Light Emitting Diode (LED), "semiconductors that emit light when zapped with [positive polarity] power" [1] are about to take over the private commercial sector and light industry. With more efficiency, longer life, and how they "clean", the LEDs are the future of light, pushing the traditional incandescent and fluorescent species. Only the higher production costs for LEDs is the existence of extendedincandescent bulbs.
History
When considering the history of the bulbs, the higher costs associated with the production of LEDs are not an insurmountable obstacle to overcome. The bulb stayed for about 70 years before moving "candles, oil lamps and gas lamps," as the main source of light. [2] When the first light bulb was rough created in 1809 by Humphry Davy, an English chemist, made from two pieces of coal for electricity, was not feasible.Later, when the first real light bulb by Warren De la Rue was created in 1820 to create using a platinum filament for the light, it was too expensive for commercial use. Only when a light bulb Thomas Edison used carbonized filament inside a vacuum in the year 1879, the bulb practical and affordable for consumers has created.
Although relatively new, the concept of LED the first time in 1907 when Henry Joseph Round used a piece of siliconCarbide (SiC) to emit a faint yellow light. This was confirmed by experiments of Bernhard Gudden and Robert Wichard Pohl in Germany at the end of 1920, in which they used "fluorescent materials of zinc sulfide (ZnS) [treated] with copper (Cu) were prepared" to create soft lighting . [3 performed, followed], but at that time there was a major obstacle that many of these LEDs will soon not work efficiently at room temperature. On the contrary, had in liquid nitrogen (N) to be immersedperformance.
This has led to American and British experiments in 1950 that gallium arsenide (GaAs) instead of zinc sulfide (ZnS) and the creation of an LED, which made it invisible, infrared light produced is used at room temperature. These LEDs immediately found a use in photoelectric sensors, sensor applications. The first "visible spectrum" LED, the production of light "red" was used in 1962 by Nick Holonyak Jr. (born 1928) of the General Electric Company, which created GalliumArsenide phosphide (GaAsP) instead of gallium arsenide (GaAs). Once in a lifetime, were quickly adopted for use as spies.
It was not long before they were brighter than red LED light, and also orange when electroluminescent gallium phosphide (GaP) substrates were produced. Until the mid-1970, Phoshide gallium arsenide (GaP) has along with two gallium phosphide (GaP) substrates were used to make red, green and yellow to produce light. This resulted in a tendency "towards [LEDUse in] more practical applications "such as calculators, digital watches and testing, because this color extended said that" the human eye is more yellow-green. "[4]
Developed, however, the rapid growth in the field of LED has up to 1980, such as aluminum gallium arsenide (GaAIAs) should begin to offer "super bright" LEDs (10 times brighter than LEDs in use at that time) - "first red, then yellow and ...Green ", which also requires less energy savings. provides [5] This has led to the concept of the first LED flashlight led in 1984.
Then, in parallel with emerging laser diodes, which have been concentrated for maximum light output, the first "ultra bright" LEDs in the early 1990's through the use of aluminum and gallium indium phosphide (InGaAlP), in part by Toshiba creation of an LED that produces LED "reflects the 90% of the light produced ..." InAlso during this period was noted that a variety of colors, including "white" (although a light "real" White recently produced with the use of an organic LED (OLED) Cambridge Display Technology, UK) was able to "adjustments in the size of the band gap", when indium aluminum gallium phosphide (InGaAlP) has been used widely in part because of the work of Shuji Nakamura of Nichia Corporation, which has developed to produceblue LED in the world premiere of 1993 [6]. Today, this technology is used for LEDs that emit even "exotic colors" such as pink, purple and teal, as well as "real ultra-violet light to produce 'white' [7].
A major milestone was reached in 1997, when the costs of entry into force, to "high brightness" LEDs the intensity of the (benefits) exceeded the costs to produce it.
Coinciding with this milestone is the new technology, newwhich is likely to reduce costs (and improve the exposure) even more - the introduction of microscopic crystals or quantum dots ([8]
Benefits
The benefits of adoption of LED light source only be provided for each application significantly. The LEDs emit almost no heat (wasted energy) and are "... in fact they are cold to the touch" as opposed to incandescent bulbs. They are also more durable (encased in a shell tempered and resistant to vibration and shock) and howlast up to 50 times longer than conventional incandescent and fluorescent lamps (some can be used up to 10 years), and "with a higher share of electricity flowing through it," translating into "savings for consumers. " [9] According to the U.S. Department of Energy ", the widespread adoption of LEDs could be the U.S. consumption of electricity for lighting reduced by 29%" [10], as they require less power to operate and by their nature, to reduce the amount ofAir conditioning needed to keep areas cool and comfortable.
The shape of the LEDs provides advantages even when the light bulbs on that comparison. Unlike incandescent and fluorescent lamps, LEDs do not use an external reflector to collect light and direct it. In addition, "LEDs are very fast ... rag [ing] full brightness in approximately 0.01 seconds - 10 times faster." Conventional light bulbs [11]
LEDs do not produceHarmful ultraviolet output, the fabric can, unlike conventional bulbs, are lightweight, environmentally friendly and can have different colors (without using color filters) on the amount of power that each primary color base that produce electricity is not wasted . The Massachusetts Institute of Technology (Nano Structures Lab) is doing research aimed at creating an LED, "in which color and intensity (brightness) can be set, could leadelectronically. "[12]
Uses and the future
Since LEDs are gaining a greater share of the lighting market, are present in a variety of devices and applications, the use of traffic control devices (eg lights, the individual signal units, the colors from green to include yellow to red for a change), Barricade lights, warning signs, a message (such as Times Square, New York, and news, message boards, panels), cell phones, televisions, large videoScreens during sports and other external events (such as Miami Dolphins end-zone screen), pocket calculators, digital clocks and watches, flashlights (including models for second hand lift and 60 hour of light, eliminating the need new batteries used for emergency reserves), buoy Christmas lights, start and runway lights, the lights and automotive applications (such as lights and head and signal lights in some vehicles, drivers of the new 2006 FordMustang can also change the color (125 different ones) of its "LED dashboard full of clicking on the" "function" MyColor [13]).
In fact, the industry expects to replace all incandescent lamps with LEDs by 2010, while efforts are currently underway to replace all traffic lights with LED lights. At the same time, plans are now underway to use LEDs, roads and much of the Third World and in other areas "without the aid of electricity," because"Solar battery" that can power the LEDs for the duration of each night. [14]
In addition, "Phillips Electronics develops remote-controlled LED lighting [while] Boeing Corp. plans LEDs throughout the interior of the new 787 Dreamliner commercial aircraft to use." [15]
With the promise that LEDs last, it is likely that one day will be lighting homes and offices, X-ray in the medical field, provide Power PC monitor, anda selection of other devices and applications. The possibilities are endless. But before LEDs can replace the light bulb, "the designers and promoters need to overcome the usual barriers to adoption of the technology ... the mainstream market. Industry-approved standard should be developed and costs must be reduced" [16] Currently, costs are down and some companies in this industry-standard motion (for example, Phillips Electronics is working on LED lamps that canScrew in the light of existing outlets, while besthomeledlighting.com already screwed provides LED light bulbs - one of 70 LEDs that have a "warm white light similar to a light bulb" is [17] with only 3 watts of energy and other LED bulbs actually change colors when lit). Thanks to these efforts, as well as exploitation of adoption, and the production of LED technology by a growing number of companies, it is inevitable that the LEDs are the only source of illuminationtraditional incandescent and fluorescent extinct. In short, the LEDs are the light of the future, a light that not only consumers but also industry and the world at large will benefit.
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[1] Evan Ramstad and Kathryn Kranhold. Change the bulb. The Wall Street Journal. June 8, 2006. B1.
[2] The story of the bulb. June 9, 2006.http://invsee.asu.edu/Modules/lightbulb/meathist.htm
[3] A brief history of Light Emitting Diode (LED). Wavicle Ltd. 2002-2006. June 9, 2006. http://www.wavicle.biz/led_history.html
[4] The history of LED technology. Marktech Optoelectronics. 2006 June 8, 2006. [Http: / / www.marktechopto.com / Engineering 20Services/leds-drivers-displays-driver-technical-%]
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[5] A brief history of lightEmitting Diode (LED). Wavicle Ltd. 2002-2006. June 9, 2006. http://www.wavicle.biz/led_history.html
[6] The history of LED technology. Marktech Optoelectronics. 2006 June 8, 2006. [Http: / / www.marktechopto.com / Engineering 20Services/leds-drivers-displays-driver-technical-%]
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[7] A brief history of Light Emitting Diode (LED). Wavicle Ltd. 2002-2006. June 9, 2006.http://www.wavicle.biz/led_history.html
[8] Joab Jackson. Search accidentally "Lights Out" for the signal bulb? National Geographic.com. November 1, 2005. June 9, 2006. http://news.nationalgeographic.com/news/2005/11/1101_051101_quantum_lightbulb.html
[9] Joab Jackson. Search accidentally "Lights Out" for the signal bulb? National Geographic.com. November 1, 2005. June 9, 2006.http://news.nationalgeographic.com/news/2005/11/1101_051101_quantum_lightbulb_2.html
[10] Joab Jackson. Search accidentally "Lights Out" for the signal bulb? National Geographic.com. November 1, 2005. June 9, 2006. http://news.nationalgeographic.com/news/2005/11/1101_051101_quantum_lightbulb_2.html
[11] Light-emitting diode. Wikipedia.com. 2006 June 9, 2006. http://en.wikipedia.org/wiki/LEDs
[12] A brief history of LED lighting. June 9, 2006.[Http: / / 216.239.51.104/search q = cache: ach2mPa9iP0J: www.artisticlicence.com/]
app 2520notes/appnote022.pdf% + + + + A brief history of + LED + lights & hl = en & gl = en & ct = clnk & cd = 3
[13] Evan Ramstad and Kathryn Kranhold. Change the bulb. The Wall Street Journal. June 8, 2006. B6.
[14] A brief history of Light Emitting Diode (LED). Wavicle Ltd. 2002-2006. June 9, 2006. http://www.wavicle.biz/led_history.html
[15] Evan Ramstad and Kathryn Kranhold. Changethe bulb. The Wall Street Journal. June 8, 2006. B6.
[16] Joe Knisley. Understanding the LED technology. EC & M 1 April 2002. June 8, 2006. http://www.ecmweb.com/mag/electric_understanding_led_technology/
[17] 70 LED bulbs, White Large Globe. June 10, 2006. [Http: / / www.besthomeledlighting.com/product/G32-120-E27-70-W]
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