Luminous flux measuring apparatus using an integrating hemisphere or an integrating quarter sphere

摘要

A luminous flux measuring apparatus includes an integrating hemisphere which has a hemisphere shape and an inner wall. The inner wall has a light diffusing material applied thereto. A flat mirror is installed to cover the first opening of integrating hemisphere. A second opening is located at the center of the flat mirror and the window has the same configuration of longitudinal cross section of the illuminant to be measured. A light detector which has a light-intercepting window is located inside the integrating hemisphere. Finally, the flux measuring apparatus includes a means for holding the illuminant in the window of the mirror at the center of curvature of the integrating hemisphere.