Personalizable Security Document with Dual-Mode Laser Images

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Solution Overview

Problem

Existing security documents lack effective personalizable metallic features that are difficult to forge and provide a switchable image mode from metallic to non-metallic upon observation change.

Innovation Solution

A personalizable security document with a metallic layer and a laser-engravable material embedded below, allowing simultaneous laser-engraving of personalized images that change reflectivity and color under different observation modes, using specific laser parameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a laser-engraved image is provided in a polycarbonate substrate, then the document security is improved, but the ability to provide personalized metallic features is limited

Engineering Contradiction:
Improvedocument securityVSAvoidpersonalizable metallic features
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent combines a metallic layer with a polycarbonate substrate to create a composite security document. The metallic layer provides personalized metallic features that are difficult to forge, while the polycarbonate substrate provides structural integrity and additional security features. This composite structure resolves the contradiction by enabling both high security and personalization capability simultaneously.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The metallic layer is embedded within the polycarbonate substrate, with the metallic layer containing the first personalized image and the substrate containing the second personalized image. This nested structure allows both metallic and non-metallic personalized features to coexist within a single document, enhancing both security and adaptability.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If multiple layers with different features are combined, then the security is enhanced, but the manufacturing complexity increases

Engineering Contradiction:
ImprovesecurityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the personalization process into a single simultaneous laser-engraving step that creates both the first personalized image in the metallic layer and the second personalized image in the polycarbonate substrate. This combined approach enhances security through multiple layers while avoiding the need for separate manufacturing steps, thus not increasing manufacturing complexity.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If a metallic layer is laser-engraved from the first side, then the personalized image is visible in reflection, but the underlying layers may be affected

Engineering Contradiction:
Improvevisibility in reflection modeVSAvoidpattern integrity of underlying layers
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent applies local quality by making the polycarbonate substrate transparent or translucent in the regions where the second personalized image is formed. This allows the laser to engrave the metallic layer from the first side for reflective visibility while the laser-engravable material in the substrate below enables the second image to be formed without being affected by the metallic layer, maintaining pattern integrity in both layers.

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

Enhances document security by making it difficult to forge and providing a switchable image that is visible in both reflection and transmission modes, combining multiple secure features for enhanced authentication.

Implementation Method 1

The metallic layer exhibits a change in reflectivity upon irradiation with laser light and is visible when the substrate is viewed from the first side under white light

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Implementation Method 2

The laser-engravable material exhibits a color-change effect upon irradiation with the laser light

Methodology Applied
Scientific EffectPhotochromism: Photochromism

Data Source

PatentEP4600048A1Personalizable security document and method of personalizing the same
Publication Date: 2025.08.13 TOPPAN SECURITY SAS
  • EP4600048A1 patent drawingFigure 1~2
  • EP4600048A1 patent drawingFigure 3~4
  • EP4600048A1 patent drawingFigure 5~7

AI summary

A personalizable security document (10) includes a security feature which has a metallic layer (4) configured to have a first personalized image (5a) laser-engraved in the same. A laser-engravable material (6), which exhibits a color-change effect upon irradiation with laser light (L), is embedded in the security document (10) below the metallic layer (4). Using the laser light (L), the first personalized image (5a) and a second personalized image (5b) can be simultaneously engraved in the metallic layer (4) and the laser-engravable material (6) using appropriate laser parameters. The combination of the metallic layer (4) and the laser-engravable material (6) results in that a switch from a metallic image to a non-metallic image can be obtained when a mode of observation of the security document (10) is changed from reflection to transmission.