Luminescent Color Gradient Security Feature for Anti-Counterfeiting

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Solution Overview

Problem

There is a need for new, individualizing security features that are secure against counterfeiting and falsification, easily recognizable, and can be implemented cost-effectively and quickly, particularly for valuable and security documents, which lack suitable raw materials and printing tools for luminescent images and color management.

Innovation Solution

A security feature with a gradient structure formed by pattern elements arranged in a grid, using digital printing with luminescent agents that change spectrally, allowing for the display of patterns in multiple colors under excitation conditions without complex material development, and can be implemented as a color gradient structure using additive mixing of luminescent colors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional manufacturing methods for luminescent portraits and patterns are used, then security features can be produced, but suitable raw materials and printing inks are lacking, and tools for calibrating individual colors or printing all colors together are not available

Engineering Contradiction:
Improvesecurity feature authenticityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies parameter changes by utilizing the spectral properties of luminescent materials that change under different excitation conditions. The security feature displays different colors when excited by different wavelengths of light, creating a dynamic visual effect that is difficult to replicate. This parameter-based approach (using spectral shifts rather than static pigments) resolves the contradiction by providing reliable authentication without requiring complex color calibration tools.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces conventional mechanical printing systems with digital printing technology. The digital printing process allows for precise deposition of luminescent materials in patterned arrangements, eliminating the need for complex mechanical color calibration and multiple printing passes. This substitution enables cost-effective production of high-security features with exacting precision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If a security feature is made easily recognizable and visually appealing, then it can be easily identified, but it may become more susceptible to counterfeiting and falsification

Engineering Contradiction:
ImproverecognizabilityVSAvoidcounterfeiting resistance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies dynamics by creating a security feature that changes its visual properties under different excitation conditions. The luminescent pattern displays different colors and intensities when illuminated by different wavelengths of light, creating a dynamic authentication mechanism. This dynamic behavior makes the feature easily recognizable during verification while simultaneously providing strong counterfeiting resistance, as the specific spectral response is difficult to replicate.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent directly applies color changes through the use of luminescent materials that emit different colors under different excitation wavelengths. The security feature exhibits striking color transitions that are easily visible during authentication, yet the specific color sequence and intensity profile serve as a unique fingerprint that is extremely difficult to counterfeit. This resolves the contradiction by making the feature both visually appealing and secure.

Inventive Principle:
Principle #32Color changes

3Reliability

If a security feature is placed in an internal product layer secure against counterfeiting, then security is improved, but the feature must be applied before final document assembly, limiting flexibility

Engineering Contradiction:
Improvecounterfeiting protectionVSAvoidimplementation flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies segmentation by separating the security feature into a distinct, self-contained layer that can be independently produced and then integrated into the final document. The luminescent pattern is created on a separate substrate or layer that can be manufactured using digital printing, then laminated or bonded to the final document structure. This segmentation provides both security (the feature is embedded in an internal layer) and flexibility (the layer can be produced independently and assembled later).

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 provides a visually appealing, easily recognizable security feature that appears colorless or gray under normal lighting but displays a color gradient under luminescent conditions, making it difficult to reproduce and thus secure against forgery, while being cost-effective and quick to implement.

Implementation Method 1

The gradient structure is produced with at least two spectrally different luminescent colorants

Methodology Applied
Scientific EffectLuminescence: Luminescence

Implementation Method 2

The security feature appears colorless or gray under normal lighting but displays a color gradient under luminescent conditions

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Data Source

PatentEP2906430B2Security feature with a colour progression structure for a value product and/or security product, and value document and/or security document having the security feature
Publication Date: 2023.05.03 BUNDESDRUCKEREI GMBH
  • EP2906430B2 patent drawingFigure 1~2
  • EP2906430B2 patent drawingFigure 3~4
  • EP2906430B2 patent drawingFigure 5

AI summary

The present invention relates to a novel security feature 100 for a value product and/or security product 400, which feature is formed by a pattern 300 made on at least one carrier surface 210, the pattern having a colour progression structure made from pattern elements 310 that are formed by means of a digital printing process and are arranged in a grid. According to the invention, the colour progression structure is produced by means of at least two luminescent means with spectrally different luminescence. The value product and/or security product 400 according to the invention has one or more product carriers 200 and at least one security feature 100 according to the invention arranged on and/or in the product carrier(s) 200.