Abstract: Display adapted to the local configuration, so that it does not cause a mask during observation. It comprises an entirely transparent optical module grouping a spherical mirror, which is preferably a partly transparent diffractive optics used on the axis, and a partly transparent flat mirror inclined with respect to the axis. The mirrors are joined at the bottom by a bonded plate and assembled at the top by a thin part, whose faces pass through the centre of the spherical mirror. The electronic part is essentially located in a case, whose shape is such that it is located in the natural mask of a pillar of the cockpit. The display is also used for helmet displays.

Abstract: A sight such as a gunsight for a helicopter comprises a movable assembly including a reticle generator and a single optical component which is both semireflecting and capable of collimating the image of the reticle. The movable assembly is driven by drive means under servo control to superpose the image of the reticle at an aiming point on a landscape. The aiming point may be computed to make corrections for the behaviour of a ballistic weapon. The single optical component may comprise a hologram physically in the shape of a portion of a surface of a sphere, but acting optically like a portion of the surface of a paraboloid. The optical component may be fixed to the reticle generator by mechanical fixing means which mask the field of view around the optical component very little.

Abstract: A helmet-mounted system for display of complex video images projected to infinity with a miniature cathode-ray tube, an optical device for transferring the image from the tube to the focal surface of a spherical mirror, and a semi-reflecting plane mirror in the form of a thin film. The image projected to infinity by the spherical mirror which is utilized on the axis is reflected from the plane mirror while enabling the viewer to see his normal surroundings at the same time. The collimating unit is advantageously constituted by two juxtaposed and cemented prisms.