Multilayer Security Element with Translucent Metallization and Color Shift

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Standard holograms with aluminum reflective layers are becoming increasingly available, leading to a reduction in security standards for documents of value, making them more susceptible to forgery.

Innovation Solution

A multilayer security element is developed, comprising a first transparent layer structure with translucent metallization and diffraction structures, and a second opaque layer structure with a color shift effect, arranged one above the other to partially overlap, enhancing security through a combination of translucency, color shift, and diffraction effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If standard holograms with aluminum reflective layers are used, then manufacturing cost and availability are improved, but security against forgery deteriorates

Engineering Contradiction:
Improvemanufacturing cost and availabilityVSAvoidsecurity against forgery
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The security element is divided into multiple transparent layer structures (first, second, and third layer structures) with different optical functions. Each layer structure contains specific transparent areas and optically active elements, creating a segmented architecture that combines multiple security mechanisms in one element, thereby maintaining high security while remaining manufacturable.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention uses composite transparent layer structures combining different materials with specific optical properties: transparent polymers for substrate, metallizations for reflective effects, liquid crystal materials for color shift effects, and diffraction grating materials. This composite approach creates a security element with multiple simultaneous optical effects that are difficult to forge while using commercially available materials and processes.

Inventive Principle:
Principle #40Composite materials

2Reliability

If multiple transparent layer structures with overlapping transparent areas are used, then security against forgery is improved, but device complexity increases

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

Solution Approach 1:

Multiple transparent layer structures with different optical functions (diffraction gratings, color shift effects, reflective metallizations) are merged into a single integrated security element. The transparent areas of different layers are positioned to overlap, allowing light to pass through multiple layers and accumulate multiple optical effects simultaneously, thereby enhancing security while maintaining a compact single-element structure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention exploits the third dimension (depth/layers) by stacking multiple transparent layer structures with overlapping transparent areas. This vertical arrangement allows light to interact with multiple optically active elements at different depths, creating cumulative optical effects that are difficult to replicate, thereby enhancing security without significantly increasing lateral complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Ease of manufacture

If translucent metallization and diffraction structures are added to the first layer structure, then optical effect complexity is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improveoptical effect complexityVSAvoidalignment precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The first layer structure contains translucent metallization and diffraction structures only in specific local areas (first transparent areas) rather than uniformly across the entire layer. This localized approach allows precise optical effects where needed while reducing overall manufacturing complexity and alignment requirements compared to full-coverage structures.

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 multilayer security element significantly increases the difficulty of forgery by providing a visually appealing and complex optical effect that is challenging to replicate, thus enhancing the security of documents of value.

Implementation Method 1

The first partial areas additionally have diffraction structures

Methodology Applied
Scientific EffectDiffraction: Diffraction

Implementation Method 2

The color shift effect of a multi-layer thin-layer structure is based on interference effects due to multiple reflections in the various sub-layers of the thin-layer element

Methodology Applied
Scientific EffectInterference: Interference

Implementation Method 3

The second layer structure comprises a layer of liquid crystal material and a dark layer

Methodology Applied
Scientific EffectLiquid crystal optical effect: Liquid Crystals

Data Source

PatentEP2173571B2Security element
Publication Date: 2018.12.26 GIESECKE & DEVRIENT CURRENCY TECHNOLOGY GMBH
  • EP2173571B2 patent drawingFigure 1~2a
  • EP2173571B2 patent drawingFigure 2b~3a
  • EP2173571B2 patent drawingFigure 3b~4a

AI summary

The invention relates to a multi-layer security element having a first transparent layer construction with first translucent sub-regions, and a second, opaque layer construction which exhibits a colour flop effect and has second transparent sub-regions.