L.E.D.

by Bob Johnstone

  28 One wag commented: “We look forward to version 2.0: a shoal of bees.” Such fancy one-off demonstrations were all very well, but as the years passed and mass markets for OLEDs failed to materialize, Philips lost patience. In March 2015, the company announced that it was pulling the plug, selling off its Aachen production facility to OLEDWorks, a US startup formed in 2010 by former Kodak employees. Philips felt that for the foreseeable future, the appeal of OLEDs would remain limited to niche markets. This opinion was echoed by Osram. “We will invest in OLED, but not for general lighting,” Osram CEO Olaf Berlien said in early 2016. “I don’t think that it will be important in the future for general lighting,” he concluded, adding “it’s too expensive.” Both Philips and Osram were concerned that OLEDs might cannibalize their traditional lamp business. Amid the pessimism about OLED’s prospects, however, the technology still had one staunch supporter: Peter Ngai of Acuity Brands, LG’s largest OLED customer.

  Lighting professionals joke that no-one goes into lighting on purpose; rather, people stumble into the field by accident. Peter Ngai was no exception to this rule. Ngai was born in China in 1949, amid the chaos of the communist revolution. His family fled the mainland, initially landing in Macau then subsequently moving to Hong Kong. When he was nineteen Ngai came to California, where he studied electrical engineering at UC Berkeley. At the time, mainframe computers were booming. Makers of silicon chips were springing up across the San Francisco Bay. Programming languages like Fortran were being applied in ways that amazed the young man. “I was very excited about that,” the soft-spoken Ngai told me, “my preparation was to become a computer engineer.” His fate, however, lay elsewhere. In his final year at Berkeley, to fulfil the requirements of his degree course, Ngai was obliged to take an elective in a technical field outside his major. Having to work his way through school left the young man little time for burdensome extra studies. Reluctant to enrol in one of the tougher electives like aerodynamics or quantum mechanics he leafed through the catalog until he chanced upon a course called “illumination engineering.” It sounded undemanding. Ngai met with Dan Finch, the professor who took the course. He seemed like an easy-going guy. “So I thought, What the heck?” and signed up. It was a casually-taken decision that would change his life.

  Lighting, Ngai quickly discovered, is multi-dimensional. “It’s not just engineering, or physics, or optics,” he explained, “it’s also about architecture and art, about biology and physiology and psychology, and ergonomics, and a lot of other things, too.” In fact it was a field that encompassed pretty much the whole of human experience. On questioning Finch, the young man was astonished to discover that many things in lighting were still unknown. “And when he said, No, we really don’t know too much about that, I felt, Wow — then I should go in and look.” Like the proverbial kid in the candy store, Ngai found himself surrounded by tempting opportunities. “I was like a sponge, soaking up everything I could get. I just fell in love with lighting, with every aspect of it.”

  In 1972, the year that Ngai graduated, Finch retired, forcing him to look elsewhere in order to continue his studies. He moved to the University of Colorado at Boulder. By good fortune, he arrived at a time when lighting was transitioning from a craft to a science. Previously, to determine the proper amount of illumination for an interior and what the result would look like, designers were largely dependent on intuition and back-of-the-envelope guesstimates. Sure there were equations that could help with prediction, but they were far too complex to work out by hand. Now, with the advent of powerful computers, it was possible to calculate exactly how much light a given space would need and how the light should be distributed within that space. At Boulder Ngai encountered Dave DiLaura, a kindred spirit who was applying mathematics to take the science of lighting to new, previously undreamed-of heights. The energy crisis of 1974 added fresh impetus to their research as, almost overnight, it became imperative to improve the efficiency of lighting. From having been almost an afterthought, an add-on that architects delegated to lowly electricians to implement, lighting was beginning to win respect as a discipline in its own right. Ngai was in the vanguard of this movement.

  From academe, he went into industry, returning to Berkeley in 1976 to join a small, high-end fixture maker called Peerless. The firm had just invented a method for extruding aluminum into a variety of shapes. (Aluminum has long been the fixture maker’s metal of choice because it is reflective, lightweight, and does not rust.) This allowed the creation of fixtures that blended in with the interiors they lit. Lighting designers would no longer be limited by one-sizefits-all boxes that caused visual clutter on the ceiling, disrupting the harmony of the spaces they lit. First, however, the fixtures had to perform. “I can put a Porsche engine into these shapes,” Ngai promised his new boss. Over the years his contributions to product development, based on a deep knowledge of the science of light, helped turn Peerless into the premier maker of architectural lighting in the US. (The firm was acquired by Acuity Brands in 1999.) Having begun by addressing the technical issues of illumination, as time went by, Ngai became more involved with its design and artistic aspects. He came to understand that merely creating a good-looking fixture, even one with superior performance, was not enough. There had to be a reason for that performance, something he called a ”lighting philosophy.”

  One example of a lighting philosophy was embodied in an approach which Peerless pioneered, the indirect illumination of spaces like offices, where the visual comfort of workers is important. Most offices are lit by direct fixtures. Recessed into the ceiling, they aim most of their light downward onto the desks below. The problem with this reflection-less approach is that if fixtures are not spaced properly, they can create an unevenly-lit environment. Direct lighting can cause shadows and excessive contrast between light and dark. Employees who sit immediately beneath fixtures receive too much light, those who sit away from them receive too little. Direct light can also create glare on computer screens, contributing to blurry vision, eye fatigue, and headaches. A 1997 study by the American Society of Interior Designers found that more than two-thirds of office workers complained about the lighting in their workspaces. Their dislike had negative consequences, such as reduced productivity and increased absenteeism.

  Indirect lighting works using pendant fixtures suspended from the ceiling. These aim most of their output upward so that the light hits the ceiling then is reflected back down onto the workspace. The light that indirect fixtures throw is shadow-free and evenly distributed — everyone receives the same amount regardless of where they are sitting. When you walk into a space where most of the illumination is indirect, the effect is like being bathed in light. It satisfies people’s psychological appetite for brightness. But the light should not all be indirect: another human need must also be met; namely, to see some light coming directly from the fixture. “You need to have a hint of luminance,” Ngai explained. The Peerless researchers worked with colleagues at Penn State University, which specializes in measuring the psychological aspects of lighting, to validate their hypothesis. When experiments proved them correct, they came up with new ways of creating luminance, developing fixtures in which over ninety percent of the lighting is indirect. Ngai became a leading advocate for indirect lighting in the US, helping usher the approach into the mainstream. Peerless also worked with other institutes such as the Lighting Research Center at Renssselaer Polytechnic. Such collaborations with academe were highly unusual in an industry not known for spending much on R&D. “That’s what distinguishes us from the rest of the industry,” Ngai said, “we want to push the boundaries.”

  After an illustrious career spanning three decades during which he had published countless articles, filed numerous patents, and won many awards, Peter Ngai would have been entitled to rest on his laurels. But his passion for lighting drove him on. In 2008 Ngai saw his first OLED panel, brought to his office by a long-time business associate. He was immediately enchanted. With the encouragement of
Acuity’s top management, he took a sabbatical during which, characteristically, he poured himself into learning everything he could about this new technology. One reason OLEDs had such an impact on Ngai was that he had been working on ways of turning LEDs into area sources, creating a planar light by attaching a strip of light emitters to the edge of a translucent plastic material known as a wave-guide. One of Ngai’s waveguide designs had recently won an award for the most innovative product at a trade show. But no matter how slick their design, wave-guide LEDs looked bulky and clunky by comparison with OLEDs, which were thin and elegant. In addition to which, forcefitting LEDs to wave-guides reduced their output efficiency by as much as 25 percent, thus undermining the rationale for using solid-state lighting in the first place.

  OLEDs, it seemed to Ngai, were something completely new and different. They could do things that conventional light sources could not. If LEDs had been the beginning of modern lighting, accelerating it into the fast lane of high technology, then OLEDs were a fusion of humanity and technology. They brought illumination back to its core purpose: lighting for people. In singing the praises of this unique new light source, Ngai waxed lyrical, employing the evocative rhetoric of the evangelist in preference to the prosaic parlance of the engineer. Here, for the first time, was a light that had its own character: it did not need to be covered up. “Every light source known to us is meant to give us some light so we can see things, but it’s never meant to be appreciated,” Ngai told me. “You have to mask the light, because it is not comfortable, it’s not inviting to see the source.” Whereas the light emanating from this new source was without speck or blemish. OLED light did not need to be ornamented or accessorized, it was perfect just the way it was. “OLED gives us the chance to celebrate lighting with a light source that demands to be noticed,” he enthused. At the same time, its thinness - less than a millimeter thick - meant paradoxically that “OLED has form without volume, it celebrates what is not there.” In the future, OLED also had the potential to become transparent, so it could be applied as a see-through panel that when not lit could be used as a window or skylight.

  Lighting was all about function, but OLED moved lighting beyond simple function. It added a new, emotional aspect to what lighting could bring people. You could not have an emotional connection with a light that you could not see. The flawless brightness and uniform diffusion of OLED were especially important when the light was located close to the user. Its soft, minimal-shadow lighting made the expressions on faces visible. Conventional light sources like halogen were not only hidden, they were also hot, burning the fingers of anyone foolish enough to get too close to them. OLED by contrast was cool, positively encouraging intimacy. “We want to touch it, to befriend it,” Ngai said. “That is the very special and precious character of OLED.” With OLEDs it was possible, he believed, to create fixtures that brought people together. Immersing people in a soft volume of light promoted a sense of companionship and collaboration. Indeed, so strong was this feel-good factor that, as he liked to joke, “there’s no way you can fire anybody under this lighting system — you may actually end up giving that person a raise!” All solid-state lighting was energy-efficient. In Ngai’s view, however, talk of simply saving energy missed the point. “If you make a worker a little bit happier with a better quality of light,” he argued, “then that is far more significant economically than saving a few hundred dollars a year in electricity.” To Ngai this was intuitively obvious. Lighting designers knew what exactly he was talking about, that quality of design trumps efficacy. But it could be frustrating trying to persuade the purse-string holders, like building owners for example, who demanded to see numerical proof.

  In 2009 Acuity Brands set up a new OLED Lighting Design Center in Berkeley. It was staffed by a small team consisting of diverse talents and headed by Ngai. The center’s mission was to create fixtures that targeted one of the largest chunks of the lighting market, the commercial and institutional sector, which includes offices. Acuity’s management, including CEO Vern Nagel, were supportive. “Go make it happen,” they told him. One of the first fixtures to emerge from the center was named Kindred. It was a sculpted pendant that featured a uniquely slim profile which sloped gently down. The downward curve - a “gesture,” Ngai called it - made the fixture “almost like a friend, a companion who will softly touch your shoulder.” Such a psychological gesture would be impossible with a fluorescent fixture because tubes are straight and rigid: you can make them thinner and shorter, but you cannot make them flat. In addition, due to their size and the amount of light they produce, tubes dictate how lights are spaced across the ceiling, forcing fixtures to conform to an inflexible grid pattern. For a lighting designer to be bound by such a cookie-cutter approach was, Ngai said, “like being born with a ball and chain.”

  Recessed fluorescent fixtures - known in the trade as “troffers,” an unlovely word that grafts “trough” onto “coffer” - were anonymous, unnoticed by and unconnected with the workers whose spaces they lit. Tens of millions of troffers are installed in office ceilings everywhere. For specifying such unsightly appliances lighting designers sometimes felt obliged to apologize. “Sorry I had to put those things up there, they look ugly I know — but you need light,” they would mumble shamefacedly. “How awful is that?” Ngai said accusingly. “But what if you could put in something that will make people feel good about a space?” That was the aim of the Acuity Brands OLED team. “We can put in clusters of fixtures that are smaller, that can deliver the light where it needs to be, and that are visually and architecturally appealing.”

  With OLED, as he had done with indirect lighting, Ngai was pointing the way. “The lighting industry has always been considered a slow-moving slumbering giant,” he said. “We want to take the lead, to show people that with OLED, lighting can be very exciting.” If building owners were going to replace their lighting with solid-state fixtures, why try to emulate the past, why not do something more creative? It would be wrong to see OLED merely as a replacement, Ngai said. The technology was destined to generate entirely new concepts in lighting design. And there was much more to look forward to. OLED could be flexible, foldable, free-form in shape, transparent, high brightness, with tunable colors and shapable intensity. “These are not pipe-dreams,” Ngai insisted, all would come to pass in the foreseeable future. Such attributes - some of them beyond the reach of LEDs - would, he believed, elevate the art of lighting to an entirely new level.

  By 2016, Acuity had commercialized a range of high-end architectural OLED fixtures. At the company’s Center for Light and Space in Conyers, Georgia, an entire room was dedicated to demonstrating the technology. Inside, suspended overhead, were graceful pendants like Kindred and Olessence, a flowing wave-shaped luminaire that combined LEDs for indirect light and OLEDs for direct. Clusters of flower-like OLED sconces traced patterns across the ceiling and walls. When Ngai’s colleague Jeff Quinlan hosted what he called “significant customers,” that is, professionals who really understood lighting, their reaction on entering the room was invariably to gasp and go “Wow!” The company was also selling two small OLED fixtures at Home Depot, giving ordinary consumers their first chance to purchase OLEDs. There, too, the response was striking, according to Acuity’s Jeannine Fisher Wang. “When people saw the lights,” she said, “they stopped in the their tracks.”

  Other than Acuity’s initial offerings, however, OLED fixtures were dispiritingly few and far between. The technology was still, in Quinlan’s word, “cuspy.” OLED panels remained expensive because of high manufacturing costs. This of course was not unusual for any new technology: increasing volumes would inevitably drive down the price, as had already occurred with OLED displays. “All the research and investment that’s going on will solve [the manufacturing cost] problem,” Quinlan predicted. “I have yet to hear of anybody associated with OLEDs who doesn’t believe that that’s solvable.” In fact, though still too high the cost of OLED lighting was dropping fast, falling b
y around 40 percent between 2014 and 2105. There was speculation that Apple might follow Samsung in switching to OLEDs for its smartphones, which would further drive down prices and encourage further investment. The business, according to the DoE’s Jim Brodrick, was “really starting to gell.” Though OLED lighting was still in its infancy, the architectural market was beginning to take notice. To be sure OLEDs were unlikely ever to overtake LEDs, but they could conceivably provide an attractive alternative in some applications. As Quinlan pointed out, “lighting has never been a single play — in the modern era there’s always been at least two major players. What I would expect to see, as the last vestiges of the traditional technology start to fade, is OLEDs to come in as a complementary source. OLEDs will probably never generate the monster volume of fluorescent lamps. But they could still be an important source, and we’re OK with that.”