Optical security device providing color switching or image switching effect
US12370825B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 9, 2024 |
| Grant date | Jul 29, 2025 |
| Priority date | — |
| Expiry date | Mar 9, 2044 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07D7/1205
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
An optical security feature has pixels with faceted microstructures supporting nano-patterned optical filters. Each of the pixels includes a substrate and a nanostructure. The substrate is configured to emit light of at least a first wavelength and a second wavelength different than the first wavelength. The microstructure includes a first facet, a second facet non-parallel to the first facet, a first nano-patterned optical filter disposed on the first facet, and a second nano-patterned optical filter disposed on the second facet. The first nano-patterned optical filter includes a first stopband that includes the first wavelength and excludes the second wavelength. The second nano-patterned optical filter includes a second stopband that includes the second wavelength and excludes the first wavelength. For each pixel, the first nano-patterned optical filter inhibits emission of light at the first wavelength from the pixel via the first facet.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.