| 摘要 |
PURPOSE:To obtain this device that uses a condensing optical system that photometry distribution is altered, by forming a photometry distribution change means to one portion of the condensing optical system. CONSTITUTION:A diffusion surface 6 is made up to an optical axis portion of a lens 13 applied to this photometry device as a means that modifies photometry distribution. The diffusion surface 6 is built up by means of a mat surface of frosted glass, etc., a diffraction grating surface, etc., and has diffusion characteristics that rays projected to at least this portion diffuse in value larger than a photometry element surface. Photometry distribution is altered because some portions of rays passing through a central portion of the lens 13 are not projected to a photometry element by diffusion. |
