Interference Pigment Printing Method for Wide Color Gamut

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Solution Overview

Problem

Current printing processes struggle to produce multicolored images using only interference pigments, as they fail to achieve a wide range of colors across the entire color space with the required quality and efficiency, especially in analogue printing methods.

Innovation Solution

A method involving three colored printing inks – red, green, and blue – each pigmented with interference pigments, applied successively to form yellow hues, using specific hue angles and saturation values in the CIELUV color space, allowing for the creation of multicolored images with high color saturation and brilliance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If conventional CMYK printing with absorption pigments is used, then a wide color gamut is achieved, but the printing process becomes complex and requires four different printing inks

Engineering Contradiction:
Improvenumber of printing inksVSAvoidprinting process complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the yellow printing ink from the traditional CMYK system by generating yellow color through the optical mixing of red and green interference pigments. This reduces the number of printing inks from four to three while maintaining the ability to produce a wide color gamut through the additive optical effects of interference pigments.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the fundamental parameter of color generation from subtractive mixing of absorption pigments to additive mixing of interference colors. By using interference pigments with specific hue angles and saturation values in the CIELUV color space, the system achieves photorealistic color reproduction with only three printing inks (cyan, magenta, yellow generated from red+green interference pigments).

Inventive Principle:
Principle #35Parameter changes

2Illumination intensity

If interference pigments are used to create special optical effects, then visual appeal is enhanced, but production cost increases due to combined use of absorption and interference pigments

Engineering Contradiction:
Improveoptical effect intensityVSAvoidproduction cost
Core Design Contradiction:
Illumination intensityVSQuantity of substance

Solution Approach 1:

The invention merges the functions of color generation and optical effect enhancement into a single system using exclusively interference pigments. The interference pigments simultaneously provide the base colors (red and green that mix to yellow) and the desired optical effects (gloss, glitter, optically variable effects), eliminating the need for separate absorption pigments and reducing production costs.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The interference pigments used in the invention serve multiple functions: they generate the yellow color when red and green interference pigments are overprinted, they provide the desired optical effects (gloss, glitter, variable effects), and they maintain color saturation and brilliance. This multi-functionality reduces the overall material requirements and production complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Device complexity

If three printing inks with interference pigments are used, then the printing process is simplified, but achieving wide color gamut across entire color space becomes difficult

Engineering Contradiction:
Improveprinting process simplicityVSAvoidcolor gamut coverage
Core Design Contradiction:
Device complexityVSQuantity of substance

Solution Approach 1:

The invention fundamentally changes the color generation mechanism from subtractive to additive mixing, and selects interference pigments with specific parameters (hue angles and high saturation values in CIELUV color space) that enable three printing inks to cover the entire color space with photorealistic quality.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses composite interference pigment systems where red and green interference pigments with specific optical properties are combined in printing inks. The composite effect of these pigments when overprinted generates yellow with the same visual impact as traditional yellow printing ink, while maintaining the ability to reproduce the full color gamut through the optical properties of the interference pigments.

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

This method enables the production of multicolored images with a wide color gamut and photorealistic quality, achieving high color intensity and brilliance, overcoming the limitations of previous methods by using only three interference pigments, thereby simplifying the printing process and enhancing visual appeal.

Implementation Method 1

The optical effect of interference pigments is based on the difference in refractive index between materials arranged one above the other in the form of thin layers within the pigments. These materials reflect, transmit, and sometimes absorb incident light differently depending on the refractive index of the respective layer and the medium surrounding the interference pigment. Differences in the refractive index between adjacent layers result in path differences in the reflected light rays, causing them to overlap and selectively amplify or attenuate light of specific wavelengths.

Methodology Applied
Scientific EffectInterference: Interference

Implementation Method 2

The optical effect of interference pigments is based on the difference in refractive index between materials arranged one above the other in the form of thin layers within the pigments.

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP3253832B1Method for printing multicoloured images
Publication Date: 2024.05.22 MERCK PATENT GMBH
  • EP3253832B1 patent drawingFigure 1
  • EP3253832B1 patent drawing

AI summary

The present invention relates to a method for printing multicoloured images using only interference pigments for the colour pigmentation of the inks; to printed products produced by such a method; to the use thereof; and to suitable interference pigments.