Head-up display independent test site

摘要

An independent test sight is described for a pilot's head-up display (HUD). In one embodiment, the independent test site comprises a collimator assembly and an aligned periscope assembly. The collimator assembly comprises a source of light, a reticle, and a lens for projecting the image of the reticle. The periscope assembly comprises a rhomboid prism housed within the chassis of the HUD in such a manner that it can be pivoted from a stowed position to an erect position where it projects a reticle pattern in the field of view of the HUD combiner.