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LED & Video – Playing to its strengths

test 1 July 2008

Talking to the industry there is a shared perception that LED technology looks set to become increasingly pervasive, not only because of what it can achieve in applications such as digital signage and outdoor entertainment, but also because of the way in which it can uniquely enable hugely creative solutions.

“Today, we take big screens everywhere for granted – and, for the most part, that familiarity has been enabled by LED displays,” says Graham Burgess, founder and CEO of DisplayLED, whose large-screen career has seen him at Barco, Sony and Lighthouse. “The great thing is, we’ve not started yet. There are a huge number of applications and environments that LED can serve in a way that no other display technology can. The opportunities are really exciting.”  

“We’re also seeing a crossover market developing,” says Simon Taylor, Northern Europe general manager for LED display manufacturer Lighthouse Technologies, which recently introduced the LEDscape series for creative video solutions. “The boundaries between video and lighting are becoming blurred – and LED is the hardware platform. That’s making it increasingly popular with architects, television set designers and event organisers.”  

“ This is a new and rapidly developing market,” says Bush Cherroud, sales manager at XL Video, a company focused on providing video display solutions for the special events industry. He has worked with Mitsubishi on shows by Dutch singing superstar Marco Borsato – demonstrating in the process that ‘traditional’ LED displays can be used creatively to deliver extraordinary effects.  

“Trade shows, TV shows and other events are getting more and more creative, really exploring the possibilities of LED. This gives the set or show an extra dimension that cannot be achieved by any other technology. Creative LED is a technology in between video and lighting, where two worlds are converging towards one unified system to control both creative video element and light elements.” So what is state-of-the-art in LED? “The definition of state-ofthe- art really depends on the application,” he continues. “For high-resolution indoor applications, such as trade shows and high-profile corporate events, 4mm LED is now the standard, where it used to be 6mm. The price of 4mm has dropped by something like 50% in the past three years. For creative use, transparent LED effects are being used in a huge variety of different shapes and pixel pitches. Some examples are LED balls, LEDs in curtains, pixels mounted on different fabrics, different kinds of acrylics in front of pixels and so on.”  

Traditional approach

But to return, for a moment, to more traditional applications for LED displays. “The race to achieve finer pixel pitches has to a large extent run its course,” says Russell Hartwell, European sales manager for Diamond Vision LED products, Mitsubishi Electric. “Pixel density is far from the only factor that influences image quality. For us, the single biggest enhancement has been the use of ‘Black Package’ LEDs. In essence, these are LEDs that use specially developed black mountings to create maximum contrast. We introduced Black Package technology into our 4mm and 6mm indoor screens last year, and the effect on image quality was quite significant. We have also further enhanced image quality with the introduction of more sophisticated image processing.” Black Package technology is now widely used throughout the industry.  

“Customers are less interested in pixel pitches or contrast ratios than they are in the overall quality of the product – in particular its longevity and reliability,” he continues. “It’s this ability to maintain screen uniformity and reliable performance over a lifespan of many years that distinguishes between the various LED systems in the market.”  

He goes on to note the danger of buying ‘off the spec sheet’. “It’s becoming harder and harder to perceive a visible dif ference between one manufacturer’s LED display and another’s in terms of day-one image quality,” he points out. “The real difference in quality only emerges over time – and that can be a very short time. In applications such as digital signage, that can be disastrous as it reflects badly on the advertiser’s brand and can significantly affect the return on investment.”  

Jeremy Harwood, managing director of LED display manufacturer and supplier Polycomp, agrees with this view of pixel pitches. “They’re unlikely to get much smaller than they are today,” he says. “While there are some applications where very fine pixel pitches are required – for close-up viewing, for example – that market is already well served by other technologies. When it comes to image quality, a 20mm display 100m away delivers sufficient resolution to look as clear as a plasma screen – and that’s the market that LED is best placed to serve.”  

Paul Beswick, founder of Pro Display, a UK manufacturer of display solutions, notes that there have been other significant developments in the ‘traditional’ LED display market, beyond the finer pixel pitches enabled by surface mount device (SMD) technology and reduced component sizes. The reduced costs enabled by greater automation in manufacturing as unit volumes increase have also been a factor. “We now better understand how to increase the brightness and stability of the lamp without compromising the longevity of the display,” he says, “and we can manage heat dispersal better without compromising image quality.”  

Others point to the superior energy efficiency of LED technology – an aspect which, combined with its creative possibilities, led to the design and construction of a 20,000sq ft GreenPix Zero Energy Media Wall at the Xicui entertainment complex near the site of the Beijing Olympic Games. It is the largest such wall ever built, and is powered entirely by solar energy. Peter Ed is a freelance consultant with a long history in theatrical lighting design. His clients include German visual technology company G-LEC, with which he’s been working on applications for low-resolution LEDs. For him, the excitement is nothing to do with finer pixel pitches and everything to do with the creative use of the technology.  

“Low-resolution LED displays are, in effect, transparent,” he says, echoing Cherroud’s earlier point. He defines ‘low resolution’ as pixel pitches where the distance between the pixels is greater than the width of the pixels themselves. “There is a great deal of interest in making building facades come alive with branding messages and advertising without the screen being visible on the building surface, and letting in daylight, allowing the rooms inside to be used. Transparency also means that air can pass through – avoiding the need, in windy locations, to use heavy structural supports. Also, sound can be passed though the screens, allowing loudspeakers – and even whole orchestras – to be hidden behind the screen without impeding the audio. As all the hot and heavy electronics are removed from the actual screen, they become much lighter than traditional high-resolution screens, enabling a whole host of possible opportunities – including three-dimensional applications – both in terms of where it can be installed, and what you may want to do with it.”  

“In fact,” he continues, “the low resolution – the visible pixellation – is a real strength in itself: it can create a lighting effect that TV cameras love because it adds colour, sparkle, dynamism and depth of field.”  

Beswick is certainly seizing the opportunity for creative LEDbased solutions. “It’s important to understand that, in terms of lighting, general ef fects and advertising, it’s not always about the display being a standard TV. It’s about the visual effect you can create and its impact – it doesn’t need to be high resolution to get the message across. In many cases, unusual shaped screens have a greater impact than conventional displays.  

“We’ve been involved in many unusual projects using full-colour LED solutions, including LED globes on top of buildings, LED sculptures and LED rail screens fitted on the sides of buildings. The beauty of most LED systems is that they are made up of modules which allow the flexibility to create different shapes and sizes. Because we’re a comprehensive LED manufacturer, we can custom make screens and modules for specific projects and applications.”  

Certainly, there have been numerous introductions in recent times of LED-based products – Lighthouse’s LEDscape Bar and Barco’s MiPIX are just two that indicate how the market is becoming increasingly mainstream – that are responding to the growing demand for creative display solutions. And there are more to come. “Later in the year,” says Burgess, “we’ll be launching a new product that we previewed at ISE. It’s a completely f lexible LED panel, capable of being wrapped around corners. It’s thin and lightweight, and has the potential to make a big difference and open up a whole new world of possibilities for LED display technology.  

“And it’s not just about helping to create new applications; it is also about improving today’s applications. In the rental and staging industry, for example, the possibility to put several displays into a flight case that would otherwise contain just one is enormously attractive.”  

But if it’s easy enough to, in effect, deconstruct LED technology in order to generate highly creative solutions – is it equally easy to drive the resulting hardware configuration? Driving a rectangular panel, or a block of rectangular panels, is a well-understood process in the industry – but has the industry mastered the challenges of driving what may be individual pixels?  

“Actually, for a media server, an LED display is often one of the easiest displays to drive, simply because it is usually made of a very ordered, relatively low-resolution array of pixels, so the overhead on the system is very low,” says Nigel Sadler, project sales director at Green Hippo, whose Hippotizer media servers are widely used for real-time video manipulation.  

“The current trend for LED displays is to break the design into smaller shapes and blocks, and use it to fill a much larger space, displaying bold computer-generated graphics where large gaps in the

display are not a problem as the eye can fill in the gaps. “Even with disjointed LED displays, media servers generally do not have a problem driving them as the displays usually have some sort But what of the question Sadler raises about content development? Designing content for a rectangular screen could be considered ‘Digital Signage 1.01’ – but for disparate groups of pixels? “The content provider needs to understand the resolution and brightness of the system that will be used,” Cherroud says. “In some cases, we are talking about millions of spaced pixels that need to be driven – for example, the Genesis Turn It On Again world tour used a backdrop of more than 9 million LEDs. Some new state-of-the-art media servers can handle this and the required pixel mapping – but it is still a process that requires a great deal of skill and technical knowledge to achieve.”  

The excitement may be focused on the evolving market for creative applications for the technology, but it would be wrong to overlook the progress it’s making in the markets it has historically served. As Hartwell points out, the high ambient light environments in which LED displays thrive aren’t just to be found outdoors, they can be anywhere – such as atria, where large amounts of glass can cause other screen technologies to fade.  

“The other area in which LED has made remarkable progress has been in the corporate hire market,” he says. “As pixel pitches have reduced, LED is beginning to replace other forms of display in applications such as high-end exhibitions and conferences where high brightness is an absolute requirement. Lang AG and Gahrens & Battermann in Germany have successfully spearheaded the use of HD LED into the corporate arena using their 4mm and 6mm Mitsubishi systems.”  

There’s growth and progress everywhere you look. “The market has never been more fluid than it is now – there’s so much going on. Ten years ago, there were four manufacturers with two products each. Now, there are many more manufacturers, all with extensive product lines,” says Burgess. For him, as for many in the industry, the way forward for LED technology is not to attempt to compete with other flat-panel display technologies – something which, with the focus on reducing pixel pitches, it seemed determined to do.  

“To try to compete in that space is to miss the point of what LED is all about,” concludes Burgess. “Plasma and LCD will always have advantages over LED when it comes to close up viewing indoors – but LED will always be more flexible, allow for greater creativity and be much better suited for high-visibility applications.” The LED display industry is, thankfully, now playing to its traditional strength – the ability to grab attention. What’s really interesting, though, is the new and exciting ways in which it’s doing that. 

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