Animated security device for a document

Abstract

An optical device, and preferably a security device for a security document, and methods for the production thereof are provided. The device includes a diffractive optical element (DOE) including a plurality of subregions, wherein each subregion is configured to produce a projected image corresponding to a frame of an animation, the animation includes both a static component and a variable component, and the sub-regions are arranged such that when the DOE is illuminated by a point light source and moved in at least one direction, the animation is viewable as a projected image.

Description

Technical field [0001] The present invention relates to optical devices for vouchers, such as security devices for security vouchers such as banknotes, and in particular to security devices including diffractive optical elements. Background technique [0002] Paper money (and other security documents) include visual security features that are difficult to reproduce (and therefore counterfeit) using conventional devices (such as copiers). Such visual security features usually display optical effects, so that when viewed from different positions, the visual security features take on a different appearance (optical variable effect). When making a forged copy of a security certificate, it is difficult for the counterfeit to reproduce the effect, and therefore it is difficult to make a copy of the passable security certificate. [0003] However, as the experience of counterfeiters increases, the ability to reproduce or imitate complex security features increases. Therefore, it is poss...

AI Technical Summary

Problems solved by technology

This makes it easier for counterfeiters to create passable counterfeit versions of banknotes that are visually close enough to the visual security features of genuine banknotes to deceive or at least confuse the public

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