Dynamic appearance-changing optical devices (DACOD) printed in a shaped magnetic field including printable fresnel structures
First Claim
1. A security device comprising an image having a first plurality of at least 1000 magnetically alignable reflective flakes resting upon a surface of a substrate in a first pattern so as to define a ring or curve, wherein the first plurality of magnetically alignable reflective flakes are tilted at a first angle with respect to the surface of the substrate and wherein planes extending from surfaces of the first plurality of magnetically alignable reflective flakes intersect with one another so that the image appears to be a three-dimensional object with a non-planar surface, wherein a bright or dark kinematic spot moves within the image when the security device is tilted thereby providing dynamic shading to the image.
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Accused Products
Abstract
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.
195 Citations
22 Claims
- 1. A security device comprising an image having a first plurality of at least 1000 magnetically alignable reflective flakes resting upon a surface of a substrate in a first pattern so as to define a ring or curve, wherein the first plurality of magnetically alignable reflective flakes are tilted at a first angle with respect to the surface of the substrate and wherein planes extending from surfaces of the first plurality of magnetically alignable reflective flakes intersect with one another so that the image appears to be a three-dimensional object with a non-planar surface, wherein a bright or dark kinematic spot moves within the image when the security device is tilted thereby providing dynamic shading to the image.
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21. The security device comprising an image having a first plurality of at least 1000 magnetically alignable reflective flakes resting upon a surface of a substrate in a first pattern so as to define a ring or curve, wherein the first plurality magnetically alignable reflective flakes are tilted at a first angle with respect to the surface of the substrate and planes extending from surfaces of the first plurality of magnetically alignable reflective flakes intersect with one another so that the image appears to be a three-dimensional object with a non-planar surface, wherein a bright or dark kinematic spot moves within the image when the security device is tilted thereby providing dynamic shading to the image, wherein the image is a rolling hemisphere.
Specification