Patent ID: 8400696

Claim:
A three-dimensional image displaying apparatus, comprising: a spatial light modulation element having a discrete pixel structure and expressing a hologram; an illumination optical system generating reconstruction light by causing illumination light to enter said spatial light modulation element that expresses the hologram; a reconstruction image converting optical system displaying a reconstruction image by producing a virtual image wavefront-converted from the reconstruction light; a mask provided on the back focal plane of said reconstruction image converting optical system while said mask is located a predetermined distance away from said spatial light modulation element, said mask blocking at least light components obtained through diffraction of a different order other than the specified order in said spatial light modulation element; and an opening portion provided on said mask, said opening portion transmitting light components in the reconstruction light from said spatial light modulation element, wherein at least one of each interval between bright points and each initial phase value of the bright points is set such that peaks of the reconstruction light are produced at different plural points on the back focal plane of said reconstruction image converting optical system, the bright points constituting a target reconstruction image to be displayed, the reconstruction light reaching said opening portion where the observation of reconstruction image obtained through diffraction of the specified order is permitted.