Thursday, September 20, 2012

LED Sign 101: Myths and Misunderstandings about LED/EMC/Digital Signage

-Deacon Wardlow

Technology is confusing. Looking from the outside-in, one would think the people in technology-sector jobs work hard to keep it that way. NITs, Lux, Flux, EMC, LED, EDS, OOH, DOOH, OA, IC, RJ-45, DVI, HDMI, and the alphabet soup list goes on and on. To clarify things I put together an online (PDF) reference guide (The ABCs of LED Displays); there are still a lot of myths and misunderstandings about LED Signage out there and it almost seems like you need a “Geek Speak” interpreter so here are a few of my favorite myths/misunderstandings simply answered and explained.

LEDs last forever!
That’d be great, but
unfortunately, this is not the case. Most LEDs sourced for LED Signage are carefully qualified to last 100,000+ hours (24/7 = 11.4 years, 18/7 = 14.8 years, 12/7= 22.8 years, 8/7 = 34.2 years... a fairly long time for a produced light source!). With proper care and strategic use of heat sinks, it’s possible to get even more optimal lifetime performance before the LED is no longer good. What happens at the end? LEDs don’t really “die” like other light sources. They gradually dim over time. Given enough time, they reach a point where they degrade beyond usefulness (the agreed upon level is less than 70% of the original starting brightness levels = LED “death”).

There’s a bright-light race in the industry and some companies will stoop low to achieve high light levels. Be cautious about manufacturers who tout super bright LEDs, it’s possible they’re overdriving the LED (running a larger amount of power than is recommended and thus increasing the light output, but shortening the lifetime of the LED). Many achieve brightness through fair-play practice, but “caveat emptor” (buyer beware) still reigns out there.

All LED Signs are the same...
With LED signs (as with life) not all things are equal. You’ve got to dig deeper and go beyond the LED. There was a time when due diligence meant what LED is the company using, that’s simply not enough. It’s important to know the LED source is solid and proven to last, but you’ve got to check the other components. Are the power supplies good? How does the manufacturer prevent oxidation on sensitive contacts and leads on the PCB (printed circuit board) in their sign and in the components? Is the software simple to use? Are the communications reliable (and if wireless, do they operate in the 5GHz range as opposed to the 2.4GHz (2.4GHz is more prone to interference)? A knowledgeable salesperson should be able to explain all this and more in easy-to-grasp terminology an show how the overall system performs to meet your needs.

Virtual Resolution is a sham!
This is only true if the manufacturer represents a “virtual” system as containing the same quality as a real pixel (for example a 20mm 64x128 LED sign which is virtualized, saying it’s the same as a 10mm 128x256 LED sign). You can read more on virtualization here.

Size doesn’t matter...
Not true with LED Signage. Make sure what you’re getting quoted is based on the matrix (number of pixels high by number of pixels wide). Some manufacturers and resellers go by size alone. Check this blog on size issues. Systems are rarely standardized across manufacturers and unfortunately this means the retainer (border, if one exists) can be anywhere from 1.5” around the viewing size to 7”. That’s a fairly large difference.

There’s a lot of misdirection and half-truths out there. Please take the time to dig deeper and learn more about the product line before you buy so you’re sure what you’re getting is what you want. A little time spent up front to ensure you’re getting the best system at a fair price will save you a lot of time and money on the back end.

*I invite you to comment here and/or email me directly with requests at Vantage LED has white paper resources and more educational material on the website (, please check it out when you have a moment. Note all posts/thoughts/writings are strictly the viewpoint of me and me alone and do not reflect nor speak for Vantage LED’s beliefs, attitudes, thoughts, etc. unless specifically stated.

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