Home theater projector makers at the recent Consumer Electronics Show (CES) demonstrated
a new technological twist: using light-emitting diodes (LEDs) to power their
At least two
manufacturers at CES showed off LED-based home projectors. Chi Lin Technology Co. Ltd.
and Delta Electronics, Inc. are said to
be the first of a wave of manufacturers making digital light processing (DLP)
projectors and using high-powered LEDs as a source of illumination. Both
companies employed DLP technology from Texas Instruments and PhlatLight PT-120 LED chipsets
from Luminus Devices in their home
logical step after rear projection televisions is home theater systems," notes
Matt Mazzuchi, general manager of the Projection Display Business Group at
Luminus Devices. "A lot of consumers are starting to invest in high-definition
projection systems for the home. And they want the benefits of LED technology
so they can get the best bang for their buck."
serve as a replacement for conventional mercury vapor arc lamps, commonly
employed in DLP-based projectors. LEDs are said to offer several advantages
over the mercury lamps, including instant start-up and no warm-up time. They
also last the lifetime of the projector, and maintain their color stability
Up to now, however, LEDs have more
often been integrated into smaller applications, such as Christmas lights and
flashlights. They haven't typically served in home theater projectors because
they weren't big enough or bright enough.
engineers say they've solved those problems because their devices are
significantly larger and can operate at higher current levels. Unlike many LEDs
that measure about 1 mm2 and operate at about 350 mA, Luminus'
PT-120 measures about 12 mm on a side and can run at currents as high as 30 A.
"We put out
enormously more light than other LEDs," Mazzuchi says. "And that light can be
used in these large panel projection systems very efficiently."
says that its technology is also significant for home theater projectors
because it employs a so-called "photonic lattice" - a micro-structure embedded
in the surface of the LED that affects the light output of the device. In
contrast to conventional LEDs, which use a "Lambertian" method of light
reflectance that allows light to be equally distributed across a 180Â° plane,
Luminus' PhlatLight systems maximize light extraction out of the top of the
LED. The effect is that the light is more concentrated.
an optical systems designer and you have to shoot all your light into a pipe, the
Lambertian system could be unusable for you because the light shoots off at all
angles," Mazzuchi says. "In ours, all the light shoots out of the top, so you can
get more of the light into the system."
is employing the PhlatLight technology in its HT-8000 projector, which serves
in Vivitek USA's
H6080FD home theater system. Similarly, Chi Lin is combining the PT-120 chipset
with TI's DLP technology in its new home theater system.
projector manufacturers worked closely with Luminus and with Texas Instruments on
the construction of the optical engines, which process the light from the LEDs
through separate channels for red, green and blue light devices. Projectors
from both companies are due out in 2009.
engineers predict that large LEDs like theirs will be key in driving the move
toward LED-based projectors in home theater systems.
"Up to now,
the LEDs simply weren't big enough and didn't offer enough brightness to make
it happen," Mazzuchi says. "But the big LEDs work because they deliver a lot of
brightness into the optical aperture of the system."