An optical device is formed by hot stamping a demetallized hologram to an optically variable foil or to a coating of optically variable ink. In another embodiment a hologram is hot stamped to a banknote or document printed with a color-shifting ink.

A method for producing a hologram (1), (1) for security elements (1a) and/or security documents (1b). One or more virtual hologram planes (10) are arranged in front of and/or behind one or more virtual models (20) and/or one or more virtual hologram planes (10) are arranged such that they intersect one or more virtual models (20). One or more virtual light sources (30) are arranged on one or more partial regions of the surface (21) of one or more of the virtual models (20). One or more virtual electromagnetic fields (40) are calculated starting from at least one of the virtual light sources (30) in one or more zones (11) of the one or more virtual hologram planes (10). In the one or more zones (11), in each case, a virtual total electromagnetic field (41) is calculated on the basis of the sum of two or more, of the virtual electromagnetic fields (40) in the respective zone (11). One or more phase images (50) are calculated from the virtual total electromagnetic fields (41) in the one or more zones (11). A height profile (60) of the hologram (1) is calculated from the one or more phase images (50) and the height profile (60) of the hologram (1) is incorporated into a substrate (2) to provide the hologram (1).

An optical device is formed by hot stamping a demetallized hologram to an optically variable foil or to a coating of optically variable ink. In another embodiment a hologram is hot stamped to a banknote or document printed with a color-shifting ink.

An optical device is formed by hot stamping a demetallized hologram to an optically variable foil or to a coating of optically variable ink. In another embodiment a hologram is hot stamped to a banknote or document printed with a color-shifting ink.

A display including a relief structure forming layer having a major surface with a relief type diffractive structure that displays a three-dimensional object as a diffraction image; and a reflective layer at least partially covering a region of the major surface where the diffractive structure is provided. A portion of the diffractive structure in a first region includes first and second linear parts forming a first lattice, and first parts arranged in respective gaps of the first lattice. The first and second linear parts each having a solid line shape form a first pattern. A portion of the diffractive structure in a second region includes third and fourth linear parts alternately arranged in the width direction thereof. The third linear parts each having a dashed line shape and the fourth linear parts each having a dashed or dotted line shape form a second pattern.

A method for producing a hologram (1), (1) for security elements (1a) and/or security documents (1b). One or more virtual hologram planes (10) are arranged in front of and/or behind one or more virtual models (20) and/or one or more virtual hologram planes (10) are arranged such that they intersect one or more virtual models (20). One or more virtual light sources (30) are arranged on one or more partial regions of the surface (21) of one or more of the virtual models (20). One or more virtual electromagnetic fields (40) are calculated starting from at least one of the virtual light sources (30) in one or more zones (11) of the one or more virtual hologram planes (10). In the one or more zones (11), in each case, a virtual total electromagnetic field (41) is calculated on the basis of the sum of two or more, of the virtual electromagnetic fields (40) in the respective zone (11). One or more phase images (50) are calculated from the virtual total electromagnetic fields (41) in the one or more zones (11). A height profile (60) of the hologram (1) is calculated from the one or more phase images (50) and the height profile (60) of the hologram (1) is incorporated into a substrate (2) to provide the hologram (1).

Disclosed herein is a method for forming a surface relief microstructure, including the steps of A) applying a curable composition to at least a portion of the frontside of the paper substrate, B) contacting at least a portion of the curable composition with surface relief microstructure, C) curing the composition by using at least one UV lamp which is arranged on the backside of the paper substrate, and D) depositing a metallic layer, and optionally a layer of a transparent high refractive index material, on at least a portion of the cured composition, wherein the UV lamp has an emission peak in a UV-A range of 320 nm to 400 nm and additionally in a near VIS range of 400 nm to 450 nm, the curable composition comprises a photoinitiator which absorbs in the UV-A range and also in the near VIS range.

An optical device is formed by hot stamping a demetallized hologram to an optically variable foil or to a coating of optically variable ink. In another embodiment a hologram is hot stamped to a banknote or document printed with a color-shifting ink.

Disclosed herein is a method for forming a surface relief microstructure, including the steps of A) applying a curable composition to at least a portion of the frontside of the paper substrate, B) contacting at least a portion of the curable composition with surface relief microstructure, C) curing the composition by using at least one UV lamp which is arranged on the backside of the paper substrate, and D) depositing a metallic layer, and optionally a layer of a transparent high refractive index material, on at least a portion of the cured composition, wherein the UV lamp has an emission peak in a UV-A range of 320 nm to 400 nm and additionally in a near VIS range of 400 nm to 450 nm, the curable composition comprises a photoinitiator which absorbs in the UV-A range and also in the near VIS range.

A method and an apparatus for forming a surface relief microstructure, especially an optically variable image on a paper substrate are provided, the method comprising the steps of: A) applying a curable composition to at least a portion of the frontside of the paper substrate; B) contacting at least a portion of the curable composition with surface relief microstructure, especially optically variable image forming means; C) curing the composition by using at least one UV lamp (1, 2, 3) which is arranged on the backside of the paper substrate; D) optionally depositing a layer of a transparent high refractive index material and/or a metallic layer on at least a portion of the cured composition, wherein the lamp (1, 2, 3) having emission peak(s) in the UV-A and near VIS range and the curable composition comprises at least a photoinitiator which absorbs in the UV-A region and preferably in the near VIS range. A paper product obtainable uses the method and an apparatus for forming a surface relief microstructure on a paper substrate. Surface relief microstructures, such as holograms may be replicated rapidly and with accuracy on a paper substrate by using the method and the apparatus.