Optical device
US5310222A · kind A · utility
101Cited by
10References
21Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 8, 1992 |
| Grant date | May 10, 1994 |
| Priority date | — |
| Expiry date | Apr 8, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H2270/52
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical security device for use on a security article comprises a number of layers including an optically diffracting layer and an at least partially reflective layer which together generate a first image. A non-optically diffracting second image is provided within the device in association with the first image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.