Nisa Khan says LED and OLED Lighting Markets are Rising

Lighting and electronic display-industry professionals continue their efforts to improve LED and OLED lighting technologies to create expanding uses and applications, but, in truth, the pursuit is a technological and competitive effort to overtake the market share of incumbent lighting products.
LED-based products have enjoyed healthy double-digit growth in recent years, but the organic light-emitting diode (OLED) market has lagged, although it’s having success in the smartphone-display field. The two — LED and OLED — have different, unique advantages and, of course, challenges and, therefore, stand primary in the R&D labs for many companies and research institutions.
This prevalence was most notable at this year’s annual, LED Professional Symposium (LpS 2013) and Exhibition — a leading, international event that showcases the latest LED lighting technologies.

LpS: Europe’s leading led conference
More than 1,100 attendees from 34 countries enjoyed LpS 2013. The venue — Festspielhaus Bregenz, Bregenz, Austria — is popular for special events, operas and concerts. Event statistics detailed the attendees’ interests:
• Manufacturing companies (60%)
• Distributors (10%)
• Engineering and design services (8%)
• Universities (5%)
• Journalists, government officials and others (17%)

Several points from one keynote presentation caught my interest:
1) Presently, lighting draws 14% of Europe’s total energy consumption
2) The projected European lighting-market growth rate for the next decade is 7%

These figures contrast with the U.S. market where light-energy consumption is roughly 20% of the overall energy use, and it’s expected to decrease in a few years, due to more-efficient lighting products and the use of daylight harvesting,
I asked if these aspects (increasing efficiency and harvesting methods) were considered in the European market analysis. And, because the European lighting-consumption percentage was significantly lower than the U.S. scenario, I also asked if this could be due to more efficient lighting — or if the percentage is off balance because of the regions’ high electricity usage in other applications — electric-powered trains and buses, heating, air conditioning or other applications, for example.
In both instances, the speaker said such data was not available.
The European Union’s demography is diverse, and the low,14% statistic may be affected by inadequate lighting in many areas — less light, less power consumption. Further, the inequality, and accompanying plan for supplementary light provisioning in many regions may be the reason for positive lighting-use growth projections. Still, a thorough study would be useful, one that reveals how daylight harvesting, energy-efficient lamps and electronic-control systems could affect the European plan.
LpS 2013 also comprised 46 talks from presenters who work and research around the world. The presentations were divided into 16 sessions: Light Sources I-IV; LED Future I; LED Systems I-II; Driver and Controls I-IV; Optics I-II; Thermal Management I-II; and Applications I. In addition, the symposium offered workshops on testing and standardization, 3-D system design and print technologies, computer-aided design of LED and OLED systems, and LED qualification and reliability.
More than 80 international exhibitors displayed innovations, products and services across the sold-out, 2,000-sq.-meter floor space. Numerous supply-chain vendors displayed both prototypes and products that encompassed materials, optical components, thermal solutions, drivers, software-design tools and measurement instruments.
Among the established were Osram Optosemiconductors, UL, Arrow, and Bayer Materials. Noticeable new firms are GL Optic (a subsidiary of Just Normlicht, Weilheim Tech, Germany); Breyer (Singen, Germany); and Techno Team (Ilmenau, Germany)
GL Optic offers reasonably priced, light-measurement instruments with high spectral accuracy (a latest is the handheld spectrometer GL Spectis 5.0 Touch). Breyer builds precise, LED-illuminated, active-lightguide panels (A-LGP), which incorporate refractive structures that produce energy-efficient, uniform and bright LCD panels widely used in Sony, Panasonic and other displays.
First-time exhibitor Techno Team exhibited high-resolution, near-field, light-intensity distribution-measurement systems for variously sized lamps.

OLED developments
For the first time, LpS combined OLEDs with inorganic LEDs in its technical-paper presentation sessions for light sources. I moderated the sessions on OLEDs. The active-matrix, organic, light-emitting diode (AMOLED) technology has recently become the preferred screen choice for Samsung’s Galaxy S4 and the Note II smartphones. Samsung also offers several cameras that use similar technologies. It believes OLED displays will become the mainstream in the near future — dominating over LCDs, especially where small, but bright displays are needed.
In contrast to LCD technology, OLED displays are self-emissive (they provide their own light). They do not require backlighting, which leads to the fabrication of extremely thin screens. In addition, advance-pixel arrangements and electronic controls can be embedded within OLEDs, which have enabled such technologies as Super and Super-plus AMOLEDs. These provide true black, a broader color gamut and bright screens that can be viewed outdoors.
In China, Samsung sells its Galaxy full-HD panel smartphones with flexible, 5.7-in. (diagonal) OLED screens.
Several market-research reports say the flexible OLED market will soar in 2018.
In terms of material and integration capabilities, OLED and AMOLED technologies and the manufacturing infrastructures, are moving quickly forward, and this gain should allow fabrication of larger, brighter and thinner panels. OLEDs’ attractive features are sure to obsolete the current products, especially when volume manufacturing allows affordable pricing.
OLEDs function via the electroluminescence response of thin-film organic materials that are sandwiched between two, opposite-polarity, preferentially biased electrodes.
They will significantly affect the electronic-digital signage and display industries, in both the active and passive form.

Claims and misunderstandings
Despite OLEDs’ success in the display industry, their use as lighting devices faces several challenges. While regular (inorganic) LED-lamped displays aren’t suitable for close-up viewing, especially in hand-held gadgets and TVs, the present generation of OLEDs aren’t as energy efficient or long-lasting as inorganic LEDs and, therefore, can’t compete for mainstream lighting applications. But, as large-size, flexible luminescent panels, OLEDs can become decorative luminaires and other special, architectural-lighting assets.
Regular LEDs are not suitable for such uses.
Obviously, the two shouldn’t compete for the same market.
In a general analysis, such OLED and LED lighting characteristics as efficacy and luminance should not be compared. These depend on the end-to-end system requirements where, for valid comparisons, such parameters as total lumen output and color properties should be held constant.
Currently, the most challenging problem is OLEDs’ instability characteristics under high-temperature and humidity conditions.

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Ongoing LED challenges
The disciplinary gap still remains between the electronic- (or optoelectronic-) based LED industry and the traditional lighting industry. Nevertheless, the ongoing improvements in LED and OLED technologies create both opportunities and challenges in the lighting and display markets.
For example, problems with LED or OLED-based light include glare and lack of omnidirectional light radiation. LEDs produce much higher glare than their OLED counterparts. However, OLED-based lamps are still not as desirable for comfort lighting as incandescent lamps.
To solve the glare problem, certain manufacturers are using diverse, secondary-optic techniques that, in turn, add to the many challenges already facing SSL standard communities. My explorations led to further research and my book, Understanding LED Illumination (CRC Press, August 2013), which provides a new theory that describes why LED lights have glare. It also offers new insights and novel techniques to improve LED illumination.

Caption:
Samsung’s 5.3-in., Super AMOLED Galaxy Note Android v2.3 Phone with 1,280 X 800 resolution. The phone is 9.65 mm thick and weighs 178 grams.