Abstract: A digitally printed security document includes: a security document substrate; a first digitally printed print working on a first surface of the substrate in a first region, the first print working including a first array of printed elements arranged according to a first grid of lattice points having a first pitch; and a second digitally printed print working on the first surface of the substrate in a second region, the second print working including a second array of printed elements arranged across a second grid of lattice points having a second pitch different from the first pitch.

Abstract: A security element including: a first layer having a first surface; an array of image regions across the surface, each region including at least first and second sub-regions; a first diffractive optically variable effect generating structure in or on the surface across the first sub-regions; and a second diffractive optically variable effect generating structure in or on the surface across the second sub-regions; wherein the surface is arranged so each first sub-region has a first average inclination and each second sub-region has a second average inclination different from the first, wherein the first structure and inclination provide that the first effect is exhibited across the first sub-regions at least at a first viewing angle and the second structure and inclination provide that the second effect is exhibited across the second sub-regions at least at a second viewing angle different from the first. Also, a method of manufacturing the security element.

Abstract: A method for forming an optical device and an optical device, wherein upon illumination, exhibits diffractive images dependent upon viewing angle, the device having a diffractive structure including grating regions, each region corresponding to a component of a respective diffractive image, wherein: each region of the diffractive structure includes grating elements along a first direction having a principal orientation component within the device plane that is substantially orthogonal to the first direction; wherein, the grating elements within each grating region have a constant pitch and the same orientation wherein each grating region, upon illumination, exhibits a diffractive color wherein the corresponding diffractive image is exhibited; wherein, the diffractive structure includes first and second grating regions elongated along a common first direction, the regions being adjacent along the first direction, and wherein the pitch and/or orientation of the grating elements of the first and second grating r

Abstract: A method of inspecting a substantially transparent light control layer for an optically variable security device and a corresponding inspection apparatus, the substantially transparent light control layer including a surface relief defined by an array of substantially transparent refractive microstructures. The method includes: directing a beam of substantially collimated light towards a first region that is expected to contain the surface relief of the light control layer so as to generate an inspection light pattern; providing reference data that is indicative of a light control layer that meets a predetermined quality threshold; comparing the inspection light pattern with the reference data; and determining whether the light control layer meets the predetermined quality threshold based on the comparison.

Abstract: A security device includes a diffractive structure, including grating elements and having a first area, the grating elements within a region have a constant pitch or spacing; the first area regions pitches or spacings increase from one region to the next between a first region having a grating element pitch or spacing of less than or equal to 0.6 microns and an end region having a grating element pitch or spacing of greater than or equal to 5 microns; upon illumination and viewing along a first viewing direction substantially orthogonal to the first axis, the device exhibits a first optical effect in that at least one region exhibits a diffractive colour; each region has at least first and second sub-regions having different grating element orientations within the plane of the device such that the first optical effect is exhibited at more than one angle of tilt about the second axis.

Abstract: A method of forming a security device includes: a holographic image layer, diffusion element, and barrier layer. A region of the barrier layer includes a heat-transformable material. The method further includes selectively applying heat at a plurality of positions within the region of the barrier layer, in accordance with a predetermined pattern, so as to modify the heat-transformable material such that the region of the barrier layer is selectively rendered passable to the diffusible substance at each of the plurality of positions, thereby permitting diffusion of the diffusible substance between the regions of the diffusion element and the holographic image layer such that, at a plurality of positions within the region of the holographic image layer and corresponding to the predetermined pattern, the volume hologram is dimensionally modified so as to become viewable in a second observable colour, different from the first observable colour.

Abstract: A security device is provided, comprising: a colour shifting element that exhibits different wavelengths of light at different viewing angles, and; an at least partially transparent light control layer covering at least a part of the colour shifting element and comprising a surface relief adapted to modify the angle of light from the colour shifting element, wherein; a first region of the light control layer comprises a first optical characteristic, whereby light at a first viewing angle from the first region of the light control layer is perceived to have a resultant optical effect that is the resultant of the wavelength of light exhibited at that viewing angle due to the combination of the colour shifting element and the surface relief of the light control layer, and the first optical characteristic, and; a second region of the light control layer either: (i) is substantially colourless such that light at the first viewing angle from the second region is perceived to have a resultant optical effect exhibite

Abstract: A method of manufacturing a document of a series identical documents in content except for a respective identifier which identifies each document within the series, each identifier having at least a first indicium, the or each indicium defining a boundary; the method having the steps of: providing a substrate; applying a first background print, defining part of the boundary of an indicium receiving area; applying the respective identifier on the substrate, such that the first indicium is provided in the indicium receiving area; the first background print and the respective identifier being applied such that when the document is viewed in at least one of transmission and reflection the juxtaposition of the first background print and the first indicium is such that a keyline extending around a portion of the boundary of the first indicium is defined between the first indicium and the boundary of the indicium receiving area.

Abstract: A security print medium for forming security documents therefrom, the security print medium comprising a core having opposing first and second sides. The core comprises a radiation-responsive substance distributed within the core across at least a first region of the core, the radiation-responsive substance being responsive to a predetermined input radiation by producing a predetermined output radiation. The security print medium further comprises a first encoding layer disposed on the first side of the core and a second encoding layer disposed on the second side of the core, each of the first and second encoding layers comprising an encoding material that modifies the intensity of the predetermined input radiation and/or the predetermined output radiation produced by the radiation-responsive substance transmitted through the respective encoding layer, wherein the first and second encoding layers overlap each other across the first region.

Abstract: device includes an array of reflective sampling elements. A non-dispersive colour-generating relief structure is formed in a surface of the reflective sampling elements. The non-dispersive colour-generating relief structure defines an array of image elements across the array of reflective sampling elements. The array of image elements defined by the non-dispersive colour-generating relief structure and the array of reflective sampling elements cooperate to exhibit an optically variable effect.

Abstract: A security device includes an array of reflective elements including at least first and second sets of reflective elements, which are regularly or irregularly interlaced along at least a first interlacing direction across a first area of the security device. A non-dispersive colour-generating structure is in the surface of first and/or second sets of reflective elements. The first set of reflective elements is configured to collectively exhibit a first image across the first area of the security device to a viewer within a first viewing zone and direct incident light convergently and/or divergently towards this zone. The second set of reflective elements is configured to collectively exhibit a second image across the first area of the security device to the viewer within a second viewing zone. The structure is modulated across the first and/or second sets of reflective elements such that the first and/or second images include multiple colours.

Abstract: There is described a printing press (100***; 100****) adapted to carry out printing on a sheet-like or web-like substrate (S), in particular for the production of security documents such as banknotes, comprising a printing unit (2*; 2**; 2***; 2****) designed to print a first side (I) and/or a second side (II) of the substrate (S). The printing press (100***; 100****) further comprises an in-line casting device (80; 80*; 80**; 80***) adapted to apply a layer of material acting as an optical medium on a portion of a first side (I, II) of the substrate (S) and to replicate and form a micro-optical structure (L) in the layer of material acting as optical medium.

Abstract: A security device includes a luminescent material arranged in a first region, wherein the material luminesces in response to irradiation one excitation wavelength wherein the first region exhibits a luminescent visible colour; an array of viewing elements; and a masking layer positioned between the decorative layer and the array of viewing elements, the masking layer partially overlaps with first region, including first pattern elements defined by the masking material, and second pattern elements defined by the absence of the masking material wherein the decorative layer is visible through the second pattern elements; the masking material is non-luminescing in response to one excitation wavelength, and when the security device illuminates by at least one wavelength, where the array of pattern elements overlaps with the first region, the second pattern elements exhibit the luminescent visible colour, and the first pattern elements exhibit a visual appearance that's different to the luminescent visible colour.

Abstract: A digitally printed security document includes: a security document substrate; a first digitally printed print working on a first surface of the substrate in a first region, the first print working including a first array of printed elements arranged according to a first grid of lattice points having a first pitch; and a second digitally printed print working on the first surface of the substrate in a second region, the second print working including a second array of printed elements arranged across a second grid of lattice points having a second pitch different from the first pitch.

Abstract: A security document and a method of forming a security document are disclosed. The method comprises: (a) providing a security document substrate having a security article integrated within or attached thereto, the security article being exposed within an aperture region in the security document substrate, the security article comprising a first optical effect layer that is visible within the aperture region, and; (b) applying, in said aperture region within which the security article is exposed, an array of substantially transparent refractive structures on the exposed security article, wherein the array of refractive structures cooperates with the first optical effect layer to exhibit a first optically variable effect.

Abstract: A method of manufacturing a document of a series identical documents in content except for a respective identifier which identifies each document within the series, each identifier having at least a first indicium, the or each indicium defining a boundary; the method having the steps of: providing a substrate; applying a first background print, defining part of the boundary of an indicium receiving area; applying the respective identifier on the substrate, such that the first indicium is provided in the indicium receiving area; the first background print and the respective identifier being applied such that when the document is viewed in at least one of transmission and reflection the juxtaposition of the first background print and the first indicium is such that a keyline extending around a portion of the boundary of the first indicium is defined between the first indicium and the boundary of the indicium receiving area.

Abstract: A security device and method of making thereof. The security device includes a colour shifting element that exhibits different colours dependent on the angle of incidence of light impinging upon the colour shifting element, and; an at least partially transparent light control layer covering at least a part of the colour shifting element and including a surface relief adapted to modify the angle of light incident upon the light control layer, wherein; the light control layer includes at least first and second functional regions having different refractive indices such that light incident upon the first functional region impinges upon the colour shifting element at a first angle of incidence, and light incident upon the second functional region impinges upon the colour shifting element at a second, different, angle of incidence.

Abstract: An optical device is disclosed, comprising; a colour shifting layer that exhibits different colours dependent on the angle of incidence of incident light, and; an array of substantially transparent microstructures covering at least a part of the colour shifting layer and configured to modify the angle of light incident to, and reflected from, the colour shifting layer, said array of microstructures arranged in accordance with a plurality of pixels of a colour image to be exhibited by the optical device, each pixel exhibiting a uniform colour, wherein; the array of microstructures comprises at least first and second sub-arrays of microstructures corresponding to respective first and second colour channels, each sub-array covering an area within a pixel corresponding to the proportion of the respective colour channel within the pixel such that the pixel exhibits the uniform colour, and further wherein; the microstructures of the first sub-array are configured to modify the angle of light incident to, and reflec

Abstract: A method of forming a security device includes selectively providing a high refractive index (HRI) layer to a first outwardly facing surface of a security device substrate, the HRI layer having a substantially transparent host material and particles having a dimension along at least one axis less than 200 nm, such that they are substantially non-scattering to visible light and the HRI layer is substantially transparent to visible light, and wherein; the particles have a refractive index of at least 1.8 and are present within the host material in a proportion such that the resultant refractive index of the HRI layer is at least 1.6. A corresponding security device, as well as security articles and security documents, are also disclosed.

Abstract: A digital printing press for printing security documents is provided.