| 摘要 |
The present invention relates to a thin-film element (30) having an interference layer structure for security papers, value documents and the like, having at least two semitransparent absorber layers (34, 38) and at least one dielectric spacing layer (36) arranged between the at least two absorber layers. According to the present invention, it is provided that the two absorber layers (34, 38) are each formed from a material having a complex refractive index N whose real part n and imaginary part k differ at least in a portion of the visible spectral range by a factor of 5 or more. |
| 主权项 |
1. A thin-film element comprising an interference layer structure for security papers, value documents and the like, comprising at least two semitransparent absorber layers and at least one dielectric spacing layer arranged between the at least two absorber layers, in which
the two absorber layers are each formed from a material having a complex refractive index N whose real part n and imaginary part k differ at least in a portion of the visible spectral range by a factor of 5 or more, the thin-film element is configured to appear shiny metallic and substantially color neutral when viewed in reflected light and colored in transmitted light, the thin-film element configured to exhibit a chroma C*ab, specified in the CIELAB color space, of more than 15 in transmitted light; and wherein when viewed vertically, the thin-film element is configured to appear green in transmitted light and exhibits a chroma C*ab of more than 40, or yellow in transmitted light and exhibits a chroma C*ab of more than 20, or red in transmitted light and exhibits a chroma C*ab of more than 30, or blue in transmitted light and exhibits a chroma C*ab of more than 30. |
