| 摘要 |
PURPOSE:To remove mirror surface reflected light from a sample and to reduce the size of an integrating sphere by maintaining a diffuse lighting and vertical photodetection system lighting optical system for mirror surface reflected light removal. CONSTITUTION:A cylinder 2 is projected in the integrating sphere from its top surface, its projection end opening part is used as a colorimetric area control opening, and a photodetection opening is provided in the cylinder. The cylindrical internal surface up to this opening is processed for light absorption, and a collar part by after light absorption processing is provided on the outer peripheral surface of the cylinder 2 which faces a sample 3. Here, the outer periphery of the collar 7 is positioned outside a mirror surface reflected light line C-D having a maximum angle of incidence to the center line of the cylinder 2 and inside a maximum incidence angle E-F-D of incidence on the center E of the photodetection opening A while put as close to a point D as an intersection of two light beams as possible. Namely, the outer periphery of the collar 7 on the sample surface side is at the point D. Consequently, light within a certain angle range including perpendicularity is incident on the photodetection surface from the sample control range, and consequently a mirror surface reflected component is mixed, but it is cut off by the collar 7 and the angle of light projection on a sample measurement area is controlled. |
