L.E.D.

by Bob Johnstone

  Novel form factors and esthetically pleasing luminaires were all very well. But LEDs were not just smaller and more flexible, they were also, as Color Kinetics had shown, intrinsically digital devices. The introduction of electronics was enabling a far bigger change: the convergence of lighting and controls. Once you had installed an electronic light engine in your fixture it cost next to nothing to add sensors that could detect motion, occupancy, and daylight (thus eliminate “dayburn,” meaning lights left wastefully on during the day). The information the sensors picked up could be communicated wirelessly to turn lights on and off, or to dim them. And that was just the obvious stuff. “Our view was that [fixtures] would go from being the dumb terminal in the ceiling to something substantially more,” Acuity CEO Vern Nagel explained at a Strategies in Light conference in London in November 2015. “As we get more and more into miniaturization with sensors and things of that nature, what we’re seeing is the ability to take advantage of what electronics can do.”

  Acuity was adopting what Nagel called “a tiered solutions approach.” Tier one was just devices. In a parking garage, for example, retrofitting LED fixtures was a simple one-for-one switch-out that gave the owner an immediate forty- to fifty-percent energy savings. Tier two was adding an occupancy sensor on each fixture, allowing lights to be turned off when there was no activity on a particular floor (many parking garages leave their lights on 24/7 even when no-one is there). If for safety reasons you wanted some illumination, the lights could be dimmed to twenty percent, say. Then, when someone passes by, the lights would immediately ramp up to full brightness. The net effect of adding this feature was to double the energy savings. Most customers would not even notice the difference. However, having each fixture come on when someone walked by could be distracting. Worse, as critics were quick to point out, it illuminated potential targets. A robber hiding in the shadows would know exactly where his intended victim was walking. Also, you didn’t want the lights turn off all of a sudden, for example, when a mother was loading stuff into her car that happened to be partly hidden by a column. The way an intelligent system should work, the moment motion was no longer detected the lights started to dim gradually, over several minutes. The main thing was to ensure the customer had enough time to do what she needed to do.

  Tier three was networking the fixtures together with wifi, so that all the lights in that area or on that floor of the garage came on, in groups, when any of the occupancy sensors was triggered. That would provide a better visual environment, yet still save a lot of energy. Going beyond simple occupancy sensing, tier four was collecting other types of data. For example, counting the number of cars on each floor so you could give incoming drivers accurate information about where to park. Or, having a sensor at each spot that turned on a green light to let drivers know when it was vacant, so they didn’t have to waste time hunting for a spot. Once data been sucked up by sensor-laden luminaires, it could be sent gushing down what Nagel called a “digital pipe.” In Silicon Valley, he claimed, firms were eager to sic their analytics onto all that data as it came flooding out the other end.

  In 2008 Acuity had virtually no in-house controls capability. But, having anticipated the oncoming convergence between lighting and controls, the company’s canny management was willing to place their bets and be aggressive in order to establish a foothold in evolving markets. Acuity embarked on an extended shopping spree, splurging on a string of small technology firms. It began by acquiring Lighting Control and Design, a maker of dimmers (February 2009) and Sensor Switch, a specialist in occupancy sensors (March 2009). “Sensor Switch was really the first indicator to anybody who was really paying attention that we were moving into the lighting solutions market,” Mark Hand said. “We were intending to build lighting networks as opposed to luminaires, because we could see that controls were going to be part of it all.” By 2010 the company had incorporated a controls interface into all its luminaires and was shipping the feature as standard, even for customers who had not requested it. The idea was that having the connectivity already built-in would make the transition to digital much easier. These initial purchases were followed a few years later by others: Adura, a specialist in wireless lighting and energy management systems (acquired January 2013); eldoLED, a Dutch company which had pioneered digital drivers for LEDs (March 2013); and Distech Controls, a leader in building automation (March 2015). Indeed, so voracious was the company’s appetite for acquisitions that industry wags dubbed Acuity “The Borg,” after the cybernetic aliens in Star Trek who assimilate everyone they come into contact with. (“Your culture will adapt to service us. Resistance is futile.”)

  Three of its most recent purchases seemed particularly portentous. ByteLight (acquired April 2015) was a Boston-based startup that had developed an indoor positioning system which used location-specific information gleaned from LED lamps. It turned each light into a beacon that switched on and off too fast for the human eye to see. These signals could then be picked up by the camera on a user’s smartphone and decoded by an app on the phone. The system gave store owners the ability to track a smartphone as its owner moved around a big-box store. Alabama-based GeoMetri (acquired January 2016) provided geo-spatial tools for creating indoor floor-plan maps for venue owners that enabled their customers to navigate to points of interest. DGLogik of Oakland, California, (July 2016) specialized in software for visualization of data, turning pie charts and line graphs into slick geographic and physical dashboards linked to the most relevant information, making it easier for operations managers to understand.

  All of this was a long way from simply lighting a space. Acuity’s challenge was now how to control and monitor that space, and to provide its owners with additional data about what was happening in it. That required mastering unfamiliar new skills. The company’s latest core competence was software. Acuity was hiring programmers to write smart lighting apps that could transform the data that its fixtures collected into actionable information. If it had been hard for Acuity to move from an electro-mechanical world into digital electronics, then moving into software was an even tougher challenge. Especially for someone like Rick Earlywine, who freely admitted that his last encounter with programming had been back in the days of Fortran punch cards. His approach, as ever, was to “put some really smart people together, surround them with the right folks, then just let them do their job.” Or, as ByteLight CEO Dan Ryan put it, “the company has allowed its entrepreneurial-type folks to operate in a way that gives those folks a lot of autonomy.”

  We will return to take a more detailed look at controls in Part III. Meantime, as we shall see in the next chapter, controls were not the only place where Acuity Brands was showing the rest of the industry what the new technologies of solid-state lighting were capable of.

  C H A P T E R T W E L V E

  The Lamp Shade Is the Lamp

  LEDs were radically different from traditional light sources in all respects, except one. Namely that, in order to avoid their dazzling glare, it was necessary to hide the light emitters behind a shade, louvre, baffle, or diffuser. And this, Peter Ngai thought, was odd. “The first thing we do is invent a light source,” Ngai said, “the second thing is invent ways to keep its light from us.” But solid-state lighting also came in another, very different form, known as organic light emitting diodes. OLEDs - pronounced “oh-leds”- did not need to be concealed. Unlike LEDs, which were point sources, OLEDs were area sources — paper-thin sheets of nanoscale materials that produced a uniform lambent glow across their surface. If LEDs were bright and glare-y like the sun, then OLEDs were soft and gentle like the sky. They were meant to be seen, appreciated, even celebrated.

  For this newer variant of the technology Ngai, a vice president at Acuity Brands, was the preeminent ambassador. To characterize the nature of the light that OLEDs emitted, Ngai liked to employ three adjectives: “pure, simple, and honest,” sometimes adding a fourth descriptor, a word that had seldom, if ever, been applied to artificial light
before. It was, Ngai asserted, “noble.” With their much simpler construction, sans reflector, housing, or socket, OLEDs more or less demanded to be integrated, into walls, ceilings, windows, even furniture. The new source had the potential, or so it seemed, to utterly transform the way lighting was designed.

  It had been known since the 1960s that, on being fed an electric current, certain organic - carbon-based - materials were capable of producing light. But it was not until twenty years later that two young chemists at Eastman Kodak’s laboratories in Rochester, New York, managed to persuade organic materials to emit light efficiently. A latterday embodiment of the freewheeling ethos that had proved so successful at US corporate research hubs like Bell Laboratories, RCA’s Sarnoff Center, and Xerox PARC, Ching Tang and Steve Van Slyke were “just a couple of guys in the lab having a good time,” as Van Slyke modestly put it. While attempting to make organic solar cells, they noticed that some of their samples glowed. Curiosity aroused, Tang and Van Slyke found that by varying the chemicals they could generate different colors: red, green, and most significantly blue, at a time when regular LEDs were more or less incapable of producing that hue. The voltage required to drive organic devices was low, the efficiency reasonably high. The problem with early OLEDs was that they didn’t last very long. “You could turn on the voltage and watch [them] die in front of you,” Tang told me back in 2000. But the pair persisted: eventually they managed to crack the longevity problem. In 1987 they published a seminal paper describing their work. It caused a sensation. “Almost immediately we had ten or fifteen companies wanting to come to Kodak to discuss what this new device was all about,” Tang recalled. The company’s management was nonplussed by this sudden, unexpected show of interest in their work.

  Whenever a new field opens up, it attracts ambitious scientists looking for uncharted territory in which to make their mark. In the case of OLEDs, among the most eager explorers were two professors at Princeton, Stephen Forrest, a former Bell Labs researcher, and Mark Thompson. “Tang and Van Slyke’s work got us excited,” Thompson told a reporter, “they had demonstrated exciting stuff and left open a million scientific questions.” The most important question was, How to improve the efficiency? The devices that Tang and Van Slyke had made were only capable of converting around a quarter of the input electrical energy into light. The Kodak pair had worked with fluorescent materials. Forrest and Thompson substituted phosphorescent emitters. With these new compounds they were able to hike the internal conversion efficiency to one hundred percent, a four-fold increase.27 Their 1998 breakthrough catapulted OLEDs from a technological curiosity into the most efficient light source known.

  There was more. To make their devices OLED researchers coated materials on individual pieces of glass. In future, they speculated, it might be possible to deposit light emitters on plastic, opening up the way to mass production via roll-to-roll processing in much the same way as cling film is manufactured. This was a beguiling prospect, one which did not go unnoticed in Washington among those whose job is to predict the future, and to ensure that US industry is equipped to meet it. The wonks convinced themselves that OLEDs would be the next big thing in lighting.

  The first surge of interest in OLEDs came mostly from Japanese firms like Sony, Sanyo, and Pioneer. They were not interested in lighting per se, but in applying the technology as displays for flat-screen televisions and handheld devices like smartphones. For such uses OLEDs offered compelling advantages over the conventional technology, liquid crystal displays. Unlike LCDs, OLEDs do not need a backlight, making them intrinsically thinner. Less obviously, OLEDs offer better contrast because whereas LCDs function as a shutter, alternately blocking light or allowing it to pass through, OLEDs emit light directly. Their colors can thus be more vibrant; their blacks more stygian. OLED displays can also be viewed from any angle without the attenuation from which LCDs suffer. And OLEDs switch on and off lighting-fast, reducing motion blur. Ching Tang was confident that, as mass production drove costs down, OLEDs would become the dominant display technology.

  On factfinding missions to Japan in the early 2000s Senator Jeff Bingaman and his staffers would ask manufacturers to show them the OLEDs they were working on. But the companies were cagey, unwilling to reveal much, making it hard to tell how advanced their product development actually was. Nonetheless, the Americans came away convinced that if the US was to be competitive in this new industry, then OLEDs would need government backing. Their conclusion was enthusiastically supported by lobbyists for companies like DuPont, GE, and 3M, which stood to gain from Washington’s largesse. With the result that precious research funding in the Department of Energy’s solid-state lighting programs would be split between LEDs and OLEDs. Roland Haitz fought this unwelcome competition tooth and nail. OLEDs were merely a distraction, he argued, LEDs would run circles around them on cost. “I said, [OLEDs] should get a little money, maybe ten percent, because they are so far behind,” Haitz told me. That way, the OLED guys could do some basic research instead of wasting taxpayer dollars trying to develop roll-toroll manufacturing processes when they did not even have a proven technology. This rivalry was unfortunate, especially since as an area source, OLEDs were actually more complementary with LEDs than competitive. However, as time went by and LEDs were commercialized and became profitable, the argument in favor of federal funding for OLEDs grew stronger. Organic devices lagged perhaps seven years behind their inorganic cousins. Surely this promising wild-card technology deserved more government money to help it gain traction?

  27 Efficiency here refers to quantum efficiency, that is, the conversion of electrons to photons within the device. The actual light output - aka “wall-plug” efficiency - of OLEDs is much lower, around 25% versus 40-50% for the best white LEDs. However, optical tricks can be used to boost the efficiency of OLEDs as high as 50%.

  In the event, it was not Japanese firms but the Korean conglomerates LG and Samsung which made most of the running in producing OLED displays. LG concentrated on large-scale TVs, in both flat- and curved-screen formats, while Samsung focussed on producing OLEDs for its Galaxy range of smartphones. In 2013 the company would ship, as Steve Van Slyke proudly noted, some 250 million phones equipped with OLEDs. Samsung’s Edge model, introduced in 2015, was the first to feature a new, flexible plastic OLED display that bent around both sides of the phone. It provided curved areas that could be viewed from both front and sides, also when the phone was placed face-down. At a trade show in early 2016, LG demonstrated a paper-thin prototype plastic OLED screen that could be rolled up. In addition to making screens for its own use, the company also invested in facilities for mass producing OLED panels to sell to lighting fixture makers.

  Because oxygen and moisture degrade their performance, all OLEDs must be hermetically sealed. It had been hard to find a plastic which could resist humidity and water. Now, with the plastic encapsulation problem seemingly solved, lifetimes soaring above 15,000 hours, and panel size and brightness increasing, the way was opening up for designers to fashion lights in entirely new form factors. “When you start getting plastic lighting, and the lamp shade is the lamp, that will blow people away,” predicted Mike Hack, of Universal Display Corporation, a Trenton, New Jersey based firm that in addition to licensing and extending the Forrest-Thompson OLED patents also supplied panel makers with phosphorescent materials. “This transition to the flexible, the bendable, the rollable is going to happen over the next five years — that’s going to have a huge impact.”

  For the moment, however, despite their ongoing success in displays, in lighting OLEDs were struggling to make their presence felt. Their manufacturing costs were still at least an order of magnitude too high. In order to drive the costs down, real-world applications were needed. The first of these was, as brake lights in cars. By coincidence, this was the very same application in which high-brightness inorganic LEDs had initially been used, almost thirty years earlier. For car designers OLEDs offered several compelling advantages. OLEDs are in
effect strips of material that can be molded into any shape that designers desire. In addition to being highly formable, at less than a millimeter thick OLEDs are also thinner than LEDs. “Cars have all these curved surfaces,” Hack said, “you can follow the contours, merge the lighting into the skin of the vehicle and not take up space.” In addition, further reducing bulk, OLEDs do not require heat sinks to cool them or the standard optical paraphernalia of reflectors to guide their light. OLED tail-lights provide a flat, homogenous light with continuously variable dimming. The lights can also be organized into clusters of different colors and brightness, offering new functional possibilities. For example, in 2013 Audi demonstrated a large, continuous light spread across the entire rear end of a prototype car. The surface displayed, an Audi spokesman said, “small points of light flickering dynamically like a swarm of fish [sic].”28 In addition to indicating braking and turns, this signal was also capable, using various combinations of patterns and colors, of relaying additional information to the car behind, such as pitches and turns in the road ahead.

  Unsurprisingly, actual implementations have thus far been more conventional. In 2016 another German firm, BMW, became the first to introduce OLEDs in the tail-lights of a high-end production car, the M4 GTS. “We try to create a three-dimensional light sculpture with OLEDs,” explained Andreas Knoedler-Bunte, head of exterior detail design at BMW, adding, “it’s almost like a dinosaur spine, with different elements in an OLED lamp that you can light one by one. So it creates a very different feeling, a very different form language.” Automotive applications for OLEDs were the focus of Europe’s second largest lighting manufacturer, Osram. Its great rival Philips had started research on OLED displays back in 1991, beginning work on applications in 2004. Four years later the company shipped its first, experimental OLED panels. In 2009, with the help of a grant from the German government, Philips set up the world’s first OLED production line in a former television factory in Aachen, about an hour’s drive across the border from Eindhoven. In 2011, the Dutch company invested heavily (40 million euros) to increase production capacity, announcing that its target markets for OLEDs would be decorative lighting and “ambience creation” aka mood lighting. That year the company’s chief designer, Rogier van der Heide, worked with the Black Eyed Peas, an American hip-hop group, on incorporating OLED panels into stage outfits for the band, in particular for its lead singer, Fergie. “We realized that we could control all the OLEDs on her suit individually,” van der Heide told me, “so we could actually start creating choreography that was in sync with the music.”