| 摘要 |
PURPOSE:To attain automatically the display of presence of an opposite car and the mutual talking, by irradiating a call signal for communication among cars and a presence confirming signal of other cars at an intersection as different ultrasonic waves. CONSTITUTION:When a driver operates a confirming switch 120, signals of prescribed plural periods are outputted from a time set circuit 34, a signal exciting an ultrasonic wave oscillator appears at an output of a power amplifier circuit 44 via a gate 35, a confirming ultrasonic wave is irradiated from an antenna 311 and received with other cars. On the other hand, a call signal in a frequency different from that of the confirming ultrasonic wave is outputted from an oscillating circuit 100 with the off-hook and a transmission switch 13 turned on at calling, and irradiated from an antenna 312. As a result, the mutual talking with other cars is attained. |
