Piezoelectric Head Unit Timing for Residual Vibration Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing inkjet printer technologies suffer from inadequate detection accuracy of residual vibrations in the nozzle due to insufficient examination of the timing between applying vibration to ink and detecting residual vibration, which can further degrade the accuracy of determination based on detection results.

Innovation Solution

A head unit with a piezoelectric device that includes a residual vibration detector, a first switch to control the application of a drive signal, a second switch to control the detection of residual vibration signals, and a controller to synchronize these switches with the extreme points of residual vibration signals, ensuring accurate detection timing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the timing of switching between applying vibration to ink and detecting residual vibration is not optimized, then the device operation is simple, but the detection accuracy of residual vibration deteriorates

Engineering Contradiction:
Improvedetection accuracy of residual vibrationVSAvoidcomplexity of switching control
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The controller determines the detection start timing in advance by acquiring extreme point timing from the residual vibration signal, then switches the second switch to start detection at this predetermined timing. This preliminary determination of optimal detection timing improves measurement precision without requiring complex real-time adjustments during operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses the detected residual vibration signal and its extreme points to determine the optimal detection start timing for subsequent measurements. This feedback mechanism allows the system to learn and optimize detection timing based on actual vibration characteristics, improving detection accuracy while maintaining simple switching control.

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If the switching timing between vibration application and residual vibration detection is insufficiently examined, then the control process is simple, but the accuracy of determination based on detection results deteriorates

Engineering Contradiction:
Improveaccuracy of ejection state determinationVSAvoidcomplexity of timing control
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The controller determines the detection start timing in advance by analyzing the residual vibration signal characteristics and switching the second switch accordingly before detection begins. This preliminary timing determination ensures accurate ejection state determination without requiring complex real-time control adjustments.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses the detected residual vibration signal characteristics to determine optimal detection timing for subsequent operations, creating a feedback loop that improves determination accuracy. The controller adjusts detection start timing based on feedback from extreme point timing of the residual vibration signal.

Inventive Principle:
Principle #23Feedback

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

Enhances the detection accuracy of residual vibrations by synchronizing the application and detection of signals, thereby improving the overall precision of ink ejection in inkjet printers.

Implementation Method 1

an ejection section (W1) that ejects a liquid by a piezoelectric device (200) displaced by a drive signal being fed

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

a residual vibration detector that detects a residual vibration signal generated by residual vibration of the ejection section (W1)

Methodology Applied
Scientific EffectVibration detection: Vibration

Data Source

PatentEP4400319B1Head unit, liquid ejection device, and control method
Publication Date: 2026.02.18 SEIKO EPSON CORP
  • EP4400319B1 patent drawingFigure 1
  • EP4400319B1 patent drawingFigure 2
  • EP4400319B1 patent drawingFigure 3

AI summary

A head unit includes an ejection section that ejects a liquid by a piezoelectric device displaced by a drive signal being fed, a residual vibration detector that detects a residual vibration signal generated by residual vibration of the ejection section caused by the displacement of the piezoelectric device, a first switch that switches whether or not to feed a first drive signal to the piezoelectric device, a second switch that switches whether or not to feed the residual vibration signal to the residual vibration detector, and a controller that controls the first switch and the second switch. The controller acquires a detection start timing based on an extreme point of the residual vibration signal detected by the residual vibration detector, the first switch is switched such that the first drive signal is not fed to the piezoelectric device at the detection start timing, and the second switch is switched such that the residual vibration signal is fed to the residual vibration detector at the detection start timing.