![FremontStExperience LasVegas](https://upload.wikimedia.org/wikipedia/commons/1/15/FremontStExperience_LasVegas.JPG)
A LED display is a
flat panel display
A flat-panel display (FPD) is an electronic display used to display visual content such as text or images. It is present in consumer, medical, transportation, and industrial equipment.
Flat-panel displays are thin, lightweight, provide better li ...
that uses an array of
light-emitting diode
A light-emitting diode (LED) is a semiconductor device that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The color of the light (cor ...
s as
pixel
In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a raster image, or the smallest point in an all points addressable display device.
In most digital display devices, pixels are the smal ...
s for a
video display
A display device is an output device for presentation of information in visual or tactile form (the latter used for example in tactile electronic displays for blind people). When the input information that is supplied has an electrical signal the ...
. Their brightness allows them to be used outdoors where they are visible in the sun for
store signs and
billboard
A billboard (also called a hoarding in the UK and many other parts of the world) is a large outdoor advertising structure (a billing board), typically found in high-traffic areas such as alongside busy roads. Billboards present large advertise ...
s. In recent years, they have also become commonly used in
destination sign
A destination sign (North American English) or destination indicator/destination blind (British English) is a sign mounted on the front, side or rear of a public transport vehicle, such as a bus, tram/streetcar or light rail vehicle, that dis ...
s on
public transport
Public transport (also known as public transportation, public transit, mass transit, or simply transit) is a system of transport for passengers by group travel systems available for use by the general public unlike private transport, typical ...
vehicles, as well as
variable-message sign
A variable- (also changeable-, electronic-, or dynamic-) message sign, often abbreviated VMS, CMS, or DMS, and in the UK known as a matrix sign,
is an electronic traffic sign often used on roadways to give travelers information about special ...
s on highways. LED displays are capable of providing general
illumination in addition to visual display, as when used for
stage lighting
Stage lighting is the craft of lighting as it applies to the production of theater, dance, opera, and other performance arts. or other decorative (as opposed to informational) purposes. LED displays can offer higher contrast ratios than a projector and are thus an alternative to traditional projection screens, and they can be used for large, uninterrupted (without a visible grid arising from the bezels of individual displays)
video wall
A video wall is a special multi-monitor setup that consists of multiple computer monitors, video projectors, or television sets tiled together contiguously or overlapped in order to form one large screen. Typical display technologies include L ...
s.
microLED
microLED, also known as micro-LED, mLED or µLED, first invented in 2000 by the research group of Hongxing Jiang and Jingyu Lin of Texas Tech University while they were at Kansas State University, is an emerging flat-panel display technology. ...
displays are LED displays with smaller LEDs, which poses significant development challenges.
History
Light-emitting diodes
A light-emitting diode (LED) is a semiconductor device that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The color of the light (cor ...
(LEDs) came into existence in 1962 and were primarily red in color for the first decade. The first practical LED was invented by
Nick Holonyak
Nick Holonyak Jr. ( ; November 3, 1928September 18, 2022) was an American engineer and educator. He is noted particularly for his 1962 invention and first demonstration of a semiconductor laser diode that emitted visible light. This device was t ...
in 1962 while he was at
General Electric
General Electric Company (GE) is an American multinational conglomerate founded in 1892, and incorporated in New York state and headquartered in Boston. The company operated in sectors including healthcare, aviation, power, renewable energ ...
.
The first practical LED display was developed at
Hewlett-Packard
The Hewlett-Packard Company, commonly shortened to Hewlett-Packard ( ) or HP, was an American multinational information technology company headquartered in Palo Alto, California. HP developed and provided a wide variety of hardware components ...
(HP) and introduced in 1968.
Its development was led by Howard C. Borden and Gerald P. Pighini at HP Associates and
HP Labs, who had engaged in
research and development
Research and development (R&D or R+D), known in Europe as research and technological development (RTD), is the set of innovative activities undertaken by corporations or governments in developing new services or products, and improving existi ...
(R&D) on practical LEDs between 1962 and 1968. In February 1969, they introduced the HP Model 5082-7000 Numeric Indicator.
It was the first LED device to use
integrated circuit
An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material, usually silicon. Large numbers of tiny ...
(integrated
LED circuit
In electronics, an LED circuit or LED driver is an electrical circuit used to power a light-emitting diode (LED). The circuit must provide sufficient current to light the LED at the required brightness, but must limit the current to prevent damag ...
) technology,
and the first intelligent LED display, making it a revolution in
digital display
A display device is an output device for presentation of information in visual or tactile form (the latter used for example in tactile electronic displays for blind people). When the input information that is supplied has an electrical signal t ...
technology, replacing the
Nixie tube
A Nixie tube ( ), or cold cathode display, is an electronic device used for displaying numerals or other information using glow discharge.
The glass tube contains a wire-mesh anode and multiple cathodes, shaped like numerals or other symbo ...
and becoming the basis for later LED displays.
Early models were monochromatic by design. The efficient
Blue LED
A light-emitting diode (LED) is a semiconductor device that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The color of the light (co ...
completing the color triad did not commercially arrive until the late 1980s.
In the late 1980s, Aluminium Indium Gallium Phosphide LEDs arrived. They provided an efficient source of red and amber and were used in information displays. However, it was still impossible to achieve full colour. The available "green" was hardly green at all – mostly yellow, and an early blue had excessively high power consumption. It was only when Shuji Nakumura, then at Nichia Chemical, announced the development of the blue (and later green) LED based on Indium Gallium Nitride, that possibilities opened for big LED video displays.
The entire idea of what could be done with LED was given an early shake up by Mark Fisher's design for
U2's
PopMart
The PopMart Tour was a worldwide concert tour by rock band U2. Staged in support of the group's 1997 album '' Pop'', the tour's concerts were performed in stadiums and parks in 1997 and 1998. Much like the band's previous Zoo TV Tour, PopMart ...
Tour of 1997. He realized that with long viewing distances, wide pixel spacing could be used to achieve very large images, especially if viewed at night. The system had to be suitable for touring so an open mesh arrangement that could be rolled up for transport was used. The whole display was 52m (170ft) wide and 17m (56ft) high. It had a total of 150,000 pixels. The company that supplied the LED pixels and their driving system, SACO Technologies of Montreal, had never engineered a video system before, previously building mimic panels for power station control rooms.
Today, large displays use high-brightness diodes to generate a wide spectrum of colors. It took three decades and
organic light-emitting diodes
An organic light-emitting diode (OLED or organic LED), also known as organic electroluminescent (organic EL) diode, is a light-emitting diode (LED) in which the emissive electroluminescent layer is a film of organic compound that emits light i ...
for Sony to introduce an OLED TV, the
Sony XEL-1
The XEL-1 is the world's first organic light-emitting diode (OLED) television, designed by Sony in 2007 and produced for sale the following year. It was also the world's thinnest television during its production, at 3 mm. It has a screen siz ...
OLED screen which was marketed in 2009. Later, at
CES 2012, Sony presented
Crystal LED
Crystal LED (CLED) refers to a screen manufacturing technique. It was invented by Sony and revealed at CES 2012.
Overview
This technology makes use of light emitting diodes mounted on each segment RGB of the display, such that each pixel is ill ...
, a TV with a true LED-display, in which LEDs are used to produce actual images rather than acting as backlighting for other types of display, as in
LED-backlit LCD
An LED-backlit LCD is a liquid-crystal display that uses LEDs for backlighting instead of traditional cold cathode fluorescent (CCFL) backlighting. LED-backlit displays use the same TFT LCD (thin-film-transistor liquid-crystal display) technol ...
s which are commonly marketed as LED TVs.
Large video-capable screens
The
2011 UEFA Champions League Final match between
Manchester United
Manchester () is a city in Greater Manchester, England. It had a population of 552,000 in 2021. It is bordered by the Cheshire Plain to the south, the Pennines to the north and east, and the neighbouring city of City of Salford, Salford to ...
and
Barcelona
Barcelona ( , , ) is a city on the coast of northeastern Spain. It is the capital and largest city of the autonomous community of Catalonia, as well as the second most populous municipality of Spain. With a population of 1.6 million within ci ...
was broadcast live in
3D format in
Gothenburg
Gothenburg (; abbreviated Gbg; sv, Göteborg ) is the second-largest city in Sweden, fifth-largest in the Nordic countries, and capital of the Västra Götaland County. It is situated by the Kattegat, on the west coast of Sweden, and has ...
(Sweden), on an
EKTA screen. It had a
refresh rate
The refresh rate (or "vertical refresh rate", "vertical scan rate", terminology originating with the cathode ray tubes) is the number of times per second that a raster-based display device displays a new image. This is independent from frame rate ...
of 100 Hz, a
diagonal
In geometry, a diagonal is a line segment joining two vertices of a polygon or polyhedron, when those vertices are not on the same edge. Informally, any sloping line is called diagonal. The word ''diagonal'' derives from the ancient Greek δ ...
of 7.11 m (23 ft 3.92 in) and a
display area of 6.192×3.483 m, and was listed in the
Guinness Book of Records
''Guinness World Records'', known from its inception in 1955 until 1999 as ''The Guinness Book of Records'' and in previous United States editions as ''The Guinness Book of World Records'', is a reference book published annually, listing world ...
as the largest LED 3D TV.
Development
Early prototypes
A claim for the 'first all-LED flat panel television screen‘ is presented in this section. It was possibly developed, demonstrated and documented by James P. Mitchell in 1977. Initial public recognition came from the Westinghouse Educational Foundation Science Talent Search group, a Science Service organization. The paper entry was named in the "Honors Group" publicized to universities on January 25, 1978. The paper was subsequently invited and presented at the Iowa Academy of Science at the University of Northern Iowa. The operational prototype was displayed at the Eastern Iowa SEF on March 18 and obtained a top "Physical Sciences" award and IEEE recognition. The project was again displayed at the 29th International SEF at Anaheim Ca. Convention Center on May 8–10. The ¼-inch thin miniature flat panel modular prototype, scientific paper, and full screen (tiled LED matrix) schematic with video interface was displayed at this event. It received awards by
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research.
NASA was established in 1958, succeeding t ...
and
General Motors Corporation
The General Motors Company (GM) is an American Multinational corporation, multinational Automotive industry, automotive manufacturing company headquartered in Detroit, Michigan, United States. It is the largest automaker in the United States and ...
. This project marked some of the earliest progress towards the replacement of the 70+-year-old high-voltage analog CRT system (
cathode-ray tube
A cathode-ray tube (CRT) is a vacuum tube containing one or more electron guns, which emit electron beams that are manipulated to display images on a phosphorescent screen. The images may represent electrical waveforms (oscilloscope), pictur ...
technology) with a digital x-y scanned LED matrix driven with an NTSC television RF video format. Mitchell's paper and operational prototype projected the future replacement of CRTs and included foreseen applications to battery operated devices due to the advantages of low power consumption. Displacement of the electromagnetic scan systems included the removal of inductive deflection, electron beam and color convergence circuits and has been a significant achievement. The unique properties of the light emitting diode as an emissive device simplify matrix scanning complexity and have helped the modern television adapt to digital communications and shrink into its current thin form factor.
The 1977 model was monochromatic by design.
Recent developments
MicroLED
microLED, also known as micro-LED, mLED or µLED, first invented in 2000 by the research group of Hongxing Jiang and Jingyu Lin of Texas Tech University while they were at Kansas State University, is an emerging flat-panel display technology. ...
displays are currently under development by numerous major corporations such as Sony, Apple, Samsung, and LG.
These displays are easily scalable, and offer a more streamlined production process. However, production costs remains a limiting factor.
See also
*
OLED
An organic light-emitting diode (OLED or organic LED), also known as organic electroluminescent (organic EL) diode, is a light-emitting diode (LED) in which the emissive electroluminescent layer is a film of organic compound that emits light i ...
*
AMOLED
AMOLED (active-matrix organic light-emitting diode, ) is a type of OLED display device technology. OLED describes a specific type of thin-film-display technology in which organic compounds form the electroluminescence, electroluminescent materia ...
*
MicroLED
microLED, also known as micro-LED, mLED or µLED, first invented in 2000 by the research group of Hongxing Jiang and Jingyu Lin of Texas Tech University while they were at Kansas State University, is an emerging flat-panel display technology. ...
*
QLED
References
External links
*
{{Display technology
Display technology
Light-emitting diodes
American inventions