Dynamic appearance-changing optical devices (DACOD) printed in a shaped magnetic field including printable fresnel structures
US8343615B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 4, 2006 |
| Grant date | Jan 1, 2013 |
| Priority date | — |
| Expiry date | Jul 3, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/25
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.