JPS56126705A - Diffusion illumination device - Google Patents

Abstract

PURPOSE:To make it possible to illuminate a substance to be measured uniformly with low output by a single light source by arranging a rotary prism inside an integrating sphere and also by making the rotating shaft thereof being in accord with the optical axis of an illuminating light introduced into the integrating sphere from a light introduction port provided at the integrating sphere. CONSTITUTION:The column-shaped rotary prism 2 driven for its rotation by a motor 10 is installed in the semispherical integrating sphere 1. The rotating shaft of the rotary prism 2 is set to be in accord with the optical shaft of the illuminating light introduced from the light introduction port 5 and, in addition, one end surface of the prism on the side of the light introduction port 5 is finished to be a mirror surface, while being formed into a slant surface titled at an angle of 45 deg. to the rotating shaft and the optical axis. Moreover, inside the light introduction port 5, a half mirror 6 tilted likewise at an angle of 45 deg. to the optical axis. Thus, the illuminating light falling into the integrating sphere 1 from one direction is diffused throughout the whole area of the inside of the integrating sphere 1, whereby uniform diffused illumination by means of the single light source can be obtained.