METHOD OF PRODUCTION OF RELIEF-PHASE HOLOGRAPHIC PROTECTIVE MARK Russian patent published in 1998 - IPC

FIELD: holography. SUBSTANCE: electronic hologram is exposed onto a layer of electronic photoresist located on a precoat made of material that is opaque to optical radiation, and then it is developed. After development a layer of optical photoresist is applied onto the obtained relief of electronic hologram, analog hologram is exposed onto sections of optical photoresist that do not overlap the relief of electronic hologram, then an additional illumination of the layer of optical photoresist is accomplished with an exposure known to be longer than it is necessary for exposure of analog hologram, and is developed again. Prior to application of the layer of optical photoresist, the obtained relief of electronic hologram is transferred to the precoat, and additional illumination of the layer of optical photoresist is accomplished on the side of the precoat, or prior to application of the layer of optical photoresist, the obtained relief of electronic hologram is hardened through mask and additionally developed; additional illumination of the layer of optical photoresist is accomplished through the same mask. EFFECT: enhanced protection of documents. 3 cl, 2 dwg