09-07-2011, 03:46 PM
Light-emitting diodes (LEDs) offer longer life expectancy, higher tolerance to humidity, lower power consumption and generate less heat than incandescent lights. They are incorporated in message display boards, signal devices and other illumination systems. When fitted with the appropriate electronics, LEDs become semiconductor devices capable of fast switching. Visible light emitted by LEDs can be modulated and encoded with audio information for broadcasting, making LEDs part of a wireless optical communication system.This article describes simultaneous use of visible LEDs for signaling and communication called iLIGHT, offers new and interesting applications in traffic light and indoor applications. High brightness LEDs are getting more popular and are opening up a number of new applications, especially with the improved efficiency and new colors. In this article, the novel idea is based on the fast switching of LEDs and the modulation of visible light is developed into a new kind of information system. A visible-LED audio system that makes use of visual-light rays to transmit audio messages to remotely located receiver is described. Such a system made up of high-brightness visible LEDs can provide the function of open space, wireless broadcasting of audio signals. It can be used as an information beacon for short-distance radio communication. Any illumination device making using of high brightness visible LEDs can be used as a kind of short-range information beacon.. One example is an LED traffic light for the support of roadside-to-vehicle communications. There are many potential novel uses of visible light from LEDs as a communication medium. This concurrent use of LEDs for simultaneous signaling and communications will open up many new applications.