Optical structure, in particular for a security document and/or a document of value
US8439402B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Nov 16, 2006 |
| Grant date | May 14, 2013 |
| Priority date | — |
| Expiry date | Jul 31, 2029 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB42D2035/20
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
An optical structure comprising first and second opposite outside faces, at least a first interface comprising a first screen of microreliefs and arranged in such a manner that travel through the first interface from the first outside face towards the second outside face, passes from a first medium having a first refractive index to a second medium having a second refractive index that is greater than the first, and at least one second interface comprising a second screen of microreliefs and arranged in such a manner that travel through the second interface from the first outside face towards the second outside face, passes from a third medium having a third refractive index to a fourth medium having a fourth refractive index less than the third.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.