Patent ID: 9342049
Filing Date: 2016-05-17
CPC Classification: B42D,G03H

Claim Text:
1. A method of making a multi-spectral holographic security marker comprising: recording, in a film data carrier of a multi-spectral holographic security maker, an image plane volume hologram having a first replay frequency, the hologram being a hologram of graphic data or a linear code or a matrix code containing security data, wherein the multi-spectral holographic security marker comprises an image plane volume hologram recorded to have the first replay frequency in a light-sensitive film data carrier, the film data carrier comprises a polymeric material that is pressure-sensitive so that on compression the final replay frequency of the recorded volume hologram is shifted away from the respective first replay frequency, the image plane volume hologram recorded in the film data carrier comprises graphical data or a linear code or a matrix code containing security data, and different areas of the film data carrier have been compressed after recordal of the volume hologram therein, with the result that a plurality of different areas of the film data carrier have a plurality of different final replay frequencies for the hologram recorded therein, with the different areas having boundaries which together form a security identification code or pattern which provides further security data, and a surface hologram is impressed, on the surface of the film carrier or on a surface coating thereon, over areas of the security marker in which the recorded volume hologram has the same replay frequency, with the boundary or boundaries of the surface hologram corresponding precisely with the boundary or boundaries of the said areas of the security marker in which the recorded volume hologram has the same replay frequency; preparing a die one or more portions of which have a given thickness and one or more other portions of which have at least one thickness greater than the given thickness, the boundaries of the different thickness portions of the die together forming a security code or pattern; and pressing the die into the surface of the film data carrier or into a surface covering thereon, the pressure being sufficient to move the final replay frequencies of the portions of the volume hologram recorded directly beneath those portions of the die having the greater thickness or thicknesses to one or more final replay frequencies each different from the first replay frequency; thereby creating in the film data carrier an image plane volume hologram of the graphic data or the linear code or matrix code security data, of which at least one area has the first replay frequency and at least one other area has a final replay frequency differing from the first, with the different areas having boundaries which together form the said security identification code or pattern which provides further security data, wherein the die is a holographic master die, with either the one or more portions thereof with the given thickness or the one or more portions thereof with the thickness greater than the given thickness having a surface carrying the negative of a surface diffraction grating embodying a surface hologram, so that when the master die is pressed into the surface of the film data carrier or into the surface coating thereon, the pressure is sufficient to create, in the said one or more portions of the surface or surface coating, a surface hologram which is directly above and in alignment with an area or areas of the recorded volume hologram which have a single replay frequency.