Real-time automultiscopic 3D video display using holographic optical elements (HOEs)

摘要

An inexpensive electronic display that presents 3D images by binocular parallax is disclosed. The effect produced is that of a real- time holographic stereogram. The pixels of a 2D display are spatially multiplexed by two HOEs to produce a plurality of lateral viewing zones of 2D rasters, similar to the method used in lenticular screen systems. A directional screen HOE scatters incident light over a lateral viewing zone so small that typically only one eye of a viewer can occupy it at a time. A multiplexer HOE comprised of thousands of tiny holograms, each when reconstructed projects a spot onto the directional screen HOE. The sum of all these spots forms a two-dimensional raster of spots on the directional screen HOE. Each spot can be projected onto the directional screen HOE from at least two laterally different angles and thus reconstruct the directional screen HOE from at least two laterally offset angles, consequently creating at least two laterally offset viewing zones of each spot. A real-time 2D image generator is used to control the brightness of light entering or immediately after exiting each hologram or portion of each hologram of the multiplexer HOE. Varying the 2D image generated thus varies which spots are visible in each viewing zone and thus the automultiscopic (or autostereoscopic) image the viewer sees. When each view presented corresponds to a 2D perspective view of an image, the viewer perceives a 3D image.