Tamper evident optically variable device and article utilizing the same
US4721217A · kind A · utility
106Cited by
4References
21Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 7, 1986 |
| Grant date | Jan 26, 1988 |
| Priority date | — |
| Expiry date | Aug 7, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S206/807
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
Tamper evident optically variable device comprising an optically variable device having at least first and second layers with a spacer layer therebetween providing a color shift with change in viewing angle. A release layer is disposed between the first and second layers to permit the first and second layers to be separated from each other and to thereby destroy the optical shifting properties of the optically variable device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.