| 摘要 |
PROBLEM TO BE SOLVED: To perform bi-directional communication with a on-vehicle communication device and detection of a vehicle with a single light-emitting part, drive part, photo- detecting part, and amplification part by providing a signal addition part, etc., wherein sensing light-projection pulse signal and communication pulse modulation signal are added together. SOLUTION: Communication modulation pulse signal 101 generated at a communication modulation pulse signal generating part 5 and sensing light-projecting pulse 117 generated at a sensing light-projecting pulse generating part 20 are added together at a signal addition part 21, and a common light-emitting part 23 projects common irradiation light 120. The common irradiation light 120 is photo-detected not only with an on-vehicle communication device 3 but with a common photo-detecting part 24 as reflection light 121 from a road surface 1 and a vehicle 2. An irradiation light 104 of transmission data from the on-vehicle communication device 3 is also photo- detected with the common photo-detecting part 24. An amplification signal 123 of a reception signal 122 which is the output of the common photo-detecting part 24 is distributed into two channels with a signal distribution part 26a. One of them is used for vehicle detection while passing the first BPF 27, while the other is signal- processed with a signal processing part 11 while passing the second BPF 28. |
