Piezoelectric Liquid Ejection Stability Via Residual Vibration

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Solution Overview

Problem

Existing liquid ejecting apparatuses face challenges in evaluating ejection stability and determining drive signal waveforms for piezoelectric elements without requiring external imaging environments, leading to increased setup loads.

Innovation Solution

A liquid ejecting apparatus with a detection mechanism to detect residual vibrations of a diaphragm caused by piezoelectric element driving, allowing for evaluation of ejection stability and determination of drive signal waveforms based on these vibrations, without the need for external imaging environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If image analysis method is used to evaluate ejection stability, then measurement precision is improved, but device complexity increases due to requirement of imaging environment

Engineering Contradiction:
Improveejection defect detection accuracyVSAvoidimaging environment setup
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the evaluation function from an external imaging system and integrates it into the liquid ejecting apparatus itself. By using the existing piezoelectric element to generate residual vibration and a simple vibration detection mechanism, the complex imaging environment (cameras, lighting, positioning systems) is eliminated while maintaining evaluation capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The liquid ejecting apparatus evaluates its own ejection stability using its own piezoelectric element and vibration detection system. The piezoelectric element serves dual purposes: as the actuator for liquid ejection and as the source of residual vibration for self-evaluation, eliminating the need for external evaluation equipment.

Inventive Principle:
Principle #25Self-service

2Device complexity

If residual vibration detection method is used, then device complexity is reduced, but measurement precision deteriorates for evaluating ejection stability

Engineering Contradiction:
Improveevaluation system setupVSAvoidejection stability evaluation accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by intentionally generating residual vibration through the piezoelectric element before actual liquid ejection evaluation. The drive signal is designed to produce a characteristic residual vibration pattern that serves as a reference for evaluating subsequent ejection stability, enabling accurate measurement without complex external equipment.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The vibration detection portion provides feedback about the residual vibration characteristics to the control portion. This feedback loop enables the system to continuously monitor and evaluate ejection stability by comparing detected vibration patterns against expected patterns, maintaining high measurement precision with simple hardware.

Inventive Principle:
Principle #23Feedback

3Ease of operation

If ejection stability evaluation is performed without imaging environment, then ease of operation is improved, but reliability deteriorates without external verification

Engineering Contradiction:
Improveevaluation setup simplicityVSAvoidevaluation accuracy
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The piezoelectric element serves multiple functions: it acts as the actuator for liquid ejection, the source of residual vibration for evaluation, and the component whose vibration characteristics provide information about ejection stability. This multi-functionality enables reliable self-evaluation without external imaging equipment, improving ease of operation while maintaining reliability through the inherent physical connection between the piezoelectric element and the ejection mechanism.

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

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 efficient and accurate evaluation of ejection stability and drive signal waveform determination directly within the apparatus, reducing setup complexity and costs.

Implementation Method 1

a piezoelectric element which corresponds to the nozzle, a diaphragm which vibrates by driving the piezoelectric element

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

a detection portion which detects residual vibration of the diaphragm caused by driving the piezoelectric element

Methodology Applied
Scientific EffectVibration detection: Vibration

Data Source

PatentEP4606575A1Liquid ejecting apparatus and control method for liquid ejecting apparatus
Publication Date: 2025.08.27 SEIKO EPSON CORP
  • EP4606575A1 patent drawingFigure 1
  • EP4606575A1 patent drawingFigure 2
  • EP4606575A1 patent drawingFigure 3

AI summary

A liquid ejecting apparatus includes a liquid ejecting head that includes a nozzle which ejects an ink, a piezoelectric element which corresponds to the nozzle, a diaphragm which vibrates by driving the piezoelectric element, and a detection circuit which detects residual vibration of the diaphragm caused by driving the piezoelectric element, and an evaluation control portion which executes first evaluation for evaluating an ejection stability of the ink from the nozzle, in which in the first evaluation, the evaluation control portion causes the detection circuit to detect the residual vibration caused by continuously executing ejection driving of driving the piezoelectric element with a drive signal for ejecting the ink from the nozzle as first residual vibration, and evaluates the ejection stability of the ink from the nozzle based on the first residual vibration detected by the detection circuit.