| 摘要 |
PURPOSE:To attain personal talking without being intercepted by the 3rd party between automobiles running comparatively closely by using a light excellent in the directivity as a communication medium. CONSTITUTION:A front light emitter and photodetector 1 and a rear light emitter and photodetector 2 are provided to front and rear parts of an automobile and the photodetectors 1, 2 are connected to a handset 11 in a cabin. Then reception signals 1a, 2a, from the photodetectors 1, 2 are fed to a call detection circuit 6 and a reception circuit 8, the circuit 6 uses the presence of the signals 1a, 2a to discriminate whether the signal comes from the front or the rear part and a call tone is generated from the circuit 8. When selection signals 4a, 5a from selection switches 4, 5 are not inputted to a changeover circuit 7, then switching signal 7c, 7d to change over the devices 1, 2 according to discriminating signals 6a, 6b from the circuit 6 are outputted. Further, the selecting state of the devices 1, 2 is displayed in response to the signals 7c, 7d to a display device 10. Then a light excellent in the directivity is used as a communication medium and a personal talking is attained between automobiles running comparatively closely. |
