Print Head N-Channel Switching for Accurate Residual Vibration Detection

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Solution Overview

Problem

Existing techniques for detecting residual vibrations in piezoelectric elements of liquid discharge apparatuses, such as inkjet printers, lack sufficient accuracy for determining the discharge state, necessitating further improvements.

Innovation Solution

Incorporation of a pressure chamber, piezoelectric element, residual vibration detection circuit, and an N-channel type transistor switch circuit to enhance the detection of residual vibrations, allowing for improved determination of discharge states.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a conventional switch circuit is used to supply the residual vibration signal to the detection circuit, then the circuit can operate, but the detection accuracy of the residual vibration signal is insufficient

Engineering Contradiction:
Improvedetection accuracy of residual vibrationVSAvoiddischarge state determination accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent changes the electrical parameters of the switch circuit by using an N-channel transistor with specific gate control voltage levels. The gate is controlled by a signal that switches between a first voltage level (turning off the transistor) and a second voltage level (turning on the transistor), optimizing the switching characteristics to improve residual vibration signal detection accuracy while maintaining reliable discharge state determination.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the volume of the pressure chamber changes to discharge liquid, then the liquid discharge function is achieved, but residual vibrations are generated that need to be detected accurately

Engineering Contradiction:
Improveliquid discharge efficiencyVSAvoidresidual vibration detection accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent implements a feedback mechanism where the residual vibration signal generated by pressure chamber volume changes is detected by a detection circuit, processed through an N-channel transistor switch, and used to determine the discharge state. This feedback loop allows the system to monitor and adjust based on actual vibration characteristics, improving both liquid discharge efficiency and detection accuracy.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces direct mechanical observation of discharge state with an electrical sensing system. The residual vibration mechanical phenomenon is converted into an electrical signal through the piezoelectric element, then processed through the N-channel transistor switch circuit, substituting mechanical measurement with electrical detection to achieve higher precision.

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

Enhances the accuracy of detecting residual vibrations, thereby improving the precision of liquid discharge operations in devices like inkjet printers and other liquid discharge apparatuses.

Implementation Method 1

a piezoelectric element configured to output a residual vibration signal corresponding to a residual vibration caused by a change in the volume of the pressure chamber

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP4613488A1Print head and liquid discharge apparatus
Publication Date: 2025.09.10 SEIKO EPSON CORP
  • EP4613488A1 patent drawingFigure 1
  • EP4613488A1 patent drawingFigure 2
  • EP4613488A1 patent drawingFigure 3~4

AI summary

A print head includes a pressure chamber whose volume changes according to a drive signal, a nozzle communicating with the pressure chamber and configured to allow a liquid to be discharged, a piezoelectric element configured to output a residual vibration signal corresponding to a residual vibration caused by a change in the volume of the pressure chamber, a residual vibration detection circuit configured to receive the residual vibration signal and output a residual vibration detection signal corresponding to the residual vibration signal, and a first switch circuit configured to switch whether to supply the residual vibration signal to the residual vibration detection circuit. The first switch circuit is an N-channel type transistor.