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26-29 Sept 2010 | Huntington Beach, CA

LD+A The Magazine of the Illuminating Engineering Society of North America

LED Testing & Application

OLEDs TAKING SHAPE

Luminaire manufacturers are cautiously optimistic about the future prospects of OLED products. What form they take, however, is open to debate

A contributor to LD+A had this to say about an emerging but sometimes misunderstood technology: “Many products have resulted—the earliest of which deliver dynamic lighting effects [that] have and will continue to change the way we perceive architectural space both indoors and out . . . .[They are] commercial successes that add to the palette of tools available to apply light in space; products that spark the emotional response that made us gravitate to lighting as our chosen profession in the first place.”
The technology in question was LEDs, and that article, by Mark Roush, was penned in December 2007. Not even three years later, LEDs have been mainstreamed into the world of architectural lighting, and the words above may soon apply to the next emerging and misunderstood light source: organic LEDS (OLEDs). In contrast to LEDs, which are small point sources, self-luminous OLEDs can be manufactured as flexible sheets to provide a diffuse area light source (think OLED wallpaper and ceilings).
Jim Anderson, director of strategic marketing and innovation, Philips Color Kinetics, cites other OLED attributes: “In addition to what OLEDs are known for—very thin (1/8 in.), flat uniform glowing light sources—it’s also possible to make OLEDs that are either reflective or transparent in the off state.” Philips shifted its OLED R&D focus from display applications to lighting in 2004 and is one of the few companies actively playing in the market. Its OLED panels are commercially available under the sub-brand Lumiblade. Philips has also installed what it calls the first-ever production line for OLED lighting in Aachen, Germany.
Traditional luminaire manufacturers are also introducing products. At LIGHTFAIR, WAC Lighting unveiled its first commercialized OLED product using a panel from OSRAM. It’s a decorative chandelier for the luxury market—a likely “early adopter” of OLEDs, says company president Shelley Wang.
But can manufacturers—who have been known to mimic existing product design when incorporating new sources—move beyond the luminaire and leverage the other opportunities offered by OLEDs? We asked a few. In addition to Anderson and Wang, they are Mark Lien, director of the Lighting Solutions Center for Hubbell Lighting; Peter Ngai, vice president, research and development, Acuity Brands Lighting; and Ann Reo, io brand general manager for Cooper Lighting.

— Paul Tarricone

1. What is your company doing in terms of OLED R&D?
Lien: Our solid-state team is well informed on the state of our industry as it relates to OLED technology. The lack of standards, high cost and limited availability of architectural lighting OLED components discourage immediate fixture development of all but niche products. The 20,000-hour lamp life is a negative compared to many of our existing sources and the variation in intensity depending on the viewing angle will need to be improved for mass acceptance. OLEDs are a promising emerging technology but their promise is unrealized, and product disadvantages pose significant barriers to sales.
Reo: We are staying close to OLED technological advancements but are not allocating resources to short-term product development. Understanding the long-term potential has sparked many ideas, but improved pricing and additional technological improvements will have to take place in order to develop commercially viable products.
Ngai: Acuity Brands’ OLED R&D efforts have the objective of enabling luminaires that meet the aesthetic and performance targets necessary for general illumination, and just as importantly, meet the cost targets required for OLEDs to eventually make the transition from a niche source to a lighting platform that will become pervasive over the next decade. Many of the current challenges in the industry are not technical or scientific at all. Rather, they stem from the cultural differences created when display technology merges with lighting technology. Legacy differences in vocabulary (brightness vs. luminance emittance) and key benchmarks (lumen maintenance of 50 percent vs. 70 percent or higher) are starting to disappear as industry participants work toward the shared goal of making OLED suitable for general lighting.

2. When would you expect OLED products for architectural lighting to be widely available?
Lien: The estimates of three-and-a-half years until OLED technology is competitive sound valid, unless other competing technology proves more promising prior to OLEDs penetrating our industry.
Ngai: The answer to that question depends on a number of variables, not the least of which is OLED availability. Many firms have announced plans to produce OLED panels for general lighting, but in relative terms, global capacity is still quite miniscule when compared to the potential demand for OLEDs. In addition, manufacturing processes are still improving, as evidenced by reductions in cycle times and increases in material utilization, both of which serve to reduce costs of production. The dynamic nature of the technological landscape will also impact the broad-scale availability of OLED products and systems. There is significant investment in all of the aforementioned areas: supply chain, costs and technology development. Positive developments in those areas, coupled with OLED products that possess a meaningful value proposition to the customer will result in a scenario where supply and demand are more aligned. Customers should not be surprised to see OLED luminaires in the marketplace within the next two to three years.
Wang: OLEDs are appropriate for luxury decorative lighting applications now. We anticipate our architectural lighting designs—which have more robust performance needs—to be commercialized in two to three years when we can consistently manufacture them at 100 lumens per watt and with a longer potential life.
Anderson: There were a number of OLED products exhibited in April at Light + Building and during the furniture fair in Milan/Italy, with commercial product availability starting in late 2010. We also would expect many more products targeting additional architectural lighting applications as the performance of OLEDs improve and the cost decreases—comparable to what is happening with LED lighting products.
Reo: No one has a crystal ball, but I have heard momentum has slowed down due to the economic downturn. I also think that LED suppliers—who are also developing OLED solutions—are focusing resources on the current challenges associated with LED technology. After having spent the past 10 years developing LED-based luminaires, I am thrilled to have witnessed great advancements in the quality of the white light, but there is still a lot of room for improvements and standardization. I have heard OLED developers say that it will take five years for OLEDs to become commercially viable.

3. What form do you think these products will take?
Reo: Certainly any luminaire that could incorporate a luminous plane could potentially use OLEDs as the source for illumination. Today’s OLED offering is very limiting in terms of scale and geometry. The luminous panels are really sized for consumer electronics.
Wang: I think it will tend towards luminous surfaces. I’d like to think that OLEDs will be used in conjunction with point source luminaires to achieve layered lighting and reduce perceived glare in interior spaces.
Lien: The luminous wallpaper, simulated window shades and OLED room dividers force us to rethink traditional luminaire design. Armstrong is positioned to start competing with us when they offer 2-ft by 2-ft OLED tiles with their ceiling products. These non-traditional products will likely come from outside of our industry initially with the big four lighting companies trying to re-imagine existing fixtures with this new source. The ability of OLED fixtures in their off state to be mirrored or transparent is an exciting option but so removed from typical lighting products that it may be window or glass companies that incorporate the illumination option into their offerings.
As we further restrict the amount of wattage that lighting can use in applications and lower the recommended illuminance values, OLEDs designed into office furniture, machinery, store shelving and warehouse racking as task lights seem like ideal solutions. Very low general lighting levels with solid-state lighting supplementing intensity close to the task is an energy-saving strategy that will drive this technology. Whether these integral lights will be manufactured by our industry or the furniture and other construction material providers is a turf war yet unresolved.
Concerns about toxic aspects of the OLED that will affect recycling need to be resolved. While we wait for this new source to mature, other similar products such as graphene are progressing. Graphene is also available in large thin sheets and does not have the recycling concerns of OLEDs. The eventual result of these uniform solid-state general light sources could be a light that can have variable color temperatures for photobiological concerns and can shift function from an architectural light source to showing high-definition video or stills. Integrating it into previously non-illuminated products like the new Kenwood OLED speakers being sold in Japan seems logical and represents another example of how industries unrelated to ours are positioned to compete with us.
Anderson: In the future, their extremely thin (1/8 in.) and flat profile will allow OLEDs to be surface mounted or integrated into most materials. That gives designers a lot of freedom to incorporate OLEDs into traditional lighting planes like ceilings, and everyday objects and surfaces, like chairs, clothing, walls, windows and skylights. In addition to producing ambient and task lighting, designers could use OLEDs to accent design elements and architecture.
Ngai: OLEDs are a new medium that can be used to celebrate lighting and to enhance our visual environment. They blur the distinction between the light source and the luminaire, and their unique attributes, such as thinness, will enable innovative new methods of lighting a space. It is imperative that we embrace this opportunity, discard traditional notions of how to develop luminaires using traditional lamp sources and instead explore new ways to utilize the OLED platform to deliver light in creative and aesthetically pleasing ways. If we do this, the possibilities of how OLEDs can be used are endless, and ultimately, the customer will decide on which lighting approach appeals most to them.

4. Do you expect OLEDs to be integrated within traditional luminaires?
Wang: Yes. Consumer preference is an evolution. Many experts I’ve met anticipate that OLED adoption will likely mirror the acceptance of LEDs.
Ngai: OLEDs may very well be integrated within traditional luminaires and will likely be integrated with traditional luminaires as part of the overall lighting design. Stylistically, we have seen OLED concepts that remain rooted in familiar luminaire forms, partly due to necessity and partly by choice. This is not necessarily a bad thing. Many of the design attributes of some traditional luminaires evolved as a direct response to the needs of particular lighting applications, so, at least in the near term, there may be some benefit of using OLED technology in conventional and recognizable forms.
That said, this is not our grandfather’s lighting industry, and we now have an exciting new design platform with which to express our vision. When you compare OLEDs to a traditional fluorescent or incandescent luminaire, it’s clear that the potential exists to eliminate some or all of the distracting or undesirable physical elements of the luminaire due to the distinctly different form and character of the OLED light source. For example, since OLEDs are naturally diffuse light sources, many of the design elements used to control glare can be modified or completely removed. Instead of hiding the light source, we can liberate the light.
Anderson: I’m sure there will be some integration with traditional luminaires, but we certainly hope that product designs take advantage of what OLEDs offer and not just replace conventional luminaires with OLEDs.
Lien: Two years of product development on 2 by 2 OLED ceiling tiles indicates the desire by manufacturers to integrate OLEDs into traditional shapes. The wild, game-changing potential of this new source will be higher risk than mimicking familiar luminaires like troffers and sconces. The idea of a round OLED product resembling a downlight, but having no trim, housing or large ceiling hole, could have cost advantages due to reduced material, as well as being marketable internationally. Downlighting designed for the U.S. market differs dramatically by requiring a housing, but the simplicity of the OLED design has universal application opportunities in the global marketplace.

5. Gazing into your crystal ball, what will likely be the first applications and market sectors for OLEDs?
Ngai: Perhaps a crystal ball comprised of transparent OLED panels should be the first application! In all seriousness, at this time, OLEDs are best suited for indoor applications and will likely coexist well with LED luminaires, so that the needs for both area and directional lighting are met when lighting a space. Some logical products include wall sconces in decorative lighting, or indicator lighting such as pathway and step lighting—all applications where the lighting performance is relatively forgiving. An OLED is the first light source that, in itself, has a beauty to rival the spaces it illuminates. As a result, one can envisage applications where the OLED luminaire is the design focal point. Conversely, the purity of the OLED light can bring out the best in illuminated objects, so shelf and retail lighting applications also are real areas of opportunity.
The manner in which OLEDs are introduced to the general lighting market should be carefully thought out, since first impressions are often the most lasting. Introducing products that underwhelm customers through lack of creativity and innovation would be a grave mistake. Another caution would be to avoid errors made in the very early stages of inorganic LED commercialization.
Lien: A solid-state general light source is needed to fill a gap that LED products have failed to address. LEDs are excellent point sources but their efficacy remains lower than many fluorescent and HID options, especially when lenses are used to widen distribution on lower mounting heights. The OLED promises solid-state general, uniform lighting solutions without the efficiency losses inherent with lenses. Assuming that OLED product improvements overcome current concerns, the first uses will be as a replacement for fluorescent and HID used in lower ceiling height applications that require bright, uniform lighting.
Anderson: At this stage, most of the product concepts are designs for high-end residential, hospitality and retail. For example, at last September’s 100% Design London exhibition, Philips showed four concepts: a marker light, designed to “lead” people on a voyage of discovery; an interactive reflective wall; a contemporary “candle” for high-design lounges, restaurants and homes; and “Mr. Ed,” a tribute to Edison, which shows how OLEDs can give decorative images the added dimension of light.
Reo: I think all markets have potential. OLEDs offer many of the attributes LEDs have (i.e., longevity, minimal scale, high efficacy). Different markets demand different requirements from luminaires. It will be the clever companies that identify the “killer apps” for each of these markets.

June 2010