| 摘要 |
PURPOSE:To obtain a device which can measure light under uniform conditions and has no deficiency of sensitivity by combining a photodetector group disposed on a spherical surface centering at the position of a diffusion plate concentrically with the optical axis and a lens which forms the image of the light source to be measured on the diffusion plate. CONSTITUTION:An interference filter 1 and a photodetector 2 are disposed on a spherical surface centering at the position of a diffusion plate 3 concentrically with the optical axis 5 running through the center of the plate 3 and intersecting orthogonally with the plane thereof. A lens 4 is disposed movably toward the axis 5 in such a way that the image of the light source to be measured is formed on the plate 3. The lens 4 consisting of a lens of such brightness (F value) at which the angle 7 that the effective aperture of said lens makes over the plate 3 is larger than the angle 6 between the axes of the photodetectors 2 and the axis 5. |
