Optical security element and system for visualising items of concealed information

Abstract From the Canadian patent

The invention concerns an optical security element and a system for visualising items of concealed information comprising such an optical security element. The optical security element has a substrate layer in which a relief structure defined by relief parameters in particular relief , shape, relief depth spatial frequency and azimuth angle, is shaped in the surface region defined by an X-axis and a Y-axis for producing an optically , perceptible effect. One or more of the relief parameters defining the relief structure are varied in the surface region (27) in accordance with a parameter variation function. The surface region (27) is divided into one or more pattern regions (29, 30) …