Lenticular Security Document Alignment via Radiation Marks

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Solution Overview

Problem

Existing security documents, such as passports, face challenges in ensuring the authenticity of the data page, as it can be easily removed and replaced with a falsified page, leading to potential identity fraud.

Innovation Solution

The solution involves linking the data page to the consecutive paper page using a security element comprising a lenticular network on the plastic page and printed frames on the paper page, which are perfectly aligned using radiation-sensitive positioning marks to ensure authentication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the data page is made removable from the booklet, then ease of operation is improved, but security is worsened as it enables falsification

Engineering Contradiction:
Improveremovability of data pageVSAvoidauthenticity of data page
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

A security element is pre-integrated into the booklet structure, comprising a first part in the data page and a second part in the paper page. This preliminary integration creates an intrinsic link that must be violated to remove the data page, thereby maintaining security while allowing operational flexibility.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The security element is nested within the booklet structure, with components embedded in both the data page and paper page. This nested configuration creates a hierarchical security mechanism where the data page cannot be removed without compromising the integrated security element.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Manufacturing precision

If the lenticular network and printed frames are aligned manually, then manufacturing precision is worsened, but device complexity is improved

Engineering Contradiction:
Improvealignment between lenticular network and printed framesVSAvoidalignment mechanism
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The system uses self-aligning features where the lenticular network and printed frames automatically align through their geometric and optical properties. The lenticular lenses are designed to focus light in a way that naturally guides the alignment with the printed frames below, eliminating the need for complex external alignment mechanisms.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces mechanical alignment systems with optical alignment mechanisms. The lenticular network uses light refraction and focusing properties to achieve precise alignment with the printed frames, substituting complex mechanical positioning systems with optical field-based alignment.

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

3Manufacturing precision

If radiation-sensitive positioning marks are added to the metal sheet, then manufacturing precision is improved, but device complexity is worsened

Engineering Contradiction:
Improvepositioning accuracy of printed framesVSAvoidpositioning mark system
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent changes the physical-chemical parameters of the metal sheet by introducing radiation-sensitive materials that undergo detectable changes when exposed to radiation. This allows precise positioning marks to be created through radiation exposure patterns, achieving high manufacturing precision through material property changes rather than mechanical adjustments.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The radiation-sensitive positioning marks act as an intermediary between the manufacturing process and the final alignment. These marks mediate the alignment process by providing visible reference points that guide the positioning of printed frames relative to the lenticular network, simplifying the overall positioning system.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of manufacture

If Moiré effects are avoided through perfect alignment, then visual quality is improved, but manufacturing complexity is worsened

Engineering Contradiction:
Improvevisual quality of security elementVSAvoidalignment control system
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent converts the potential harm of Moiré effects into a beneficial alignment verification mechanism. By designing the lenticular network and printed frames with specific geometric relationships, any misalignment that would cause Moiré effects actually serves as a visible indicator of alignment status, allowing quick quality verification without complex measurement systems.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 guarantees the perfect alignment of the printed frames with the lenticular network, preventing unwanted visual effects like Moiré and ensuring the authenticity of the security document, thereby enhancing security and simplifying manufacturing.

Implementation Method 1

a moiré effect appears since an angular offset is introduced between the lens array and the printed image

Methodology Applied
Scientific EffectMoiré effect: Moiré Interferometry

Implementation Method 2

The beam is configured to remove the metal sheet without burning the paper sheet located beneath it

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Data Source

PatentEP4545310A1Security document and method for producing such a security document
Publication Date: 2025.04.30 IN SMART IDENTITY FRANCE
  • EP4545310A1 patent drawingFigure 1~2
  • EP4545310A1 patent drawingFigure 3~4
  • EP4545310A1 patent drawing

AI summary

The invention relates to a method for manufacturing a personalized security document (10) comprising a step of manufacturing a booklet having at least one paper page (12) and a paper page, a step of forming a lenticular array (22), the lenticular array (22) being adapted to be positioned opposite an area (20) of the paper page (12) when the booklet is in a determined open position, a step of covering the area (20) of the paper page (12) with a radiation-sensitive metallic foil (28), a step of applying radiation (28) to the metallic foil, through the lenticular array (22), capable of locally modifying the metallic area so as to produce positioning marks (30) defining at least the first longitudinal direction and the second direction of the lens array (24), a printing step,in a printing area (31) included in the area (20) of the paper page (12) of a colored pattern formed of at least two printed halftones (32) observable alternately through the lenticular grating (22), the position of each halftone being referenced on the positioning marks (30), so that the halftones (32) are parallel along the first direction of the lenticular grating (22).