Patent ID: 7281810
Filing Date: 2007-10-16
Classification: B41M,B42D,B44F,G02B,G03C,G03H

Abstract:
1. A method of manufacturing an optical device which generates an optically variable image, the image being optically variable in that it varies according to the position of observation, the method including the steps of: dividing an optically invariable image into multiple pixels; determining colour component values for each pixel; for each of the pixels of the optically invariable image, determining an associated pixel surface structure which has a three-dimensional surface shape and curvature which is related via a mathematical or computer algorithm to the colour component values of the associated pixel in the optically invariable image, each pixel surface structure being an individual non-diffractive reflective surface structure which produces an observable optical effect; and producing an assembly of the non-diffractive reflective pixel surface structures which when illuminated generates a plurality of observable optical effects which combine to form an optically variable reproduction of the optically invariable image.