This paper discusses the effectiveness of head-up displays (HUDs) in the following two major applications based on the results of preliminary visual-optical experiments: (1) as an interactive display system that improves both operating ease and display legibility; and (2) as a navigation system capable of giving drivers a large quantity of complex information efficiently and safely. It is shown that drivers can receive some critical or emergency information from their effective forward field of view while looking at a HUD, when the angle of depression of the display is small. The use of HUDs as interactive display systems can capitalize on the small angle of depression that is one of the advantages of the HUD design. that is one of the advantages of the HUD design. A new HUD system for navigation use is also proposed. Other advantages of HUDs include the long distance to the displayed image, and the ability to superimpose the displayed information on the forward view in a compatible manner. The use of HUDs in navigation systems can effectively exploit these advantages. It is thought that a navigation system built around a HUD could contribute to enhanced driving safety, because drivers need not divert their attention from the road in order to see the displayed information. (A)
Abstract