Light Emitting Diode, which is conveniently called as LED lights in electronic term is a semi conductor light that emits light as soon as an electric current is applied to it. They are extensively used as indicator lights on electronic devices and also in higher power applications as in case of flashlights and area lighting. As per the technological methodology, an LED is a light source which can be infrared, visible or ultra violet. The color is determined by the composition and condition of the semi conducting material used. Discovered in the year 1907 by H.J Round, a British experimenter, earlier these bulbs were used as replacements for incandescent indicators only.
Methodology
The white color of the LED bulbs come from a narrow band blue that is emitted naturally by GaN LEDs. The yellow on the other hand is generated by a phosphor coating on the die which absorbs a proportion of the blue and converts it to yellow. These GaN die are able to produce operational wavelengths from green to ultraviolet by varying the relative amounts of indium and gallium during production. When electric applied in the forward direction of the device it results in a form of electro luminescence where incoherent and narrow-spectrum light is discharged from the p-n junction in a solid state material.
Advantages
LED technology has taken the world to a whooping stage of development as it is very useful in conservation of energy and pollution. Some of the important advantages of the bulb are –
1. LED lights are more efficient when compared to the conventional bulbs and tube lights. They produce more light per watt against an incandescent bulb and this facet makes it very useful when used in battery powered or energy-saving devices.
2. This technology has the capacity of emitting various colors of light without the use of colors filters that traditional lighting methods require, thus saving initial costs.
3. Due to their small size, they can be easily placed and they also light up very quickly and achieve full brightness in microseconds.
4. These LED light have a better cycling life as compare to incandescent bulbs and also radiate much less heat in the process of switching on and off.
5. They have a better life span around 35,000 to 50,000 hours of useful life and LEDs mostly fail by dimming over time, rather than the abrupt burn-out of incandescent bulbs as in comparison to incandescent lights.
6. These lights are shock resistant and the solid package of the LED can be designed to focus its light. The fact that they are non toxic (do not contain mercury) also favors the application of these bulbs.
Disadvantages
However, withstanding all the advantages, there are certain short comings faced by these LED lights as well. they are listed below –
1. As compared to incandescent bulbs the LEDs are much more expensive and its execution largely depends on the ambient temperature of the operating environment. They require adequate heat sinking in order to make it more durable.
2. These LEDs are also voltage sensitive and one needs to be vigilant as they involve series of resistors or current-regulated power supplies. As they work on the mechanism of area light source, it becomes difficult for them to operate in spherical light field.
3. Of recent it is being observed by the scientists that blue and cool white LEDs emit blue light hazard that is unsafe for eyes. The cool white LED lights should not be used for outdoor lighting near astronomical observatories. Together these lights have certain limitations that are termed as blue pollution.
Applications
LED lights are perhaps the most advanced technology that is taking its tool over the people all over the world. Their application is diverse and hence they can be divided in three distinct categories – Visual signal application where the lights transpires from the bulb to the human eyes directly, Illuminations where LED light is reflected from an object to give visual response and finally, technological approach that does not require the contact with human visual system as in case of light photosynthesis in plants.
In the past decade, LED technology has expanded its scope to almost every household in the world. From little red spots that tells one that the wi fi connection is on, to the excellent light source that we see in our rooms just by switching on a plug, applications of LED is ubiquitous. Production quality LEDs are now capable of efficiencies of around 70 lm/W, compared with 12 lm/W for incandescent light bulbs, and single die devices are producing over 100 lm
Today one can find the implication of these LED lights in many areas. Be it the LCD screen of the computers or the latest version of the mobile phones, be it Ipods or safety and security hardware like LED enabled drainage system or Led micro lights for reading at nights, LED technology is vast and growing by leaps and bounds. The newest trend in the electronic market is the green influence that has not left the LED world bereft. The most recent launches in the LED market are theLight bulbs that can help one save up to 90% of electricity costs plus reduce the heat output and even more than this the bulbs claim to last up to 10 times longer than a standard light bulb or compact fluorescent. Some of the most advanced LED enabled products in the electronic world are –
LED enabled Faucet Lights – Install this in your homes to give a new look to the monotonous water taps. Available in red and blue they are heat sensitive and alarm the user by changing colors, as soon as the water temperature goes above 89 degrees centigrade.
LED Jellyfish Mood Lamps – These are unique desktop tank that plays trick with the eyes by displaying three jellyfish that swim, with the aid of the 6 bright colorful LEDS that are placed at the top of the tank.
Sony's Walkman – Sony, the largest supplier of electronic goods has launched a new Walkman called NWZ-X1000 that features an OLED (Organic light emitting diode) touchscreen.
