Security paper
US4534398A · kind A · utility
72Cited by
6References
11Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Apr 30, 1984 |
| Grant date | Aug 13, 1985 |
| Priority date | — |
| Expiry date | Apr 30, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07D7/003
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
This invention relates to a security paper document incorporating counterfeit deterrent, optical variable devices that display their optically active properties in reflectance when there are changes in the angle of incodent light with respect to the eye of the viewer. The devices are applied by means of a carrier paper and a base web format during the papermaking process. An embedment roll presses the device within the base web while the base web fibers are unconsolidated and pliable.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.