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Interview : Energy-saving policy and standard research for solid-state lighting in the United States−169−Synthesiology - English edition Vol.2 No.2 (2009) so if the standard cannot catch up, there is a danger that development may go in the wrong direction producing inefficient products.Currently, the mainstream for white LED is the method in which blue emission and phosphor are combined. Some people say that RGB method is high cost and has very poor color rendering (CRI). Yet the color rendering to the eye is not that bad. The companies that are working on RGB support us with great enthusiasm. (Ono)RGB is composed of three wavelengths with a relatively narrow spectral width. So you will use the CQS rather than the CRI. By the way, what would the Japanese terminology for CQS be? (Ohno)I never thought about the Japanese for color quality scale. I’d better think of something.(Ono)How about shikishitsudo?(Ohno)Yes, shikishitsudo sounds good. For this research project, we received about half million US dollars as budget for the facilities in addition to cost of labor, so we are creating a new experimental facility where the entire room can be illuminated while freely changing the spectra, the first of its kind in the world (Fig. 4).(Ono)I see. You are going from a booth to a room.(Ohno)In a room, there is great advantage in that you can actually work in it, talk in it, and see the colors of people’s faces. We can’t do a final check of the new metric unless we go that far. Currently in this room, we have a temporarily installed system with only three RGB colors. In February 2009, we will have a system that can control peak wavelengths for 25 separate colors. We can study color perception under various lighting conditions, and I believe this will contribute greatly to the research on SSL.Full Research at NIST (Tanaka)You are getting good results of Full Research for the DOE policy on SSL. (Ohno)Yes. As I mentioned earlier, I think the industrial standard for the chromaticity specification and another standard for the test method called LM-79 are our major outcomes. Chromaticity is the color of light, but even when the color of light is at a good setting, this does not necessarily mean that the color rendering is good. Both are related, but we first need to set the color of light as an industrial standard. Next will be the standard for color rendering.Although I wasn’t in charge, there are additional standards published, for example, the industrial standard of life testing of LEDs. The lifetime of LEDs is very long like 30,000 to 50,000 hours or even longer. Therefore, the current practice in the industry is to test LEDs only for 6,000 hours and extrapolate the degradation curve to 30,000 to 50,000 hours. This method involves very large uncertainties for projected lifetime and it was not agreed upon. Since we had a deadline for the Energy Star, this standard was published without inclusion of the projection method. How far we can go in standardizing such lifetime prediction will be our next challenge. (Ono)Newly created technology will progress in a good direction if there is an accumulation of data. In creating such industrial standards, what are the contributions of Japanese companies and researchers? (Ohno)Since ANSI and IESNA are American standard organizations, there is basically no participation from Japan. However, Japanese corporations that have companies in the United States can participate. For international standardization such as CIE, there are participants from around the world, but there is not yet very active participation by Japanese companies in LED lighting.Carrying out research while staying in touch with the demand of industry (Ono)Photometry is basic research oriented while at the same The Spectrally Tunable Lighting Experiment Facility at NIST・ In development・ Currently RGB system・ A 25 channel system will be completed in February 2009Fig. 4 The Spectrally Tunable Lighting Experiment Facility at NIST

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