US 11,892,355 B2
Very wide-angle viewing accessory for infrared detector
Christophe Martinsons, Le Touvet (FR); and Pierre Lepretre, Grenoble (FR)
Assigned to CENTRE SCIENTIFIQUE ET TECHNIQUE DU BÂTIMENT (CSTB), Champs-sur-Marne (FR)
Appl. No. 17/419,989
Filed by CENTRE SCIENTIFIQUE ET TECHNIQUE DU BÂTIMENT (CSTB), Champs-sur-Marne (FR)
PCT Filed Jan. 8, 2020, PCT No. PCT/EP2020/050310
§ 371(c)(1), (2) Date Jun. 30, 2021,
PCT Pub. No. WO2020/144230, PCT Pub. Date Jul. 16, 2020.
Claims priority of application No. 1900159 (FR), filed on Jan. 8, 2019.
Prior Publication US 2022/0082443 A1, Mar. 17, 2022
Int. Cl. G01J 5/07 (2022.01); G01J 5/00 (2022.01); G02B 17/06 (2006.01); G02B 17/08 (2006.01); H04N 5/33 (2023.01)
CPC G01J 5/07 (2022.01) [G01J 5/0025 (2013.01); G02B 17/061 (2013.01); G02B 17/0808 (2013.01); H04N 5/33 (2013.01)] 10 Claims
OG exemplary drawing
 
1. An optical device, intended to be arranged on a detector equipped with an infrared sensor in order to increase an angle of the field of view of the detector, comprising:
a primary mirror of circular overall shape, comprising a circular opening at its center,
a secondary mirror of circular overall shape and of diameter smaller than the diameter of the primary mirror, comprising a circular opening at its center,
at least one connecting means for connecting the primary mirror and the secondary mirror, so as to arrange a reflective surface of the primary mirror facing a reflective surface of the secondary mirror,
the primary and secondary mirrors being designed to reflect radiation in the infrared; and
the primary mirror and the secondary mirror being configured to form an afocal system and to form a continuous very wide-angle image with the center of the image obtained by the central circular openings, the angle (α) of the field of view of the device being greater than 90°.