Transparent Security Window With Microlenses for Anti-Counterfeit Imaging
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Solution Overview
Problem
Existing security documents lack advanced features to enhance security and authenticity verification, particularly in transparent windows, which can be easily replicated or tampered with.
Innovation Solution
Incorporation of an optically imaging structure with plano-convex microlenses into the substrate of security documents, allowing for machine-readable and visually perceptible effects such as flip images, three-dimensional effects, and animations, utilizing special inks that are only visible under specific electromagnetic excitations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If transparent windows are used in security documents, then visibility and aesthetic appeal are improved, but security and authenticity verification are worsened
Solution Approach 1:
The patent applies color-changing inks and optical elements that display different colors or images depending on viewing angle, illumination conditions, or environmental factors. This allows the transparent window to maintain visibility while incorporating security features that change appearance under different conditions, making counterfeiting difficult
Solution Approach 2:
The patent uses composite structures combining transparent materials with embedded security elements such as microencapsulated pigments, liquid crystals, or optical layers. These composite materials provide both the desired transparency/visibility and integrated security verification capabilities
2Reliability
If complex security features are added to transparent windows, then authenticity verification is improved, but device complexity and manufacturing difficulty are worsened
Solution Approach 1:
The patent divides the security document into distinct functional layers or zones, with specific security features placed in specific regions. This segmentation allows for standardized manufacturing of individual components that are then assembled, reducing overall manufacturing complexity while maintaining high security
Solution Approach 2:
The patent designs security features that serve multiple functions simultaneously - for example, optical elements that provide both aesthetic visual effects and authentication verification, or inks that provide both color information and security coding. This multi-functionality reduces the number of separate components needed
3Reliability
If advanced optical structures are incorporated into the substrate, then security features are improved, but manufacturing precision requirements are worsened
Solution Approach 1:
The patent incorporates registration marks, alignment features, or pre-positioned elements during earlier manufacturing stages that guide subsequent processing steps. This preliminary action ensures proper alignment of optical structures and security features without requiring extremely high precision in each individual step
Solution Approach 2:
The patent designs self-aligning structures where components automatically position themselves relative to each other through geometric interlocking, optical alignment, or material properties. This self-service mechanism reduces the need for high-precision external alignment equipment and processes
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
Enhances security and authenticity verification by providing complex animations and smooth transitions, while ensuring machine-readability through invisible inks, making counterfeiting more difficult and improving document integrity.
Implementation Method 1
at least in the area of the transparent window a micro-optical structure consisting of microlenses is arranged on one side of the substrate
Implementation Method 2
utilizing special inks that are only visible under specific electromagnetic excitations
Data Source
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AI summary
The invention relates to a security document (02) with a transparent window (04) which is formed in the security document substrate (26) and which comprises a micro-optical structure (03) consisting of microlenses (11). At least one printed image (27) is arranged on the other substrate (26) face lying opposite the micro-optical structure (03) at least in the region of the transparent window (04), wherein the printed image (27) in question has multiple image elements (28a to 28j) in a punctiform or linear pattern, and the pixel size (38) or the line thickness (38) of said image elements (28a to 28j) is designed to be smaller than the lens width (18) of the microlenses (11) arranged in the micro-optical structure (03) in each case. A laminar expanded layer (39) which covers the printed image (27) in question is arranged on at least one section of the printed image (27) in question on the printed image face facing away from the micro-optical structure (03). The layer (39) which covers the printed image (27) in question is produced in an inkjet printing method, and the layer (39) is designed to be transparent to an electromagnetic radiation with a wavelength ranging from 380 nm to 780 nm, the degree of transparency to said electromagnetic radiation ranging between 10% and 90%. The transparency is designed to vary gradually over the planar two-dimensional extension of the layer (39) covering the printed image (27) in question such that at least one location of the layer (39) or some locations of the layer (39) are formed with a degree of transparency which differs from that of other locations of the layer (39). A second printed image (41) can be provided on the layer (39) and become visible after a folding process.