Device for recognizing diffraction optical markings
US6365907B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 22, 2000 |
| Grant date | Apr 2, 2002 |
| Priority date | — |
| Expiry date | Mar 22, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K19/16
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The invention relates to a device for the simultaneous machine recognition of Q diffraction optical markings (11) of a security element (4), which devices comprises a light source (1) for projecting parallel light (10) onto a document (3) provided with said security element (4), an optical collector element (2), photodetectors (5; 6) for converting the light (15; 16) diffracted on the markings (11) or the rays reflected on the substrate (3) into electrical signals, as well as an evaluation unit for evaluating said signals. The photodetectors (5; 6) are positioned in the focal plane (8′) of the optical collector element (2). In each case two photodetectors (5; 6) form a photodetector pair. The electrical signals of each pair are analysed and the results of all photodetector pairs are compared with corresponding reference values in the evaluation unit. All the optical markings (11) are read simultaneously and form a code for identifying the security element (4).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.