LED Projectors 101

For enthusiasts and environmental supporters, the rapid deployment of light-emitting diode (LED) technologies in the video industry could end up becoming a landmark culmination of energy savings and performance - making everybody happy.

For just more than a year, LED technology has slowly filtered into the video category through pico projectors and less commonly known products.

The technology seemingly burst upon the specialty electronics marketplace through product introductions from manufacturers like SIM2, Runco, Digital Projection Inc. (DPI) and projectiondesign. Companies like Wolf Cinema, LG and Samsung have joined in the LED development race because of the technology's attractive characteristics such as local dimming, plentiful colors and lack of dimming or burnout over time.

LED 101

Leading the video industry's charge into this frontier is Luminus Devices, a suburban Boston-based company that is developing lighting solutions for a variety of applications. The company's patented PhlatLight LED is a solid-state technology that Luminus describes as a combination of LED and laser light.

PhlatLight LEDs' name comes from "the underlying, enabling technology that we call photonic lattice, which is a nano structure embedded into the LEDs, and essentially helps with light extraction," explains Stephane Bellosguardo, product marketing director, projection display business. He says the key to the technology is how it manages light, stemming from the Ph.D. work of Alexei Erchak, who founded the company in 2002 and is chief technology officer.

"He developed the manufacturing processes to implement this technology into an LED that can be cost effective and produced in high volume," says Bellosguardo. The development of this technology, he adds, facilitates Luminus' ability to produce LEDs that are bigger than those of traditional size, to be used for more demanding applications like home theater projectors.

"Luminus develops large LED s with very high brightness and high power. The rationale on why Luminus developed large-format LEDs is in response to industry demand and applications that traditional LED s could not achieve."

The first commercial product became available in 2006 in rear-projection TVs from Samsung, Bellosguardo says. Since then, Luminus has worked with companies such as Acer, BenQ, Chi Lin, Delta, LG and Samsung to include LEDs into small pico and more traditional size projection systems.

"Many more companies in the lighting industry are using PhlatLight LEDs in a variety of indoor and outdoor applications that include architecture, avionics, entertainment, medical and dental, manufacturing, machine vision street lighting," he adds.

Friendly Technology

PhlatLight is not a light-engine technology, but rather a new type of light source that replaces the need for traditional bulbs (and effectively eliminates your clients' worries about replacing those bulbs every couple of years). Bellosguardo acknowledges the use of LED lighting does require some changes to how light-engine companies develop their products, but notes that PhlatLight can be used with any manufacturer's product.

"PhlatLight is applicable to all of these technologies [DLP, LCoS and 3LCD] and with each of them you will see some benefits and drawbacks and different optical architectures," he says.

"For instance, LED DLP projectors do not need color wheels any longer since the LED chipset provides the primary red, green and blue colors required by the system. They can take great advantage of the fact that unlike lamps, each LED primary color can individually be controlled very accurately at the micro second level.

"The elimination of the color wheel removes the constraints of having fixed-color segments, and the very fine and accurate control of the LED allows for completely new DLP algorithms. This dramatically enhances the brightness and picture quality of the system. This overall level of sophistication is impossible to match with conventional lamp technology."

Beyond its performance benefits, environmental impact is another major reason the video industry is examining ways in which LEDs can be implemented. LEDs don't consume a lot of energy, they don't contain any mercury or other harmful substances and LEDs essentially never need replacement.

"LED technology is on the fast lane in terms of improvements in efficiency and lower power consumption so more improvements will be made in the forthcoming years," Bellosguardo says. "This is, by far, the biggest advantage over traditional lamps. Also, it's accepted now in the industry that LEDs can achieve very long lifetimes, and we have to think about lifetimes in products and systems that are well in excess of 50,000 to 60,000 hours compared to 2,000 hours with traditional lamps. As LEDs deliver higher and higher performance levels, an ever-increasing number of applications in both the commercial and residential markets will come to fruition."