Charge Control Inkjet Printer Real-Time Feedback

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Solution Overview

Problem

Charge control-type inkjet printers face challenges in maintaining optimal printing conditions in real time, particularly due to variations in operating environments and ink properties, leading to inconsistent ink particle charging and poor printing quality.

Innovation Solution

A charge control-type inkjet printer system that includes a printing head with a nozzle unit, pressure reduction valve, and an imaging unit to observe and control ink particle shape and charging state in real time, using a camera and image processing to adjust excitation frequency, voltage, and pressure for optimal particle formation and charging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If optimal printing conditions are controlled based on pre-created software relationships between temperature and viscosity, then the system is simple to operate, but the system cannot adapt to unpredicted environments or real-time changes

Engineering Contradiction:
Improveease of operationVSAvoidadaptability to environment
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent implements real-time feedback control by measuring actual ink viscosity and temperature during operation, comparing these measurements against optimal values, and automatically adjusting printing parameters. This closed-loop feedback system enables the printer to adapt to environmental changes and ink deterioration dynamically, resolving the contradiction between operational simplicity and environmental adaptability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-diagnosis and self-adjustment by automatically monitoring its own operating conditions (ink viscosity, temperature, pressure) and correcting deviations without user intervention. This self-service capability allows the system to maintain optimal performance across varying environments while keeping the operation interface simple.

Inventive Principle:
Principle #25Self-service

2Device complexity

If ink particle charging conditions are not optimized in real time, then the printing process is simple, but printing quality deteriorates due to insufficient charging

Engineering Contradiction:
Improveprinting process complexityVSAvoidprinting quality
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent uses real-time feedback from sensors monitoring ink particle charge, viscosity, and temperature to dynamically adjust charging electrode voltage and other printing parameters. This ensures optimal printing quality by continuously adapting to actual conditions while automating the complexity of real-time optimization.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically changes critical parameters such as excitation voltage, charging voltage, and ink pressure based on real-time measurements of ink properties and environmental conditions. This parameter adaptation enables consistent printing quality despite variations in ink formulation, temperature, or humidity.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If multiple printing conditions (ink viscosity, excitation frequency, excitation voltage, discharge pressure) are individually optimized, then printing quality improves, but the time and complexity of setup increases

Engineering Contradiction:
Improveprinting qualityVSAvoidsetup time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent implements comprehensive feedback control that simultaneously monitors and adjusts all critical printing parameters (viscosity, excitation frequency, voltage, pressure) based on real-time measurements. This coordinated multi-parameter control achieves optimal printing quality without requiring time-consuming individual optimization of each parameter.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control system serves multiple optimization functions simultaneously by integrating sensors and actuators that manage viscosity control, pressure regulation, voltage adjustment, and temperature compensation within a single unified control architecture, eliminating the need for separate optimization processes.

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

4Manufacturing precision

If ink material selection and printing conditions are individually set and examined, then optimal printing performance is achieved, but the development process takes time

Engineering Contradiction:
Improveprinting performanceVSAvoiddevelopment speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent incorporates real-time feedback during ink formulation and printing condition development, using sensors to automatically measure and report the effects of material changes and parameter adjustments. This accelerates the optimization process by providing immediate data on performance impacts, eliminating time-consuming trial-and-error cycles.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system replaces manual, time-consuming optimization processes with automated electronic control and computer-based monitoring. Sensors and microcontrollers automatically adjust printing parameters and record results, substituting manual experimentation with automated data-driven optimization that is both faster and more precise.

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

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 continuous stable printing by ensuring optimal ink particle shape and charging state, allowing for real-time adjustments to maintain consistent printing quality even under varying conditions.

Implementation Method 1

The ink pressure-fed to a nozzle in the printing head is vibrated by vibration of several ten kilohertz by a piezoelectric element 23 in the nozzle

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

The charged ink particles are subjected to electrostatic force by a deflection electrode during flight and are deflected

Methodology Applied
Scientific EffectElectrostatic force: Electrostatics

Data Source

PatentEP3360683B1Charge control-type inkjet printer and printing method using same
Publication Date: 2022.08.03 HITACHI IND EQUIP SYST CO LTD
  • EP3360683B1 patent drawingFigure 1~2
  • EP3360683B1 patent drawingFigure 3~4
  • EP3360683B1 patent drawingFigure 5~6

AI summary

The present invention addresses the problem of enabling a charge control-type inkjet printer to enable real-time control during an operation and to maintain optimal printing conditions while operating. This charge control-type inkjet printer is provided with: a printing head including a nozzle unit for discharging ink; a pressure reduction valve for adjusting the pressure of the ink to be supplied to the nozzle unit of the printing head; and an ink container for accommodating the ink to be supplied to the nozzle unit of the printing head, wherein an imaging unit is further provided which images an image of ink that is discharged from the nozzle unit and is in a particulate state.