What is LED video display?

Display technology

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 diodes

A LED display is a flat panel display that uses an array of light-emitting diodes 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]

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 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 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 Utrecht

See also

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References

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• LED displays at Wikimedia Commons

If you’re in the market to rent a video wall, you’ve probably run into all sorts of confusing info. Here’s the lowdown on LCD vs. LED video walls so you can make the right choice for your next conference, trade show, or other event.

Why are video wall rentals a worthwhile investment?

We’re about to throw a whole lot of info at you. So let’s first take a second to remember why both LED and LCD video walls are a good investment in the first place.

The old adage, “the bigger the better,” is definitely true when it comes to AV. A video wall immediately symbolizes your company is established, and sends a subconscious message that people should take your business seriously. Video walls help you stand out, and compete with all the other businesses who are investing in splashy, eye-catching displays.

So, is a video wall a good choice for you? Here’s what to consider.

• Distance – The further your video wall is from viewers, the bigger it needs to be. If you’d like a video wall on the back of your trade show booth, you’re going to need a different option than if you’d like a video wall as an entire backdrop of a general session stage. As one of your first steps, decide on distance.
• Content – Do have the resources to produce custom content for your video wall? After you finalize the size of your video wall, your AV provider can tell you the exact dimensions and resolution your content needs to be. From there, a designer or video editor can create custom video wall content — which is the most important part of any great video wall.
• Venue Type – An outdoor venue presents a different challenge than an indoor trade show without windows. There’s a great video wall solution for lots of different venues, but be sure your venue and the basic event details are confirmed first.
• Price – A video wall system is always going to cost more than monitors, projectors, or other digital signage. Make sure you have enough room in your budget for a video wall — which can start in the ballpark of $10,000 and go upwards from there.

What’s the difference between an LCD and LED Video Wall?

Once reserved for stadiums and shopping malls, LED walls have become much more accessible for corporate events in recent years. An LED wall is made of many smaller LED panels. Each panel has hundreds of tiny light sources called “light emitting diodes” that can change color to create a large, seamless image.

Technicians can add panels until the LED wall is as massive as you need it to be. Random fact: The Suzhou Sky Screen in China is the largest LED video wall in the world, measuring 1,640 feet long — about 4.5 football fields.

Meanwhile, an LCD video wall is a large surface for video or images built from many LCD screens. You’ve interacted with an LCD screen before — they’re on your laptop, TV monitor, and more. However, the LCD video wall screens are designed to run longer and have thinner edges, called bezels.

Technicians use special hardware and tools to stack the LCD screens on top of one another, and calibrate the wall so that an image shows up across every screen. Temporary LCD walls can usually only be about five screens across and five screens high.

Temporary LCD walls can be configured to be in many different sizes and shapes, both large and small, but typically don’t go larger than five screens across and five screens high.

Comparison Between LED and LCD Video Walls

LED Video Wall LCD Video Wall Cost Usually the most expensive video wall option. Usually less expensive than LED walls. Maximum Size Our walls can use hundreds of LED panels, but since you can combine them in any width or height combination, there isn’t necessarily a maximum size. Our most popular LCD walls are about 16’ wide by 10’ tall. Also, when measuring your ceiling height, keep in mind that most walls don’t go all the way down to the floor. So you’ll need to add that into your total height need. Appearance People need to view LED walls from a distance to get the full picture. Think of them like a Lite Brite, or an impressionist painting — you get the full picture when you’re further away. Though made of LED panels, there are no seams. The image on an LCD wall will be sharper than on LED walls, especially while standing nearby, since it’s made from HD panels. Will have very thin seams between each LCD screen, called bezels. Content Once you know the exact size, your AV provider will give you the exact dimensions and resolution so your media creator can customize your content. Since an LCD Wall are basically fancy computer monitors, it’s typically easier to create content. If your content looks great on a standard computer monitor with a 16:9 aspect ratio, it will look good on an LCD wall. Your AV provider will give you dimensions and resolution requirements once you decide on the size you need, and can also help you determine where the seams (or “bezels”) will be so none of your image gets cut off. Installation Installation time will vary depending on the wall size, but can take from half a day to multiple days. Be sure to bake in enough time. While usually quicker to install than LED walls, still be sure to schedule in at least half to a whole day. Brightness An LED wall can get face-meltingly bright, which makes them a great option for outdoor events. LCD walls can be very bright, but are suited for indoors. (They’re also not waterproof, unlike outdoor rated LED tiles.) Power Requirements Much lower than LCD — but you’ll still need to make sure your venue has enough power capabilities. Your video wall provider can tell you how much power you’ll need. You need a lot of power. Each screen requires about 4amps. Make sure your venue has the power capacity, or make special arrangements. Loading Requirements Relatively lightweight and easy to transport in many pieces. Comes in huge containers. A venue might need to have freight elevator, and you’ll have to make sure you have enough space to get it into your venue.

Still confused about the difference?

Imagine an LCD video wall is like a tray of lasagna. Reliable, beautiful, and sturdy — but you can only increase the size of a tray of lasagna so much. Affordable, but it has a limit in size.

Meanwhile, imagine an LED wall like a limitless, footlong sub. It might not be quite as satisfying and vibrant as a steaming tray of lasagna, but you can keep adding to it until it’s as massive as you’d like.

 

Video walls are a great way to increase the professionalism and engagement of your event. As national video wall experts, we’d love to learn more about what you’re looking for, and how we can help make your vision come to life.