Shipment of LED lighting equipment in Japan has reached 10 Billion yen and it is said that the shipment of LED lamps will reach 5 million in 2010. Japanese LED related market is expanding at very high annual growth rate. Japanese government shows high interest to promote LED application and LED related industry in its Growth Strategy Plan published in the end of last year.
Recent rapid growth of global attention to energy saving promotes research and development for solid state lighting (SSL). Accurate and recognized photometric and radiometric measurement for SSLs are indispensable to ensure the reliability of SSL products. In this article, recent topic, trend and future prospect about the standardization of LED photometry and radiometry is reviewed mainly through the activity in the CIE.
Luminous efficacy of white LED has been improving rapidly in the past decade. Now, extremely high efficacy of around 150lm/W is reported in the latest research. Superior performance than other conventional devices was achieved at last, and then practical lighting products like LED-bulbs was launched on the market. It is expected that these new products contribute to energy saving and carbon reduction as green devices. This article reviews technical progress and future possibility of which each factor connected to improvement of luminous efficacy.
LED and an OLED are rapidly gaining ground throughout the world as weapons for the fourth lighting revolution. As we look at current LED products, however, there are too many products that are not worthy of the lighting revolution and nothing but the replacement of conventional lightings. To realize the true lighting revolution, each institute on lighting should thoroughly pursue how lighting can be innovated with LED. Thus, we have to get back to lighting application, optical design, photometry, and colorimetry, when we design the LED fixture.
Using light emitting diodes (LEDs) as a light source for lighting has been increasing in the 21 century. It has become necessary to prepare safety standard before the problem will occur. Commission Internationale de l'Eclairage (CIE), International Electrotechnical Commission and Japanese Industrial Standards Committee already prepared safety standard or technical standard of lights and lighting systems including LEDs. However, there are many problems of the optical radiometry of LEDs, and unknown effects of non-visual physiological reaction induced by irradiation using LEDs. This paper describes these problems and future works.
In current practices of architectural planning, advantages of the LEDs are not always leveraged. We cannot deny that, in some cases, just using LEDs is prioritized over how they are used. Furthermore, the advantages of LEDs may not be made the most use of. In this article, the author gives his opinions about LEDs, apparently spotlighted under world-wide trend of suppressing greenhouse gas, from the perspective of applications to architectural planning.