The LED (light emitting diode), has a very long history. It dates back to as early as 1907, and is still evolving today. It took years to perfect the design and to make LED lighting products available in many different shapes and forms, so that it could become easy for consumers to buy it and use it within their homes and businesses.
Electroluminescence was discovered in 1907, by an experimenter and scientist from Great Britain named H.J Round. However, there was no practical use for the discovery for many decades. Another inventor by the name of Oleg Vladimirovich Losev published an article on “Luminous carborundum (silicon carbide) detector and detection with crystals” in the Russian journal Telegrafiya I Telefoniya bez Provodov (Wireless Telegraphy and Telephony). Losev’s work was not looked at for many decades, until in 1962, Nick Holonvak Jr., developed the first practical ‘Light Emitting Diode’ more commonly known today as LED or LED Lights. The first LED solar power system manufacturer products became available to the public in the late 1960’s, and produced a red light. They were used mainly as indicators on laboratory equipment and in place of incandescent indicators.
In 1968, gallium arsenide was found to make the LED much more affordable and available to the public. LED lighting products were still very expensive; this meant that not everyone could afford LED. It was later discovered that adding a phosphide would make it much cheaper and still work just the same as the previously used materials.
As years went on, LED lighting became more popular and more and more people started to use this for other domestic appliances such as electronics like radio, television, telephone, calculators and even watches. LED technology was at its peak, as it was the most innovative product on the market.
The first LED screen was developed by James. P. Mitchell in 1977. The first display of the LED television was at an engineering exposition in Anaheim, in May 1978. This LED Flat panel TV display received a special award from such organisations as NASA, General Motors and the University of California Irvine, and a special mention was given by Robert M. Saunders, Professor of Engineering and IEEE President of 1977.
Low-cost, efficient blue LED’s did not come out until the early 1990’s. This is when the RGB colour triad was completed. This enabled new designs to be created, these included new designs for outdoor signage and huge video displays for billboards and stadiums.
As the LED material technology became even more advanced, the light output was increased, and LED’s became bright enough to be used for illumination such as LED downlights, LED flood lights, LED garden lights, LED street lights and many other forms of LED lights.
Most LED’s were made in the very common 5mm T1-3/4 and 3mm T1 packages, but as higher power was becoming increasingly necessary, packages needed to become more complex to dissipate heat. Today, high power LED lighting products bear little resemblance to the early LED’s.