Electronic measurement device determining distance between two cars - uses reflected beam to determine distance and detect when car in front starts to move

摘要

The measurement device has a box (1) attached to the front of the vehicle (B), generating an infra-red, laser or ultrasound beam which is directed towards a second vehicle (A) in front of the first vehicle. A receiver in the same box detects any signal reflected from the vehicle. An electronic circuit within the vehicle evaluates the distance between the first and second vehicles from the reflected beam, and activates a warning when this distance starts to increase. USE - Device warns driver when car in front in traffic jam starts to move.