Choosing Video Displays Wisely

by / Wednesday, 03 November 2010 / Published in Feature Articles

Written by Chris Curtis

With the proliferation of LED video products in the market today, how does a live event production company even begin the daunting task of finding the right product for their applications? After all, distinguishing quality products from those that merely appear to be is no simple proposition.

Back in the “old days” (circa early-1990s), the options were extremely limited. Mitsubishi was first to market with the revolutionary Diamond Vision. Then, Sony introduced its JumboTron and quickly vaulted ahead. In a matter of a few years, a brand that had become synonymous with its industry (Diamond Vision) was completely supplanted by another (JumboTron).

Today, roughly a decade after Sony abandoned the market, “JumboTron” is still the prevailing generic term for big screens. The market is ripe for the next savvy manufacturer with the right marketing campaign to position its brand as the leader in the industry.

Which brings us back to the challenge of distinguishing quality products from the myriad inferior screens now flooding the market.

A Brief History of LEDs

LEDs have been used for large-screen displays since the mid-1970s. They were generally limited to indoor use due to intensity and durability constraints, and only three colors were available – red, green and amber.

In the 1990s, technological breakthroughs enabled blue to join the high-intensity LED palette, thus making full color possible. The brightness of LED displays quickly improved enough to allow for basic outdoor use, and it wasn’t long before manufacturers began making pixels even brighter to allow daytime viewing outdoors. They accomplished this by placing multiple LEDs of the same color in each pixel – usually the red LEDs, since they have the brightest output.

In recent years, manufacturers have continued to push the technological limits of LED intensity. It is no longer necessary to place more than one red LED in a single pixel. And though the newer, brighter red LEDs cost more than their dimmer predecessors, they quadruple the brightness, making displays viewable in even the brightest sunlight, while drawing less power.

Buyer Beware

As in any industry, some manufacturers operate at the cutting edge, and others focus on offering cheap imitations at a bargain price (while a disreputable few look for a quick buck before disappearing into thin air).

With the rapid increase in the popularity of LEDs, it’s no surprise that the number of manufacturers and designers has exploded to meet the demand. Countless upstarts have flooded the market with low-quality LEDs, along with inexperienced packaging and LED design engineers. Needless to say, it’s difficult – if not impossible – to determine the strengths and weaknesses of such suppliers, let alone knowing for certain whether they’ll even be in business a month down the road.

Some LED manufacturers use low-wage labor as an advantage to compete as low-cost suppliers. But as with most products, you get what you pay for. The low-cost providers often fall short on quality control, and they tend to incorporate very low-end components into their systems – a cost advantage on the front end, but a potential risk over the longer term. That said, many of these manufacturers have improved significantly over the past decade, and that trend is likely to continue. For now, vendor quality – and the associated risk – is all over the board.

Focusing on the End Product

Superior LED manufacturers are distinguished not only by the quality of the chips they manufacture, but by their ability to sort LEDs into various bins based on color, intensity, voltage drop and viewing angle. High-quality LED suppliers offer customers consistent operating characteristics while lower-quality manufacturers offer a mix of LEDs.

Note that a low-quality LED may initially appear brighter than a superior one if the low-quality device has a higher drive current. But that extra current causes the LED to heat up quickly and ultimately fade or burn-out well short of the typical 100,000-hour lifetime of quality displays. You can see this in some older displays where faded or burned-out LEDs have created a patchwork image.

Because a multitude of factors affect the ultimate operation of the LED – including ambient heat, circuit design, voltage spikes, operating currents and environmental variability – it is essential that product assembly and circuitry are suitably designed to protect the LED and ensure its performance. The assembler’s experience can make or break the LED’s overall performance and reliability. And as we’ve seen, not all display manufacturers are created equal.

The safest approach is to find a vendor that focuses solely on high-quality LED displays that meet specific brightness, contrast, uniformity, resolution, weight and lifetime criteria. Look for companies that use state-of-the-art LEDs and displays that can withstand repeated mobile or modular use, especially if your event is subject to harsh outdoor conditions (like festivals and sporting events) or heavy travel (such as concert tours). Also, make sure the vendor and the LED manufacturer will be available 24×7 – including weekends – in the event of any unforeseen problems on-site. It’s imperative that your screen perform perfectly at your event, because you rarely get a do-over.

The proliferation of LED video displays, while creating a range of challenges for manufacturers, suppliers and end-users alike, offers extraordinary opportunities for creative applications and continued growth. It’s a dynamic environment that seems to change by the day. Just imagine what’s waiting just around the corner.

Chris Curtis is founder and president of Argyle, TX-based GoVision, LP (jumbo.tv), a supplier of turnkey mobile LED units and customized modular LED walls. The company has supplied video displays for many national events including the 55th (George W. Bush) and 56th (Barack Obama) Presidential Inaugurations, the Breeders’ Cup and the Boy Scouts of America’s 100th Anniversary Jamboree.

(from PLSN – October 2010 issue)

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