On the number of viewing zones required for head-tracked autostereoscopic display

A head-tracked display could be made from a two-view autostereoscopic display where head-tracking allows the display to swap the two views when the eyes move from viewing zone to viewing zone. Variations in human interpupillary distance mean that this basic two-view version will not work well for the significant minority of the population who have interpupillary distance significantly different from the average. Woodgate et al. proposed, in 1997, that a three-view system would work well. Analysis of an ideal version of their proposal shows that it does work well for the vast majority of the population. However, most multi-view, multi-lobe autostereoscopic displays have drawbacks which mean that, in practice, such a system would be unacceptable because of the inter-view dark zones generated by the inter-pixel dark zones on the underlying display technology. Variations of such displays have been developed which remove the inter-view dark zones by allowing adjacent views to overlap with one another: the views appear to smoothly blend from one to the next at the expense of a little blurring. Such displays need at least five viewing zones to accommodate the majority of the adult population with head-tracking and at least six viewing zones to accommodate everyone.