Discomfort glare caused by white LED light sources

It is expected that lighting employing white LED will become popular in the future. However, the influence of the arrangement as well as the number of LED lights and luminance distribution of the surface of light sources on discomfort glare has not yet been clarified. The aim of this study is to clarify such influences by conducting an experiment using simulated light sources. The results of the experiment show that the closer the ratio of luminance of the peripheral area against luminance of the LED lighting (luminance of the peripheral area/luminance of the LED lighting) is to 1, the smaller the discomfort glare. It is also clarified that when the total area of the light source is constant, although the BCD average luminance increases as the number of LED lights increases, the level of increase in the BCD average luminance is smaller than that in the number of LED lights. Further, when the interval of LED lights is constant, it is found that although the BCD average luminance decreases as the total area of the light source increases, the level of the decrease is smaller than the level of the increase.