction between orthogonal polarizers and the LC layer. The rear and front polarizers are oriented at 90 degrees to each other, blocking light transmission in the absence of polarization rotation; however, when LC molecules twist the light's polarization plane by 90 degrees under no voltage (in twisted nematic mode), the light aligns with the front polarizer and passes through. The intensity of transmitted light follows Malus's law, expressed as I = I_0 \cos^2 \theta, where I is the transmitted intensity, I_0 is the incident intensity, and \theta is the angle between the polarization direction and the polarizer axis—here, \theta = 0^\circ allows full transmission, while \theta = 90^\circ blocks it completely./University_Physics_III_-Optics_and_Modern_Physics(OpenStax)/01%3A_The_Nature_of_Light/1.08%3A_Polarization) Environmental factors, particularly ambient light levels, significantly influence backlight visibility, as higher external illumination reduces and washes out the display image. In outdoor settings, where can exceed 10,000 cd/m², backlights require elevated levels—often several times higher than indoor standards—to maintain against this , ensuring the emitted light overpowers surrounding brightness.

Light Source Technologies

Cold Cathode Fluorescent Lamps (CCFL)

Cold Cathode Fluorescent Lamps (CCFLs) consist of sealed tubular glass envelopes filled with a low-pressure mixture of mercury vapor and an inert gas, such as argon or neon, with the interior surface coated in phosphor materials. The lamps feature cold cathode electrodes at both ends, which rely on high-voltage fields to emit electrons through secondary emission or field emission, without requiring filament heating. This design allows for compact, linear light sources suitable for edge-lit or direct-lit backlight configurations in displays. In operation, an electronic inverter converts the low-voltage DC supply from the into high-voltage , typically at frequencies between 20 kHz and 60 kHz, to create an within the . The ionizes the mercury vapor, generating (UV) radiation at wavelengths around 254 nm, which excites the coating to produce visible white light through . CCFL backlights achieve typical efficiencies of 50–70 lm/, depending on design and drive conditions. CCFL technology peaked in popularity during the for LCD monitors and early flat-panel televisions, where it enabled high-brightness illumination with individual lamps delivering lumen outputs up to 2,000 in larger formats. Key advantages include superior light uniformity over extended areas, thanks to the linear emission profile, and a reliable lifespan of 20,000–50,000 hours under normal operating conditions. These qualities made CCFLs the dominant backlight choice for consumer and displays in that era, powering the transition from bulky CRTs to slim LCD panels. As of 2025, CCFLs are obsolete in consumer displays. Despite these strengths, CCFLs present notable drawbacks, including the presence of mercury—typically 3–5 mg per lamp—which poses environmental and health risks during manufacturing, use, and disposal. They also necessitate high-voltage drivers (often 600–1,500 V ), contributing to increased complexity and a thicker overall compared to newer technologies. Regulatory pressures, particularly the European Union's Restriction of Hazardous Substances () directive implemented in 2006 with ongoing exemptions expiring around 2010–2023 for specific applications, accelerated the phase-out of CCFLs in favor of mercury-free alternatives like LEDs, which offer superior efficiency.

Light-Emitting Diodes (LED)

Light-emitting diode (LED) backlights have become the dominant technology in displays (LCDs) since the 2010s, replacing older fluorescent systems due to their superior efficiency and design flexibility. These backlights utilize arrays of small semiconductor devices that emit light through , where electrons recombine with holes in a p-n junction, releasing photons in the . In particular, blue LEDs are commonly fabricated using (GaN) semiconductors, which enable high-efficiency emission at wavelengths around 450 nm. LED backlights are structured in two primary configurations: edge-lit and direct-lit. In edge-lit designs, LEDs are positioned along the edges of the display panel, with distributed across the screen via a light guide plate that employs and scattering to achieve uniform illumination. This approach allows for thinner profiles, making it ideal for laptops and slim televisions. Direct-lit configurations, by contrast, place an array of LEDs directly behind the LCD panel, providing more uniform brightness without relying on light guides but resulting in thicker assemblies. White in these backlights is generated either through conversion, where a LED chip excites a yellow coating to produce a broad-spectrum white output, or via RGB LED combinations that mix red, green, and emissions for tunable color. The method dominates due to its simplicity and cost-effectiveness, achieving luminous efficiencies of 100-150 lm/W while enabling good color rendering through the phosphor's spectral broadening. Compared to predecessors like fluorescent lamps, LED backlights offer key advantages, including a compact , absence of mercury for , and a wide dimming range that supports precise from near-zero to full output. These traits facilitate ultra-thin designs in , such as televisions and laptops, where edge-lit LEDs reduce overall thickness to under 10 mm in many models. Variants include conventional white LEDs for general use and RGB setups, which expand the color gamut by directly controlling primary colors, achieving up to 100% coverage of standards like in premium displays. By 2015, LED backlights had been adopted in approximately 90% of LCD shipments worldwide, according to industry analyses. Despite these benefits, LED backlights face challenges in heat management, as elevated temperatures can cause color shifts toward cooler tones and reduce efficiency. Effective thermal design is essential to maintain junction temperatures below 85°C for optimal performance and longevity. The junction temperature T_j can be modeled using the equation: T_j = T_a + (P \times R_{th}) where T_a is the ambient temperature, P is the power dissipation, and R_{th} is the thermal resistance from junction to ambient. This relationship underscores the need for heat sinks or advanced packaging to mitigate thermal throttling in high-brightness applications.

Emerging Sources

Mini-LED technology represents a significant advancement in backlight sources, utilizing thousands of LEDs smaller than 200 micrometers to enable direct backlighting with precise local dimming capabilities. These tiny LEDs, typically ranging from 50 to 300 micrometers in size, allow for a high number of dimming zones—often exceeding 1,000 in premium implementations—resulting in improved contrast ratios and reduced blooming effects compared to traditional LED backlights. introduced the first commercial Mini-LED backlit televisions in 2021 as part of its Neo QLED lineup, building on prototypes from 2019, which marked the transition to widespread adoption in consumer displays by the mid-2020s. Micro-LED backlights, featuring LEDs under 100 micrometers, offer even greater potential for with LCD panels, serving as solutions that enhance and without fully replacing the . These sources achieve luminous efficiencies exceeding 200 lumens per watt, surpassing conventional LEDs, while enabling finer control over light output for superior image quality. However, high manufacturing costs—often in the range of tens of thousands of dollars for large panels as of 2025—limit their use primarily to prototypes and premium products, such as Samsung's 115-inch RGB Micro-LED backlit LCD TV launched in August 2025. Quantum dot-enhanced LEDs incorporate semiconductor nanocrystals to broaden the color gamut, achieving coverage up to 100% of the DCI-P3 standard by converting blue LED light into purer red and green wavelengths. This enhancement is particularly evident in Mini-LED implementations, where TCL's 2023 QM8 series televisions delivered peak brightness levels of over 2,000 nits, enabling vivid HDR performance in large-screen displays. Such advancements have become standard in high-end QD-Mini LED TVs by 2025, with models like the QM8K reaching up to 5,000 nits in optimized configurations. Beyond these, laser backlights have emerged for specialized applications like projectors, leveraging coherent sources to attain higher and color accuracy than incoherent LED alternatives, with single diodes enabling brighter outputs up to several thousand lumens. Trends toward are also driving exploration of LEDs (OLEDs) as backlight components, offering flexible, low-power alternatives that align with eco-friendly manufacturing goals, though their integration remains experimental as of 2025. These emerging sources enhance LCD contrast when integrated into full display systems, but face ongoing hurdles in scalability. Key challenges in adopting Mini-LED and Micro-LED backlights include manufacturing scalability, particularly in yields for tiny chips, which have historically driven panel costs above $1,000 in 2020. By 2025, cost reductions exceeding 60% have been achieved through process optimizations like monolithic and improved defect repair, accelerating commercial viability for Mini-LED implementations despite persistent issues below 99.99% for Micro-LEDs and high costs for large Micro-LED panels.

Optical Enhancement Components

Diffusers and Light Distribution

Diffusers in backlight systems are essential optical components consisting of thin sheets or films, typically made from materials such as polymethyl methacrylate (PMMA) or polycarbonate, that scatter incoming light to eliminate hotspots and achieve uniform illumination across the display surface. These diffusers work by incorporating scattering agents, such as fine particles dispersed within the resin matrix, to redirect light rays in multiple directions, thereby blurring images of individual light sources like LEDs or CCFLs. In multi-layer backlight stacks, diffusers are often combined with directional control elements, such as prism sheets or lenticular films, to not only ensure even spread but also to collimate light toward the viewer for improved efficiency. The design of diffusers prioritizes a high haze factor, typically in the range of 80-95%, which quantifies the degree of light scattering and is crucial for effective without excessive forward loss. These components are engineered with thicknesses ranging from 0.2 to 1 mm to balance mechanical stability and optical performance in compact backlight modules. Light uniformity is a key performance metric, often targeted to achieve variation less than 10% across the panel, commonly measured by the standard deviation (σ) of the distribution, where lower σ values indicate superior homogeneity. Diffusers are categorized into bulk types, which rely on embedded diffusing particles within the volume for isotropic , and surface microstructure types, featuring etched or molded patterns on one or both sides to control direction more precisely. Holographic diffusers represent an advanced variant, using volume holograms or surface-relief gratings replicated on substrates like to provide tailored angular control and higher efficiency in beam shaping. Recent advancements include the integration of films directly into or alongside diffuser layers, enhancing color gamut and conversion efficiency by absorbing blue LED light and re-emitting it at targeted wavelengths, often positioned between the light guide and diffuser in edge-lit configurations. In edge-lit backlight systems, diffusers are particularly vital for expanding the narrow beam from linear LED strips into a broad, uniform area light source, mitigating non-uniformity from the side-entry illumination. Diffusers typically have a light transmittance of 85-95%, introducing 5-15% loss due to scattering and material absorption, with advanced designs achieving transmittance over 95%. A notable trade-off exists between diffusion strength and viewing angle; higher scattering improves off-axis uniformity but can broaden the angular distribution, potentially reducing peak on-axis luminance and contrast in narrow-viewing applications.

Reflective Polarizers and Efficiency

Reflective polarizers enhance backlight efficiency in displays (LCDs) by selectively managing , allowing unutilized light components to be recycled rather than absorbed. A prominent example is 's Dual Brightness Enhancement (DBEF), a multilayer optical that transmits p-polarized light while reflecting s-polarized light back toward the light source. This reflected light interacts with the backlight cavity, where it is depolarized and redirected, increasing the overall light output available for transmission through the LCD panel. Introduced in the late , DBEF and similar films have become standard in LCD backlights, effectively doubling the perceived by that traditional absorbing s would discard—improving from approximately 50% in basic setups to 80-90% for the desired state. The efficiency gain stems from , which minimizes losses at the rear interface and boosts without requiring additional power to the source. These films feature a sophisticated structure of hundreds of alternating thin layers (typically 100-500 thick) with varying refractive indices, formed via co-extrusion of birefringent polymers followed by uniaxial stretching to induce optical . The design leverages the Brewster principle, where p-polarized light at the layer interfaces experiences near-zero reflection due to matched refractive indices in the , while s-polarized light is efficiently reflected across a range of s. For a single interface under normal incidence, reflectivity follows the Fresnel equation: R = \left( \frac{n_1 - n_2}{n_1 + n_2} \right)^2 This is extended in the multilayer stack through constructive interference, achieving high extinction ratios (>1000:1) and broadband performance in the visible spectrum. Alternative types, such as wire-grid polarizers, employ sub-wavelength metallic wires etched on a substrate to achieve polarization selectivity via diffraction and offer superior thermal stability for high-temperature applications, enduring up to 200°C. These are particularly useful in demanding backlight environments where polymer-based multilayers might degrade. By optimizing light reuse, reflective polarizers reduce backlight power requirements by 40-50%, lowering thermal output and extending life in portable devices. Recent developments as of include nano-imprinted enhancement films that provide up to 30% higher compared to conventional options. Despite these advantages, their performance is angularly sensitive, with reflectivity dropping for off-axis , which can constrain viewing angle uniformity in wide-field displays.

Implementation and Control

Dimming and Modulation Techniques

Dimming and modulation techniques for backlights enable precise control of light output to enhance display performance, particularly in displays where backlight intensity directly influences image quality and energy use. applies uniform adjustment across the entire backlight, typically using (PWM) at frequencies between 100 and 1000 Hz or (DC) modulation. PWM rapidly cycles the backlight on and off, with the determining perceived brightness, while DC dimming varies the forward current to LEDs or inverter voltage to cold cathode fluorescent lamps (CCFLs), both avoiding visible at high frequencies but limiting local contrast enhancement since the entire array operates as a single zone. Local dimming divides the backlight into multiple independently controlled zones, ranging from 8 to over 1000, allowing targeted intensity adjustments that significantly improve , such as achieving contrast ratios up to 10,000:1 in televisions. Full-array local dimming (FALD), which places LEDs behind the entire screen, became a standard feature in premium televisions starting in 2014, enabling deeper blacks and brighter highlights by dimming zones corresponding to dark image areas. For CCFL backlights, dimming relies on inverter control to modulate voltage and current, whereas LED backlights use dedicated driver integrated circuits (ICs) to handle PWM or analog signals per zone or string. Advanced implementations support () content with peak brightness exceeding 1000 nits, where zone mapping algorithms compute the target for each area based on . A common approach sets the target as the maximum value within the , adjusted via a gamma curve or function to preserve perceptual detail: L_{\text{target}} = \max(L_{\text{pixels in zone}}) \times f(\gamma) where f(\gamma) applies the gamma correction. However, local dimming introduces challenges like halo or blooming artifacts, where light from bright zones leaks into adjacent dark areas, creating unwanted glows around high-contrast edges such as or stars against backgrounds. As of 2025, AI-driven adaptive dimming techniques analyze video content in to optimize zone intensities, reducing overall power consumption by more than 20% through intelligent allocation without compromising visual fidelity. This lowers energy use in dynamic scenes, such as by dimming non-essential areas during low-light content.

Power Consumption and Efficiency

Power consumption in backlights is typically measured in watts per square meter (W/m²), reflecting the energy required to illuminate a given display area, while efficiency is quantified in lumens per watt (lm/W), indicating luminous output per unit of electrical input. For LCD displays, backlight power density ranges from 20 to 30 W/m² in smaller screens to up to 150 W/m² in larger ones, depending on size and configuration. In a typical 55-inch LCD TV, total power draw is 60-150 W, with the backlight accounting for 40-60% of this consumption. The type of light source significantly influences overall power usage. LED backlights consume 40-60% of the total power in an LCD system, a notable reduction from the 70% typical of CCFL backlights due to LEDs' higher inherent efficiency and lower voltage requirements. Dimming techniques can further reduce backlight power by 20-50%, enabling adaptive brightness that aligns with content luminance and ambient conditions. For local dimming implementations, total power P can be approximated as P = V \times I \times N, where V is voltage, I is current per zone, and N is the number of active dimming zones, allowing precise control to minimize unnecessary illumination. Comparisons across configurations highlight efficiency variations. Edge-lit LED backlights in laptops typically draw around 20 , benefiting from compact designs and lower overall demands. In contrast, direct-lit LED backlights for 55-inch TVs contribute approximately 80-120 to the total power draw, driven by the need for uniform illumination across larger areas. standards, under Version 8.0 effective as of 2025, cap on-mode power for a 50-inch TV at around 100 to promote , with certified models averaging 34% better performance than non-certified counterparts. Optimizations like reflective polarizers combined with dimming can double overall by unpolarized light that would otherwise be lost, yielding gains of 1.6-1.7 times in backlight output. Environmentally, the shift to LED backlights eliminates mercury content found in CCFLs—reducing annual emissions by up to 1.5 tons globally from disposed units—but introduces dependency on rare-earth elements in phosphors, raising concerns over mining impacts. Emerging trends with mini-LED backlights push toward 200 lm/W through denser zoning and higher luminous output, though this increases initial draw due to more LEDs and control circuitry. Despite the added complexity, mini-LED systems achieve efficiencies comparable to displays while maintaining LCD's longevity advantages.

Applications and Comparisons

In Liquid Crystal Displays (LCDs)

In liquid crystal displays (LCDs), the backlight module serves as the primary light source, comprising approximately 70-80% of the overall display thickness and weight due to its essential components that ensure uniform illumination across the panel. This module typically consists of the light source (such as LEDs or CCFLs), a light guide plate to distribute light evenly, multiple diffuser sheets to scatter and homogenize the output, and reflective films to recycle unabsorbed light, all integrated behind the LCD panel's rear polarizer for efficient light transmission. The polarizers, positioned on both sides of the liquid crystal layer, further modulate the polarized light from the backlight to control pixel transmission, enabling image formation while minimizing energy loss. The evolution of backlights in LCDs began in the 1990s with cold cathode fluorescent lamps (CCFLs) as the standard for replacing bulky (CRT) displays, providing reliable illumination for early flat-panel monitors and TVs. By the mid-2000s, CCFLs dominated due to their brightness and cost-effectiveness, but limitations in efficiency and environmental concerns (e.g., mercury content) prompted a shift to light-emitting diodes (LEDs), with early commercial introductions around 2004, such as Sony's 005, and broader adoption by 2008 with manufacturers like and , marking a significant advancement in slimness and energy savings. This transition accelerated in the late 2000s, as LEDs offered wider dimming ranges and better recyclability, becoming the norm by the early . In panel variants, in-plane switching () LCDs require brighter backlights—typically around 500 nits—to maintain consistent luminance and color across wide viewing angles, compared to twisted nematic (TN) panels that suffice with about 300 nits due to their narrower angle tolerance. Performance-wise, backlights enable LCDs to achieve a native of approximately 1000:1 in standard configurations, where the backlight's uniform output interacts with the crystal's to differentiate bright and dark areas. Local dimming techniques, which independently control backlight zones, can elevate this to an effective 5000:1 or higher by darkening unused areas for deeper blacks, significantly enhancing in high-end models. Color accuracy is further optimized when the backlight's spectral output closely matches the LCD's color s, allowing precise reproduction of , , and primaries; for instance, narrow-band LED spectra reduce overlap with curves, minimizing color and expanding coverage up to 100% in optimized systems. Vertical alignment () panels, in to TN and , benefit from backlights that emphasize high native (often 3000:1 or more) to leverage their inherent ability to block more effectively, resulting in superior black levels for applications like video viewing. Challenges in backlight design include mitigating , which arises from the sample-and-hold nature of LCD pixels; scanning backlights address this by sequentially flashing rows in sync with the , effectively inserting black frames to reduce perceived without sacrificing brightness. As of mid-2025, LCDs with backlight technologies continue to dominate the display market, accounting for approximately 85-90% of shipments in like TVs and monitors, according to reports from Display Supply Chain Consultants, underscoring their cost-effectiveness and versatility despite the growing share of alternatives like (around 10-15% in premium segments). Recent integrations, such as mini-LED backlights, further boost contrast in LCDs by enabling thousands of dimming zones for finer control.

In Other Display and Illumination Systems

Backlights extend beyond traditional displays to various specialized systems, where they provide illumination tailored to unique environmental and functional demands, often adapting principles of and similar to those in LCDs but scaled for portability or . In displays, edge-lit LED backlights enable see-through LCD panels for applications, such as shelf labels that overlay product information without obstructing visibility. These systems use side-mounted LEDs to achieve high brightness levels, up to 3000 nits, while maintaining and low profile for into vending machines or display cases. For instance, advanced LED backlighting in LCDs minimizes power use and supports eco-friendly operation in interactive setups. Automotive applications incorporate backlights in instrument clusters and head-up displays (HUDs) to ensure readability under varying lighting conditions. LED backlighting in clusters addresses design challenges like resistance and uniform illumination, enhancing driver safety by providing clear visibility of gauges and alerts. In HUDs, backlight control adjusts based on ambient light sensors for optimal contrast. Emerging hybrid systems, combined with Mini-LED backlighting, appear in 2025 electric vehicles (EVs) to enable adaptive brightness, improving energy efficiency and display performance in luxury models from European brands. For and large-scale , edge-lit acrylic panels serve as efficient backlights in billboards and luminous displays, guiding light uniformly across surfaces for 24/7 operation. Materials like ACRYLITE LED sheets facilitate slim, large-format installations with low energy draw, supporting continuous use in . LED configurations in these panels achieve efficiencies around 10W per square meter, balancing and for environmental . In medical and portable devices, low-power LED backlights illuminate e-readers and , prioritizing minimal heat and energy use for extended operation. Endoscope light sources, such as the ENDOLIGHT LED, consume 80% less power than traditional lamps, delivering homogeneous illumination with silent, for surgical precision. UV backlights, often using UV-C LEDs, activate sterilization indicators in medical tools, confirming disinfection by changing color upon exposure to germicidal wavelengths around 254 nm. Comparisons with frontlights in e-ink displays highlight backlights' role in transmissive versus reflective technologies; e-ink relies on frontlights for low-light reading to preserve paper-like reflection, while backlights in transmissive systems like LCDs provide direct illumination but can increase in dark environments. Emerging uses include backlights in (AR) glasses, where micro-LED arrays project virtual overlays onto transparent lenses, enabling holographic imaging for immersive content without bulky projectors. Challenges in these systems include heat management in confined spaces, where LEDs' low emission—far below incandescent bulbs—reduces risks in portable or enclosed devices, aided by heat sinks and . In smartphones, backlight power consumption evolved to under 1W by 2020 through efficient LED designs, including early nano-LED integrations that enhanced while minimizing draw, typically around 20 for standard modules.

References

  1. [1]
    What is a backlight in an LED TV? - TCL
    Nov 14, 2023 · A backlight in an LED TV is the light that allows an LCD screen to create an image, using LEDs instead of CCFLs.
  2. [2]
    5 Advantages of LED Backlight Technology - Nauticomp
    Jun 30, 2020 · As the name suggests, backlighting involves providing lighting for digital displays from behind, making it easier for users to see what’s on ...
  3. [3]
    A Deep Dive into LED Backlights and Their Core Components
    Apr 11, 2025 · LED backlight is a key component of liquid crystal display, providing light to the screen, so that images and text can be displayed.
  4. [4]
    TV backlights explained: Edge-lit vs. full array vs. Mini-LED
    Oct 9, 2021 · Direct lit LED backlighting uses LED lighting across the back of the TV, directly behind the LCD panel, providing a fairly uniform amount of ...
  5. [5]
    The History of LCD Technology - Orient Display
    Charles Mauguin was the first to begin placing thin layers of liquid crystals between plates, an idea that would later found the structural concept of LCDs.
  6. [6]
    LCD Backlighting: History, Applications, and Types - Cevians
    Apr 4, 2024 · CCFL backlights were the primary technology used in the 2000s before the widespread adoption of LEDs. A CCFL backlight contains mercury vapor ...
  7. [7]
    The Evolution of LED Backlights - PC Monitors
    Jan 8, 2023 · When LED backlighting first took off, manufacturers were all too keen to promote what were essentially misleading or even fabricated performance ...
  8. [8]
    The Evolution of LED Technology: A Brief History - DDW Display
    Jan 8, 2025 · Traditional LCDs, which relied on cold cathode fluorescent lamps (CCFL) for backlighting, were replaced by LED-backlit LCDs. This transition ...
  9. [9]
    Display Backlight Technologies: Direct LED vs Edge LED - Rjoytek
    Jul 9, 2024 · Backlight technology is a crucial component of LCD because LCD themselves do not emit light and require a backlight source for illumination. The ...<|control11|><|separator|>
  10. [10]
    LCD Display Backlight Options - SEACOMP
    Mar 4, 2015 · There are many different backlight options available for your LCD. The most common types are LED, fiber optic, EL, and CCFL backlights.
  11. [11]
  12. [12]
    Lighter, Brighter Displays - IEEE Spectrum
    Dec 31, 2012 · A typical LCD [PDF] screen consists of many optical and electronic layers, at the bottom of which is the backlight. Above it are two filtering ...
  13. [13]
    What's the difference between transmissive and emissive displays?
    In LCD, there's a backlight that projects light through a liquid crystal layer that's sandwiched between two pieces of glass.
  14. [14]
    Transmissive vs Reflective vs Transflective Displays
    Jan 31, 2023 · Transmissive LCDs require a backlight for clear visibility. Reflective LCDs do not have a backlight and rely on external light sources.
  15. [15]
    Flagship OLED and LCD TV Display Technology Shoot-Out
    The so-called LED TVs are just LCD TVs that have a backlight that is made of white LED lights. The LEDs are not the display, just the backlight, nothing more!
  16. [16]
    LCD Display Principle
    ### Summary of Light Transmission Process in LCD
  17. [17]
    How does the LCD Work? - Tailor Pixels
    A polarizer is to convert natural light without polarization into polarized light and control which light patterns can pass through the LCD panel. Without these ...
  18. [18]
    How does the backlight affect an LCD panel display? - Blog
    Jul 14, 2025 · Backlight uniformity is often overlooked but is crucial for a high - quality display. Non - uniform backlighting can result in visible bright or ...
  19. [19]
    Six Important Aspects of Monitor Calibration You Need to Know
    Monitor luminance is measured in candelas per square meter (cd/m2), sometimes referred to as “nits”. A new LCD monitor is usually far too bright (e.g. over 200 ...
  20. [20]
    Colour temperature on an LCD monitor - EIZO
    A colour temperature of 6500 K is standard for ordinary PC use and for the sRGB standard. Most LCD monitors offer a setting of 6500 K among their colour ...Missing: 6500K | Show results with:6500K
  21. [21]
    Introduction to the structure and working principle of polarizer of ...
    Jul 15, 2025 · LCD uses the optical rotation of liquid crystal. Liquid crystal molecules with moderate thickness can rotate the polarization direction of light ...
  22. [22]
    Sunlight Readable - Litemax
    When an LCD is used in a high ambient lighting area, outdoors or even in direct sunlight a normal brightness display becomes almost unreadable.
  23. [23]
    3 Common Ways to Enhance the Display Quality in Daylight
    The first and simplest way is to increase the brightness of the backlight. Typical LCD panels' brightness is between 250 cd/m2 to 450 cd/m2.
  24. [24]
    [PDF] Development of gallium-nitride-based light-emitting diodes (LEDs ...
    Light-emitting diodes (LEDs) fabricated from gallium nitride (GaN) have led to the realization of high-efficiency white solid-state lighting.
  25. [25]
    [PDF] LED Lighting Efficacy: Status and Directions - OSTI.GOV
    Near term, phosphor converted LED packages have the potential for efficacy improvement from 160 lm/W to 255 lm/W. Longer term, color-mixed LED packages have ...
  26. [26]
    Edge-Lit vs. Direct-Lit vs. Full-Array TVs: What's the Difference?
    Oct 13, 2023 · LCD TVs can be grouped into three categories based on the type of LED backlighting system: Direct-lit, edge-lit, and full-array.
  27. [27]
    [PDF] LED Color Characteristics
    This chart shows the spectral power distributions for four different light sources, including phosphor coated (PC) and a red-green-blue (RGB) color-mixed LED.
  28. [28]
    [PDF] Efficiency Improvement Opportunities in TVs: Implications for Market ...
    TV manufacturing is highly globalized, and LED backlit LCD TVs are likely to increase significantly, from 50% to 90% of the TV shipments in 2012 and 2015.Missing: percentage industry
  29. [29]
    [PDF] Thermal Management White LED Challenges LED Lighting Control ...
    Color Shift. As junction temperatures rise, the color of light emitted by white LEDs also shifts slightly toward the cooler tones of white (i.e., slightly ...
  30. [30]
    Preventing Excessive LED Junction Temperature - DigiKey
    Nov 1, 2016 · This article shows how to calculate junction temperature and notes the importance of thermal resistance.Missing: challenges backlights
  31. [31]
    TV Panel Types: What Is Mini LED? - RTINGS.com
    Oct 10, 2025 · This difference in size allows the TV to adjust the light output of the backlight by breaking it down into many separate zones, a technique ...
  32. [32]
    LCD Fights Back Against OLED With MiniLED Backlight Technology
    Sep 16, 2021 · The idea was to use smaller LEDs (50 to 300 micrometers [μm] in size) to increase the number of local dimming zones in direct-lit backlights.
  33. [33]
    Mini-LED TV: What It Is and How It Improves Samsung, TCL ... - CNET
    Jan 10, 2022 · Mini-LED is an evolution of traditional LCD TV backlight tech that uses thousands of tiny light-emitting diodes to improve picture quality.
  34. [34]
    Year of the mini-LED TV: Samsung, LG and TCL getting this huge ...
    Jan 24, 2021 · Mini LED promises significant improvement over this development, allowing for a much higher number of discrete dimming zones. Measuring about ...
  35. [35]
    Global Market for Micro and Mini LEDs 2025-2035: MicroLED Set to ...
    Mar 13, 2025 · Mini-LEDs (50-200 micrometers) have achieved significant commercial traction as LCD backlights, enhancing contrast ratios and brightness while ...
  36. [36]
    Samsung RGB Micro-LED backlit LCD TV Up To 115" Coming 2025
    Apr 9, 2025 · Samsung's TV chief has confirmed the launch of LCD TVs with micro-LED backlights up to 115 inches in 2025. The company also plans to increase sales of OLED TVs.
  37. [37]
    An update on highly anticipated—and elusive—Micro LED displays
    Feb 12, 2025 · Micro LED TVs are currently available for purchase, but they cost six figures, making them unattainable for the vast majority of people.
  38. [38]
    TCL QD-Mini LED, The Next-gen of Large-screen Display-TCL Global
    Compared with traditional single-core light-emitting chips, TCL uses the industry's breakthrough 6-core LED chip, which brings a 27.5% increase in brightness ...
  39. [39]
    TCL 98" Class QM7K Series 4K UHD HDR QD Mini LED Smart TV ...
    In stock Rating 4.7 (201) With Peak Brightness 1500 and more than double the local dimming zones as last year, along with Quantum Dot Color, Dolby Vision HDR, and Low Reflecton panel ...
  40. [40]
    TCL 65" QM8K Series QD-Mini LED QLED 4K UHD Smart TV with ...
    7-day returnsThanks to its peak brightness of 5000nits, the QM8K features an ultra-high contrast ratio of 30 million:1 and a higher dynamic range.
  41. [41]
  42. [42]
    The difference between LED and laser projectors - Barco
    Apr 4, 2017 · Laser light is by definition coherent. This means that all light photons are in exact pace and moving in exactly the same direction. LED ...
  43. [43]
    The Future of LED Technology: Innovations and Trends Shaping the ...
    Aug 25, 2025 · Emerging technologies, such as organic LEDs (OLEDs), promise to offer more sustainable alternatives. OLEDs are thinner, lighter, and can be ...
  44. [44]
    Mini/Micro LED Market 2025: Backlight & COB Breakout
    Aug 15, 2025 · Mini/Micro LED enters 2025 harvest phase: LCD backlight and COB direct-view lead growth, costs down 60%+, MIP extends to P1.5-3.5, ...
  45. [45]
    Display Dynamics – May 2025: The manufacturing costs of RGB ...
    May 29, 2025 · In conclusion, as shown in Figure 1, the costs of RGB Mini LEDs can be reduced from $731 to $660—a 10% decrease—by replacing the red light ...
  46. [46]
  47. [47]
    [PDF] Light Diffuser Plates for LCD-TV Backlight Systems
    We have developed diffuser plates with properties which are specially optimized for this type of backlight system, and have released them onto the market. In ...
  48. [48]
    High‐Transmittance and High‐Haze Composite Particle‐Free ...
    Oct 22, 2021 · At an optimized form, a composite optical diffuser is capable of achieving superhigh haze (88%), while maintaining a high degree of transparency ...Missing: factor | Show results with:factor
  49. [49]
    Led Light Diffuser Sheet(2922+) - Alibaba.com
    Acrylic (PMMA): 2mm to 8mm – Offers excellent rigidity and clarity; ideal for ceiling panels and signage. · Polycarbonate (PC): 0.2mm to 1.5mm – Thinner but ...
  50. [50]
    Design method for a thin uniform direct backlight using a diffuser ...
    The illuminance uniformity of the diffuser plate was improved to 0.98 by the diffuser plate with a pattern that makes the TAD nearly constant distribution.
  51. [51]
    Holographic diffusers for LCD cockpit displays - SPIE Digital Library
    These diffuser properties allow the fabrication of efficient, uniform backlights for LCD displays in aircraft cockpits. The performance advantage offered by a ...
  52. [52]
    [PDF] 3M™ Quantum Dot Enhancement Film (QDEF)
    The diffuser is commonly positioned in the backlight between the lightguide and the light control films that direct and recycle light. The BLU's other ...
  53. [53]
    Engineered Optics For Edge Lit Displays - BrightView Technologies
    Get brighter edge lighting from your edge lit displays back light unit. Bright View now offers down diffusers for a boost in brightness!
  54. [54]
    What percentage of the light is lost in diffusors? | Forum for Electronics
    Nov 14, 2013 · A good diffuser will only lose a tiny amount of light. Obviously, it disperses it so the illumiation pin each sq cm is less but the total should only be 1- 2% ...Missing: backlight 10-20%
  55. [55]
    Luminance enhancement without sacrificing the viewing angle in a ...
    Essentially, using prism film(s) is a trade-off between luminance and viewing angle; in addition, a certain amount of light loss occurs [7], [10], [12].
  56. [56]
    3M™ Dual Brightness Enhancement Film (DBEF) | 3M United States
    It is a reflective polarizer film that improves polarization efficiency by transmitting one polarization state and reflecting the other, recycling light back ...
  57. [57]
    (PDF) Design Optimization of Reflective Polarizers for LCD Backlight ...
    We systematically study and optimize the design of multilayer birefringent reflective polarizers for recycling the back-light of liquid crystal displays.Missing: gain | Show results with:gain
  58. [58]
    [PDF] Reinterpreting Brewster's Law | 3M
    Unlike Brewster's Law, which says there's one angle where you get that reflection of one polarization, these birefringent multilayered films can be engineered ...Missing: multilayer | Show results with:multilayer
  59. [59]
  60. [60]
    Pulse Width Modulation (PWM) - TFTCentral
    Feb 16, 2012 · PWM is one method of reducing the perceived luminance in displays, which it achieves by cycling the backlight on and off very rapidly.Missing: global | Show results with:global
  61. [61]
    How to Address Computer-Related Eye Fatigue - EIZO GLOBAL
    There are 2 dimming techniques applied to LCD monitors: PWM (Pulse-Width Modulation and DC (Direct Current). PWM Dimming, Controls brightness by cycling the ...
  62. [62]
    [PDF] Common LED Functions and LED Driver Design Considerations
    Oct 6, 2020 · Analog dimming with a DC voltage input adjusts the output current by applying a DC voltage signal. The dimming ratio of this method is ...
  63. [63]
    LCD Dimming in HDR Displays Explained
    The LEDs in the backlight change their brightness level, allowing the display to dim the backlight for darker blacks and brighten it for brighter whites.
  64. [64]
    [PDF] Backlight Local Dimming Algorithm for High Contrast LCD-TV
    Abstract: A backlight local dimming algorithm is proposed to achieve high static contrast more than. 10000:1 on the LCD-TV which is mounted by an LED-.
  65. [65]
    LED local dimming explained - CNET
    Jan 22, 2014 · Local dimming can be a way to get near-OLED levels of picture quality. Or, it can offer some improvement compared with basic TVs, creating a ...
  66. [66]
    Breakthrough Step-Up in Picture Quality with Advanced Local ... - Vizio
    Feb 26, 2014 · VIZIO is introducing advanced local dimming technology and Full-Array LED backlighting on most of the new models, with up to 18 Active LED Zones delivering ...
  67. [67]
    [PDF] CCFL backlight half-bridge topology based on L6574 and STD7NS20
    May 23, 2008 · Cold cathode fluorescent lamps (CCFL) are widely used in the backlighting of television and. PC monitor applications due to their low cost ...
  68. [68]
    What Is FALD Blooming Or Halo Effect? [Simple] - Display Ninja
    Apr 3, 2025 · FALD blooming occurs when light from small bright objects bleeds into surrounding dimmed zones, creating a halo effect.
  69. [69]
    BOE Drives Green Development Trends with Technological ...
    This intelligent algorithm enables real-time image processing at 8K 120Hz for displays, cutting power consumption by more than 20% while simultaneously ...
  70. [70]
    AI-Driven Content Adaptive LCD Backlight Market Research Report ...
    This technology leverages artificial intelligence algorithms to analyze content in real time and dynamically adjust backlight intensity, significantly improving ...
  71. [71]
    LED or LCD Display: Which One Is More Energy-Saving? - LEDMAN
    Jun 3, 2024 · Typical power consumption for LCDs ranges from 20 to 30 watts per square meter for smaller screens and up to 150 watts for larger displays.
  72. [72]
    TV Electricity Usage: Complete Guide To Power Consumption (2025)
    Jul 7, 2025 · Summary of Average Costs and Consumption. For a typical 55-inch LED TV used 5 hours daily: Power Consumption: 80 watts active, 1.3 watts standby ...
  73. [73]
    LED driving techniques reduce power in LCD TVs - EE Times
    Jan 15, 2013 · Since LED backlighting power ranges from 30 percent to 70 percent of overall system power in LCD TVs, improvements in the efficiency of the ...
  74. [74]
    Backlight and Brightness...Energy use @ Life expectancy - AVS Forum
    Aug 19, 2009 · CCFL backlight brightness level is by far the biggest contributor to LCD TV power usage. It contributes to around 70% of total power consumption ...Missing: percentage | Show results with:percentage
  75. [75]
    TVs May Be Consuming $1.2 Billion More Energy Than Expected
    Sep 21, 2016 · Almost all TV manufacturers include ABC, which our earlier study found can reduce energy use by 17 to 93 percent, depending on the model.
  76. [76]
    LCD / LED panel power consumption - Electronics Stack Exchange
    Apr 23, 2012 · The backlight have way more impact on power consumption. This monitor consumes 45 Watts (when display black) and 48 Watts (when display white) ...Missing: percentage | Show results with:percentage
  77. [77]
    How much power does a 55 inch TV use? - Quora
    Nov 15, 2020 · What is the wattage of both the TV and the light? How long do you use each device for? The TV in my living room is a 55” LED and uses 55 watts.What is the average wattage consumption of an LED television while ...How much electricity does a 55-inch smart TV use? - QuoraMore results from www.quora.com
  78. [78]
    Televisions | ENERGY STAR
    ENERGY STAR certified televisions are, on average, about 34% more energy efficient ... Local dimming turns off or dims sections of the LED backlighting to help ...Explore models · For Partners · Televisions Key Product Criteria
  79. [79]
    Efficient and cost-effective polarized-light backlights for LCDs
    Sep 2, 2008 · The efficiency has been measured to be 1.6-1.7 times higher than for a conventional backlight. Costs, thickness and complexity are decreased ...<|separator|>
  80. [80]
    What are the Connections between Mercury and CFLs? | US EPA
    Mar 6, 2025 · Using CFLs (and other fluorescent bulbs) instead of incandescent bulbs reduces the amount of mercury released into the environment.
  81. [81]
    (PDF) Stocks and environmental release of mercury in backlight cold ...
    CCFLs and mercury started to flow to waste phase around the year 2007 and will likely peak in 2018 with an annual flow of 324.8 million units and 1.5 tons ...
  82. [82]
    Characterization of end-of-life LED lamps for the recovery of ...
    Our paper contributes directly to the formation of a database about management of end-of-life LED lamps, focusing on precious metals and rare earth elements.
  83. [83]
    How to improve luminous efficiency for LED lights? - Logos Lighting
    Apr 2, 2025 · Currently, commercially available LEDs achieve 200–220 lm/W, while laboratory prototypes have reached over 300 lm/W. The theoretical maximum ...Missing: mini- | Show results with:mini-<|separator|>
  84. [84]
    Mini-LED, Micro-LED and OLED displays: present status and future ...
    Jun 18, 2020 · From the ηW viewpoint, mLED-LCDs have similar power consumption to RGB-chip OLED displays (ηRGB,W = 3.9 cd/W). These displays are approximately ...
  85. [85]
    Introduction to the structure of LCD display backlight module
    Nov 30, 2022 · Using optical principles to increase reflection, it is generally about 500 layers, a total of 0.065mm thick. At best, 3M uses this technology ...
  86. [86]
  87. [87]
    Exploring LCD Polarizer film: Origins, Concepts, Structures, and ...
    May 19, 2024 · A LCD Polarizer film is a sheet of optical functional material that generates and detects polarized light, and is a key component that ...
  88. [88]
    LEDs for liquid crystal display (LCD) backlighting – Part 1 - EDN
    Jan 6, 2015 · Abstract : Over the past decade, light-emitting diodes (LEDs) have been adopted for use in various liquid crystal display (LCD) devices, from ...
  89. [89]
    Our Monitor Picture Quality Tests: Contrast - RTINGS.com
    Nov 4, 2021 · The 'Contrast with Local Dimming' test is nearly identical to the 'Native Contrast' test, but this time, we measure the contrast ratio with the ...
  90. [90]
    Going beyond the limit of an LCD's color gamut | Light - Nature
    Mar 10, 2017 · In this study, we analyze how a backlight's peak wavelength, full-width at half-maximum (FWHM), and color filters affect the color gamut of a liquid crystal ...
  91. [91]
    What Is A VA Panel?: The Pros And Cons Of VA Monitors
    Aug 29, 2025 · The greatest strength of a VA panel is its ability to display deep blacks in dark rooms, as they have better contrast than other LCD panel types ...
  92. [92]
    Motion Blur Reduction Backlights - TFTCentral
    Mar 17, 2015 · In this article we will have a look some relatively new technique which can greatly reduce motion blur from LCD's.
  93. [93]
    DSCC Report Projects the End of Flat Panel Display Oversupply and ...
    Sep 3, 2024 · With minimal capacity additions planned and steady demand growth, LCD makers' profitability is likely to continue to improve in 2025 and 2026.<|control11|><|separator|>
  94. [94]
    High dynamic range liquid crystal displays with a mini-LED backlight
    As discussed above, more local dimming zones and higher LC contrast ratio can reduce the halo effect and improve the display performance. However, the ...
  95. [95]
  96. [96]
    Transparent LCD Vending Display | Digital Panels - DisplayMan.com
    Up to 3000+ nits with edge lighting. Lighting Options, 2-edge / 4-edge LED bar or rear lightbox. Touch Support, Optional Capacitive. Power Supply, 12V or 24V DC.
  97. [97]
  98. [98]
    Instrument Cluster/ Head-Up Displays - SFO Technologies
    HUD Feature competencies: Display of APIX data received from driver information module; Backlight control based on forward luminance, twilight sensor, tunnel ...
  99. [99]
    2025 Automotive HUD Head-Up Display: Mini LED Backlighting ...
    Jan 16, 2025 · Explore the future of automotive displays with Mini LED backlighting technology. From improving display performance to enhancing smart ...
  100. [100]
    Display Dynamics – May 2023: Starting in 2025, automotive ... - Omdia
    May 16, 2023 · Starting in 2025, several European luxury car brands plan to incorporate hybrid OLED technology to demonstrate their commitment to revamping ...Missing: EVs adaptive
  101. [101]
    ACRYLITE® LED light guiding edge lit sheet
    ACRYLITE LED light guiding edge lit is the ideal material for very slim, large-scale luminous displays and picture frames, luminous ceilings and walls.Missing: backlights 10W/ m²
  102. [102]
    Edge Lit Acrylic Panels - Brighten Your Space Efficiently - Alibaba
    4.1 10 Shop high-quality edge lit acrylic panels for lighting and display. Find durable, clear, and customizable options from top suppliers.
  103. [103]
    ENDOLIGHT LED Light Sources - Richard Wolf
    Can be used for any kind of white light endoscopy; 80% less power consumption compared to Xenon light sources; Plug & Play; Silent cooling with passive heat ...
  104. [104]
    An Introduction to UV-C LED Lighting for Germicidal, Sterilization ...
    In this article, we'll go over the various types of UV lamps as well as technologies and wavelength ranges that do and do not effectively work for UVGI.
  105. [105]
    Front Light vs. LCD Backlight Comparison - Azumo
    With a proper front light, reflective LCDs are easy to read in low- or no-light conditions and are safer than backlit LCDs in the dark.
  106. [106]
    Augmented reality and virtual reality displays: emerging ... - Nature
    Oct 25, 2021 · Augmented reality (AR) and virtual reality (VR) are emerging as next-generation display platforms for deeper human-digital interactions.Missing: overlays | Show results with:overlays
  107. [107]
    Advantages of Explosion Proof LED Lighting in Confined Spaces
    Reduced Heat Emission. Unlike traditional lighting, LEDs emit very little heat, which is crucial in confined spaces where temperature control is challenging.
  108. [108]
  109. [109]
    16x2 LCD Display How Much Power Does it Consume?
    Jul 1, 2019 · The backlight on the LCD draws about 20 mA (in most cases) while the LCD itself draws less than 1 mA. It will in fact draw only half of that if you correct a ...Missing: 1W | Show results with:1W
  110. [110]
    How NanoLED Will Enable Next‐Generation Displays - Ishida - 2023
    May 17, 2023 · These unique properties allow QDs to create a wide color gamut (WCG) and low power consumption when used in displays. With this in mind, we ...Missing: 1W | Show results with:1W