| 摘要 |
PURPOSE:To realize the transmission and reception of light in a distance longer than ever, by arranging a great number of transmission lenses with small diameters in the neighborhood of a reception lens annularly while the reception lens is formed as a lens with a large diameter. CONSTITUTION:The titled device is equipped with the reception lens 13 with the large diameter provided with a light receiving element 15 on an optical axis, the transmission lens 12 with the small diameter, plural sets of which are arranged in the neighborhood of the reception lens 13 annularly and provided with a light emitting element 14 on the optical axis, and a transmitter-receiver connected to the light receiving element 15 and the light emitting element 14. Therefore, it is possible to increase light receiving sensitivity with comparatively simple constitution and by forming the reception lens 13 larger, and to easily increase a light transmission output. Also, since a great number of transmission lenses 12 are arranged along a concentric circle around a light receiving optical axis, it is possible to respond with an average transmitting optical axis. Consequently, even when the deviation of an angle between the receiving optical axis and an individual transmitting optical axis exists to a certain extent, the difference of the angles is offset by averaging a great number of optical axes, and an average transmitting optical axis coincides with the receiving optical axis. In such a way, the distance margin of the transmission and reception of the light can be extended. |
