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The History of Illumination and LED's Technology Light Emitting Diodes or LED's have been around for more than 15 years, but they are still considered by many to be a product of the future. The history of illumination has seen us progress through many mediums of candlepower. The dirty oil and gas lamps of the medieval age, gave us dull light from the large quantities of fuel that were consumed. Then came the magical discovery of the light bulb which ran an electrical current through a tin filament generating a white hot light. This was called incandescence. The bulbs gave off a tremendous amount of heat thus wasting large amounts of energy. Since this marvelous invention we have given some merit to the cool-running fluorescents which illuminate our streets and office towers. But even though fluorescent lighting has gained widespread usage, it too has drawbacks such as bulky tubing and noisy, temperamental ballast's. All the above is now history! Welcome to the world of the LED's - the Energy Savers! The simple LED has two differing layers of semi-conductor materials. One layer is overloaded with electrons while the other layer has a shortage of them. A tiny electric current is passed through the structure causing a "rush" from the "rich" to the "poor" layer of electrons. When this occurs, particles of light called protons are released. This is known as electro-luminescence. The light that comes from the LED's is directional - it comes straight at you from the active surfaces rather than radiating the way that incandescent bulbs do. A viewing angle of 20° - 70° can be achieved depending on the chosen LED's. In addition, the cool LED's use one-tenth the electricity than the common light bulb given the same luminosity. Other favorable attributes of these flashy, midget marvels, is a life span exceeding 100,000 hours, fast speed response for eye-catching messages and much lower maintenance costs. The LED industry is considered to have technology of the future, but given the many positive characteristics of these light emitting diodes, the future looks extremely exciting and bright.
Characteristic of the Electronic LED's Sign Even though electronic LED's sign has been
available for many years, recent technical improvements and advancements have
made them even more attractive to architects, designers and private business.
When the situation calls for creative and dramatic signage, LED's provides some
very noteworthy benefits. Long Lifespan Light Emitting Diodes (L.E.D.) according to
manufacturer estimate last a minimum of 100,000 hours (11 1/2 years)! That
lifespan is extended even further because the actual illuminated time percentage
of each diodes is utilized approximately 40%. Most incandescent bulbs can only
last up to five thousand hours. Low Power Consumption LED's
consumes an average of 90% less
electricity than incandescent bulbs according to studies conducted in 1992 by
Carolyn DeCusatis, an associate at the Lighting Research Center of the
Rensselaer Polytechnic Institute in Troy, New York. She looks at the 20,000 7
watt bulbs at the great Yule tree at New York city's Rockefeller Center. If they
were replaced by 20,000 clusters of four LED's each, producing the same
brightness, she figures that it would cut the tree's electricity bill from
$14.00/hour to 90 cents/hour! In fact, most Hydro authorities in North America
are offering incentives to owners of old fashion bulb signs to replace them with
less costly means. Low Service Cost Most quotations for service to incandescent bulbs amount to a large cost, because incandescent bulbs burn out so fast. Sunitron's LED's systems require considerably less maintenance. Light Emitting Diodes run trouble free for years, and in the event of a malfunction downtime can be reduced due to the quick replace of a solid state module. This usually takes only a few minutes and its quick and easy.
The LED's industry has been improving the performance of the products steadily over the last decade working towards replacing old, "power-hungry" technologies that are becoming obsolete in an environment conscious world. Now, light emitting diodes (LED) can be used in applications that were not dreamed of just a few years ago. Advertising in full color, employee information, in offices and plants, electronic art in shopping centers, road way signage, LED's. can meet the requirements and challenges of society today and tomorrow. Copyright Sunitron Inc. 1992 |
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