A color shifting security device has a Fabry-Perot type structure wherein a dielectric layer is disposed between a reflector and an absorbing layer. The absorber and reflector layers may be conforming and the dielectric layer therebetween is non-conforming, filling the regions in the micro structured adjacent absorbing or reflecting layer, at least one of which has a microstructure therein or thereon. By having the dielectric layer not conform to the microstructure it is next to, its thickness varies in cross section, which allows for different colors to be seen where the thickness varies.

The invention relates to a process for securing an identification document and to a secure identification document. More particularly, the process uses UV sensitive ink(s) to define a pattern only visible under UV radiations, by printing a first layer of a transparent ablation varnish (13), printing a layer (14) of UV sensitive ink(s) over said first layer of transparent ablation varnish, removing parts of the layer (14) of UV sensitive ink(s), by means of a laser beam, some remaining areas of said UV sensitive ink(s) defining said pattern to be revealed in color under UV radiations, and some areas, where the UV sensitive ink(s) has been removed and the laser beam has interacted with the ablation varnish (13), absorbing the UV radiations with effect of creating black color. Other systems and methods are disclosed.

There is described a security element or document comprising a substrate (20) and at least a first dynamic-effect feature (100; 120; 121; 122; 123; 130; 135; 140; 150; 171; 181; 191; 200) provided on the substrate which includes a dynamic-effect component that is responsive to illumination stimulus of a selected excitation wavelength or wavelength band to produce an optical spectral response, which optical spectral response changes dynamically over an observable period of time between multiple color appearances (C, F, M; C1, M1) upon and while being subjected to the illumination stimulus. The first dynamic-effect feature is provided in a region of the substrate which is proximate or adjacent to at least one proximity feature (101, 102; 120a, 120b; 121a, 121b; 122a, 122b; 123a, 123b; 131, 132, 133; 136, 137; 141, 142; 151, 160; 172; 182, 183; 192; 201, 205, 206) provided on the substrate, which at least one proximity feature has a color appearance which is selected to enhance and/or complement at least one of the multiple color appearances of the first dynamic-effect feature.

A display includes a first interface section provided with a relief-type diffraction grating constituted by a plurality of grooves, and a second interface section provided with a plurality of recesses or projections arranged two-dimensionally at a center-to-center distance smaller than the minimum center-to-center distance of the plural grooves, and each having a forward tapered shape.

An integrated security structure is provided employing an external source of energy to change the appearance of the structure rendering the structure more challenging to duplicate due to its complexity. The security structure includes a substrate forming part of a bank note, identification document, or other security device; an active device within the substrate changing color between at least two colors wherein a color of the substrate surrounding the active device matches one of the at least two colors to form a metameric device. At least one Interference Security Image Structure (ISIS) is configured to be metameric with a bleached state of the active device and is therefore invisible at normal incidence. Another ISIS is metameric with the colored state of the electrochromic device and consequently becomes invisible during coloration. When the whole device is tilted, both ISIS's change color while the rest of the device essentially remains the same.

A display includes a first optical effect layer including a first interface part, the first interface part being provided with recesses or protrusions arranged two-dimensionally at the minimum center-to-center distance in a range of 200 nm to 500 nm, each of the recesses or protrusions having a forward-tapered shape; a reflective material layer covering at least a part of the first interface part; and a second optical effect layer including, at a position of a first portion of the first interface part that is covered with the reflective material layer, a portion that faces the reflective material layer with the first optical effect layer interposed therebetween or faces the first optical effect layer with the reflective material layer interposed therebetween, the second optical effect layer containing at least one of a cholesteric liquid crystal, a pearl pigment and a multilayer interference film.

(EN) The invention relates to an optically variable security element (20) for securing data carriers, having a flip image comprising first and second identifiers (24, 26) which can be detected from different first and second viewing directions (40, 42). According to the invention, the first and second identifiers (24, 26) of the flip image are present in an optically variable recording layer (30), which has a reflective layer (52) produced by a vacuum deposition process, and the security element (20) contains a viewing element screen (32) which is spaced apart from the recording layer (30) and which, when viewed from the first or second viewing direction (40, 42), reveals the first or second identifiers (24, 26), respectively.

The application discloses apparatus and systems for authenticating physical object, identification documents and security documents. Some such methods and apparatus involve signal encoding or digital watermarking.

A document and an Anti-counterfeiting method for use in such documents are described. Said document and Anti-counterfeiting method include introducing a plurality of raised nanoscopic to microscopic structures, here referred to as reconfigurable structures, formed over a polymer substrate to induce optical changes, such as structural color and/or optical fuzziness. Dynamic changes using liquids provide the anti-counterfeiting measures.

There is described a printed security feature (10) provided onto a printable substrate, which printed security feature includes a printed area (11) with at least a first printed section consisting of a multiplicity of geometric elements (GE, 15) printed with a given distribution over the printed area. The geometric elements are printed with at least first and second inks which exhibit the same or substantially the same optical appearance when illuminated with visible white light, such that the printed security feature produces a first graphical representation (A1) when illuminated with visible white light. At least the first ink is an ink which responds to non-visible light excitation by producing a characteristic optical response differentiating the first ink from the second ink. The printed security feature produces a second graphical representation (B1) when illuminated with non-visible light, which exhibits a distinctive two-dimensional graphic element (B) which is revealed only when the printed security feature is illuminated with non-visible light. The first printed section is subdivided into at least first and second printed portions (P1, P2), adjacent to the distinctive two-dimensional graphic element, and a third printed portion (P3), inside boundaries (200) of the distinctive two-dimensional graphic element. In the first, respectively second printed portion, the geometric elements are printed with the first, respectively second ink. In the third printed portion, the geometric elements are sub-divided into first and second contiguous portions (GE_a, GE_b) which are respectively printed with the first and second inks. The first and second inks are printed in register one with respect to the other so that the boundaries of the distinctive two-dimensional graphic element are not visible when the printed security feature is illuminated with visible white light and the distinctive two-dimensional graphic element only becomes visible when the printed security feature is illuminated with non-visible light.