| abstract |
Light from an image displayed on a display screen 10 is transmitted to an observer's eye 11 by way of a dynamic optical element 12 (such as a spatial light modulator or an electrically switchable holographic composite) which acts as a lens. The characteristics of the dynamic optical element 12 can be altered so that it acts sequentially to direct light of different colors to the observer's eye. n In one optional embodiment emitters 17 on the display screen 10 emit infra-red radiation which is projected by the dynamic lens 12 as a broad wash onto the eye 11. Infra-red radiation reflected back from the eye 11 is focussed by the dynamic lens 12 onto detectors 18 also provided on the display screen 10. The detectors 18 are thus able to sense the direction of eye gaze, and the dynamic lens 12 is controlled in dependence on this to create an area of high resolution in an area of interest centered on the direction of gaze, which is moved to follow the eye gaze as its direction alters. Other than in the area of interest, the dynamic lens 12 has a relatively low resolution. |