| 主权项 |
1. A security device for verifying an authenticity of a security document, in particular of a banknote, a passport a document of value, a certificate, or a credit card, the security device comprising:
an at least partially transparent substrate and with a first surface and a second surface, a first pattern arranged on the first surface of the substrate, a second pattern arranged on the second surface of the substrate, wherein the first pattern on the first surface is arranged fully in register with the second pattern on the second surface, wherein, the first pattern and the second pattern each comprise a plurality of pixels with at least three different gray levels visible from a macroscopic perspective, wherein the first pattern and the second pattern cover only gray levels in a range between 20% black and 80% black, in particular between 35% black and 65% black, wherein the first pattern is inverted with respect to the second pattern, such that a level of x % is inverted to a level of (100%-x %). |
