| 摘要 |
PURPOSE:To concentrate a control circuit and thereby to reduce the number of light emitters and light receivers, by fitting the light emitters and light receivers to a tower on the same side, by making lights reflected, and by detecting different positions by forward and backward lights. CONSTITUTION:A tower 11 emitting and receiving lights and a reflecting tower 12 are installed on the opposite sides of a road. Inside the tower 11 are fitted light emitters L1-L4 and light receivers S1-S5. Inside the tower 12,a mirror 13 is fitted. A light emitted from the light emitter L1 is reflected by the mirror 13 and the reflected light is received by the light receivers S1 and S2. The light from the light emitter L2 is received likewise by the light receivers S2 and S3. The directivity of the light emitter L2 is adjusted by a lens system so that the light therefrom covers a range phi1 on the mirror 13 and a range phi2 in the tower 11, as shown by dotted lines. By this constitution, a resolution is doubled compared with that of conventional devices. |
