Security device with metameric features using diffractive pigment flakes
US7729026B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 12, 2006 |
| Grant date | Jun 1, 2010 |
| Priority date | — |
| Expiry date | May 31, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H2270/24
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A metameric optical structure is disclosed having first optical structures comprising diffractive flakes having diffractive structures thereon, and a second optical structures having non-diffractive flakes which may have other special effect properties, such as color shifting. At one angle of incidence or one viewing angle, near normal. The hues match and at other angles they do not match. The diffractive flakes are preferably magnetically aligned so that the grating structures are parallel. Disclosed is also an image formed of at least a first region of diffractive flakes and a second region of non-diffractive flakes wherein the regions are adjacent one another and wherein one of the regions forms a logo, symbol or indicia that appears or disappears in dependence upon the angle of viewing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.