Optical variable element based on diffractive moire patterns

Abstract

Provided is a personalized medium that includes a core layer having at least a clear window or transparent portion, at least a first diffraction grating on an upper surface or a lower surface of the core layer, and a second diffraction grating on an opposing side of the core layer from the first diffraction grating, wherein the first and second diffraction gratings create a Moire pattern. The diffraction gratings have at least one of slightly different periods, shifted horizontal and vertical positioning, or shifted rotation positioning to create the Moire pattern, for example, wherein the first diffraction grating, the opaque core layer and the second diffraction grating are laminated together to form the personalized medium. The Moire pattern can shift rapidly upon tilting or movement and provides a strong color variation combined with dark or bright fringe pattern movement. Other embodiments disclosed.

Dependencies are inferred from the claim text.