Anticopying film
US5569522A · kind A · utility
7Cited by
5References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 24, 1994 |
| Grant date | Oct 29, 1996 |
| Priority date | — |
| Expiry date | Aug 24, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31504
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An anticopying film (2) for covering documents (1) appears opaque in vertical plan view (5) as a result of total reflection for protection against copying and appears transparent in the oblique viewing direction (6), the film having an irregular sawtooth structure (3). This makes it virtually impossible to produce an identical second film with the aid of which, by placing said second film on top, the effect of the anticopying film (2) might be eliminated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.