Optical structures providing dichroic effects
US10838218B2 · kind B2 · utility
5Cited by
27References
24Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 3, 2018 |
| Grant date | Nov 17, 2020 |
| Priority date | — |
| Expiry date | Aug 3, 2038 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29D11/0073
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A document, product, or package, such as a banknote, passport or the like comprises structures having dichroic effects that change color with viewing angle in both transmission and reflection. Such structures can be useful as security features that counter the ability to effectively use counterfeit documents, products, packages, etc.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.