Print Head Residual Vibration Detection Circuit for Faster Ejection Monitoring

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Solution Overview

Problem

Existing techniques for detecting residual vibrations in piezoelectric elements of liquid ejection apparatuses are insufficient in terms of detection speed and require further improvement.

Innovation Solution

A print head and liquid ejection apparatus are designed with a first pressure chamber, a piezoelectric element, a switch circuit, and a residual vibration detection circuit to enhance the detection of residual vibrations by outputting a detection signal corresponding to the residual vibration generated due to volume changes in the pressure chamber.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a conventional detection circuit is used to detect residual vibration, then the detection function is provided, but the detection speed is insufficient

Engineering Contradiction:
Improvedetection speedVSAvoidresidual vibration detection accuracy
Core Design Contradiction:
SpeedVSMeasurement precision

Solution Approach 1:

The detection circuit is segmented into two independent parts: a first detection circuit that detects residual vibration signals during the drive period, and a second detection circuit that detects residual vibration signals after the drive period. This segmentation allows each circuit to be optimized for its specific detection window, improving overall detection speed without sacrificing accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first detection circuit performs preliminary detection of the residual vibration signal during the drive period, before the second detection circuit takes over after the drive period. This preliminary action captures early vibration characteristics that would otherwise be missed, enabling faster overall detection while maintaining comprehensive measurement accuracy.

Inventive Principle:
Principle #10Preliminary action

2Loss of information

If the detection circuit monitors the entire drive period, then comprehensive vibration data is obtained, but the detection speed decreases

Engineering Contradiction:
Improvevibration signal informationVSAvoiddetection time
Core Design Contradiction:
Loss of informationVSLoss of time

Solution Approach 1:

The monitoring period is segmented into two phases: during-drive detection by the first detection circuit and post-drive detection by the second detection circuit. This segmentation distributes the information collection burden across two specialized circuits operating in sequence, reducing the time each circuit needs to operate while capturing complete vibration information.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The detection process uses periodic action by switching between two detection circuits at different time periods: the first circuit operates during the drive period and the second circuit operates after the drive period. This periodic switching enables comprehensive information gathering without requiring a single circuit to continuously monitor the entire duration, thus reducing total detection time.

Inventive Principle:
Principle #19Periodic 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

The solution improves the detection speed and accuracy of residual vibrations, allowing for better monitoring and control of the ejection process, ensuring consistent and reliable ink ejection.

Implementation Method 1

a first piezoelectric element configured to output a first residual vibration signal according to first residual vibration generated due to a volume change of the first pressure chamber

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP4617065A1Print head and liquid ejection apparatus
Publication Date: 2025.09.17 SEIKO EPSON CORP
  • EP4617065A1 patent drawingFigure 1
  • EP4617065A1 patent drawingFigure 2
  • EP4617065A1 patent drawingFigure 3

AI summary

A print head includes: a first pressure chamber whose volume changes according to a drive signal; a first nozzle communicating with the first pressure chamber and configured to allow a liquid to be ejected; a first piezoelectric element configured to output a first residual vibration signal according to first residual vibration generated due to a volume change of the first pressure chamber; a first switch circuit having one end to which the drive signal is input and the other end electrically coupled to the first piezoelectric element, and configured to switch whether to supply the drive signal to the first piezoelectric element; and a first residual vibration detection circuit configured to output a first residual vibration detection signal corresponding to the first residual vibration signal, in which the first residual vibration detection circuit has one end electrically coupled to the one end of the first switch circuit and the other end electrically coupled to the other end of the first switch circuit.