Diffractive device having a surface relief structure which generates two or more diffraction images and includes a series of tracks
US6088161A · kind A · utility
23Cited by
1References
14Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 19, 1998 |
| Grant date | Jul 11, 2000 |
| Priority date | — |
| Expiry date | Oct 19, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H2001/303
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A diffractive device has a surface relief structure which when illuminated by a light source, generates one or more diffraction effects which are observable from a range of viewing angles around the device. At least part of the surface relief structure is arranged in a series of tracks, each track being less than 0.25 mm in width. The device, which may be embossed onto a metallised foil, is suitable for use as an anti-forgery authentication element on valuable documents.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.