New LED PJ's.....

LEDs Fueling New Lampless Projectors



Samsung’s P400 projector

LED technology is behind new projectors which offer brighter colors and a longer life-span.



Sep. 30, 2008 — by Dennis P. Barker

Earlier this year, we profiled LED-based rear projection TVs using Luminus Devices’ PhlatLight technology. Several readers also expressed interest in LED-based front projectors. Well, after returning from the 2008 CEDIA show, I can definitely say that LED-based front projectors will be coming to a home theater near you in the not-so-distant future.
At this time, LED illumination seems to be focused solely on those projectors utilizing Texas Instruments’s DLP imaging technology. But Epson, who created the competing 3LCD display technology, believes that LED illumination will also be used in their projectors sometime in the future (but would not specify if it was next year or a couple of years from now).

Arc Lamps and Color Wheels
Currently, front projectors that use DLP technology require an arc lamp, color wheel, and mechanical shutter to produce images. Lamps offer terrific brightness, but burn out after a couple of thousand hours or so, and need to be replaced. Replacement bulbs can run several hundred dollars. LEDs, on the other hand, offer a stable light output solution during the entire life of the projector. Whereas, arc lamps decrease in brightness over time because of fading (and become dimmer), LEDs offer a constant and consistent light source over time. And, unlike arc lamps, there is no mercury in LEDs so there’s no replacement hazard or stockpiling of hazardous materials in landfills. LEDs are also an energy-efficient and green technology.

Color wheels have always been problematic in my mind. They spin at high RPMs, but can be subject to noise and mechanical degradation over time. Color wheels may also contribute to the annoying (for some people) “rainbow” effect that has plagued DLP projection displays for years. In my life as a product reviewer, I’ve even had sets with color wheels that wobbled distorting the on-screen image. Employing a stable light source such as LED (rated at somewhere between 50,000 and 100,000 hours of viewing) to illuminate front projectors eliminates another potential defect by taking away the color wheel entirely. Lastly, LED illumination also takes away the mechanical shutter, which has its own set of problems. Overall, the LED illumination system replaces the lamp, the color wheel and the shutter of a traditional projector. What is crucial here is that various companies have come together to produce a precise and complex control algorithm that allows the LED to work with the DMD to get high image quality.

The benefits of LED illumination are many fold including: Deep saturated colors (160-percent of color gamut as compared to NTSC), Precise brightness control (8-bit brightness for red, green & blue that improves contrast ratio, color resolution and grayscale), Fast and precise on/off switching (less than 1 millisecond), High stability of light output (for deeper blacks without mechanical iris), Long lifetime (between 50,000 – 100,000 hours), and Energy efficient (reduced power consumption). In fact, LED lighting is also moving throughout the home and your automobile.

PhlatLight LEDs
Projectors powered by PhlatLight produce a reported 40-percent more color than traditional lamp-based displays due to the technology’s ability to individually create pure, primary colors. Luminus has been manufacturing its patented PhlatLight LEDs for DLP TVs since 2006 and claims PhlatLight LEDs remain the only LEDs that are bright and efficient enough to replace arc lamps in front projectors. They are much larger than conventional LEDs and are designed to operate reliably at significantly higher intensity.
According to Luminus, PhlatLight LEDs are environmentally friendly, and free of hazardous materials such as mercury or lead. Reportedly, these projectors consume approximately one-third the power of comparable lamp-based projectors and produce an instant-on image at full brightness without the cost and inconvenience of lamp replacement.

New Projectors
Delta Electronics announced at IFA and CEDIA that it has completed the development of a Full HD LED projector for the consumer market. Delta estimates the life of their LED module at more than 20,000 hours of normal operation. With its experience and close partnership with Texas Instruments, Luminus Devices and other key suppliers, Delta believes it has an early advantage in recognizing the feasibility of PhlatLight LED and the value of LED projectors, and hopes to commercialize this product in the near future.


At CEDIA, I received a private demonstration of Chilin’s new 1080p HD home theater projector with, what they claim is, the world’s first liquid cooling LED light source. Utilizing PhlatLight and TI’s 1080p DMD technology, this projector offers a brightness of 600 ANSI lumens and a contrast ratio greater than 100,000:1. According to a spokesman, this proprietary cooling technology uses water to dissipate heat directly from the PhlatLight LEDs, which are operated at a high electric current of 30A. Chilin believes that its liquid cooling technology will help achieve a conservative LED lifetime of 50,000+ hours of use. Chilin claims that the projector delivers an unbelievable 128-percent NTSC color gamut, which is 80-percent greater than what can be achieved through convention UHP lamp-based projectors. Utilizing superior optics and color management performance, picture quality and color performance was quite striking. I was able to view 1080p pictorial content (created by display manufacturers), and the Blu-ray disc trailer from “Click.” It was thrilling!

Luminus and TI have been working together to increase brightness in LED-based DLP projectors by creating brighter and more efficient PhlatLight LEDs, as well as through improvements in the DLP processing algorithms. These improvements are enabling multiple projection manufacturers, such as Chilin, Delta Electronics, for example, in hoping to introduce DLP home theater projectors beginning in late 2008/early 2009.

Other developments in the wings for LED-based illumination will come from LG and Samsung this year. Luminus Devices announced at IFA that its PhlatLight LEDs will be also powering two of the newest portable LED based projectors—the Samsung P400 Pocket Imager and LG Electronics’ HS-102 Ultra-Mobile Projector. Both projectors are lamp-free, weigh less than two pounds and easily fit in the palm of your hand. The PhlatLight PT54 LEDs used in both units enable brightness to reach and exceed 150 lumens, which is seemingly a breakthrough for pocket projectors. The pure RGB color from the PhlatLight LEDs produce a brighter more vivid image than the ANSI brightness specs would suggest, for a picture that’s easily viewable when projected to a 40-inch size even in a well lit office or college dorm room. Other future developments by TI and Luminus will further lead to the introduction of lamp-free projectors for corporate and education markets also in the future.

Conclusions
LEDs for front projectors provide home theater viewers with benefits that are not available from any lamp-based systems; superior color, long operational life, free of mercury and UV/IR. With the advantages of operational reliability and convenience, LED projectors will finally reach the market shortly, and soon evolve from commercial products to consumer and home use. Companies that hope to bring LED-based front projectors to market include Optoma, SIM2, Projectiondesign, and Runco.
From my discussions with projection manufacturers at CEDIA, they are quite bullish on the arrival of LED illumination. According to Jeff Fu, Director for Projection Display at Delta’s Display Solutions Business Unit, “The LED projector is not only a new product; it truly opens a new horizon for the projector industry.” And, Jon Grodem, Director of Product & Marketing at Optoma sums up, “LED projectors have the potential to re-segment the Home Theater marketplace. LED based projectors will be the preferred choice for anyone installing dedicated a theater with light control.”

So, stay tuned to Electronic House for future product announcements from Optoma, Projectiondesign, Runco, and SIM2 among others. The projectors from Chilin and Delta Electronics will be available next year also. Although, they will probably have someone else’s nameplate on them. 2009 will certainly be the year of LED!

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