Turboult Jean, Morion Marcel: Headup display systems for aircraft piloting. CSF Compagnie Generale de Telegraphie Sans Fil, September 28, 1971: US3609023 (4 worldwide citation)

A lighting arrangement for illuminating reticles in a headup display system comprises a hollow shaft having opaque walls and fixed to a movable assembly controlled in position, the reticle being formed in an end wall of this shaft, and a lampholder slidably mounted in this shaft for carrying plugin ...