[opendtv] White LEDs warm up for indoor lighting

  • From: "Manfredi, Albert E" <albert.e.manfredi@xxxxxxxxxx>
  • To: <opendtv@xxxxxxxxxxxxx>
  • Date: Wed, 21 Mar 2007 11:43:12 -0400

Interesting. Australia is banning incandescent light bulbs, which IMO
makes a *whole* lot more sense than fussing over the power requirements
of OTA STBs, and just in time these other alternatives appear to the
already available fluoresent light bulb replacements.

A 60 watt incandescent bulb emits about 870 lumens. So the LED
replacement would draw about 12 to 14 watts, which makes it almost
identical to the efficiency of those fluorescent lamp lightbulb
replacements. But I would expect the LED to last many more years than
even the longlasting fluorescents. Also, if white light is made by
combining red, blue, and green LEDs, you should be able to adjust the
color temperature to whatever you prefer. And, LEDs would not create the
hazardous waste problem of fluorescents.


White LEDs warm up for indoor lighting

David Roman
(03/21/2007 12:01 AM EDT)
URL: http://www.eetimes.com/showArticle.jhtml?articleID=198100295

MANHASSET, N.Y. - Cree Inc. has increased the brightness and efficiency
of its XLamp XR-E and XLamp XR-C white light-emitting diodes by more
than 20 percent, enough to make them suitable for indoor "warm white"
lighting applications.

"This is a performance breakthrough in the warm LED area," said Paul
Thieken, director of marketing for solid-state lighting at Cree (Durham,
N.C.). "We've overcome some of the challenges to getting white LEDs into
general illumination applications. One of them is the ability to drive
into the 700 mA range. This allows us to produce about 142 lumens of
brightness. Another is color point stability, which is critical for
lighting designers."

The improvements yield "a new class of warm LED that will enable a
number of new applications right away," Thieken claimed.

Production volumes of the brighter white XR-E and XR-C LEDs are
available immediately. Cree did not provide pricing information.

The new LEDs deliver 142 lumens at a correlated-color-temperature (CCT)
of 4,000 K and 124 lumens at a CCT of 3,000 K when driven at 700 mA.
They deliver 73 or 63 lumens per watt at a CCT of 3,000 K when driven at
350 mA. "The competition and our previous products were producing 50
lumens and below," Thieken said. The brighter LEDs can be applied to
general illumination downlighting and undercabinet lighting applications
that previously relied on incandescent bulbs, he said.

One lighting supplier, LED Lighting Fixtures Inc. (Morrisville, N.C.),
plans to use Cree's XR-E LEDs in a commercial and residential six-inch
downlight that produces approximately 650 lumens or 60 lumens per watt.
The company said it will ship the fixture in two color temperatures,
2,700 K and 3,500 K, for warm and cool white applications, in the second

"We believe LED lighting for the mainstream has finally been enabled,"
Neal Hunter, CEO of LLF Lighting Fixtures, said in a statement. "This
unprecedented technology will not only change the industry, but also
reshape the way the average consumer views lighting."

Cree has steadily improved its white LEDs to broaden their application
areas. It announced production availability of white XLamp 7090 LEDs in
October 2006 that achieved 160 lumens at 700 mA, sufficient for
applications such as outdoor street lighting and low bay lighting.
Warmer lighting is preferred for indoor applications.

Color point stability has traditionally proved difficult in producing
warm white LEDs, but Cree said its newly available white LEDs have
minimal CCT shift. "There is a measureable shift in color, but the human
eye cannot detect it," said Paul Scheidt, Cree's product marketing
manager for solid-state lighting.

In addition to greater brightness and efficiency, the parts are also
more efficient in terms of lumens per dollar-a ratio that is closely
watched by industry, Thieken said. Cree did not provide a lumens per
dollar ratio for the new LEDs.

A competitor, Philips Lumileds Lighting Co., lists the following Luxeon
warm white LEDs on its Web site: the LXHL-BW03 emitter with a unit price
of $2.99 and a lumens per dollar ratio of 6.7; the LXHL-MWGC Star Hex
priced at $3.59 and with a lumens/dollar ratio of 5.6; and the LXHL-NWGB
Star O priced at $4.59 and with a lumens/dollar ratio of 4.4. All unit
prices are for complete reel quantities.

Cree said it has also changed the way it sorts its new LEDs, a process
know in the semiconductor industry as "binning," Thieken said. "How we
characterize and sell the products will be based on some ANSI standards.
We produce the semiconductors and we bin in two dimensions: one is color
point, the other is how much light they put out. That's a change to make
it more applicable to lighting designers," he said.

Cree reported revenue of $88.8 million and net income of $16.5 million
for its most recent fiscal quarter ended Dec. 24, 2006, down from $105.6
million in revenue and $17.7 million in net income in the year-ago
quarter. The company earlier this month agreed to acquire Cotco Luminant
Device Ltd., a Hong Kong-based supplier of high brightness LEDs, for
$200 million in cash and stock. Last year the company paid $46 million
to acquire Intrinsic Semiconductor Corp. (Dulles, Va.), a developer of
silicon carbide substrates. That purchase will accelerate Cree's
commercialization of 150- and 200-mm substrates, the company said.

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