Patent EA-000355-B1 (EA)
Title: Method of protecting precious metal articles from copying (variants)
Inventor: PUTILIN ANDREI NIKOLAEVITCH
IPC: B23H9/06
Filed: 1996-06-25
Abstract: 1. Method of protection precious metal articles from copying in which an image of the marker is produced on the surface of the article and its further visual identification, characterized in that the marker on the surface of an article made of gold or other precious metal is formed as a combination of a holographic microelief and a macrorelief, and identification of the marker image is performed, putting its hologram in the field of a restoring wave. 2. Method according to Claim 1, wherein the macrorelief portions are formed by a electric-spark method. 3. Method of protection precious metal articles from copying in which an image of the marker is produced on the surface of the article and its further visual identification, wherein said marker on the surface of the article made of gold or other precious metal is formed as a constituent hologram, for which the holographic microrelief, on which a hidden image is applied in the form of a encoded hologram, and the marker is identified by a visualization of the hidden image, for which said compound hologram is put into the optic field of the wave, restoring the encoded hologram 4. Method according to Claim 1, wherein the encoded hologram on the holographic micro-relief of the marker is formed, using several reference beams of point sources, having predetermined location in space, and the restoring wave at the identification of the marker is produced, putting coherent light sources in the points, where reference beams were located. 5. Method according to Claim 4, wherein the encoded hologram on the holographic microrelief of the marker image is formed as a synthesized multiplex hologram, comprising combination of holograms of each symbol of the hidden image. 6. Method according to Claim 5, wherein in the synthesized multiplex hologram separate holograms of symbols of the hidden marker image are produced by removing the microrelief crowns in microportions, which in combination form a negative image of two-dimensional Fourier-conversion of the hidden image symbol. 7. Method according to Claim 5, wherein a polished hologram is concealed by applying on it another multiplex constituent hologram, comprising holograms of several images, and for visualization of the hidden image a preliminary made amplitude, phase code mask is used, having transparent openings for the beams of the hidden image. 8. Method of protection precious metal articles from copying in which an image of the marker is produced on the surface of the article and its further visual identification, wherein said marker on the surface of the article made of gold or other precious metal is formed as a holographic microrelief on which a film of an amorphous diamond-like substance is applied, and the marker image is identified by putting its hologram in the field of the restoring wave. 9. Method according to Claim 8, wherein applying the film, the film thickness is less on the microrelief crown than that on its grooves. 10. Method of protection precious metal articles from copying in which an image of the marker is produced n the surface of the article and its further visual identification, wherein said marker on the surface of the article made of gold or other precious metal is formed as a multiplex constituent hologram, the microreliefs of which are spatially-shifted towards each other to a distance lesser the length of the restoring wave, further a transparent film of dielectric is applied on several portions of the constituent hologram so as at the visual identification of the marker in the restoring wave to compensate a shift of the constituent portions of the marker image.