Security Element Colored Image Laser Microstructure

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Solution Overview

Problem

Existing methods for enhancing anti-counterfeit protection in security documents, particularly with colored images, face limitations in color saturation and distinguishing laser-marked elements from fully printed images due to the need for light pre-prints with white components, which restricts the quality of the color representation.

Innovation Solution

A security element comprising a first layer with alternating colored surface areas and a second optically transparent layer, where structural elements with dimensions in the micrometer or nanometer range are arranged to create a colored image that differs from the first layer's image, allowing for high color saturation and contrast without requiring a bright pre-print, and can be produced using ultra-short laser pulses or high-resolution 3D printing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a light pre-print with white components is used for laser marking, then the laser marking process can be performed, but the color saturation is reduced and the achievable color space is limited

Engineering Contradiction:
Improvelaser marking processabilityVSAvoidcolor saturation
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent divides the image into two separate layers: a colored pre-print layer and a laser-marked structural layer. This segmentation allows each layer to be optimized independently - the pre-print can use saturated colors without white components, while the laser marking creates structural contrast on top, resolving the contradiction between manufacturability and color quality

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a single-layer approach to a multi-layer dimensional structure. By adding the structural layer with micrometer/nanometer features on top of the colored pre-print, it creates a new dimension of contrast that doesn't rely on light backgrounds, enabling full color saturation while maintaining laser mark distinguishability

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

2Reliability

If laser marking is used to personalize the document, then anti-counterfeit protection is increased, but it becomes difficult or impossible to distinguish the personalized element from a fully printed portrait without additional aids

Engineering Contradiction:
Improveanti-counterfeit protectionVSAvoiddistinguishability of laser-marked elements
Core Design Contradiction:
ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent applies color changes by creating a colored pre-print layer with saturated hues that is then overlaid with laser-marked structural elements. The laser marking process creates contrast through structural modification rather than color change alone, and the combination produces a visually distinct appearance that is easily distinguishable from standard printing while maintaining high anti-counterfeit reliability

Inventive Principle:
Principle #32Color changes

Solution Approach 2:

The patent uses composite materials by combining the colored pre-print layer with the laser-marked structural layer. This composite structure integrates two different manufacturing processes and material states, creating a security feature that combines the visual quality of printed colors with the authenticity verification capability of laser-marked structural changes

Inventive Principle:
Principle #40Composite materials

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

This approach enables improved color saturation and contrast, making it easier to distinguish laser-marked security elements from fully printed images, thereby enhancing counterfeit security and achieving a higher quality representation without the need for additional aids.

Implementation Method 1

can be produced using ultra-short laser pulses

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Data Source

PatentEP3578379B1Security element having a coloured image
Publication Date: 2023.10.04 BUNDESDRUCKEREI GMBH
  • EP3578379B1 patent drawingFigure 1~3

AI summary

A security element (2, 3) for use in a security document (1) is described, comprising a first layer (11). The first layer (11) comprises an area of ​​a plurality of surface regions (14, 15, 16), wherein adjacent surface regions (14, 15, 16) have different colors and the surface regions (14, 15, 16) are arranged in alternating colors. At least one surface (17, 18) is present, having a structure comprising structural elements (13) with dimensions of less than 200 micrometers (200 µm). The structural elements (13) are arranged with respect to the surface regions (14, 15, 16) of the first layer (11) such that a colored image is produced that differs from the image produced solely by the surface regions of the first layer.For example, the first layer comprises surface areas with at least three different colors, preferably the group red, green, and blue and/or the group yellow, magenta, and cyan. The structural elements (13) can be designed as holes and/or depressions and/or protrusions. The structure can be produced by laser radiation and/or by local foaming and/or by high-resolution 3D printing technology.