This post was written by Keith Dawson for UBM Tech’s community Web site All LED Lighting, sponsored by Philips Lumileds. It is archived here for informational purposes only because the All LED Lighting site may go dark at any time. This material is Copyright 2013-2015 by UBM Americas.


That's a Good Question

In November Ray Molony, publisher of Lux Magazine, will interview Shuji Nakamura, who invented the blue LED, enabling LEDs to produce white light. Got a question to suggest?

In the "Innovations in Light" LinkedIn group, convened by Philips, Molony asked group members that question. So far the discussion has accrued nine solid suggestions for questions to ask Nakamura, and one substantial technical diversion.

I believe you have to be both logged in to LinkedIn and a member of that group to view the discussion there. If you frequent LinkedIn and haven't yet joined the Innovations in Light group, I urge you to do so. (I would say that, even if this site were not sponsored by the Philips subsidiary Lumileds.) Lots of smart people in the business hang out at Innovations in Light, including many from this very community.

I wanted to broaden Molony's call for questions to get the thinking of this community on the record as well.

Questions, questions
Let's start with the question I contributed over at LinkedIn: What does Nakamura think of human-centric lighting? HCL is much concerned with the blue component in LED-generated light, and, after all, it was the blue LED that made possible all the white light applications around us.

The first question was posted by Gordon Routledge, who with Molony was a co-founder of Revo Media Partners in the UK, publisher of the various Lux properties. Routledge would ask Nakamura his opinion on OLEDs. It's a fair question for one of the world's experts in the inorganic materials that can be made to generate light.

Our own Dennis McCarthy would invite Nakamura to speculate on the BOM of an LED lamp with a standard form factor, next year and in 2020. (He might well have asked the OLED question if Routledge had not gotten there first.)

The question that sparked the technical diversion came from Duilio Passariello. He would ask for Nakamura's thoughts on the 2010 projection from Jeff Tsao of Sandia National Laboratories, that by the year 2030 we would see LEDs with a luminous efficacy of 260 lumens per watt with a CRI above 90.

Eric Bretschneider weighed in with the results of Monte Carlo simulations he had run. According to Bretschneider, the maximum practical luminous efficacy of radiation, under reasonable assumptions for the efficiencies internal to the process, is about 216 lm/W at a CRI of 90 and CCT of 3,000k.

Your turn
What would you ask Shuji Nakamura? Perhaps Molony will find this forum and collect some ideas; or perhaps I will forward him a link, especially if we come up with powerful questions for one of the men whose work made this industry possible.

Related links

— Keith Dawson Circle me on Google+ Follow me on Twitter Visit my LinkedIn page, Editor-in-Chief, All LED Lighting