Aerial Display Using Lenticular Lenses

An aerial display that can float a two-dimensional image or a three-dimensional object in an empty space is important as a noncontact interface. Aerial displays have two types: a reflection type that uses a mirror and a refraction type that involves a lens. The latter has the advantage of being easily miniaturized because the path of light does not bend much. The method using two commercially available lenticular lenses is inexpensive. However, the principle of the method is not yet fully understood. In this study, the rules of light rays passing through the lens were applied to explain this principle clearly. For further confirmation, a simulation was performed. Results revealed that the lens group consisting of two convex lenses arranged at the interval of twice the focal length as well as the lens group consisting of three convex lenses arranged at intervals the focal length reflected parallel rays coming from an angle as if they were mirrors. When the number of lenses was set to 3, the viewing range widened.