Binocular Disparity and Head-Up Displays

Abstract

Collimation errors present in displays such as the head-up display (HUD) will produce retinal disparity on the retinae of the observer and will have the effect of altering the spatial location of the display. It is apparent that this can, in some instances, give rise to visual discomfort. Psychophysical methods were used to examine the sensitivity and the tolerances of the visual system to binocular disparity in HUDs. It was shown that, when left to their own devices, subjects preferred a small positive disparity to exist between the HUD and the outside world and that even small amounts of negative disparity can have a disturbing perceptual effect. The effect is discussed in relation to the contradictory depth cues which can exist in this kind of electro-optical display.