| 摘要 |
PURPOSE:To attain the reception of a wide angle of optical signal, long range transmission, to improve the reliability and to make the size small through the use of a light receiving element with a small light receiving area by forming a recessed part to a bottom face of a convex lens for light reception and providing a 2nd curved face lens. CONSTITUTION:A light receiving element 1 is arranged in the middle of a amount plate 5, four light emitting elements 3 are arranged at an equal interval on a concentric circle around the element 1 and 8 light emitting elements 8 are arranged at an equal interval on the concentric circle of the outer circumference. Moreover, a convex lens 6 of an elliptic shape is used as a wide angular lens to the light receiving face of the element 1 and arranged to the front part of the light receiving face of the element 1. Then a 2nd curved face lens whose concaved part 21 is formed to a bottom face corresponding to the light receiving face of the element 1 and even if an incident angle theta of an optical signal (x) is large, the light is refracted toward the light receiving face at the border between the concaved part 21 and the convex lens 5. Thus, even if the element 1 with a small light receiving area is in use, a wide angle application is attained, the long range transmission of the light projection section is attained, the reliability is improved and the size is made small. |
