Ink Color Correction Using Spectral Extrapolation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing printing press systems require multiple correction cycles to achieve the desired color impression due to limitations in measuring and adjusting the chemical composition of printing inks, leading to inefficiencies in color reproduction.

Innovation Solution

A system and method utilizing densitometrically measured values to extrapolate information for unmeasured spectral areas, combined with decentralized ink mixing devices equipped with spectral photometers and control software, allowing for precise adjustment of ink composition and real-time correction of color impressions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If densitometric measurement is used instead of spectral photometry, then device complexity is reduced, but measurement precision deteriorates

Engineering Contradiction:
Improvemeasurement device complexityVSAvoidcolor measurement precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent introduces an intermediary computational model that translates densitometric measurements into spectral information. The system uses a pre-established mathematical relationship between densitometric and spectral data to extrapolate full spectral characteristics from limited densitometric measurements, thereby maintaining measurement precision while using simpler devices

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the physical spectral photometer with a computational approach. Instead of using complex optical hardware to measure the entire spectrum, the system substitutes mechanical measurement with mathematical extrapolation based on densitometric data and known ink spectral characteristics

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

2Manufacturing precision

If multiple correction cycles are performed, then manufacturing precision is improved, but productivity deteriorates

Engineering Contradiction:
Improvecolor reproduction accuracyVSAvoidprinting production efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent performs preliminary actions by pre-calculating and storing the spectral characteristics and correction factors for different ink formulations. When a color correction is needed, the system directly retrieves and applies the appropriate correction data instead of iteratively adjusting ink formulations through multiple printing and measurement cycles

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback mechanism where densitometric measurements of the printed output are continuously monitored and fed back to the ink mixing system. The system automatically calculates the deviation from the target color and adjusts the ink formulation in real-time, enabling precise color reproduction in a single pass rather than requiring multiple correction cycles

Inventive Principle:
Principle #23Feedback

3Adaptability or versatility

If decentralized ink mixing devices are used, then adaptability is improved, but device complexity increases

Engineering Contradiction:
Improvecolor adjustment flexibilityVSAvoidink mixing system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent creates a universal ink mixing device that can handle multiple ink formulations and color corrections through a single decentralized unit. The system is designed to work with various ink types and printing conditions, providing multi-functional capability that reduces the need for multiple specialized devices while maintaining high adaptability

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

Solution Approach 2:

The decentralized ink mixing device is equipped with autonomous control capabilities, including built-in densitometric measurement and automated calculation of correction formulas. The system performs self-diagnosis and self-adjustment, eliminating the need for complex external control systems and reducing overall device complexity while maintaining high adaptability

Inventive Principle:
Principle #25Self-service

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 enables more significant and precise adjustments to the printing picture, reducing the number of correction cycles needed and improving the accuracy of color reproduction by using extrapolated spectral data and decentralized ink mixing for real-time composition adjustments.

Implementation Method 1

The interaction between light and substrate usually comprises a reflection or a transmission of the light. Light which interacted with the printing picture (above all reflection or transmission are relevant in connection with the present disclosure) is called 'remitted light' in the present publication.

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

Behind each colour filter there is a photoelectric sensor (photodiode). During the measurement light is radiated on a printed area and the remission and/or transmission value of the light is measured often with a photoelectric sensor (photodiode) after passing a colour filter.

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Implementation Method 3

The spectral-photometer measures the remission degree of the sample (in percent) over the visible spectral range of the light (approx. 400 to 800 nm). Usually, the measured values are used to calculate the coordinates of the measured colour in a colour space with a suitable software.

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 4

The more significant 'spectrometric' measurement usually contains measured values which cover the whole spectrum of visible light. This broad spectral region is measured for example by 36 sensors with narrower spectral ranges.

Methodology Applied
Scientific EffectSpectroscopy: Absorption Spectroscopy

Data Source

PatentEP2219870B2Colour-management
Publication Date: 2019.05.01 X RITE EUROPE GMBH
  • EP2219870B2 patent drawingFigure 1
  • EP2219870B2 patent drawingFigure 2
  • EP2219870B2 patent drawingFigure 3

AI summary

A system for measuring the viscosity of printing ink during a printing and ink correction process includes a printing press having an ink supply system, and an optical measuring device for measuring actual optical values of light that has interacted with at least parts of the printing picture. The printing press has an ink mass determination device to determine the weight of at least parts of the ink located in the ink supply system, and a control and evaluation device to receive measured values from the optical measuring device and from the ink mass determination device. The control and evaluation device determines an optical deviation, and, based on the optical deviation and the values from the weighing devices, an amount of corrective ink that is to be fed to the printing press in order to approximate the actual optical values to optical reference values.