| 摘要 |
PURPOSE:To easily check safety in the rear of a vehicle when a brake is applied, by displaying detection of a rear obstacle also at decreasing operation of the brake in addition to the time when a vehicle is reversely moved. CONSTITUTION:An ultrasonic wave transceiver 1, used with an ultrasonic vibrator excited by an excitation circuit 2a, is set to the rear part of a vehicle, and a signal transmitted from here is reflected by an obstacle and the reflected signal can be received. This received signal is input to an arithmetic unit 2b of a distance detect unit 2, and a distance to the obstacle is arithmetically obtained, then the distance is displayed in a display unit 3 by this output. While a back switch 5a, closed at a reverse gear position of a speed change gear, and a brake detector switch 6a, closed at depression of a brake pedal, are provided, in this way, the unit 2 can be connected to a power source unit 4 not only when the vehicle is reversely moved but also when the brake pedal is depressed, and the distance is displayed in the display unit 3. |
