| 摘要 |
PROBLEM TO BE SOLVED: To improve light receiving characteristics, by constituting an aperture having a thin wire shield member formed in a concentric circle, in the front, concerning a center on a line stretching a shield case from the center of a receiving part toward the front. SOLUTION: A circular aperture 11 is formed in the front face 10f of a shield case 10. A light receiving center C is the center of light receiving function of a light receiving element 20 in the shield case 10. An axis A which passes the center C and stretches to the front on the light receiving function of the light receiving element 20 is made constitution passing the circle center of the aperture 11 of the shield case 10. In the circular aperture 11, a thin wire shield member on a ring is formed in a unified body with a shield case 10 on a concentric circle concerning the circle center of the aperture 11. The distance from the light receiving center C to the circular outer edge of the circular aperture 11 is constant at all angles setting the axis A as a center. The distance as far as the thin wire shield member is also constant at all angles setting the axis A as a center. Therefore, the receiving state is constant for movement in all directions, and receiving characteristics can be improved. |
