A display panel (1) comprising a body of optical material, the body having at least one optical image recorded therein in an encoded manner, wherein the image is selectively reconstructable and viewable (5, 6, 7) by illuminating the panel (1) using at least one light source (3a, 3b, 3c) under selected illumination conditions, wherein the image is reconstructable and viewable (5, 6, 7) such that at least one first optical property or parameter of the reconstructed image (e.g. its geometry, position in space, colour, its dynamic appearance) is selectable in value from amongst variable values of the at least one first optical property or parameter, or whose value is actively modifiable over time, as a function of or in dependence on the value of at least one second optical property or parameter of the illumination conditions of the at least one light source (e.g. its/their position(s) or spacing(s) relative to the panel (1), its/their colour, brightness/optical intensity, polarisation, direction of light ray propagation, application of a scanning technique to illuminate the panel (1)) which is selectable from amongst variable values thereof or which is actively modifiable in value over time.

A hologram that includes a formation layer and a reflection layer that are laminated. The formation layer has an optical phase modulation structure on a first interface in contact with the reflection layer. When reference light emitted from a point light source enters through a second interface different from the first interface of the formation layer, the entirety or part of an image to be reconstructed by the optical phase modulation structure is reconstructed as spatial information on the point light source side relative to the second interface.

A holographic security or identification device (10) comprises an object, or a flexible substrate (12) configured to be conformable to a desired, curved shape; and a plurality of structures (14) formed on or in the object to have a desired curved configuration, or formed in or associated with the substrate and arranged to adopt a desired curved configuration when the substrate is conformed to a desired shape, wherein the plurality of structures (14) are configured to receive light (20) of a selected at least one wavelength or range of wavelengths and to produce, using the received light, a desired holographic image (22) for security or identification purposes when in the desired configuration.

An optical security device (1) comprising a recorded or encoded representation of an optically variable image (40), the image (40) being reconstructable and viewable for security, authentication or identification purposes, the device (1) comprising: an optical structure (30) in which there is recorded or encoded a representation of the optically variable image (40) in the form of a plurality of discrete portions (e.g. 50) of the complete image (40) to be reconstructed, wherein the respective said plurality of portions (e.g. 50) of the optically variable image (40) can, when reconstructed, only be viewed in their totality by viewing the said image (40) at or over a plurality of different viewing angles or angle ranges (70) relative to the optical structure (30) and/or at or over a plurality of different angles or range of angles of illumination of the optical structure (10), and wherein the size, in at least one dimension, direction, axis or plane, of the complete image (40), when reconstructed, is greater than the corresponding size, in the same, or the respective same, dimension, direction, axis or plane, of a part of the optical structure (30) having the said plurality of portions (e.g. 50) of the image (40) collectively recorded or encoded therein.

A computerized system for uniquely tagging and verifying authenticity of an article comprising: an object having a curvature; a computer system adapted to: receive a three-dimensional predetermined image, create a holographic interference pattern created according to the three-dimensional predetermined image and the curvature wherein the holographic interference pattern is applied to the object, project a three-dimensional resulting image projected on a planar surface in response to the holographic interference pattern being illuminated wherein the computer system receives the three-dimensional resulting image, create validation information according to a comparison of the three-dimensional predetermined image and the three-dimensional resulting image

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.

There is provided a holographic optical element including: a hologram portion including a plurality of groups of unit regions, each group of unit regions of the hologram portion being configured to produce a respective holographic image under a respective light illumination having a respective predetermined wavelength; and a colour filter portion formed on the hologram portion, the colour filter portion including a plurality of groups of unit regions, each group of unit regions of the colour filter portion being arranged on a corresponding group of the plurality of groups of unit regions of the hologram portion, whereby the plurality of groups of unit regions of the colour filter portion is spatially arranged to form a predetermined colour image. There is also provided a method of forming the holographic optical element. There is further provided an article having optical security incorporated therein.

There are provided volume holograms and combinations of lenticular lenses and holograms in particular for security applications. In embodiments, a volume hologram comprises a holographic medium (102) including a first optical interference structure which, upon illumination, replays a first image (110); wherein the first image includes a lenticular lens layer (111) including an array of lenticules and a lenticular image layer (113) including first (114) and second (115) interlaced images corresponding with the array of lenticules.

A method for determining the validity of a parallax image, comprising: 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 of the parallax image and the predetermined spatial relationship of the at least three target identifiers.

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