Patent ID: 7061656

Claim:
A hologram duplicating apparatus adapted for duplicating a hologram in which a holographic stereogram is used as an original, the hologram duplicating apparatus comprising: a first optical system for allowing a first object light, which has been image-modulated on the basis of respective element images of a parallax image sequence to be incident on a first surface of a first hologram recording medium without diffusion, and for allowing a first reference light having coherence with the first object light to be incident on an opposite surface of the first hologram recording medium so as to successively carry out exposure recording of interference fringes produced by the first object light and the first reference light on the first hologram recording medium as element holograms, thereby producing the original; a second optical system for allowing a diffracted light obtained by irradiating a first reproduction light onto the original for reproducing the original to be incident as a second object light on a first surface of a second hologram recording medium disposed with a predetermined distance from the original, and for allowing a second reference light having coherence with the second object light to be incident on an opposite surface of the second hologram recording medium to carry out exposure recording of interference fringes produced by the second object light and the second reference light on the second hologram recording medium as holograms, thereby producing an intermediate hologram; and a third optical system in which a one-dimensional diffusion plate for diffusing incident light in a one-dimensional direction is disposed at a first surface of a third hologram recording medium disposed with a predetermined distance from the intermediate hologram produced by the second optical system in such a manner that the principal surface thereof is in contact therewith, the third optical system for allowing a diffracted light obtained by irradiating a second reproduction light onto the intermediate hologram for reproducing the intermediate hologram to be incident on the first surface of the third hologram recording medium as a third object light through the one-dimensional diffusion plate, and for allowing a third reference light having coherence with the third object light to be incident on an opposite other surface of the third hologram recording medium to carry out exposure recording of interference fringes produced by the third object light and the third reference on the third hologram recording medium as holograms, thereby producing a duplicated hologram.