Security Paper With Laser-Cut Watermark Openings

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing security sheets for documents, particularly banknotes, face challenges in providing easily recognizable security features that are difficult for counterfeiters to reproduce while maintaining aesthetic appeal and requiring complex manufacturing processes.

Innovation Solution

A security sheet with openings cut inside the watermark area, featuring a regular edge and a security film that overlaps the opening, providing different appearances in transmitted and reflected light, and incorporating optically variable devices for enhanced security.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If openings are made outside the watermark to complete the appearance, then the aesthetic appearance is improved, but the security recognition by ordinary users is reduced

Engineering Contradiction:
Improveaesthetic appearanceVSAvoidsecurity recognition
Core Design Contradiction:
ShapeVSReliability

Solution Approach 1:

Instead of placing openings outside the watermark to maintain appearance, the patent inverts the approach by placing openings inside the watermark area. This allows the opening to be integrated within the watermark itself, maintaining aesthetic appearance while preserving security recognition since the opening is now part of the watermark structure that ordinary users can identify.

Inventive Principle:
Principle #13The other way round (Inversion)

2Shape

If papermaking operations are used to create openings with irregular edges, then the opening can contribute to forming overall patterns, but the manufacturing complexity increases and reproducibility decreases

Engineering Contradiction:
Improvepattern formationVSAvoidmanufacturing complexity
Core Design Contradiction:
ShapeVSEase of manufacture

Solution Approach 1:

The patent replaces complex mechanical papermaking operations with laser cutting technology. The laser cutting process can precisely create openings with regular or irregular edges as needed, eliminating the complexity of master papermaking operations while maintaining the ability to form aesthetic patterns. The laser process is more controllable and reproducible.

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

3Manufacturing precision

If regular edge openings are created within the watermark, then the manufacturing precision is improved, but the counterfeiting difficulty is reduced

Engineering Contradiction:
Improveopening edge regularityVSAvoidcounterfeiting difficulty
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies different edge characteristics to different openings based on their specific function and location. Some openings may have regular edges for precision manufacturing, while others have irregular edges to increase counterfeiting difficulty. The local quality of the opening edge is optimized according to the specific security and aesthetic requirements of each position in the document.

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

The solution enhances document security by making it difficult to counterfeit, improves visibility and recognition, and allows for various aesthetic effects, while simplifying the manufacturing process through precise laser cutting and film application.

Implementation Method 1

The opening is made by cutting with a laser

Methodology Applied
Scientific EffectLaser: Laser

Implementation Method 2

The security film comprises a transparent support and a security element... providing different appearances in transmitted and reflected light

Methodology Applied
Scientific EffectOptical interference: Interference

Data Source

PatentEP3784498B1Security paper
Publication Date: 2025.06.25 VHP SECURITY PAPER BV
  • EP3784498B1 patent drawingFigure 1~3B
  • EP3784498B1 patent drawingFigure 4A~4C
  • EP3784498B1 patent drawingFigure 5~7B

AI summary

Security paper comprising: – at least one paper-making substrate (10), – at least one watermark (11) formed on the paper-making substrate (10), this watermark having an external contour (13), – at least one opening (12) with an even edge created by ablation of the paper-making substrate, – at least one security film (15) at least partially superposed on the watermark (11) and on the opening (12), this paper being characterized in that said at least one opening (12) extends inside the watermark (11) as delimited by its external contour.