Part 1: A Brief History of Light
Over the past 7-8 years the introduction of useful white-light High Brightness Light Emitting Diodes (HBLEDs) has captured the fancy of not only the engineering community but also the financial community.
Press releases have described how these new devices will render obsolete the 140-year-old invention of Thomas Edison and that ”the future is now!.” In fact, there is a recently published book, by Jane Brox, on the history of artificial light. The book was summarized in an 8/1/10 Boston Globe article as “The Incandescent Lamp: An Obituary”.
The Internet today is packed with hundreds of companies offering HBLED products of one kind or another. Furthermore, many component makers and design consultants - for LEDs, lenses, power supplies, heat sinks, control circuits - have an agenda - nothing wrong with that - but they are unlikely to be an expert in all the companion elements and they certainly are not going to tell you things which might be limitations of their own products.
There is evidence that, because LED technology has evolved so rapidly, there are actually very few people who really understand all the technical interactions beyond a superficial level. Unfortunately, customers are also confused, whipsawed and otherwise befuddled by the various claims being made by the many firms now hoping to cash in on this increasingly evident technology.
There is extraordinary potential here for energy savings, new functionality, longer product life and greater reliability. However, in order to separate “the steak from the sizzle,” we need to look at some of the lesser-known physical principles and manufacturing technologies that make HBLED lighting possible and at some of the irksome issues not talked about.
Hopefully, the following commentary will put a few developments in perspective and provide an understanding for some of the aspects of the market that are not usually evident.
The Lighting Market: A Two-Part Equation
In a discussion of