| 摘要 |
PURPOSE:To discriminate the sizes of vehicles and to detect the presence and passage of the vehicles accurately with high resolution by detecting the intensity distributions of the reflected light by irradiation of the laser diode light responding to oscillated outputs and discriminates in accordance with the special and time serial change in the intensity of the reflected light. CONSTITUTION:In response to the clocks of a pulse generator 1, a laser diode 4 emits light through a driver 3, and a laser light is irradiated to a road 6 in the beam pattern 7 of narrow width having high resolution over the entire width of the road. The laser light reflected from the road 6 or a vehicle, etc. is detected with a photodiode array 9, and is detected synchronously by a detector group 10. The detected light is processed with an A/D converter group and the digital bit information corresponding to the distributions of the detected intensity of the reflected light is written in a memory 12. This information is read, and a discriminator 13 makes discrimination in accordance with the special and time serial change in the intensity of the reflected light corresponding to the vehicle, etc., whereby the sizes of the vehicles are detected and the presence and passage of the vehicles are detected accurately with high resolution. |
