Multi-luminescent Security Element with Absorber for Color Contrast

Solution Overview

Problem

Existing luminescent security elements in security documents fail to produce brilliant luminescence with distinct colors under different excitation conditions due to simultaneous excitation of luminescent substances, resulting in unsatisfactory contrast and mixed colors, especially when using higher energy radiation.

Innovation Solution

A multi-luminescent security element is developed, featuring separate luminescence means excited under different conditions, with an absorber means that prevents excitation of one luminescence means under the excitation conditions for the other, ensuring pure color emission and enhanced contrast by spatially separating or shielding the luminescence means.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If multiple luminescent substances are used in the same security element, then the luminescence intensity increases, but the color contrast deteriorates due to mixed colors from simultaneous excitation

Engineering Contradiction:

Improveluminescence intensityVSAvoidcolor contrast

Core Design Contradiction:

Illumination intensityVSManufacturing precision

Solution Approach 1:

The security element is divided into multiple spatially separated luminescent zones, each containing a different luminescent substance. This segmentation prevents simultaneous excitation of multiple substances, eliminating color mixing while maintaining high luminescence intensity in each zone. The absorber means is strategically positioned to block excitation radiation from reaching specific luminescent zones, enabling independent control of each luminescent region.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

An absorber means is introduced as an intermediary component between the excitation radiation source and the luminescent substances. This absorber selectively blocks excitation radiation from reaching certain luminescent zones while allowing other zones to be excited, thereby controlling which luminescent substances are activated and preventing unwanted color mixing.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Power

If higher energy excitation radiation is used, then the excitation capability increases, but the color purity deteriorates due to simultaneous excitation of multiple luminescent substances

Engineering Contradiction:

Improveexcitation capabilityVSAvoidcolor purity

Core Design Contradiction:

PowerVSManufacturing precision

Solution Approach 1:

The security element is divided into multiple spatially separated luminescent zones, each containing a different luminescent substance. This segmentation prevents simultaneous excitation of multiple substances, eliminating color mixing while maintaining high luminescence intensity in each zone. The absorber means is strategically positioned to block excitation radiation from reaching specific luminescent zones, enabling independent control of each luminescent region.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

An absorber means is introduced as an intermediary component between the excitation radiation source and the luminescent substances. This absorber selectively blocks excitation radiation from reaching certain luminescent zones while allowing other zones to be excited, thereby controlling which luminescent substances are activated and preventing unwanted color mixing.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Manufacturing precision

If luminescent substances are placed in defined partial areas, then the color contrast improves, but the device complexity increases due to spatial arrangement requirements

Engineering Contradiction:

Improvecolor contrastVSAvoidspatial arrangement complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

Multiple luminescent substances with different excitation characteristics are combined within a single security element, but arranged in spatially separated zones. The absorber means is integrated into the element structure to control radiation distribution. This merging approach maintains color contrast while simplifying the overall structure compared to using separate elements for each luminescent substance.

Inventive Principle:

Principle #5Merging (Combining)

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 achieves excellent color contrast and saturation, allowing for selective excitation of luminescent colors, even when luminescence means are in the same area, and enhances the flexibility in selecting luminescent substances and their ratios, resulting in aging-resistant security elements.

Implementation Method 1

a first luminescence means, which can be excited to luminescence under first excitation conditions

Methodology Applied

Scientific EffectLuminescence: Luminescence

Implementation Method 2

the first luminescence means, which can be excited to luminescence under first excitation conditions

Methodology Applied

Scientific EffectFluorescence: Fluorescence

Implementation Method 3

a second luminescence means, which can be excited to luminescence under second excitation conditions

Methodology Applied

Scientific EffectLuminescence: Luminescence

Implementation Method 4

a second luminescence means, which can be excited to luminescence under second excitation conditions

Methodology Applied

Scientific EffectPhosphorescence: Phosphorescence

Implementation Method 5

at least one absorber means, which prevents an excitation to luminescence of the first luminescence means under the second excitation conditions

Methodology Applied

Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Data Source

PatentUS11879083B2Multi-luminescent security element and value or security product containing said security element

Publication Date: 2024.01.23 BUNDESDRUCKEREI GMBH

AI summary

In order to increase the security of value or security documents 100, a multi-luminescent security element 400 is provided which contains at least one first luminescence means 510 and at least one second luminescence means 520. The first luminescence means 510 can be excited under first excitation conditions Sp-1 for the purpose of luminescence, and the second luminescence means 520 can be excited under second excitation conditions Sp-2 for the purpose of luminescence, said second excitation conditions Sp-2 differing from the first excitation conditions Sp-1. The multi-luminescent security element 400 is additionally equipped with at least one absorber means 600 which prevents an excitation of the at least one first luminescence means 510 under the second excitation conditions Sp-2 for the purpose of luminescence.