Security Element with Color-Shifting and Semitransparent Thin-Film Layers
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Solution Overview
Problem
Current security elements for valuable documents lack improved production methods that enhance their authenticity verification and anti-reproduction capabilities, particularly in terms of angle-dependent optical effects.
Innovation Solution
A security element combining a color-shifting thin-film element with a semi-transparent thin-film element, which changes color when viewed in reflected and transmitted light, is integrated into a carrier substrate, allowing for enhanced authenticity checks and additional optical effects by aligning the semi-transparent element with the color-shifting element at specific viewing angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single type of thin-film element is used in security elements, then the production process is simple, but the authenticity verification capability and optical effects are limited
Solution Approach 1:
The patent combines a color-shifting thin-film element with a semi-transparent thin-film element in a single security element structure. The color-shifting element provides angle-dependent color changes through interference effects, while the semi-transparent element provides additional optical effects and color changes in reflected and transmitted light. This merging of multiple functional elements enhances authenticity verification capabilities while maintaining integration within a single security element component.
2Reliability
If multiple thin-film elements are combined to enhance optical effects, then authenticity verification is improved, but the production process becomes more complex
Solution Approach 1:
The security element is divided into distinct functional layers: a color-shifting thin-film element consisting of reflective and absorber layers with dielectric spacer, and a separate semi-transparent thin-film element. This segmentation allows each element to be optimized for its specific function while enabling independent manufacturing and assembly, thereby managing production complexity while enhancing anti-reproduction capability through multiple optical effects.
3Adaptability or versatility
If the semi-transparent thin-film element is aligned with the color-shifting element at specific viewing angles, then additional optical effects are achieved, but the viewing angle dependence increases
Solution Approach 1:
The patent introduces a new dimension to optical effects by combining angle-dependent color shifting in one plane with additional color changes in reflected and transmitted light from the semi-transparent element. This multi-dimensional optical behavior creates various color impressions depending on the viewing angle and light path, enhancing versatility while naturally utilizing the viewing angle dependence to provide security against reproduction.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This combination enables uncomplicated authenticity verification and an additional optical effect where the semi-transparent element matches the color-shifting element at certain viewing angles, providing improved security against unauthorized reproduction.
Implementation Method 1
the color shift effect is based on viewing-angle-dependent interference effects caused by multiple reflections in the various sub-layers of the element
Implementation Method 2
viewing-angle-dependent interference effects caused by multiple reflections in the various sub-layers of the element
Implementation Method 3
a semi-transparent thin-film element, which changes color when viewed in reflected and transmitted light
Data Source
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Figure 9a~9e
AI summary
The invention relates to a security element for making documents of value secure, comprising a carrier substrate, which is provided with a first thin-film element and a second thin-film element, wherein the first thin-film element is a colour-changing thin-film element, which gives a viewer the impression of different colours at different viewing angles, and the second thin-film element is a semitransparent thin-film element, which gives a viewer the impression of different colours when viewed with the light reflected and when viewed with the light shining through, wherein the first thin-film element and the second thin-film element are arranged on the carrier substrate in such a way that the second thin-film element takes the form of characters, a pattern or a coding and the first thin-film element represents a background.