Abstract: A security element including: a first layer having a first surface; an array of image regions across the first surface arranged along at least a second direction, each region including at least a first image sub-region having an average inclination defining an angle, relative to a plane of the security element, about an image region axis extending along a first direction; a diffractive optically variable effect generating structure provided in or on the first surface across the first image sub-regions, the structure including diffractive elements that extend along a direction within 45° of the first direction, wherein the structure is provided across the first image sub-regions and spatially arranged and/or modulated across the first image sub-regions in accordance with a first image so the first image is displayed by the first image sub-regions in combination at least at a first viewing angle. Also, a method of manufacturing the security element.

Abstract: A method of manufacturing a security document, including: providing a polymer substrate having first and second surfaces; and: applying an array of focussing elements to the first surface of the polymer substrate across a first region; forming an image array by: providing a die form having a surface including an arrangement of raised areas and recessed areas defining the pattern; applying a first curable material to the surface of the die form so it substantially fills the recessed areas; bringing a pattern support layer in contact with the surface of the die form so it covers the recessed areas; separating the pattern support layer from the surface of the die form so the first curable material in the recessed areas is removed from the recessed areas and retained on the pattern support layer; and at least partly curing the first curable material in one or more curing steps.

Abstract: A security device is disclosed, comprising an array of focussing elements with regular periodicity in at least a first direction, each focusing element having an optical footprint of which different portions will be directed to the viewer in dependence on the viewing angle; and an array of image elements with regular periodicity in at least the first direction overlapping the array of focusing structures, the image elements representing portions of at least two respective images, and at least one image element from each respective image being located in the optical footprint of each focusing structure.

Abstract: A security device is disclosed, comprising: a first ink (21) and a second ink (22) each arranged in respective laterally offset first and second regions of the security device, the first and second inks each comprising a respective luminescent material which both luminesce in response to irradiation at at least one excitation wavelength in the ultra-violet spectrum, the first and second inks each exhibiting substantially the same non-luminescent visible colour as one another when illuminated with visible light in the absence of the at least one excitation wavelength, and the first and second inks each exhibiting visible colours which are different from the non-luminescent visible colour and from one another when illuminated with a combination of visible light and the at least one excitation wavelength; a third ink (23) arranged in a third region of the device laterally offset from the first and second regions of the device, the third ink not luminescing in response to the at least one excitation wavelength, a

Abstract: A security document includes a first leaf having a first polymer substrate and a first reinforcement layer attached or formed with the first leaf. An outer leaf is attached to the first leaf along a fold line and is located between the first leaf and a cover. The first reinforcement layer extends along the first leaf at least partially along the fold line and at least partially away from the fold line on both sides of the fold line. The security document also has methods of manufacturing such a security document and a plurality of such security documents.

Abstract: A method of manufacturing a security device includes: a) providing a depth map of a macroimage depicting a three-dimensional object, the depth map representing the depth of each part of the three-dimensional object relative to a reference plane by different colours and/or different tones of one colour; b) segmenting the depth map into a plurality of regions based on the colours and/or tones of the depth map; c) for each region, creating a respective microimage element array; and d) providing a sampling element array of a predetermined pitch and orientation. The pitch and/or orientation of each respective microimage element array is different, and is configured such that the magnified versions of the microimage elements generated in any one of the regions have a different apparent depth relative to those generated in the other region(s), so as to form a three-dimensional representation of the macroimage.

Abstract: A security device manufacturing method includes: providing a substrate having a viewing region; providing an obscuring layer in the region; providing a first image; applying a mask to the first image and swapping colour components of first and second sub-images of the first image forming: a mask pattern, and a background pattern representing the unswapped colour components on their assigned side; and printing the mask and background patterns on corresponding layer sides. The layer reduces colours visibility on one side when the other side of the layer is viewed in reflection, and allows light through the region when the security device is viewed in transmitted light. When either side of the region is viewed in reflected light, the patterns on that side are dominantly visible and may be distinguished. When the region is viewed in transmitted light from either side, the region is transparent and the colour-composite image is visible.

Abstract: A method of forming a polymer substrate for a security sheet includes: providing first and second overlapping polymer layers each providing outwardly facing surfaces, and a colour shifting element positioned between the first and second polymer layers adapted to provide a first optical effect to a viewer, wherein the first polymer layer includes a region substantially transparent to visible light such that the colour shifting element is viewable through the first polymer layer, and; joining together the first and second polymer layers in order to generate a polymer substrate wherein, during the joining step, a surface relief is formed in the outwardly facing surface of the first layer, the surface relief being adapted to interact with light from the colour shifting element in order to modify the first optical effect to provide a second optical effect different from the first optical effect.

Abstract: A method of forming a security device includes a colour shifting element, wherein the colour shifting element provides a first optical effect, the method includes; providing a light control layer over at least a part of the colour shifting element, the light control layer including a functional region and at least one non-functional region, wherein the functional region includes a surface relief adapted to modify the angle of light from the colour shifting element so as to generate a second optical effect different from the first optical effect, and wherein the non-functional region does not substantially modify the angle of light from the colour shifting element, and; wherein the at least one non-functional region is not discernible to the naked eye.

Abstract: The present invention relates to a method of manufacturing a security sheet comprising a security element (11), a core structure (10) for forming the security sheet, a stack (29) including such a core structure (10), a security sheet comprising the core structure (10) or stack (29) and a security document comprising the security sheet. At least one perforation (20) is formed through, from a first core surface (13) to a second core surface (14) of, at least one core layer (12) comprising plastic. A security element (11) is fed through the at least one perforation (20) such that the security element (11) extends through, from the first core surface (13) to the second core surface (14) of, the at least one core layer (12). At least one first region (17) of the security element (11) is located over part of the first core surface (13) and at least one second region (18) of the security element (11) is located over part of the second core surface (14).

Abstract: A method of manufacturing a security device is provided. The method comprises providing a substrate, the substrate having opposing first and second surfaces and a relief structure formed in the first surface of the substrate. A reflection enhancing layer is applied over the first surface of the substrate such that the reflection enhancing layer at least partially overlaps the relief structure and such that a first region of the first surface of the substrate does not have the reflection enhancing layer. An absorber layer is applied over the reflection enhancing layer such that the absorber layer at least partially overlaps the reflection enhancing layer and the relief structure where the reflection enhancing layer and the relief structure overlap each other, and such that the absorber layer at least partially overlaps the first region of the first surface of the substrate.

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 diffractive security device is disclosed including at least a first diffractive structure defined in a carrier layer. The first diffractive structure is an on-axis diffractive zone plate structure of a continuously curved surface configured such that when the device is illuminated by on-axis light a first diffraction pattern generated by the first diffractive structure can be viewed from at least a first side of the device at substantially all viewing angles, the first diffraction pattern exhibiting a reference point or reference line relative to which other features of the first diffraction pattern appear to move when the viewing angle is changed.

Abstract: A holographic security device includes a holographic image layer which when illuminated exhibits the optically variable effect of viewing first and second overlapping patterns of elements, wherein; the first pattern of elements includes a first set of image elements and at least a second set of image elements, and the pitches and relative locations of the first and second patterns of elements are such that, upon illumination of the device; at a first viewing position of the security device the first set of image elements are exhibited by the holographic image layer and at a second, different viewing position of the security device the second set of image elements are exhibited by the holographic image layer. Also, an associated method of manufacture of the security device.

Abstract: A method of making a security device, comprising: forming an array of primary focusing elements on a first region of a focusing element support layer, by applying at least one transparent curable material either to the focusing element support layer or to a casting tool carrying a surface relief over an area which includes at least the first region, the surface relief comprising portions corresponding to the primary focusing elements; forming the transparent curable material(s) with the casting tool; and curing the transparent curable material(s) so as to retain the surface relief in the first region; wherein the surface relief further includes a plurality of structures of greater depth than the height of the primary focusing elements such that the cured transparent material(s) include a plurality of features protruding above the height of the primary focusing elements between primary focusing elements of the array.

Abstract: An optical device is disclosed, comprising: a colour layer which comprises elongate strips of at least two different colours alternating with one another periodically along a direction of colour periodicity, the elongate strips extending along the direction which is orthogonal to the direction of colour periodicity; and a light redirecting layer overlapping the colour layer, and defining at least a first image to be exhibited by the optical device.

Abstract: A security device is disclosed, comprising: a first ink (21) and a second ink (22) each arranged in respective laterally offset first and second regions of the security device, the first and second inks each comprising a respective luminescent material which both luminesce in response to irradiation at at least one excitation wavelength in the ultra-violet spectrum, the first and second inks each exhibiting substantially the same non-luminescent visible colour as one another when illuminated with visible light in the absence of the at least one excitation wavelength, and the first and second inks each exhibiting visible colours which are different from the non-luminescent visible colour and from one another when illuminated with a combination of visible light and the at least one excitation wavelength; a third ink (23) arranged in a third region of the device laterally offset from the first and second regions of the device, the third ink not luminescing in response to the at least one excitation wavelength, a

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 colourshifting 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 exhibited

Abstract: A diffractive security device is disclosed, including first and second diffractive structures defined in a carrier layer. The first diffractive structure is a diffractive zone plate structure of a continuously curved surface configured such that when the device is illuminated by on-axis light, a first diffraction pattern generated by the first diffractive structure can be viewed from at least a first side of the device at substantially all viewing angles, the first diffraction pattern exhibiting a reference point or reference line relative to which other features of the first diffraction pattern appear to move when the viewing angle is changed. The second diffractive structure is an off-axis diffractive structure configured such that when the device is illuminated by on-axis light a second diffraction pattern generated by the second diffractive structure can be viewed from at least the first side of the device at at least some off-axis viewing angles.

Abstract: A security device is disclosed, comprising forming an array of focussing elements on first region of first surface of focussing element support layer, applying a pedestal layer comprising one transparent material onto first region of first surface of focussing element support layer applying transparent curable material to the pedestal layer or a casting tool carrying surface relief corresponding to focussing elements, over first region forming transparent curable material(s) with the casting tool bringing first surface of focussing element support layer against the casting tool that transparent curable material between the surface relief and the pedestal layer, across first region; and curing transparent curable material(s) on the pedestal layer to retain surface relief in first region; wherein focal length of focussing elements focal plane lies on first surface of focussing element support layer, or beyond first surface of focussing element support layer relative to the location of array of focussing element