Optical imaging system with multiple paths arranged in parallel and a common entrance aperture

An optical imaging system comprising several optical pathways arranged in parallel, and for operation when a temperature of the system is included in a prescription interval, said system comprising:

• a matrix image sensor;
• and
• an imaging matrix, comprising several imaging optics which are disposed in parallel and adapted to form simultaneously, in useful zones of the matrix image sensor which are dedicated one-to-one to the imaging optics, respective images of a scene contained in an input optical field which is identical for all said imaging optics, the useful zones of the image sensor being disjoint and each imaging optic with the corresponding useful zone belonging to one of the optical pathways of the system separately from each other optical pathway;
• a thermal compensation device, disposed to produce a variable spacing between the imaging matrix and the matrix image sensor, and comprising, in at least one longitudinal cross-sectional plane which is perpendicular to the imaging matrix and to the matrix image sensor, a meander comprised of two segments each comprising a material whose thermal expansion coefficient value is different from that for the other segment, the two segments being connected to each other by respective distal ends of said segments, a proximal end of one of the segments being connected to the imaging matrix and a proximal end of the other of the segments being connected to the matrix image sensor, a difference between said thermal expansion coefficient values and respective lengths of the two segments being adapted to produce the variable spacing between the imaging matrix and the matrix image sensor so that images formed in the useful zones of said matrix image sensor are sharp when the temperature of the system has any value inside the prescription interval;
• and
• a baffle, disposed upstream of the imaging matrix with respect to a direction of propagation of a radiation that enters the system to form images, the baffle having an aperture for the radiation that is common to the optical pathways of the system,
• and the aperture of the baffle is dimensioned to laterally limit lighting in each image which is formed by any of the optical pathways, referred to as the optical pathway under consideration, in order to avoid said image overflowing into the useful zone of another of the optical pathways, next to said optical pathway under consideration, thus preventing any superimposition of images in all the useful zones, for any value of the temperature of the system in the prescription interval,
• and the distal ends of the segments of the thermal compensation device are located upstream of the imaging matrix with respect to the direction of propagation of the radiation which enters the system to form images,
• and the baffle is supported by the thermal compensation device upstream of the imaging matrix, also with respect to the direction of propagation of the radiation entering the system to form images.