Optical system for range finding sender:receiver - has infrared LED and focussing optical system preventing collision of vehicles

摘要

The range finding appts. can be carried on vehicles including track vehicles in e.g. mines. It protects against possible collisions. The sender has a l.e.d. and a focussing optical system to transmit a focussed, intensity modulated infra-red beam. A receiver, coaxial with the light beam, has a photodiode for reception of a reflected part of the i.r. beam. An evaluating device following the receiver responds to the reflected light phase and generates a signal corresponding to the distance to the reflecting object. The focussing device is a parabolic reflector with the l.e.d. at its focus. It is concentrical with the receiver.