Security Element Transmissive Diffraction Structures

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Solution Overview

Problem

Current security features in documents, such as banknotes, are vulnerable to forgery and lack distinctiveness when viewed under transmitted light, as they primarily rely on watermarks and security threads that do not provide sufficient contrast or color change effects.

Innovation Solution

A security element with transmissive diffraction structures that change color when tilted or rotated, utilizing multiple zones with different diffraction structures to create a range of color change effects, including from transparent to colored and vice versa, enhancing visibility and memorability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If traditional watermarks or security threads are used, then the security element is recognizable in transmitted light, but the contrast and visual distinctiveness are insufficient

Engineering Contradiction:
Improvelight transmission contrastVSAvoidsecurity against forgery
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent applies color change effects through diffractive structures that exhibit different colors or transparency states depending on the viewing angle. When the security element is tilted or rotated, the diffractive structures cause the transmitted light to change color (e.g., from transparent to colored appearances), providing high visual contrast and distinctiveness that is difficult to forge.

Inventive Principle:
Principle #32Color changes

Solution Approach 2:

The patent utilizes changes in optical parameters (transmissivity, color, transparency) based on the tilt angle and rotation angle of the security element. The diffractive structures are designed to produce different optical effects at different angles, creating dynamic visual changes that enhance security verification.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If diffractive structures are added to create color change effects, then security against forgery is improved, but the device complexity increases

Engineering Contradiction:
Improvesecurity against forgeryVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The security element is divided into multiple zones with different diffractive structures (first diffractive structure, second diffractive structure, etc.). Each zone can have different optical properties and color change characteristics, allowing complex security features to be created through modular design and combination of simpler elements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The diffractive structures serve multiple functions: they create color change effects, provide angle-dependent transparency variations, and generate distinctive optical patterns. A single diffractive structure design can simultaneously achieve several security objectives, reducing the need for multiple separate components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If multiple zones with different diffractive structures are used, then visual variability and memorability are enhanced, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvevisual variabilityVSAvoiddiffractive structure precision
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The security element is divided into multiple zones with different diffractive structures, allowing each zone to be optimized for specific visual effects. This segmentation enables high visual variability through combination of different optical properties in different regions, while each individual zone can be manufactured with standardized precision requirements.

Inventive Principle:
Principle #1Segmentation

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 significantly improves the security and visual variability of the security element, making it more difficult to forge and providing a distinctive optical security feature that changes appearance with tilt and rotation, thus enhancing counterfeit prevention.

Implementation Method 1

The security element has at least one transparent area which has transmissivity for at least one wavelength range of at least 30 nm from the wavelength range from 460 nm to 660 nm of more than 20%, in particular more than 50%, at at least one tilt angle. In the transparent area, the security element has one or more transmissive diffraction structures which, when viewed through transmitted light, show one or more optical security features.

Methodology Applied
Scientific EffectDiffraction: Diffraction

Data Source

PatentEP2892729B1Security element and security document
Publication Date: 2018.03.21 OVD KINEGRAM AG
  • EP2892729B1 patent drawingFigure 1a~1c
  • EP2892729B1 patent drawingFigure 2~3
  • EP2892729B1 patent drawingFigure 4a~4b

AI summary

The invention relates to a security element (2) comprising a first region (30) which is transparent in transmitted light. The security element (2) comprises a substrate (21) which in the first region (30) has one or more transmissive diffraction structures which, when seen in transmitted light, show one or more optical security features.