Abstract: A device to determine the position of a mobile object with respect to an immobile object, wherein it comprises means to emit a beam of infrared light fixed on the mobile object to illuminate at least partially the immobile object, means to receive the reflected beam fixed onto the mobile object and means to analyze the reflected beam to delimit its variations in intensity, the emission means being constituted by at least one electroluminescent diode whose beam is focused.

Abstract: A device to detect holes in a continuously winding strip of material of the type formed of a vertical frame which, placed in the path of said strip of material via a horizontal slot delimiting said frame into two upper and lower bodies, each opening onto said slot via windows opened opposite one another, said upper body being intended to support a first optical sub-assembly for emission for a source of light in the direction of said strip passing below said upper body, and said lower body being intended to support a second optical sub-assembly for reception for said light emitted by said first sub-assembly and able to filter through said holes in said strip of material passing above said trip, wherein said first optical sub-assembly for emission is constituted by a stimulated emission of radiation, called laser radiation, and said optical sub-assembly for reception is constituted by photodiodes sensitive to the low luminous flux emitted by said laser radiation.