UV-Luminescent Grid Layers for Counterfeit-Resistant Security Elements
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Solution Overview
Problem
Existing security elements for valuable documents lack an optical effect that is visually appealing under visible light and provides enhanced security against counterfeiting, particularly when illuminated with UV radiation.
Innovation Solution
A security element comprising a substrate with two printing layers, where the first layer consists of indistinguishable partial screen areas of different colors forming a mixed color, and the second layer comprises luminescent grid areas visible under UV radiation and transparent under visible light, interacting optically to create a static 3D effect with varying color impressions under different lighting conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multicolored solid colors are applied to embossed structures to create movement effects, then security against counterfeiting is improved, but the visual appearance becomes unattractive due to mixed colors when viewed from above
Solution Approach 1:
The printing layer is segmented into multiple individually addressable microelements (pixels) that can be independently controlled. Each pixel contains multiple colored portions corresponding to different colors, allowing selective activation of specific colors in specific pixels based on viewing angle, thereby resolving the contradiction between security (multiple colors) and visual appearance (controlled color display).
Solution Approach 2:
The security element employs dynamic color display where the activated color in each pixel changes based on the viewing angle. The control unit receives angle information and dynamically adjusts which color portions are activated in each pixel, enabling the element to present different visual appearances at different angles while maintaining security through the multicolor capability.
2Reliability
If multiple solid colors are used to create movement effects, then counterfeit resistance is enhanced, but additional information is not created for the image motif when illumination changes to UV range
Solution Approach 1:
The security element is designed with multi-functionality to operate under different illumination conditions. The same pixel structure serves both visible light viewing (displaying controlled colors based on angle) and UV illumination (displaying hidden images through fluorescent materials). The control unit can switch between these modes, allowing the element to provide both movement effects under visible light and additional information under UV without requiring separate structures.
Solution Approach 2:
The printing layer incorporates composite materials including fluorescent materials that are invisible under visible light but become visible under UV illumination. This allows the security element to maintain its visual appearance under normal lighting while providing additional information channels under UV illumination, thereby preventing information loss and enhancing counterfeit resistance.
3Reliability
If high-resolution 3D representations are provided, then counterfeit resistance is increased, but the complexity of the printing layer structure increases
Solution Approach 1:
The patent transitions from traditional 2D flat displays to a 3D spatial arrangement of microelements. Each pixel is positioned at different depths and angles, creating a three-dimensional structure that enables high-resolution 3D representations. This dimensional change allows complex visual information to be encoded in spatial relationships rather than requiring increasingly complex material compositions or layer structures.
Solution Approach 2:
The control unit dynamically adjusts multiple parameters including which color portions are activated, the intensity of activation, and the timing of activation based on viewing angle and illumination conditions. This parametric control enables high-resolution 3D representations to be achieved through dynamic parameter modulation rather than through static structural complexity, thereby reducing the inherent complexity of the printing layer structure.
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
The solution enhances the visual appeal and security against counterfeiting by providing a surprising optical effect under visible light, which is enhanced under UV radiation, offering high-resolution and complex 3D representations with increased counterfeit resistance.
Implementation Method 1
a first printing layer is formed from first screen areas, which are composed of first partial screen areas and second, color-different partial screen areas, wherein the first and second partial screen areas are indistinguishable with the naked eye and together result in a mixed color
Implementation Method 2
The substrate forming the background either has a high reflectivity or is provided with a reflective silver layer
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A security element for protecting valuable documents, comprising a substrate body (2) with first grid areas (8) composed of first partial grid areas (4) and second, differently colored partial grid areas (6), and second grid areas. The first partial grid areas (4) and the second partial grid areas (6) are indistinguishable with the naked eye and together result in a mixed color. The first grid areas (8) or the second grid areas (10) are formed from luminescent colors, are detectable when illuminated with UV radiation and transparent when illuminated only with light from the visible spectrum, and the respective other grid areas (8, 10) are formed from body colors.At at least one angle to the front side, the second raster areas (10) appear to only partially overlap the first raster areas (8), wherein between the second raster areas (10) and the first partial raster areas (4) and the second partial raster areas (6) there is in each case a degree of overlap in the range from 0% to 100%, and the security element has at least two regions in which the degree of overlap between the second raster areas (10) and the first partial raster areas (4) differs from the degree of overlap between the second raster areas (10) and the second partial raster areas (6). When illuminated with a combination of UV radiation and light from the visible spectrum, the mixed color is modified differently in the two regions.