IMPROVEMENTS IN SECURITY DEVICES

摘要

The present invention relates to improvements in security devices that can be used in varying shapes and sizes for various authenticating or security applications, and in particular to an optically variable security device utilising colourshift materials. The security device comprises a layer of colourshifting material and, at least partially applied over a first surface of the colourshifting layer, a light control layer having a surface structure which modifies the angle of light reflected by the security device. At least one region of the light control layer is indexed out using a material having substantially the same refractive index as the light control layer.