DYNAMIC APPEARANCE-CHANGING OPTICAL DEVICES (DACOD) PRINTED IN A SHAPED MAGNETIC FIELD INCLUDING PRINTABLE FRESNEL STRUCTURES

摘要

A printed image is disclosed wherein the image may be in the form of an array of magnetically aligned platelets or flakes that may by uniform in shape and size and wherein the flakes are arranged in a particularly manner to form optically illusive images useful as security devices, or useful in beam steering applications. In one embodiment of this invention printed array is disclosed a plurality of concentric rings of magnetically aligned platelets disposed upon a substrate in the form of a Fresnel structure, preferably a Fresnel reflector. Advantageously, since the magnetic field can be controlled with respect to strength and direction, one can easily design a field that will correct for spherical aberration that would otherwise be present in a typical Fresnel reflector. In other embodiments of the invention optically illusive images of funnels, domes and cones are printed.

主权项

1. An optically illusive image comprising a substrate having a region of flakes coating a surface thereof, wherein the flakes are distributed throughout substantially the entire region and oriented in a predetermined pattern therein, wherein the flakes are oriented such that lines normal to their reflecting surfaces converge along a line or to a point.