LED Lighting and the Human Eye
LEDs are the most versatile light source available on the planet. Add this to their extremely long life—in most applications they never require replacement, and their 5X efficiency factor over incandescents, and it’s easy to see why it’s well worth the trouble to address the technology challenges associated with wide use of LED lighting.
Any Color You Can Imagine
LEDs can be manufactured to emit light at a precise wavelength virtually anywhere in the visible spectrum and some wavelengths in the non-visible spectrum. LED chips cover the spectrum from blue, green, yellow, orange, red and into the infrared. Combinations of red, green, and blue LED chips can be placed in one LED light, and by addressing each LED separately and varying the intensities of each LED, can produce any color in the visible spectrum, including white light.
The range of innovative, creative products that this versatility makes possible is coming to market now. The future will only be limited by the creativity of the human mind and we can be sure it will be exciting.
Another great advantage of LEDs is that they emit (or radiate) light from their surface in a half-spherical pattern. All the light is emitted in the forward direction. Incandescent bulbs emit light in a full-spherical pattern, which wastes a lot of light.
With optics it is relatively easy to capture the total light emitted by the LED and direct it toward a specific target. The optics designer can create a very wide flood to a very narrow spot pattern and everything in between. Being able to capture virtually all the LED light (no photon left behind) in the optics and direct it to the intended target further increases the LED’s efficiency compared to incandescent and fluorescent light.
The most common way to produce LED white light is to coat blue LEDs with special phosphors that create white light. Here again, the LED technology makes possible a wide range of white light from frosty “cool” whites to cozy “warm” whites and every white in between. The choices are many and present the opportunity for designers to specify the correlated color temperature (CCT) for their LED lighting to make their products unique. The LED again brings a paradigm shift to the lighting world.
With LED lighting the possibilities are endless. Endless color options, endless options for directing the light to specific targets, endless opportunities for human factor considerations, and endless opportunities for product differentiation in the end application.