Abstract: The security object comprises a substrate, a surface structure and a hologram layer. A volume hologram is arranged in the hologram layer. The hologram layer is deformed in homogeneously by the surface structure, which gives rise to readily detectable changes in the reflections from the volume hologram. These changes can be used to verify the authenticity of the object. The surface structure can e.g. be applied using intaglio printing techniques or embossing. Alternatively or in addition to the deformation of the hologram layer by means of the surface structure, the hologram layer may also be deformed by embossing.

Abstract: A security object has a substrate (1) carrying a first motif (6) and mutually aligned thereto a second motif (7). The first motif (6) is formed by a volume hologram (8) and visible under a given viewing condition only. The second motif (7) can e.g. be a dye, a surface hologram, a perforation or any other non-variable or optically variable device. The first and the second motif (6, 7) combine to form a third motif, e.g. a legible text. The combination of the first motif (6) formed by a volume hologram (8) with the second motif provides an increased level of security.

Abstract: An optical security feature, e.g. for a banknote or other security documents, comprises a first and a second holographic layer arranged on top of each other. Each layer comprises a comparatively simple reflective volume hologram, such as it can e.g. be recorded by the interference pattern of two Gaussian light beams. The volume holograms have different grating spacing and/or orientation as well as different extension such that the observer can distinguish and verify them easily. The simple nature of the holograms make the security feature easy to manufacture, while its two-layer structure makes it hard to copy and yields high diffraction efficiency.

Abstract: A security object has a substrate (1) carrying a first motif (6) and mutually aligned thereto a second motif (7). The first motif (6) is formed by a volume hologram (8) and visible under a given viewing condition only. The second motif (7) can e.g. be a dye, a surface hologram, a perforation or any other non-variable or optically variable device. The first and the second motif (6, 7) combine to form a third motif, e.g. a legible text.

Abstract: The security object comprises a substrate, a surface structure and a hologram layer. A volume hologram is arranged in the hologram layer. The hologram layer is deformed in homogeneously by the surface structure, which gives rise to readily detectable changes in the reflections from the volume hologram. These changes can be used to verify the authenticity of the object. The surface structure can e.g. be applied using intaglio printing techniques or embossing. Alternatively or in addition to the deformation of the hologram layer by means of the surface structure, the hologram layer may also be deformed by embossing.