Discover Lighting!

Since their introduction in the early 1960s, LEDs have evolved from simple indicator lights and alphanumeric displays to sources capable of dealing with more advanced forms of lighting such as task lights, exit signs, and taillights on cement mixer trucks.

LEDs differ radically from traditional light sources as mentioned above in that there is no glass bulb or tungsten filament or arc. Then how do these things produce light? They are essentially a solid-state light source – a chemical chip embedded in a clear plastic capsule. When the chip is connected to a power source, it emits light, the color depending on the chip’s chemical composition. LEDs require an auxiliary power supply since plugging one directly into an outlet will cause it to act like an old style flashcube!

With their solid-state construction comes durability and very long life. Red or yellow LEDs can maintain up to 50% of their brightness after 100,000 hours. This statement should give you the hint that the useful life is dependent upon the color. Red and yellow are the best, green is lower, and blue lower still.

The blue LED is interesting – it was developed in the mid-1990s and was a key invention leading to the development of the white LED. These white LEDs are actually blue LEDs with a phosphor coating. The phosphor is pretty dumb – it doesn’t know if there’s an LED under it or the arc from a fluorescent lamp. It acts the same and gives off one of the shades of white mentioned above. The white LED is about as efficient as an incandescent lamp, but has about 10 times the life.

Then why aren’t we replacing all our incandescent lamps with LEDs? Well, you can probably figure out some of the answers yourself, but one of the main reasons is cost. Not only is the LED itself a cost item but remember that power supply? It costs money, too.

So for now, LEDs are most useful for applications requiring colors other than white. By integrating them into various packaging configurations and modules, LEDs can be used for backlighting signs with individual letters and contour lighting for architecture.

Low profile LED strips can highlight steps or edges, guiding or alerting people to hazards in public spaces. And since they run very cool, they do not affect materials with which they may come into contact (like my foot if I’m standing on one!).

Because of the inherent decorative nature of colored LEDs, they are an alternative to traditional decorative lighting now provided by low wattage incandescent or cold cathode (neon) lighting. While they may be more expensive initially, LEDs’ long life and reliability can reduce maintenance costs and may be more economical in the long run.

Indeed, the unique characteristics of LEDs invite one to “think beyond the bulb” and ponder a more seamless integration of lighting and building materials.

As we said, “Come on in, lighting is cool!”

So, you should now be getting an idea of the amazing capabilities of light sources and the ways we are using these sources to improve the way we see the world.