| 摘要 |
PROBLEM TO BE SOLVED: To provide a photometric device in which a photodetector receives sufficient light quantity at an appropriate light receiving angle. SOLUTION: This photometric device is constituted of a photometric window 19, a circuit board 22 and a mask member 25. The circuit board 22 is provided with the photodetector 23 for measuring the luminance of a subject. The member 25 is positioned between the window 19 and the photodetector 23 arranged at the inner part of the window 19. Plural circular light receiving holes 25a are bored on the member 25. The diameter T1 of a light receiving surface 49a and the diameter T2 of the window 19 show nearly T1=T2=6mm. The holes 25a are closely arranged to be honey-combed within the range of the diameter T2 of the window 19. The hole 25 whose diameter t1 is about 1 mm and whose depth is about 8 mm restricts the light receiving angle of the surface 49a to a very narrow range. Since the plural holes 25a are formed, the sufficient light quantity is received by the surface 49a. |
