摘要 |
A head up display system 10 comprises an image generator 11 supported and boresighted within a cockpit. The system 10 includes a housing 13 to support the generator 11 and a holographic combiner 14 which is upstandingly supported on top of the housing 13. In operation, the generator 11 forms an image at object surface 17 and a relay lens arrangement 16 receives, collimates and conveys the image along an optical pathway 19 and through an exit pupil 18. A prism 20 and a mirror 21 are arranged along the pathway 19 to fold the pathway 19 from a generally horizontal direction to a generally vertical direction towards the combiner 14. The image enters the prism 20 and is totally internally reflected from a first portion 31 of a first reflection surface 29 towards a first portion 33 of a second reflective surface 30 where it is again totally internally reflected through a second portion 32 of the first surface 29 which allows the image to pas therethrough for reflection by the mirror 21 back through the second portion 32 and through a second portion 34 of the second surface 30 and on to the combiner 14. <IMAGE> |