Abstract: A compact optical device used to superimpose an intensified infrared image onto a visible image to allow night vision. It can especially be used to make goggles to be worn under the visor of an aircraft or helicopter pilot's helmet. The device includes a combiner located in front of the pilot's eye for directly transmitting visible light to the pilot and an objective for receiving infrared light which is placed above the combiner. An optical system guides the light received by the objective towards the combiner to be forwarded to the pilot's eye. The light is guided in a single plane substantially perpendicular to the plane containing the light received by the objective. The optical system includes a light intensifier, a transport objective, an even number of mirrors to fold the optical circuit and an eye piece.

Abstract: This device is characterized in that it includes removable indexing and locking devices of the light intensifier assembly on the stationary imager operating in combination with opening and closing control devices of a light shutter of said stationary imager in such a way that the locking or unlocking of the intensifier assembly simultaneously causes the opening or closing of shutter, and that all the operations can be carried out with one hand only and blindly.