| 摘要 |
A document with an embossed macroscopic structure and acting through optical diffraction is disclosed. The structure, which serves as a security element comprises a plurality of surface portions with predetermined relief structures having spatial frequencies of over 10 lines/mm. Each surface portion is different from directly adjoining surface portions and at least some of the surface portions have a maximum dimension of less than 0.3 mm. To the naked eye, the pattern of surface portions on the document appears as a mesh of dots and lines. However, to an examiner with a magnifying device, the dots and lines appear as numbers, characters or other graphic features. |
