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The report below provides some general information on LED's for those end users that may not understand
the importance of choosing the right LED system for their corporate signage. Please take a moment to read and see why
leaving the decision, on which LED to use, to the sign manufacturer can be a big mistake.
LED's entered the signage industry back in the year 2000. The technology was finally here to use LED's for back
lit channel letters. Red was the first to be perfected. Afterall, it had already been around for decades in all types of
electronic equipment. The race to develop all the other colors began. The colors in the red family came first
(orange, amber and various colors of red), then the white family came next (blue, green and various shades of white).
LED illumination is very different then the tradional lighting sources we have used in the past. The main difference is
that LED's produce one color of light and does not use the color spectrum. A red LED is pure red. When these LED's are
manufactured they vary in color, meaning a variety of different shades. These LED's now need to be divided, which is known
as "Binning". You may have heard of this term. What "Binning" is, is the process of dividing all the shades of color and
placing them in categories.
Here is an example. Bin "A" may have a light output ranging from 2000k to 3000k. Bin "B" may have a light output of 1000k
to 4000k, and so on. In this example, Bin "A" is tighter, therefore more expensive and more uniform coloring. As you can
imagine, by reducing the range the more waste there would be. White LED's require a pretty tight Bin in order to have
the least amount of colour variances.
The white LED's are produced differently then the other colors. They are actually blue LED's with a phosphorus coating to
convert the colour to white. That is why the early versions of white and some of the less expensive, low quality, current
versions, provide a blueish white color. The higher quality available today have more then one color of white and this
is usually called "Ice White" or "Sky White" or any other name that would give you the vision of a blueish tinge.
The race was now on for uniform illumination without making the cost of the system unaffordable. Many succeeded but even
more failed and fell out of the market. Those that succeeded now had another problem, brightness! White was difficult as
the source color was Blue, and had to pass through the coating, which needed to be dense enough to get rid of the blue
tinge, and still have enough light output to illuminate a 3/16" thick plastic face. If the plastic face was any color other
then white, is was even tougher to pass light through it.
At this point the LED industry was doing what it needed to do to replace tradional light sources, and provide our
enviroment with the long awaited need for energy efficiency. Technology was advancing rapidly. Anyone can make an LED
illuminate, but not anyone can make it perform and last. LED's need to be kept cool and away from any corrosion.
"Heat and Corrosion" are the main contributors to LED failure (degradation).
In order to make the white LED's brighter, many system manufacturers decided to ignore ambient temperatures and over power
the LED's. Initially the signs a brighter and look great! As little as 6 months later, they have degraded substantially. By
over powering them, the energy consumption also rises and this energy cost doesn't reduce after the LED's degrade.
Another way manufacturers tried to increase the brightness is by over populating the signage for more light output. By
over populating you have now increased the price and the energy consumption.
This is what we mean when we say some LED's consume alot more energy then others.
How do you know which one to choose for your corporate signage? Fair question.
Click here to find out what to do.
How are LED's specified and why is it a problem?
Most specifications are derived from the previous manufacturer. How did the previous manufacturer choose an LED system?
In most cases it is because that is what they had in stock, or it is the system that their supplier carries (and
they have an account with, in other words Convenience!). This is usually the extent of their R&D. There are reputable sign
manufacturers that want to stay on top of current technology but they are few. If your sign company doesn't come to you
regularly with cost reduction options or quality improvement alternatives, then they are not working in your best
interest. If you are relying on them to develop your spec, you should expect updates as technology advances each day
and that advancement should benefit you, the end user.
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