Semiconductors have developed a pre-production green LED based on the OSTAR
platform that is twice as bright as its predecessors and has a luminous surface
that is uniform. The single-chip LED benefits from a green phosphor converter.
Initial samples are available, and OSRAM is currently
working with partners to develop appropriate LED data projectors such as those
used in the office and education markets. OSRAM Opto Semiconductors expects the LED to be widely available to projector
manufacturers in the summer of 2011.
The prototype with a single chip achieves 410 lm and emits at a
wavelength of 553 nm. 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 meters diagonal. Until now, such
applications have only been possible with projectors that use conventional
light sources such as high-intensity discharge lamps.