| 摘要 |
PURPOSE:To expand the required reception range by arranging photodetectors at the circumference of the receiver while the photodetecting face is directed outward arranging them in a recessed part toward a floor face with a prescribed tilt angle. CONSTITUTION:Infrared ray photodetectors 1011, 1012, 1013 are provided to the surrounding of the receiver while the photodetector faces 1011, 1012, 1013 are directed outward, the photodetection part of the infrared ray photodetectors 1011, 1012, 1013 is projected from a bottom face 104c of a crater recessed part 104b formed to the surface cover 104 with respect to the reflecting face 104a and the photodetector faces 1011, 1012, 1013 are tilted toward the floor with a tilt of alpha=60 deg. at the inside of a filter 101a and connects electrically to an electronic circuit board 105 fixedly. Thus, the photodetection range not required is decreased and the photodetection range of the required part is magnified. |
