CTO session on the future of lighting kicks off LS13

At the 13th Annual Symposium on the Science and Technology of Lighting, top-level technologists from LED and lighting companies presented their thoughts on the future of lighting with a heavy emphasis on SSL.

The Lighting Research Center (LRC) at Rensselaer Polytechnic Institute is hosting the 13th Annual Symposium on the Science and Technology of Lighting (LS13) through Friday, June 29, and the "CTO session: Forecasting the future of lighting technologies" got the conference off to a rousing Monday morning start. Technology executives from Cree, GE Lighting, Osram, Panasonic, Philips and Toshiba joined Mark Rea, director of the LRC and co-chair of LS13, in a discussion that primarily centered on LED lighting.

Rob Glass, vice president of technology, materials, and optoelectronics at Cree, spoke first and stirred the crowd quipping "the last place to look for an accurate prediction of the future is to a panel of industry experts." His real point was that established companies often are centered on what works and makes money in the near term. He said that technologies that will really shape the future are ones that have yet to be invented.

Glass did address solid-state lighting (SSL) specifically with some notable comments. He reminded that there is significant opportunity across the value chain to improve SSL as opposed to gains being centered purely on the LED. Examples include driver electronics, optics, and other elements.

Glass also made a statement that reflects what we at LEDs Magazine are increasingly seeing in the market. He said, "In the future, applications will drive what you do with the technology." Read our Lightfair International report in our next magazine issue and you will get the same message.

Improving light quality

Zoltán Vamos, general manager of global lighting technology at GE Lighting, focused his talk on the quality of lighting. He said the energy savings and economics are an important driver of the SSL transition. But he said LEDs afford the industry a chance to improve the quality of light.

Vamos listed a number of areas in which SSL can offer an improvement over legacy sources starting with safety and security. He said SSL will produce better light for the work environment, living conditions at home, and aesthetics everywhere. And he mentioned that the improvements will come without light pollution and with less environmental impact.

Pace of transition

When Klaus Streubel, senior vice president and head of R&D at Osram took the podium, the talk turned to the speed of the SSL transition and then a truly futurist look at what lighting might become. He said that lighting in general was poised to grow from EUR 79 million ($99 million) in 2011 to EUR 121 million ($151 million) in 2020. The largest segment, and the one with the most growth, is general illumination. Over the same time period, Streubel said that the penetrations of LEDs in residential applications will go from 9% to 71% - the largest growth sector although starting from a lower base.

Streubel also said that the lighting industry needs to coalesce around the light engine as the fundamental new light source, although he added that today people have different ideas as to what comprises a light engine. He said that the light engine includes an LED or many LEDs, driver electronics, and optics. He also said to expect light engines specialized to applications such as spot, linear, area and others. The description was very Zhaga-like.

Moving to the future, Streubel said light management systems will interact with the smart grid and enable new applications. He said that lighting in the future will be centered on our human needs and that "the biologic effects of light will play a role in our future." Examples include artificial daylight systems and lighting that improves our cognitive ability or lessens tiredness.

Streubel showed an artist's rendering of a futuristic scene with tablet computers and lights on the same network. He said ultimately there will be a merging of display and luminaire functions, and that everything will be linked together and offer support for gesture and other innovative controls.

Lighting for skin tone

Katsumasa Nakai, general manager of Panasonic's R&D center in the Lighting Business Group, discussed tuning of light and an innovative LED component and lamp concept. He discussed a Japanese metric called PS that is a rating similar to CRI but is the preference index for skin color. Nakai said that good PS scores require a light source with less energy in the 575-nm range.

Nakai went on to describe several applications where tunable color would be an important enabling technology. He showed a luminaire for a dining area that provided cool light for breakfast or lunch, much warmer light for dinner and even softer, warmer light for after-dinner drinks. He also discussed a packaged LED that could produce light over the range of 2000-5000K and that offered an illuminance adjustment as well.

Even more impressive, Nakai discussed and showed pictures of a clear LED light bulb that he said offered incandescent-like light. To get omnidirectional distribution, the Panasonic engineers mounted the LEDs on a translucent alumina substrate with phosphor on both sides of the emitters so that some light is directed downward.

LEDification and digitalization

Marc Janssen, vice president and R&D manager for light sources and electronics at Philips, described a vision of networked lighting for the future much like Streubel, but injected some new vocabulary into the discussion. He said we are in the first wave of LED adoption that he calls "LEDification." But in the LEDification stage he said people don't get the full value matching legacy sources. He said a stronger wave will come from "digitalization" where we move to "intelligent light points in connected systems."

Janssen expects a connected future whether the application is a home-automation system or a city network. He said the energy savings afforded by LEDs ultimately will offer a budget for more functionality.

A retail store in Singapore provided an example of Janssen's point. He said stores sold more clothes when they installed SSL that could offer multiple lighting effects in changing rooms. Shoppers bought more merchandise given the option to see clothes under different lighting and the retailers enjoy increased revenue.

Optimizing light distribution

The subject of proper light distribution also came up and Takeo Yasuda, general manager of the technology planning department at Toshiba Lighting & Technology, addressed a concept called Weluna that refers to a sense of brightness. The Toshiba-developed metric is a measure of indirect illuminance at the eye point as opposed to the illuminance on a work plane.

Yasuda showed side-by-side photos of two office-type spaces and asked the audience which was brighter. One had a measured horizontal illuminance of 590 lx while the second was at 420 lx, yet the latter was clearly better lit. In Toshiba's Weluna scale the first measured 30 lx while the brighter one measured 39 lx.

Biggest SSL obstacle

The Q&A session that followed the individual talks yielded a few more tidbits. The panelists were in agreement that OLEDs would not displace LEDs, but would be used in a complementary fashion. For instance, OLEDs will be used where the diffused surface is an advantage in the application at hand. In fact, Toshiba's Yasuda showed a photo of a luminaire that combined OLEDs for ambient lighting and LEDs for task lighting.

The LRC's Rea asked the panelist if they could magically solve one issue related to LED lighting, exactly which obstacle would they eliminate. The answers were mostly similar, and focused on thermal and efficiency, although neither is really a single issue. Yasuda gave what was clearly the only answer focused on a single obstacle when he said he would choose the lag in the efficiency of green LEDs relative to blue and red ones. He said low-efficiency in green LEDs is holding back the broader usage of RGB LEDs in fixtures and in essence the deployment of tunable light.

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