Optically Variable Security Feature With Angle-Selective Visibility

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Solution Overview

Problem

Existing security documents face challenges in maintaining security as forgers find ways to mimic or attack existing security features, necessitating the development of new and additional security features that are difficult to replicate without proper equipment and knowledge.

Innovation Solution

Incorporating an optically variable layered security feature with openings in the document layers, allowing security elements to be viewed in a controlled manner by changing the observation angle, utilizing materials that emit light in the visible, UV, or IR spectrum upon irradiation, and creating distinct optical appearances based on the angle of view.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional printing processes are used to create security features, then manufacturing is simple and cost-effective, but the security features become easy to forge and tamper with

Engineering Contradiction:
ImprovesecurityVSAvoidstructure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The security feature is divided into multiple layers: a substrate layer, an opaque layer with openings, and a security element layer. This segmentation creates a complex multi-layer structure that is difficult to forge while maintaining manufacturing feasibility through standardized lamination processes

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The security element is embedded within the substrate layer, and the opaque layer with openings is positioned above it, creating a nested configuration where the security element is hidden within the document structure. This nesting provides security while allowing controlled visibility through the openings

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of operation

If security elements are always visible through openings, then verification is easy, but the security feature becomes vulnerable to counterfeiting

Engineering Contradiction:
ImproveverificationVSAvoidsecurity
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The visibility of the security element is made dynamic through the use of optically variable material that changes appearance based on the observation angle. At certain angles, the security element is visible through the openings, while at other angles, it becomes invisible or appears different, providing both verification capability and anti-counterfeiting protection

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The security element utilizes optically variable material that exhibits color or appearance changes depending on the viewing angle or lighting conditions. This optical variability allows authorized verification through controlled observation while making unauthorized replication extremely difficult

Inventive Principle:
Principle #32Color changes

3Reliability

If the opaque layer completely covers the security element, then security is maximized, but the security element cannot be verified

Engineering Contradiction:
ImprovesecurityVSAvoidvisibility
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The opaque layer is designed with localized openings in specific positions and patterns that allow selective visibility of the security element. The openings are strategically placed to permit verification at certain angles while maintaining overall opacity for security, creating different optical properties in different locations

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 enhanced security by making it difficult to forge or tamper with the document, as the optical variance is challenging to replicate and requires specific knowledge and equipment, ensuring the security elements are visible only under controlled conditions.

Implementation Method 1

a first security element embedded in the substrate... The first security element is disposed such that it is not visible via the plurality of first openings when the security document is viewed from the first side under the light of the first wavelength range at a first observation angle, and visible via the plurality of first openings when the security document is viewed from the first side under the light of the first wavelength range at a second observation angle different from the first observation angle

Methodology Applied
Scientific EffectOptical variable effect: Reflection

Data Source

PatentEP4686578A1Security document including an optically variable security feature
Publication Date: 2026.02.04 TOPPAN SECURITY IRELAND TEORANTA
  • EP4686578A1 patent drawingFigure 1
  • EP4686578A1 patent drawingFigure 2
  • EP4686578A1 patent drawingFigure 3

AI summary

A security document (10) includes a first security element (40) embedded in a substrate (1) of the same. The first security element (40) is part of an optically variable security feature (3) and is not visible when the security document (10) is viewed at a first observation angle, but becomes visible when the security document (10) is viewed at a second observation angle. This is achieved by hiding the first security element (40) behind an opaque layer (31) of the substrate (1), and providing appropriate openings (42) in the opaque layer, with which the security element (40) is aligned such that it can only be seen when the security document (10) is viewed at the second observation angle. The openings (42) can be through-holes (43, see figures 2, 3) or zones without an opaque material (39, see figures 4, 5).