| 摘要 |
The invention relates to a security feature (12) for security papers, valuable documents or similar, comprising two layers (22, 24) of cholesteric liquid crystal material located one above the other, the respective layers selectively reflecting light (30, 34) in a first, longer-wavelength spectrum when viewed from a first direction perpendicular to the surface of the layer and selectively reflecting light (32, 36) in a second, shorter-wavelength spectrum when viewed from a second direction running at an angle to the perpendicular of said surface. According to the invention, a first of the two layers (22) is in the form of a motif to be represented and reflects light (34) in the green spectrum when viewed from the first direction, whereas the second of the two layers (24) reflects light (32) in the green spectrum when viewed from the second direction. |
