Patent ID: 6222650
Filing Date: 2001-04-24
Classification: G03H,G06K

Abstract:
A document having an authentication feature formed thereupon, said document comprising:a substrate having an outer surface; andan authenticating element covering at least a portion of said outer surface and capable of generating at least one color pattern constituting a first visually identifiable feature for verifying the authenticity of said document;said authenticating element including a diffractive structure and a non-diffractive micro-graphical feature providing security information embedded within said diffractive structure and each of said diffractive structure and said non-diffractive feature being integrally formed within a single common layer of material;said diffractive structure generating a visually perceptible color pattern which is dependent upon a direction of illumination and/or a direction of visual viewing; andsaid non-diffractive micro-graphical feature having a substantially constant visually perceptible appearance substantially independent of the direction of said illumination and/or said direction of visual viewing.