Do you know unknown things on LED

10/14/2014 21:24

Hello viewers I hope you heard about LED. In the world among all people 90%-99% know what is LED, the application of LED, price of LED, where it can be get. But the things the most of people does not know “ Who is the inventor” of LED, “Component” required to make LED, how LED is made, the drawbacks of LED lights & many more things. In this article I’ll tell you those uncommon things on LED.

History on LED

Here I am telling you a very short history on LED.

  • In 1907, British scientist Henry J. Round dicovered the physical effect of electroluminescence, an optical and electrical phenomenon in which a material emits light in response to an electric current passed through it or to a strong electric field.
  • In 1962 the first visible spectrum  LED light was produced by Nick Holonyak Jr. and was red in colour.
  • M. George Craford, a student of Holonyak, invented the first yellow LED in 1972 and then went on to produce a much brighter red LED. 
  • As technology progressed in the 1970's additional colors were created.
  • The first superbright LED's were developed in the 1980's and were brighter, more stable and cost efficent which saw the demand for LED's rise dramatically.
  • From 1990 the use of LED's became standard in various industrial applications.

The Invetors of LED:

The inventor of LED is:  Nick HolonyakNick Holonyak, Jr. invented the first visible-spectrum LED in 1962 while working as a consulting scientist at a General Electric Company laboratory in Syracuse, New York.

In addition to introducing the III-V alloy LED, Holonyak holds 41 patents. His other inventions include the red-light semiconductor laser, usually called the laser diode (used in CD and DVD players and cell phones) and the shorted emitter p-n-p-n switch (used in light dimmers and power tools).

There is also one scientiset whose name comes with the inventor of LED. The name of the scienctist is: Oleg Losev.  In the course of investigating biased junctions as a technician at Nizhny Novgorod, Losev noticed that when direct current was passed through a silicon carbide (carborundum) point contact junction, a spot of greenish light was given off at the contact point. Losev had constructed a light-emitting diode (LED). Although this effect had been noticed in 1907 by British Marconi engineer Henry Joseph Round, he had just published a brief two paragraph note on it. Losev was the first to investigate the effect, propose a theory of how it worked, and envision practical applications. In 1927, Losev published details in a Russian journal.

Recently invented LED:

Three Japanese-born scientists were awarded the Nobel Prize in Physics for inventing the blue light-emitting diode, which made possible a highly efficient light source that is increasingly replacing incandescent bulbs. The names of those scientiests are::: (From left to right): Undated photos of Shuji Nakamura, Japanese-born researchers Isamu Akasaki, and  Hiroshi Amano

The side effect on LED:

We all know that LED is much better than CFL, Flurocent tube light as because it is much electricity saver than those. So in modern age almost all electronics as well as electrical appliances manufacturing companies are using LED on illumination purposes. Now in cities we see the LED street light for the same reason of energy efficiency as well as more life.

But the thing maximum of us don't know the side effect of LED. The Side effects are:

  1. LED contains lead :--  LEDs do have a dark side. A study published in late 2010 in the journal Environmental Science and Technology found that LEDs contain lead, arsenic and a dozen other potentially dangerous substances. LEDs are touted as the next generation of lighting,” says Oladele Ogunseitan, one of the researchers behind the study and chair of the University of California (UC)-Irvine’s Department of Population Health & Disease Prevention. “But as we try to find better products that do not deplete energy resources or contribute to global warming, we have to be vigilant [about] toxicity hazards….”
  2. For steet light or use as Tube light :-- In present age we see that with the help of technology we use LED bulb, LED tube which is more powerful than incandicent bulb or CFL or Flurocent Tube. But there is big side effect. 
                   Unfortunately, exposure to blue-rich light at night can lead to decreased melatonin secretion in humans. Melatonin is a hormone secreted at night by the pineal gland that helps balance the reproductive, thyroid, and adrenal hormones and regulates the body’s circadian rhythm of sleeping and waking. Lower Melatonin levels have been tenuously linked to increased risk of cancer.
  3. LED can damage EYE :- Light emitting diodes (LED) are made from crystals that may contain materials such as phosphorous in order to produce a distinct color. For this long time watching LED light or directly fallen LED light bean on eye(human) can permanently damage the eye or can cause eyestrain, headaches, sleep disturbances and cancer.
    Among all the LEDs Blue light is the hardest for the eye to focus on. We actually see a halo around bright blue light. Blue light scatters more inside the eyeball than other colors, producing more glare, more eyestrain and more fatigue. Intense blue light can cause damage to the retina, because blue is the hardest color for the retina to handle.

The false note released on LED:

By the way after all the things at last I want to say all of the reader who read it, that there in know problem if you read any thing under LED light. There was a slogan that "DON'T READ UNDER LED LIGHT".... But after a long consult with eye specialist & other doctor I have come in this point if you read anything under LED lamp by giving a small range gap, there is no side effect. 

Some body also called that LCD TV is better than LED TV for eye. I want to say about this also that both LCD & LED TV's screen is LCD(Liquid Crystal Display). The main difference in backlight, which is not visible by anybode with removing back cover. By the way we only see the front side( screen) & don't need to see the back panel. So viewers don't worry about LED TV.. Buy, watch & Enjoy..

 

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