Single-chip LED with green phosphor converter

Osram Opto Semiconductors has developed a pre-production green LED based on the Ostar platform that is twice as bright as its predecessors, for use in data projectors in office or education markets.

Initial samples of the LED are already available and Osram Opto Semiconductors expects it to be widely available to projector manufacturers in Summer 2011.

Now that RGB LEDs have been established as the dominant technology to drive sequential colour-pico projectors, the next segment of growth is data projectors.

This progression has been made possible by the high brightness increase of Osram's green LEDs, the single-chip prototype of which achieves 410 lm and emits at a wavelength of 553nm.

Since a greater proportion of green than red or blue is needed in a projector to produce white light, the increase in the brightness of the green LED has a significant effect on the overall system brightness.

With these new LED prototypes, it is possible to produce systems that deliver an overall brightness of 2,000 lm, which is required for office and education applications.

LED projectors will soon be powerful enough for screen sizes of more than two metres diagonal.

Until now, such applications have only been possible with projectors that use conventional light sources such as high-intensity discharge lamps.

Osram state that, apart from providing brilliant image reproduction with saturated colors, LEDs enable projectors to be virtually maintenance-free because they have a life expectancy of over 30,000 hours.

By contrast, high-intensity discharge lamps need to be replaced after only about 4,000 hours.

Projectors with LEDs also provide instant power on and support seamless dimming, meaning they can adapt to ambient light conditions, reducing energy consumption in the process.

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