The present invention is related to the filed of optically variable security elements comprising a region based on a single cured ink comprising a cholesteric liquid crystal polymer, said region having at least two, preferably at least three, patterns exhibiting, at at least one viewing angle, a different CIE (1976) color index parameter and/or a different position of the selective reflection band for protecting security documents against counterfeiting and/or illegal reproduction. In particular, the present invention relates to processes for manufacturing said features, when the processes comprises the steps of a) applying on a substrate by a rotogravure process with the use of a gravure cylinder having at least two, preferably at least three, different engravings a single cholesteric liquid crystal precursor composition, b) heating the applied composition to bring said composition to a cholesteric liquid crystal state, and c) curing the composition so as to form the region based on a single cured ink comprising a cholesteric liquid crystal polymer.

Disclosed herein is a method for encoding an illustration on a target surface, where the illustration may be visible when light is shone on the surface from a light source with a predetermined position. The method may include converting the illustration into a grayscale illustration, specifying the position of the light source; generating a three dimensional surface having a grid of smaller surfaces thereon, where each smaller surface may represent a corresponding pixel of the grayscale illustration. Each smaller surface may be oriented with respect to the light source such that reflected light from each smaller surface has a reflection intensity equal to the light intensity of the corresponding pixel of the greyscale illustration; and making the target surface out of a material using the generated three dimensional surface as a template.

Disclosed herein is a method for encoding an illustration on a target surface, where the illustration may be visible when light is shone on the surface from a light source with a predetermined position. The method may include converting the illustration into a grayscale illustration, specifying the position of the light source; generating a three dimensional surface having a grid of smaller surfaces thereon, where each smaller surface may represent a corresponding pixel of the grayscale illustration. Each smaller surface may be oriented with respect to the light source such that reflected light from each smaller surface has a reflection intensity equal to the light intensity of the corresponding pixel of the greyscale illustration; and making the target surface out of a material using the generated three dimensional surface as a template.

A method of forming a security document includes: providing a security document substrate, the security document substrate including a security device including a colour shifting element and a light control layer covering at least a part of the colour shifting element, wherein the light control layer has a surface structure including one or more elevations and depressions that modifies the angle of light from the colour shifting element to generate a first optical effect, and; selectively modifying a part of the light control layer so as to generate a second optical effect different from the first optical effect.

A device includes at least one transient image having optical properties which vary depending on the angle of observation, with the image(s) consisting of a set of three-dimensional microstructures arranged in a plurality of subsets. Each subset consists of microstructures having an equivalent or identical planar angle ?. A security document can include such a device and the device can be used as a security element.

The present invention provides a vibration generator capable of accurately adapting to fine vibration. The vibration generator has a stationary permanent magnet, a yoke for the permanent magnet, a coil fixed to the yoke, four springs provided to the yoke, and a movable piece supported with the yoke through the four springs. The end portions of the movable piece are arranged between the respective two pairs of the projections with first gaps. The central portion of the movable piece is arranged in the through-hole with the second gaps, the second gaps having a size to allow oscillation, which is regulated by the first gaps, of the central portion of the movable piece.

Systems and methods applicable, for instance, to the generation and usage of authentication images. In one aspect, unauthorized attempts to duplicate authentication images can be thwarted. In another aspect, there can be provision for authorized authentication image generation using low-resolution print devices.

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.

A transaction card includes a first full thickness portion and a second, reduced thickness portion. Each of the first and second portions includes a top surface and an opposing bottom surface spaced from the top surface by a thickness of the card. The first, full thickness portion includes an extent of the card that remains exposed when the card is inserted into a pocket of a card-carrying case, and a feature deviating from a flat region along at least one of the top surface and the opposing bottom surface of the card. The feature is configured for tactile engagement to facilitate removal of the card from the pocket.

A transaction card includes a first full thickness portion and a second, reduced thickness portion. Each of the first and second portions includes a top surface and an opposing bottom surface spaced from the top surface by a thickness of the card. The first, full thickness portion includes an extent of the card that remains exposed when the card is inserted into a pocket of a card-carrying case, and a feature deviating from a flat region along at least one of the top surface and the opposing bottom surface of the card. The feature is configured for tactile engagement to facilitate removal of the card from the pocket.