Making Three-Dimensional Holograms Visible From All Sides

A technique for projecting holographic images to make both still and moving three-dimensional displays is undergoing development. Unlike older techniques based on stereoscopy to give the appearance of three-dimensionality, the developmental technique would not involve the use of polarizing goggles, goggles equipped with miniature video cameras, or other visual aids. Unlike in holographic display as practiced until now, visibility of the image would not be restricted to a narrow range of directions about a specified line of sight to a holographic projection plate. Instead, the image would be visible from any side or from the top; that is, from any position with a clear line of sight to the projection apparatus. In other words, the display could be viewed as though it were an ordinary three-dimensional object. The technique has obvious potential value for the entertainment industry, and for military uses like displaying battlefield scenes overlaid on three-dimensional terrain maps.