Optical security device
US6806930B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 26, 2002 |
| Grant date | Oct 19, 2004 |
| Priority date | — |
| Expiry date | Jul 26, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K2323/031
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In order to provide comprehensive and multi-purpose security, an optical security device is provided that comprises a substrate and at least a first optically structured layer. The optical security device may provide first, second and third optical inspection levels, including a first inspection level where an optical effect can be discerned with the naked eye, a second level in which an object can be discerned with the aid of an optical inspection tool, and a third level in which an encrypted object can be discerned with a decrypting optical inspection tool. The first layer may be constructed as a retarder plate of LCP material, having an array of elemental areas with different predetermined orientations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.