A Light-emitting diode, popularly recognized as LED, has been a fantastic technological breakthrough for the lighting Industry. When electric current is passed through this Light-emitting diode, which is a semi-conductor material, it emits light. This effect is a form of electroluminescence where an incoherent and narrow spectrum of light is emitted from the p-n junction. (Current flows from 'p' (+ve) ie. Anode junction to 'n' ie. Cathode junction)
An LED is an extremely small area (less than 1 mm2) light source, often with optics added to the chip to shape its radiation pattern and to assist in reflection.
Colour of light emitted can be InfraRed, UV or visible depending upon the composition and condition of the semi conducting material.
Light emitting diodes (LEDs) are electronic components that produce light without heat or the use of high voltages.
LED applications:
LEDs have numerous and varied applications falling into three major categories:
- Illumination - LED light is reflected from an object to give visual response of these objects. Eg. Lanterns, camera flash-lights, mobile phones, video displays, etc.
- Visual signal application- Where the light goes more or less directly from the LED to the human eye, to convey a message or meaning. Eg. Traffic lights, exit signs, electronic billboards, full- colour display screens, etc.
- Non-visual applications- LEDs are also used to generate light for measuring and interacting with processes that do not involve the human visual system. Eg. like remote controls, movement sensors, optical fibres, phototherapy for acne, etc.
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