Achromatically Reflective Mosaic Security Element for Adverse Lighting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional optically variable security elements, such as holograms, lose their effectiveness under adverse illumination conditions, making them less perceivable and thus less secure against counterfeiting.
Innovation Solution
An achromatically reflective micropattern in the form of a mosaic comprising small, precisely designed mosaic elements that reflect incident light without wavelength-dependent diffraction effects, allowing for high-security images to be visible even under poor lighting conditions, with features like tilt angles and reflection areas that create dynamic images upon movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If diffraction optical patterns (holograms) are used for security elements, then optical variable effects are produced, but the effectiveness is reduced under adverse illumination conditions
Solution Approach 1:
The patent replaces the diffraction-optical system with a micro-optical mirror system. Instead of using diffractive structures that rely on wavelength-dependent interference, the invention employs individual micro-mirrors (1-100 μm size) with controlled tilt angles (0-45 degrees) that reflect incident light directly. This mechanical/optical substitution eliminates the need for complex diffraction patterns and enables reliable operation under various illumination conditions including adverse lighting.
Solution Approach 2:
The patent changes the fundamental optical parameter from diffraction-based wavelength-dependent interference to direct reflection with controlled angles. By adjusting the tilt angle of micro-mirrors and their spatial arrangement, the system achieves optical variable effects without relying on diffraction. This parameter transformation allows the security element to maintain effectiveness regardless of illumination quality, as direct reflection works reliably under both good and adverse lighting conditions.
2Reliability
If conventional holograms are used, then color split and diffraction effects are achieved, but the visual effect becomes common and less perceptible as a security feature
Solution Approach 1:
The patent segments the optical function into discrete micro-mirror elements (1-100 μm each) arranged in specific patterns. Each micro-mirror acts as an independent optical unit with controlled tilt, allowing precise control over light reflection. This segmentation enables the creation of custom optical patterns that are not generic like conventional holograms, providing unique visual effects that stand out as security features rather than common design elements.
Solution Approach 2:
The patent applies local quality by giving different regions of the security element different micro-mirror configurations. Areas with different tilt angles, orientations, or densities of micro-mirrors create distinct optical responses in different locations. This local variation produces unique, non-uniform optical patterns that are characteristic of the specific security element, making them easily distinguishable from conventional holographic effects and enhancing their security value.
3Adaptability or versatility
If diffraction patterns are used, then optical variable effects are produced, but the perceptibility is restricted to certain viewing directions and good lighting conditions
Solution Approach 1:
The patent substitutes the diffraction-based optical system with a direct reflection system using micro-mirrors. Since reflection is a more direct and less sensitive optical mechanism compared to diffraction, it maintains effectiveness across a broader range of illumination conditions. The micro-mirrors reflect incident light directly according to their tilt angles, producing clear optical variable effects whether the lighting is good or adverse, and from various viewing directions.
Solution Approach 2:
The patent introduces dynamic optical effects through the controlled tilt angles of micro-mirrors (0-45 degrees). When viewed from different angles or under different lighting conditions, the micro-mirrors dynamically redirect light to create changing optical patterns. This dynamic response allows the security element to adapt its visual appearance based on viewing conditions, maintaining high perceptibility whether the observer is in good or poor lighting environments and from various viewing directions.
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 ensures high counterfeit security by maintaining the visibility of optically variable effects under adverse illumination, providing a secure and dynamic visual experience that is not easily replicable.
Implementation Method 1
achromatically reflective micropattern in the form of a mosaic comprising a plurality of achromatically reflective mosaic elements that are characterized by the parameters size, contour shape, relief shape, reflectivity and spatial orientation
Data Source
AI summary
The invention relates to an optically variable security element (20) for securing valuable articles, having an achromatically reflective micropattern in the form of a mosaic (22) including a plurality of achromatically reflective mosaic elements (26-1, 26-2) that are characterized by the parameters size, contour shape, relief shape, reflectivity and spatial orientation and that form a predefined motif in that different groups of mosaic elements (26-1, 26-2) having different characteristic parameters reflect incident light (28) in different spatial regions (30). The mosaic elements (26-1, 26-2) exhibit a lateral dimension below the resolution limit of the eye.