Laser-Engravable Security Document with Color-Change Masking

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Solution Overview

Problem

Existing security documents lack effective features that provide secure and personalized identification while maintaining the integrity of embedded security features, such as watermarks, which are not easily visible without compromising the document's authenticity.

Innovation Solution

A personalizable security document with a substrate featuring a laser-engravable portion exhibiting a color-change effect under different observation angles, combined with a second layer pattern that is selectively visible when the document is tilted, allowing for the masking and unmasking of additional security features like watermarks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a laser engraved image is used inside a polycarbonate substrate, then security features are enhanced, but the visibility of additional security features like watermarks is compromised

Engineering Contradiction:

Improvesecurity feature integrityVSAvoidvisibility of additional security features

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The patent applies the dynamics principle by making the laser-engravable material's optical properties changeable through laser irradiation. The material transitions from a transparent state (allowing watermark visibility) to an opaque state (blocking watermark visibility) based on the applied laser energy, enabling dynamic control of information visibility.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by modifying the optical transmission properties of the laser-engravable material through controlled laser irradiation. The material's transparency parameter can be adjusted between transparent and opaque states, allowing selective visibility of underlying security features like watermarks.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If additional security features are embedded in the substrate, then document authenticity is improved, but the features become invisible when viewed from the front side

Engineering Contradiction:

Improvedocument authenticityVSAvoiddetectability of additional features

Core Design Contradiction:

ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent applies preliminary action by pre-positioning the additional security features (watermarks) in the substrate before the laser engraving process. These features are prepared in advance to be visible only when the laser-engravable material above them is in its transparent state, allowing selective revelation during verification.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent utilizes color changes by employing a laser-engravable material that can transition between transparent and opaque states. This optical property change allows the underlying security features to be selectively revealed or hidden based on the material's current optical state, controlled by laser irradiation.

Inventive Principle:

Principle #32Color changes

3Adaptability or versatility

If a color-change effect material is used in the laser-engravable portion, then personalization capability is enhanced, but the complexity of the security feature structure increases

Engineering Contradiction:

Improvepersonalization capabilityVSAvoidsecurity feature structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies universality by designing the laser-engravable material to perform multiple functions simultaneously: it provides personalization capability through color-change effects, maintains security by controlling visibility of underlying features, and enables dynamic state changes through laser irradiation. This multi-functional material reduces the need for separate components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent implements composite materials by using a laser-engravable material that combines color-change properties with variable optical transmission characteristics. This composite material integrates multiple functional properties (color change, transparency control, laser responsiveness) into a single component, managing structural complexity while enhancing capabilities.

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

Enhances security by ensuring that additional features are only visible under specific conditions, making it difficult to forge the document while maintaining the document's authenticity and allowing for personalized laser-engraved images.

Implementation Method 1

The laser-engravable portion includes a first material that exhibits a color-change effect when viewed from the first-side under white light at different observation angles

Methodology Applied

Scientific EffectColor-change effect: Iridescence

Implementation Method 2

laser engraving a personalized image in the laser-engravable portion from the first side of the substrate

Methodology Applied

Scientific EffectLaser engraving: Laser Ablation

Data Source

PatentEP4303028A1Personalizable security document and method of personalizing the same

Publication Date: 2024.01.10 TOPPAN SECURITY SAS

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AI summary

A personalizable security document (10) includes a laser-engravable portion (5a) that exhibits a color-change effect when viewed under white light. This color-change effect is used to selectively mask a further security feature provided as a first pattern (27a) in a layer that is below the layer including the laser-engravable portion (5a). This is achieved by appropriately matching the color of the laser-engravable portion (5a) to the color of the first pattern (27a).