Viewable floating displays using simple secondary optical elements

Two displays that enable the formation of floating images in the air are proposed. A high-refresh-rate monitor and two Fresnel lenses are used in the first demo system to create the real image in the air. The second demo system is composed of a slanted lenticular sheet and multiple semi-transparent mirrors. The floating 3D image can be observed by multiple users simultaneously. The principle and performance of the proposed displays are analyzed in this paper. Two prototypes of the viewable floating displays have been built. The results indicate that the displays are a feasible means of producing the illusion of images with depth.