History of LED Lighting
The history of LED lighting is the story of man’s quest to banish the darkness and illuminate those long winter nights. Our journey to this moment actually started way back in the mists of time when our ancestors lit torches or gathered around fires. Our first evidence that man had found something to light his way comes from the discovery of an ancient lamp that was carved out of stone some 70,000 years ago. Archaeologists believed that grass or wood was placed on it and then sprinkled with animal fat to make it burn longer.
Around the 7th Century BC, the Greeks began to use terracotta posts with wicks to replace handheld torches and they also first coined the term lamp. This simple technology would stay the same for hundreds of years with only a few slight innovations until the beginning of the 19th century when we first began to use that life changing discovery, electricity.
This discovery began a period of rapid development that would lead first to the invention of the incandescent lightbulb and, more recently, the eco-friendly LED lightbulb.
The Carbon Arc Lamp
We have to thank Humphrey Davey for the discovery of the carbon arc lamp which produced a burst of light across two carbon conductors. Davey may have invented it but it wasn’t until a good few years later that it was used in street lighting and for large buildings. The temperature in an arc lamp can reach thousands of degrees Celsius and you can imagine the amount of power it used. In more recent times, a plasma arc light was developed in Canada that produced a 300 kilowatt light, the most powerful manufactured single light source ever seen.
The Fluorescent Lamp
Many people won’t realise that the fluorescent light was actually invented before the filament lightbulb. It’s discovery arose out of many experiments where an electric current was passed through certain gasses. The man credited with creating one of the first fluorescent lamps was Heinrich Geisslser in 1856 who discovered a strong green glow on the tube of a mercury vacuum pump when a current was applied. In fact, work undertaken by Geissler and later William Crookes actually led to the discovery of the electron towards the end of the century.
The Incandescent Lamp
Although Edison is often cited as the inventor of the lightbulb, researchers have actually found over 20 people who could be rightly credited with the discovery. For instance, Russian scientist Alexander Lodygin invented a filament bulb in 1874 and even lodged the patent for it. Another likely candidate is Joseph Swann who began working with carbonized paper filaments in a glass bulb back in the 1850s. It was Edison who patented his invention in 1880 and is largely credited with the commercialisation of the technology in the West.
Other developments were on the way in the early part of the 20th century including the mercury vapour lamp and the gas discharge lamp. It was the development of the tungsten filament however that made the incandescent bulb we came to know and love possible. The initial development was made in 1906 but it wasn’t until 1910 until a process was found to make it more ductile and easier to manufacture.
LED Light Development
The idea of electroluminescence had been around since the turn of the 20th century but it wasn’t until 1962 that Nick Holonyak, Jr. from the General Electric Company in America developed the first visible (red) LED. It wasn’t then until 1976 that the first ‘high’ brightness LED was invented by T P Pearsall that could be used fibre optic telecommunications. The discovery of blue LED led to a more effective way to produce white light but the first ones that were produced were highly expensive and not commercially viable.
In Japan the combination of blue, red and green LEDs were brought together that could produce any colour of light in combination and the scientists who discovered it, Isamu Akasaki, Hiroshi Amano and Shuji Nakamura, received the Nobel Prize for Physics in 2014 for their work. This advance has led to the next generation of LED lightbulbs which can produce a decent amount of light and have a much longer shelf life than incandescent bulbs.
Uptake of LED lighting was slow initially because of the low light emitted by the bulbs and the cost of installation. One of the first buildings to go entirely LED was the Sentry Equipment Corporation in Wisconsin in 2008 and a year later a Christmas tree in Finland was lit by 720, 2 watt bulbs. By 2010, many businesses were beginning to switch to LED lighting with the advantage that it was more cost effective over time and cut down on energy bills.
Find out about the benefits of LED lighting here.
The Future of LED Lighting
Many experts believe that the introduction of LED lighting is one of the most important developments in recent times, allowing us to have a low energy lighting solution that can be used in a wide range of situations. As performance improves, more and more homes and businesses will begin to have it installed and the cost will come down dramatically over the next few years.
Explore the different types of LED lighting.