Optically Variable Security Element for Data Carrier Authentication

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Solution Overview

Problem

Existing security elements for data carriers, such as banknotes and identification documents, face challenges in providing a simple and easily verifiable authentication feature that is difficult for counterfeiters to replicate, especially when used without technical aids.

Innovation Solution

A security element comprising a substrate with visually distinguishable areas covered by a color layer containing effect pigments and a colorant, where the color impression differs significantly between areas, enhancing visibility and authenticity verification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a color layer with effect pigments and colorant is applied to substrate areas, then the visual distinction and authentication clarity are improved, but the manufacturing complexity increases

Engineering Contradiction:
Improvevisual distinction clarityVSAvoidmanufacturing process complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The substrate is pre-formed with distinct areas (light and dark regions) before the color layer is applied. This preliminary structuring of the substrate allows the subsequent color layer application to be simpler, as the areas are already defined and ready to receive the effect pigment-containing coating.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention utilizes effect pigments that exhibit optically variable properties, creating different visual impressions (color shifts, brightness changes) when viewed from different angles or under different lighting conditions. This color variability enhances authentication clarity without requiring complex multi-layer printing processes.

Inventive Principle:
Principle #32Color changes

2Ease of operation

If a color layer with effect pigments is applied to the substrate, then the security verification ease is improved, but the production complexity increases

Engineering Contradiction:
Improveauthentication verification easeVSAvoidprinting process complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The effect pigments provide inherent optically variable properties that create clear visual distinctions and authentication features visible to the naked eye. This eliminates the need for complex printing processes or specialized equipment, as the visual effects arise from the pigment properties themselves rather than from complex printing techniques.

Inventive Principle:
Principle #32Color changes

Solution Approach 2:

The color layer with effect pigments creates a visual copy or representation of authentication information that can be easily verified without technical aids. The optically variable effects serve as a simplified copy of complex security information that is readily observable and verifiable by end users.

Inventive Principle:
Principle #26Copying

3Reliability

If different color impressions are created on different substrate areas, then the anti-counterfeiting capability is improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improveanti-counterfeiting capabilityVSAvoidcolor layer application precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The substrate is divided into areas with different local properties (light and dark regions). The color layer with effect pigments is applied to these pre-defined areas, where each area's inherent optical properties contribute to the overall security feature. This local differentiation enhances anti-counterfeiting capability while relying on the substrate's pre-existing structure rather than requiring high-precision color layer patterning.

Inventive Principle:
Principle #3Local quality

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 provides a clear and easily recognizable visual distinction between areas, making it difficult for counterfeiters to replicate, while allowing for simple production and enhanced visibility of the security feature without requiring complex printing processes.

Implementation Method 1

optical interference layers can be present either over the entire surface or in pigment form. Such interference layers typically have a thin film structure that includes a reflective layer, a partially transparent layer and one or more dielectric spacer layers located therebetween.

Methodology Applied
Scientific EffectOptical interference: Interference

Implementation Method 2

cholesteric or other liquid crystal pigments can also be used. The liquid crystal pigments are present, for example, as liquid crystalline silicone polymers. Such liquid crystal pigments, in particular liquid crystal pigments that are based on cholesteric liquid crystals, show a pronounced optically variable effect in the form of a color shift effect when the viewing angle changes

Methodology Applied
Scientific EffectCholesteric liquid crystal effect: Cholesteric Liquid Crystal

Data Source

PatentEP2694297B1Data carrier with security element and process to manufacture the data carrier
Publication Date: 2017.09.06 GIESECKE & DEVRIENT CURRENCY TECHNOLOGY GMBH
  • EP2694297B1 patent drawingFigure 1~2B
  • EP2694297B1 patent drawingFigure 3~4

AI summary

A security element (20) for a data carrier (10) comprises a substrate (30; 30') with a first region (31) and a second region (40). The first region (31) here can be distinguished visually from the second region (40). The security element (20) also comprises a layer (50) of colour, which comprises effect pigments and a colorant. The layer (50) of colour is applied to the substrate (30; 30') such that it covers over the first region (31) and the second region (40) wholly or partially in each case. The colour effect (52) of the first region (31) covered over by the layer (50) of colour has a different appearance, to an observer, from the colour effect (54) of the second region (40) covered over by the layer (50) of colour.