Infrared sensor device for motor-vehicles, adapted for detecting presence of an overtaking vehicle

摘要

An infrared sensor device for motor-vehicles, designed to detect the presence of an overtaking vehicle, comprising at least two cells sensitive to infrared radiation, placed on one side of the reflecting plate on the outside rear view mirror of a motor-vehicle, behind focusing optics. Each cell emits a signal proportional to the infrared radiation it receives. An electronic circuit emits a global signal proportional to the difference between the signals emitted by the two cells, so that said global signal enables the presence of an overtaking vehicle to be distinguished from that of other vehicles travelling in the opposite direction, as well as avoiding false alarms due to electronic and electromagnetic noise.