US Patent 7690799 Optical relay for compact head up display

Briefly, in accordance with one or more embodiments, an optical relay for a head up display, the optical relay comprises a glare trap having angularly selectivity by being capable of reflecting light having an angle of incidence greater than a first angle, and being capable of transmitting light having an angle of incidence less than a second angle, and a first optic arranged to receive light reflected off the glare trap at an angle of incidence greater than the first angle, and to direct light through the glare trap at an angle of incidence less than the second angle to exit the glare trap.