HB LEDs (High Brightness LEDs) evolution

LEDs have been valuable for both electronic billboards and as an illumination source for channel letters where it performs as an alternative lighting medium to neon lighting. Its features have been widely praised, including its small size, its low voltage efficiencies, and its robustness in lasting upwards of 60,000 - 70,000 hours before they have to be replaced. Its performance efficiency is a moving target as its overall cost is continually descending and new technological improvements are resulting in LEDs constantly getting brighter as an illumination source.

It is that last factoid that is of particular interest to the sign community as LED lighting is a critical component of signage and as its luminosity output continues to increase, has come into its own market niche known as High Brightness LEDs (HB LEDs). There are several ways to identify HB LEDs, one is very simple and visceral, that the LEDs are so bright that viewers cannot look directly at them without irritating their eyes. The second, more technical definition is based on HB LEDs manufacturing process. HB LEDs come in two forms which have evolved from a series of semi conducting materials; AllnGaP, (pronounced alan-gap), which is composed of aluminum, indium, gallium and phosphide which create HB orange-red, orange, yellow and green lighting units. The second solid state offering is InGaN (pronounced as n-gan), which includes indium and a Gallium-Nitride compound, and creates blue, blue-green, true-green and when combined with a yellow phosphor, white. HB LEDs can usually be found in a standard 5mm, 1 amp LED package which provide at least several hundred mill candela in light intensity.

HB LED state of the industry
Dr. Robert Steele, director of optoelectronics for Strategies Unlimited (Mountaiview, CA), a company that produces "Strategies in Light" the annual HB LED conference noted that in 2005 the HB LED industry had grown 8 % from last year (2004 - $3.7 billion) and is now benchmarked with an overall revenue of $4.0 billion. It was noted at the conference that HB LEDs ultimate success will be in transforming from a technology driven market to an applications-driven market. Dr. Steele observed the HB LED market share leading segments included mobile appliances (52%), and as was last year, a tie for second place between signage (14%) and automotive (14%) (see chart for full breakout). In another category application as HB LEDs continue to improve in their development of white LEDs in terms of price/performance, it will open up a retrofit market of replacing existing incandescent and fluorescent lighting sources with their LED counterparts. This retrofit will not only apply to home use, but to the sign community as well, once the appropriate LED lighting sources show up.

As HB LEDs continue to make their way into the sign community, it is generally considered that electronic billboards will become a killer application, both for the LED manufacturing community and for outdoor signage as more outdoor advertising companies seek out LED-based billboards as a preferred advertising medium. Steele note that other potential areas where HB LEDs will influence electronic signage are with large LCD displays where RGB LEDs are being used as a replacement back light to illuminate the screens (some which become various EDS systems). In another display application, HB LEDs are just beginning to be used as a light source for rear projection televisions.

Currently, several LED manufacturers produce HB LEDs including Lumileds, Cree, Osram Opto Semi Conductor, Nichia and COTCO. To gain a better understanding of HB LEDs evolution, Sign Industry.com interviewed Nichia and Osram Opto Semiconductor, both who discussed their HB LED product lines in regard to increased market demands for LED-based sign products.