Patent ID: 6873443

Claim:
A document security system, comprising: a layer of photosensitive material; an optical modulator including an image of at least part of a document and positioned near or in contact with said layer of photosensitive material, said image of at least part of the document on the optical modulator being prerecorded or formed thereon by electrical control of an electrically controllable modulator; an optical device positioned between the optical modulator and the layer of photosensitive material and configured to image the image of at least part of the document of the optical modulator in a plane of the layer of photosensitive material; a beam-splitter plate; a first light source configured to emit a first wave to the beam-splitter plate, said beam-splitter plate retransmitting the first wave to the layer of photosensitive material; and a second light source positioned on a side opposite said layer of photosensitive material with respect to said optical modulator and configured to emit a second wave that is coherent with the first wave toward the optical modulator, said second wave being modulated by the image of at least part of the document of the optical modulator and the modulated second wave being transmitted to the layer of photosensitive material through the optical device and the beam splitter plate, said modulated second wave interfering with said first wave in the layer of photosensitive material to record a hologram including the image of at least part of the document.