This article is about light-emitting diode (LED) based displays. For LED-backlit displays, see LED-backlit LCD . For matrixed text displays, see Dot-matrix display
Not to be confused with Vacuum fluorescent display
Detail view of an LED display with a matrix of red, green and blue diodesA LED display is a flat panel display that uses an array of light-emitting diodes (LEDs) as pixels for a video display. Their brightness allows them to be used outdoors where they are visible in the sun for store signs and billboards. In recent years, they have also become commonly used in destination signs on public transport vehicles, as well as variable-message signs on highways. LED displays are capable of providing general illumination in addition to visual display, as when used for stage lighting 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 walls. microLED displays are LED displays with smaller LEDs, which poses significant development challenges.[1]
A LED video cube above the ice rink at Nokia Arena in Tampere, Finland.History
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Light-emitting diodes (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 in 1962 while he was at General Electric.[2]
The first practical LED display was developed at Hewlett-Packard (HP) and introduced in 1968.[3] 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 (R&D) on practical LEDs between 1962 and 1968. In February 1969, they introduced the HP Model 5082-7000 Numeric Indicator.[4] It was the first LED device to use integrated circuit (integrated LED circuit) technology,[4] and the first intelligent LED display, making it a revolution in digital display technology, replacing the Nixie tube and becoming the basis for later LED displays.[5]
Early models were monochromatic by design. The efficient Blue LED completing the color triad did not commercially arrive until the late 1980s.[1]
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 Nakamura, 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 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 for Sony to introduce an OLED TV, the Sony XEL-1 OLED screen which was marketed in 2009. Later, at CES 2012, Sony presented Crystal LED, 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 LCDs which are commonly marketed as LED TVs.
Large video-capable screens
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The 2011 UEFA Champions League Final match between Manchester United and Barcelona was broadcast live in 3D format in Gothenburg (Sweden), on an EKTA screen. It had a refresh rate of 100 Hz, a diagonal 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 as the largest LED 3D TV.[6][7]
Development
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Early prototypes
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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.[8][verification needed] The paper entry was named in the "Honors Group" publicized to universities on January 25, 1978.[9] The paper was subsequently invited and presented at the Iowa Academy of Science at the University of Northern Iowa.[10][11] The operational prototype was displayed at the Eastern Iowa SEF[12] 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.[13] 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.[14][15] It received awards by NASA[16] and General Motors Corporation.[17][18][19] This project marked some of the earliest progress towards the replacement of the 70+-year-old high-voltage analog CRT system (cathode-ray tube 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
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MicroLED 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.[20]
The 40m large LED display at the Armin Only event in April 2008 in the Jaarbeurs UtrechtSee also
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References
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LEDs are widely used in the home and have also found their way into the world of business and commerce too. You’ll see endless situations where an LED display is put to effective use. You’ll find LED displays commonly used in a wide variety of commercial settings from sports events, education systems, transportation, and corporate management through airports, hotels, shopping centres, commercial LED screen advertising, and many other public venues.
We’ve all read how efficient and long-lasting LED displays can be, but what other advantages are there to using LED screens or LED displays, compared with more traditional LCD displays?
In this post, we’ll look at the benefits of using LED displays, before moving on to comparing them with LCD displays.
LED displays and LED screens are commonly used for advertising displays. They’re extremely versatile and you can install an LED display in a wide range of places, such as on a wall, a pole, or even on a roof. Generally, LED displays are used to broadcast valuable information about a promotion, brand, or safety information but they can be used for so many other things.
LED displays use technology that’s extremely reliable. There are many people that consider LEDs to be one of the most outstanding inventions of the last century. You’ll find LED display technology used for digital billboards, mobile phones, television screens, Blu-Ray players. You’ll even find LED technology used in medical equipment.
LED panels are very lightweight because they don’t use fluorescent bulbs. This makes installing them a piece of cake. In addition, LED panels are available in a wide range of shapes, sizes, flat or curved, whatever your needs.
With an LED screen or LED digital display, you can enjoy superb picture quality. High-quality images are possible, and they have colour range and definition that can’t be beaten by anything else. If you want to increase the impact of your LED display, there’s also the option of adding lighting effects to further improve the picture quality.
One of the most significant benefits of an LED display is that it uses such a small amount of energy. LED technology is super-efficient when it comes to energy use. Compared to an old-fashioned incandescent bulb, an LED bulb uses ten times less energy.
We’ve all become very environmentally conscious and for a business, it’s important to be as environmentally friendly as possible. Reducing power consumption rates will help you reduce your business’s environmental impact.
LEDs are environmentally friendly in other ways as well. For example, they are longer lasting so fewer materials are required for making them. Less maintenance is required along with fewer repairs. LEDs emit no ultraviolet or infrared radiation and extraordinarily little heat.
It’s not usually an issue to make media smaller, however, difficulties often arise when it comes to making something big. With an LED screen size is not an issue because you can use several LED panels together to deliver your advertising messages.
You can expect the best LED screen to far outlive the competition. To demonstrate this, let’s compare the lifespan of an LED sign with other commonly used lighting sources:
With LED screens there’s no need to worry about the angle you’re watching them from, and you have the perfect viewing angle, whatever your position.
LEDs have virtually zero “warm-up” time (response time). A red indicator LED, for example, can achieve full brightness in less than a microsecond. The LEDs that are used in communications devices have an even faster response time.
An LED screen, display, or LED monitor will mean less strain for your eyes because it produces a flicker-free image. What this means is a reduction in eye strains, eye fatigue, and headaches.
You can install an LED display outdoors without the need for any kind of protection. LED screens are waterproof, dustproof, can be seen even in direct sunlight, and able to resist a certain amount of vandalism thanks to their robustness.
LED displays are easy to install and because they are dust-proof, water-proof, and anti-corrosion, even when outside in extremes of weather, there is much less maintenance.
LEDs can reproduce a vast palette of colours that’s far superior to any other kind of technology. A full-colour LED screen can display more than fifteen million colours.
The refresh rate of an LED screen is unmatchable.
You don’t have to be directly in front of an LED to turn it on. Your location is not a problem because you can program an LED display from anywhere in the world. You do, however, need to use a device and have a reliable internet connection.
LED screens will benefit your business because they provide a good ROI (return on investment). They’re reasonably priced and their lifespan is massive.
When comparing LED displays with LCD monitors, LEDs tend to come out on top for several reasons.
Check our LED vs LCD display comparison for more information on why you should choose LED screens over LCD ones.
So, we’ve explored the advantages of LED displays in terms of quality, eco-friendliness, flexibility, and more but what are the disadvantages of LED?
Really there are only a few disadvantages of LED, one of which is light pollution. An LED screen can emit light that’s just as bright during the night as it is during the day. However, it is possible to overcome this downside by using a light sensor or setting in the operating system that detects changes and adjusts the brightness accordingly.
In addition, the cost of an LED screen is higher, although this is counteracted in part by its lifespan. Alternatively, there’s also the option of LED screen rental if budget is an issue.
Both LEDs and LCDs are popular, but now you know the benefits and disadvantages, you’re in a better position to decide for yourself which display is suitable for your business.
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