Two Fluorescent Ink Printing Method for High Contrast Security Patterns

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Solution Overview

Problem

Existing dot printing methods using three fluorescent inks for security patterns are complex, expensive, and fail to achieve good color saturation and contrast due to the need for precise transfers and limited color reproduction.

Innovation Solution

A method using two fluorescent inks with colors chosen outside the central zone of a color diagram, where the line connecting their representative points passes through the white reference point, allowing for increased saturation and maximum contrast, enabling the production of a wider range of colors, including unusual ones like cyan, yellow, and magenta.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If three fluorescent inks (red, green, blue) are used for dot printing, then good color reproduction is achieved, but the printing process becomes complex and expensive due to three successive transfers

Engineering Contradiction:
Improveprinting process complexityVSAvoidnumber of ink transfers
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent combines three fluorescent inks (red, green, blue) into a single multi-color ink formulation. This allows all three colors to be applied in one printing pass rather than requiring three separate transfers, thereby simplifying the printing process while maintaining the ability to produce high-quality fluorescent patterns with good color reproduction

Inventive Principle:
Principle #5Merging (Combining)

2Ease of manufacture

If two fluorescent inks are used to simplify printing, then the number of transfers is reduced, but color saturation and contrast deteriorate

Engineering Contradiction:
Improveprinting process simplicityVSAvoidcolor saturation
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent merges three fluorescent inks into one formulation, enabling single-pass printing that simplifies the manufacturing process while maintaining or improving color saturation through the synergistic combination of multiple fluorescent pigments in the unified ink composition

Inventive Principle:
Principle #5Merging (Combining)

3Manufacturing precision

If two fluorescent inks with colors outside the central zone are used, then color saturation increases, but the ability to reproduce all colors in the central zone decreases

Engineering Contradiction:
Improvecolor saturationVSAvoidcolor range
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent changes the color parameters by selecting fluorescent inks with emission wavelengths outside the traditional central zone (red, green, blue). This parameter change increases color saturation and creates distinctive fluorescent patterns that are difficult to reproduce, while the specific selection of wavelengths ensures adequate coverage for security application requirements

Inventive Principle:
Principle #35Parameter changes

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 simplifies the printing process while achieving high color saturation and contrast, making it difficult to reproduce the security patterns fraudulently and expanding the color palette beyond traditional red, green, and blue.

Implementation Method 1

fluorescent inks presenting fluorescence colors selected on a color diagram... which are invisible to natural light and which are revealed by ultraviolet radiation. The colors of the pattern are obtained by a combination of the radiation emitted by the different points according to their own fluorescence color

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Data Source

PatentEP1985458B1Printing method using two fluorescent inks
Publication Date: 2013.08.28 BANQUE DE FRANCE
  • EP1985458B1 patent drawingFigure 1

AI summary

The method involves choosing fluorescent colors of fluorescent inks at an exterior of a central zone of a color diagram, where the zone is delimited by red color (R), green color (V) and blue color (B). The fluorescent colors are chosen such that a line reuniting fluorescent colors representing points (C1-C4) on the color diagram passes through a reference point (E). The fluorescent colors are chosen among zones (Z1-Z3) delimited by straight lines that connect points defined by coordinates on the color diagram.