EFFECTS OF NON-UNIFORM SPATIAL RESPONSE DISTRIBUTION FUNCTIONS OF INTEGRATING SPHERE ON THE TOTAL LUMINOUS FLUX MEASUREMENT OF PANEL LIGHT SOURCE

摘要

Integrating sphere (IS) is commonly used to measure the total luminous flux emitted from a light source. Although the spatial response inside IS should be theoretically uniform regardless of the location of the IS, due to the dusts and some other causes, the spatial response distribution function (SRDF) of IS is not uniform. This nonuniformity mediates non-uniform distribution of the illuminance. For the light source has a planar configuration such as Organic LED (OLED) panel, this nonuniform SRDF might be affected to the total luminous flux depending on the size of the light source. Moreover, the larger the difference of SRDF inside IS, the larger the measurement errors. In this research, we assume the reflectance of the hemisphere walls to be uniform, and that the difference between two hemispheres were changed. Our simulation results show that the larger the size of the light source, the larger the effects on the total luminous flux. When the reflectance of the lower hemisphere is lower than 90%, the effects of the size are evident.