The detection system for obstruction to vehicle according to the invention comprises a plurality of light emitting elements disposed in the rear of a car, a modulation for emitting modulation lights from the light emitting elements, light receiving elements for receiving the reflected light that the...http://www.google.fr/patents/US4891624?utm_source=gb-gplus-shareBrevet US4891624 - Rearward vehicle obstruction detector using modulated light from the brake light elements
Rearward vehicle obstruction detector using modulated light from the brake ...
