PROTECTIVE ELEMENT WITH VISUALLY OR AUTOMATICALLY RECOGNIZABLE MARKING IN PARTICULAR FOR SAFETY MARKING OF SECURITIES AND METHOD OF CHECKING SECURITIES FOR THEIR AUTENTICITY

摘要

PCT No. PCT/EP90/00765 Sec. 371 Date Mar. 7, 1991 Sec. 102(e) Date Mar. 7, 1991 PCT Filed May 11, 1990 PCT Pub. No. WO90/13878 PCT Pub. Date Nov. 15, 1990.In a security document having an embedded security element in the form of a transparent thread with electrically conductive material in at least two layers, at least one layer is transparent or partly transparent at least in certain areas. The partly transparent layer interacts with marks located on the thread in such a way that the marks are largely concealed in incident light but are recognizable visually in transmitted light.