In a display system light from an object (14) is deflected on to a collimator (16) and superimposed on an external view through a combiner (10) from an observing position (11). Relay optics (17) in the path of light from the object (14) has spaced apart elements (L.sub.1,L.sub.2) which produce first...http://www.google.com/patents/US4714320?utm_source=gb-gplus-sharePatent US4714320 - Display systems
