Chris Bohler PhD, Director of Innovation at Cooper Lighting, was one of the speakers at the recent LEDs 2012 conference in San Diego, USA. In an interview, Bohler gave a glimpse into how Cooper Lighting innovates and what are the most interesting things happening in LEDs right now.
Q: As Director of Innovation at Cooper Lighting, where do you look for new ideas?
A: First of all, new ideas come not just from the innovation team, but throughout the organisation. This includes the product development, marketing and leadership teams. This is the advantage of having an innovative and entrepreneurial mindset within the business.
Concepts can be generated based on any number of sources, including technical references (trade journals, conferences such as the LEDs Conference, online articles, etc) which may be tied to a development directly within the lighting industry or a parallel industry.
There is also a strong body of knowledge being built by the LED manufacturers and competitive LED fixture manufacturers, which will continue to evolve and sequentially generate new ideas and concepts over time.
Q: What do you consider the most interesting innovations in LEDs right now?
A: At the fundamental LED level, there are two general trends that we find very interesting currently.
The first is simply a natural progression of the technology and manufacturing process. For the last decade, the LED manufacturers have been primarily focused on providing white light at a decent efficacy for the general lighting market, recognising that this was critical to penetration.
However, now that we, as an industry, are in the ballpark and competitive to other mainstream, traditional lighting sources, other lighting requirements are being addressed such as beam and batch colour variance, CCT options, CRI (with an emphasis on C9) and colour quality over lifetime.
Of course, thermal management continues to be a challenge, especially in high light output applications. But considering that the LED manufacturers have been able to reduce the thermal resistivity of the packages by over two orders of magnitude in the last two decades, they have positioned us well for the general lighting arena.
Secondly, LED manufacturers continue to creatively address issues that constrain the performance and cost of the technology: epitaxial growth on alternate substrates (particularly GaN and Silicon) and AC/HV LEDs are activities that come to mind immediately.
The latter is particularly interesting as it forces both the LED manufacturer and integrator to consider optimisation at the application level.
Other innovative developments are occurring on the LED systems front, such as small chip assembly on plastic; improved LED driver efficiency, dimmer compatibility and reduced footprint; and improved efficiency and colour quality through colour mixing, remote phosphors and quantum dots . . . to name a few.
And, of course, one cannot use the word ‘innovation’ in this industry without including a mention of the great progress being made in the field of OLEDs.
Finally, the advent of LED lighting control and communication is a hot topic that cannot be ignored, nor should it. Energy savings have long been the hallmark of a well designed LED luminaire and certainly one of the primary reasons that there is interest in this technology in the first place.
The ability to control light levels based on ambient conditions, and to combine functionality (eg, visual light communication) offer potentially significant cost and performance benefits beyond those available in most products today.
Q: Your presentation focuses on performance and reliability – what can LED manufacturers do to improve in this area?
A: First of all, we must accept that the performance and reliability of an LED fixture is not the sole responsibility of the LED manufacturers themselves. Although the LED is at the heart of the solution, there are many other contributing factors that must be mitigated to ensure a robust, long-lived fixture design.
I think there is a fundamental misconception in some camps in the US that the LM-80 data/report is the ‘holy grail’ on reliability, when, in fact, it addresses only a small part of the overall reliability concern.
There is some very nice work going on at the Lighting Research Centre under the auspices of the ASSIST program to better understand LED system level reliability, as well as at the Research Triangle Institute under the sponsorship of the DOE Core R&D funding.
Cooper Lighting has also made a significant investment in in-house reliability engineering and product validation testing, a must when working with rapidly progressing technologies like LED, OLED and others.
Having said this, the LED manufacturers have made some very good in-roads to reliability regarding thermal management (as mentioned previously), manufacturing variances (reduced binning tolerances), overall LED package robustness and lumen maintenance.
Inherently, cost and performance are intertwined through engineering design trade-offs at the product level. Therefore, any improvements on performance (flux, efficacy and colour quality) can be leveraged against system costs in order to address the customers’ needs.
As there is not a one-size-fits-all strategy that meets all needs, varying trade-offs will be made depending upon the situation at hand. In a high-end architectural product, aesthetics and colour quality will be accentuated, while in a high-volume market, cost will play a primary role.
Thus, higher source performance, with a tighter manufacturing tolerance (higher quality) at a lower cost gives the greatest flexibility to the designer in meeting the broadest set of requirements.
For more information visit www.cooperlighting.com
© Technews Publishing (Pty) Ltd | All Rights Reserved
printer friendly version