Luminous flux homogenizing mechanism, illuminating optical system, light-receiving optical system, reference optical system, and colorimeter

The objective of the present invention is to increase the homogeneity of a reflection coefficient of a diffuse reflecting surface possessed by a luminous flux homogenizing mechanism, and to increase the reflection coefficient of a diffuse reflecting surface possessed by a luminous flux homogenizing mechanism, without making the luminous flux homogenizing mechanism costly. An integrating sphere is provided with a base material and a film. A space is formed in the base material. The inner surface of the base material defines the space. The base material comprises a white resin, and reflects luminous flux. The film is formed by coating a transparent matte coating material onto the inner surface of the base material, and said film causes the luminous flux to diffuse. 本发明涉及光束均匀化机构、照明光学系统、受光光学系统、参照光学系统及测色计，不使光束均匀化机构变得昂贵，而提高光束均匀化机构具有的漫射反射面的反射率的均匀性，提高光束均匀化机构具有的漫射反射面的反射率。积分球具备基材以及被膜。在基材形成有空间。基材的内表面规定空间。基材由白色树脂构成，反射光束。被膜是通过将透明的消光涂料涂装于基材的内表面而形成的，使光束漫射。