Security device using liquid crystals
US9279084B2 · kind B2 · utility
2Cited by
4References
16Claims
0Family size
Assignees
Inventors
Key dates
| Filing date | Mar 13, 2014 |
| Grant date | Mar 8, 2016 |
| Priority date | — |
| Expiry date | May 16, 2034 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K2019/323
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The invention generally relates to optically variable devices, methods of preparation and applications or uses therefor. In particular, the invention includes trigger molecules employed as a dopant for a liquid crystal material. The liquid crystal material contains helical elements having a natural twist. The dopant is effective to change the natural twist of the helical elements when the dopant is addressed with incident light. Suitable dopants are selected from binaphthalene and derivatives thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.