The invention optical device comprising a self-processing photopolymer material configured to produce a variable two- or three- dimensional diffraction pattern when said material is illuminated by a light source. The invention provides a new material science and process technology which produces a serialisable anti-counterfeit optical device, based on a self-processing photopolymer.

A method for determining the validity of a parallax image including receiving a captured two-dimensional image of a parallax image having at least three target identifiers, where at least two target identifiers are located at different depth planes in the parallax image; identifying the at least three target identifiers in the captured two-dimensional image of the parallax image and determining the spatial relationship between the at least three target identifiers in the two-dimensional image of the parallax image; comparing the spatial relationship of the at least three target identifiers in the captured two-dimensional image of the parallax image against a predetermined spatial relationship of the at least three target identifiers that indicates authenticity; and adjudicating the authenticity of the parallax image based on the degree of difference between the spatial relationship of the at least three target identifiers in the captured two-dimensional image and the predetermined spatial relationship.

Variable digital optical images may be fabricated using generic optical matrices. A generic optical matrix may have pixels corresponding to color and sub-pixels corresponding to non-color effects. The pixels may include first pixels corresponding to a first color and second pixels corresponding to a second color. The sub-pixels may include first sub-pixels corresponding to a first non-color effect and second sub-pixels corresponding to a second non-color effect. Individual ones of the pixels and/or sub-pixels of the generic optical matrix may be obliterated according to a negative while remaining pixels and/or sub-pixels may be preserved. The remaining pixels and/or sub-pixels may form an optical image corresponding to a base image. The optical image may be colored based on the remaining pixels. The optical image may exhibit non-color effects corresponding to the remaining sub-pixels. The optical image may comprise a hologram or a stereo image.

A pressure sensitive holographic recording composition is described wherein the composition comprises diacetone acrylamide, glycerol and citric acid. The composition is capable of recording high diffraction efficiency reflection holograms.

An optical security device is disclosed which includes a diffraction layer having a plurality of diffraction elements and a high refractive index layer, wherein the high refractive index layer is applied on the diffraction layer such that selected regions of the diffraction layer have the corresponding diffraction elements partially uncovered by the high refractive index layer and other regions are substantially covered by the high refractive index layer. Accordingly, the optical security device has a first security feature associated with the diffraction layer and a second security feature associated with the high refractive index layer. An image is viewable from the regions of the high refractive index layer, either, covertly by placed an index matched item over the device or, overtly, through selection of the thickness of the high refractive index layer.

Variable digital optical images may be fabricated using generic optical matrices. A generic optical matrix may have pixels corresponding to color and subpixels corresponding to noncolor effects. The pixels may include first pixels corresponding to a first color and second pixels corresponding to a second color. The subpixels may include first subpixels corresponding to a first noncolor effect and second subpixels corresponding to a second noncolor effect. Individual ones of the pixels and/or subpixels of the generic optical matrix may be obliterated according to a negative while remaining pixels and/or subpixels may be preserved. The remaining pixels and/or subpixels may form an optical image corresponding to a base image. The optical image may be colored based on the remaining pixels. The optical image may exhibit noncolor effects corresponding to the remaining subpixels. The optical image may comprise a hologram or a stereo image.

The present invention relates to a security document and/or document of value with a hologram in a visually changeable window as a novel security element, and also to a method for producing the same.

A pressure sensitive holographic recording composition is described wherein the composition comprises diacetone acrylamide, glycerol and citric acid. The composition is capable of recording high diffraction efficiency reflection holograms.

A method for integrating a synthetic hologram in an image of a scene, including: forming, from a first image of the scene, a first matrix including pixels of two shades according to the gray level of the corresponding pixel of the first image, and a second matrix, image of the gray level difference between the corresponding pixels of the first image and of the first matrix; forming a third matrix based on a second image; forming a fourth matrix having each pixel including a central area with a surface area determined by the corresponding element of the second matrix and off-centered in the pixel according to the corresponding pixel of the third matrix; and performing a lithography of an opaque layer at the surface of a plate according to the pattern defined by the fourth pixel matrix.

A hologram transfer foil according to an embodiment is thermally transferrable to a transfer base member. The hologram transfer foil has a structure configured such that a peeling layer, a diffraction structure forming layer and an adhesive layer are stacked on one surface of a substrate. the diffraction structure forming layer includes fine concaves and convexes of a hologram or a diffraction grating. At least one of the peeling layer and the adhesive layer includes heat-conductive hidden information in a heat-conductive hidden information possession portion.