Development of measuring method of total luminous flux of LEDs and its application to general illumination

Abstract

Total luminous flux is one of the most important optical properties for LEDs and it is commonly measured with integrated sphere and V(lambda) (spectral responsivity corrected) photo detector, applied to conventional vacuum system light sources. As construction and energy converting processes of LEDs are largely different from those of conventional sources, additional investigation is necessary for applying V(lambda) photo detector to LED sources. In order to solve these problems, measuring system with integrating sphere and spectrophotometer has been investigated. Total luminous flux of oval type LEDs are measured with this system and a spectral power distribution standard incandescent lamp. Approximately equivalent value could have been obtained to measured values with the conventional V(lambda) photo detector system, and some of future investigating items could have been made clear.