Active-matrix liquid-crystal display

An active-matrix liquid-crystal display (AMLCD) is an extremely common type of <a href="/facts/Liquid-crystal_display/8B6xGBEz">liquid-crystal display</a> (LCD). Having supplanted <a href="/facts/Liquid-crystal_display/8B6xGBEz">passive-matrix LCDs</a> in general use, in common vernacular, an active-matrix LCD is also simply referred to as a LCD. As of 2025, the term "AMLCD" is uncommon as a matter of <a href="/facts/Jargon/eI6scBdF">technical jargon</a>; instead, due to their ubiquity, different types of active-matrix liquid crystal displays are usually specified — <a href="/facts/TFT_LCD/4Y8CbuLX">TFT LCD</a>, <a href="/facts/IPS_LCD/u7Fbag72">IPS LCD</a>, <a href="/facts/MicroLED/CeTz5jqy">MicroLED</a>, and <a href="/facts/Quantum_dot_display/HU9QE5ua">QLED</a> are but just a few examples.
Various types of AMLCDs are used as <a href="/facts/Flat-panel_display/jw0LWETN">flat-panel displays</a> in many different applications, including <a href="/facts/Television/X4YG5nT1">televisions</a>, <a href="/facts/Computer_monitor/NRaTDFHc">computer monitors</a>, <a href="/facts/In-car_entertainment/FDuCjmBy">in-vehicle infotainment systems</a>, <a href="/facts/Notebook_(laptop)/wnaDG46o">notebook computers</a>, <a href="/facts/Tablet_computer/6pGX2I7b">tablet computers</a> and <a href="/facts/Smartphone/cSIrBMWG">smartphones</a>. AMLCDs are a relatively <a href="/facts/Mature_technology/26qVA5Ky">mature technology</a>, and desirable in the above applications due in part to their low weight, flexibility, thinness, <a href="/facts/Luminous_efficacy/ryvu6nvc">luminous efficacy</a>, <a href="/facts/Pixel_density/0UbaSzsw">pixel density</a>, image quality, range of possible color <a href="/facts/Gamut/bRQc2fCr">gamuts</a>, and quick <a href="/facts/Response_time_(technology)/3kQrmztQ">response times</a>.
In comparison to other contemporaneous display technologies, most AMLCD technologies struggle with contrast. Because an AMLCD requires a <a href="/facts/Backlight/sDbctXaA">backlight</a>, one typically cannot display <a href="/facts/Black/Sl9vnhcG">true black</a> — instead, dark gray is shown.

Among other reasons, due to their smaller size, lower power consumption, lower toxicity, and higher overall brightness, AMLCDs produced since the late 2000s use <a href="/facts/Light-emitting_diode/gE8x4MDb">LED</a> backlights instead of <a href="/facts/CCFL/R8SlXCyg">CCFLs</a>.
The utilization of LED backlighting enables some AMLCDs (mostly televisions) to employ methods like <a href="/facts/Backlight/sDbctXaA">localized dimming</a> to increase their perceived <a href="/facts/Contrast_ratio/PQG4mJrS">contrast ratio</a>. When the display's controller detects darkness in the frame or <a href="/facts/Group_of_pictures/WMwn2drD">GOP</a> being displayed, groups of LEDs comprising the display's backlight are dimmed at the corresponding physical location (the number of localized dimming zones the display provides is typically in the hundreds but varies heavily, typically increasing proportionally to the display's <a href="/facts/MSRP/BWeABkuk">MSRP</a>). Unfortunately, it is not uncommon for localized dimming to cause portions of the image (for example, subtitles during a dark scene) to be incorrectly and undesirably dimmed to a level where the image is not clearly visible. Displays where localized dimming cannot be disabled are therefore unsuitable for applications like <a href="/facts/Non-linear_editing/xN4H6gw4">non-linear editing</a> or <a href="/facts/Color_grading/ehfY30XI">color grading</a>, where <a href="/facts/Color_calibration/5kBBLf7p">color accuracy</a> and <a href="/facts/Gamma_correction/cApBLTYj">correct gamma</a> are required.
The issue is very well-known, having plagued AMLCDs for decades. Amongst other technologies, it contributed to the development of <a href="/facts/MicroLED/CeTz5jqy">MicroLED</a> displays, a type of AMLCD. A MicroLED display uses one LED per pixel as its backlight, so a MicroLED display is capable of displaying black by simply turning the relevant LED off — rendering the corresponding pixel completely dark. However, as of February 2025, MicroLED displays have not been widely adopted and are considerably more expensive than other AMLCD displays.
The concept of <a href="/facts/Active-matrix/rDM2fHfb">active-matrix</a> LCDs was proposed by <a href="/facts/Bernard_J._Lechner/5BlGclH1">Bernard J. Lechner</a> at the <a href="/facts/RCA_Laboratories/J4CvrdeS">RCA Laboratories</a> in 1968. The first functional AMLCD with <a href="/facts/Thin-film_transistor/rhe3Y936">thin-film transistors</a> was made by <a href="/facts/T._Peter_Brody/juJIkKbw">T. Peter Brody</a>, Fang-Chen Luo and their team at <a href="/facts/Westinghouse_Electric_Corporation/Nln2BzI3">Westinghouse Electric Corporation</a> in 1972. However, it took years of additional research and development by others to launch successful products.

Active-matrix liquid-crystal display open-in-new

Active-matrix liquid-crystal display