Patent ID: 7315408

Claim:
A display device for video holography, in which the device enables a holographic reconstruction of a three dimensional scene, made up of multiple discrete points, to be generated; the device including a light source and an optical system to illuminate a spatial light modulator encoded with a hologram; wherein the size of the reconstructed three dimensional scene is a function of the size of the spatial light modulator because the reconstructed three dimensional scene is anywhere within a volume spanned by the spatial light modulator and a virtual observer window through which the reconstructed three dimensional scene must be viewed and in which the spatial light modulator is controlled such that, when a hologram comprises a region with information needed to reconstruct a single point in the three dimensional scene, the point being visible from the virtual observer window, then the region (a) encodes information for that single point in the reconstructed three dimensional scene and (b) is the only region in the hologram encoded with information for that point, and (c) is restricted in size to form a portion of the entire hologram, the size being such that multiple reconstructions of that point caused by higher diffraction orders are not visible at the virtual observer window.