Offset Rotary Press Ink Emulsification Control via Optical Feedback

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Solution Overview

Problem

Existing offset rotary press printing systems fail to detect ink emulsification states in real time, leading to time lags in control adjustments, resulting in excessive emulsification and paper loss due to variations in print quality.

Innovation Solution

A printing system equipped with an LED light source and camera to analyze the reflected light from the plate cylinder or ink roller surfaces, calculating the area ratio of high brightness regions to control dampening water supply and maintain optimal emulsification, incorporating machine learning for adaptive control based on operational and environmental data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If dampening water supply amount is increased to prevent ink excessive emulsification, then print quality is improved, but paper loss increases due to excessive emulsification when water supply is too large

Engineering Contradiction:
Improveprint qualityVSAvoidpaper loss
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

The system uses a camera to capture images of the plate cylinder surface and calculates the area ratio of high brightness regions (which indicate excessive emulsification). This real-time feedback is used to automatically adjust the dampening water supply amount, creating a closed-loop control system that maintains optimal print quality while preventing paper loss from excessive emulsification.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces manual operator judgment and adjustment of dampening water supply with an automated optical detection and control system. The camera-based emulsification state detection and automatic control mechanism substitutes for human experience-based adjustments, providing consistent and precise control of the dampening water supply to optimize both print quality and reduce paper waste.

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

2Manufacturing precision

If operator experience and know-how are used to judge ink emulsification state, then dampening water supply can be adjusted, but variations in print quality occur due to differences between operators

Engineering Contradiction:
Improveprint quality consistencyVSAvoidoperator dependency
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The system enables self-service control by automatically detecting the ink emulsification state through optical measurement and autonomously adjusting the dampening water supply without requiring operator intervention. The control unit processes the captured images, calculates emulsification metrics, and modifies water supply parameters independently, eliminating variability between different operators while maintaining consistent print quality.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces human operator judgment with an automated optical detection and control system. The camera-based measurement and automatic control mechanism substitutes for subjective human assessment, providing objective, repeatable, and consistent control of ink emulsification state regardless of which operator is working the press.

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

3Loss of substance

If conventional printing systems without real-time detection are used, then system complexity is reduced, but time lag occurs from ink emulsification change to control execution resulting in paper loss

Engineering Contradiction:
Improvepaper loss reductionVSAvoidsystem complexity
Core Design Contradiction:
Loss of substanceVSDevice complexity

Solution Approach 1:

The system implements continuous monitoring of the ink emulsification state by continuously capturing images of the plate cylinder surface and calculating the area ratio of high brightness regions. This continuous detection enables real-time identification of emulsification changes, allowing immediate control adjustments that prevent excessive emulsification and paper loss, while maintaining a relatively simple system architecture.

Inventive Principle:
Principle #20Continuity of useful action

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

Enables real-time monitoring and control of ink emulsification, reducing paper loss by maintaining consistent print quality and allowing for easy integration into existing offset rotary presses.

Implementation Method 1

an LED light source that irradiates an irradiation light on a surface of the plate cylinder and/or a surface of any roller of the ink device, and a camera for shooting a reflected light reflected from the surface of the plate cylinder and/or the roller

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP4166334B1Printing system of offset rotary press and offset rotary press
Publication Date: 2024.03.06 MIYAKOSHI PRINTING MACHINERY
  • EP4166334B1 patent drawingFigure 1
  • EP4166334B1 patent drawingFigure 2
  • EP4166334B1 patent drawingFigure 3

AI summary

There is provided a printing system of an offset rotary press in which an emulsification state of ink can be grasped at real time and make it appropriate on quickly so that a good printing quality can be maintained from the start to the end of printing which results in reduction of paper loss. The printing system of an offset rotary press 1 comprising a light source 32 that irradiates irradiation light 71 on a surface of a plate cylinder 6 of a printing unit 5, a camera 33 for shooting reflected light 72 of the irradiated irradiation light 71 and a control device 56 for bifurcating a shot image of the camera 33 into a high brightness region and a low brightness region of reflected light 72 and calculates an area ratio of the region of high brightness of the reflected light 72 with respect to the entire area of the shot image of the camera 33, wherein if the area ratio in the high brightness region of the reflected light 72 calculated by the control means 56 is high, the dampening water supply of the dampening water device 11 is controlled such that an appropriate emulsification state of ink is obtained.