Liquid Ejection Head Drive Waveform for Satellite Droplet Suppression

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Solution Overview

Problem

Existing liquid ejection heads face challenges in suppressing satellite droplets while maintaining high print quality and reducing power consumption, often requiring complex drive circuits that increase costs.

Innovation Solution

A liquid ejection head with a simple circuit configuration that uses a drive signal with staged expansion and contraction potential differences to cancel vibrations at frequencies higher than the main acoustic resonance, employing a piezoelectric actuator with alternating piezoelectric columns and a drive circuit that switches voltage sources to generate drive waveforms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a complex drive circuit with adjustable rise time or fall time is used to suppress satellite droplets, then print quality is improved, but power consumption and cost increase

Engineering Contradiction:
Improveprint qualityVSAvoidpower consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent applies parameter changes by modifying the drive waveform parameters (rise time and fall time) to specific optimized values. By setting the rise time to 0.05 to 0.15 milliseconds and fall time to 0.03 to 0.10 milliseconds, the system suppresses satellite droplets without requiring complex adjustable circuits, thereby reducing power consumption while maintaining high print quality.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs periodic action through driven harmonic oscillation of the liquid column in the pressure chamber. By controlling the drive waveform to create specific oscillation patterns with defined rise and fall times, the system achieves satellite droplet suppression through periodic vibration control, eliminating the need for complex continuously adjustable drive circuits.

Inventive Principle:
Principle #19Periodic action

2Manufacturing precision

If a complex drive circuit with adjustable rise time or fall time is used to suppress satellite droplets, then print quality is improved, but device complexity increases

Engineering Contradiction:
Improveprint qualityVSAvoidcircuit complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by modifying the drive waveform parameters (rise time and fall time) to specific optimized values. By setting the rise time to 0.05 to 0.15 milliseconds and fall time to 0.03 to 0.10 milliseconds, the system suppresses satellite droplets without requiring complex adjustable circuits, thereby reducing power consumption while maintaining high print quality.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs periodic action through driven harmonic oscillation of the liquid column in the pressure chamber. By controlling the drive waveform to create specific oscillation patterns with defined rise and fall times, the system achieves satellite droplet suppression through periodic vibration control, eliminating the need for complex continuously adjustable drive circuits.

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 effectively suppresses high-frequency vibrations, improving print quality by reducing satellite droplets and minimizing power consumption.

Implementation Method 1

The actuator is a piezoelectric member including a plurality of piezoelectric columns

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

cancel the vibration of an acoustic resonance frequency in a frequency range higher than a main acoustic resonance frequency of the liquid in the pressure chamber

Methodology Applied
Scientific EffectAcoustic resonance: Resonance

Data Source

PatentEP4253053B1Liquid ejection head
Publication Date: 2025.12.17 RISO TECH CORP
  • EP4253053B1 patent drawingFigure 1~2
  • EP4253053B1 patent drawingFigure 3
  • EP4253053B1 patent drawingFigure 4

AI summary

According to one embodiment, a liquid ejection head includes a nozzle plate, pressure chambers, an actuator, and a drive circuit. The nozzle plate includes nozzles for ejecting liquid. The pressure chamber communicates with the nozzles. The actuator varies the volume of the pressure chamber according to a drive signal. The drive circuit generates the drive signal for driving the actuator. The ejection waveform in the drive signal includes an expansion potential difference changes that changes in stages and a contraction potential difference change that changes in stages. The drive circuit set the timing of the stages to cancel the vibration of an acoustic resonance frequency in a frequency range higher than a main acoustic resonance frequency of the liquid in the pressure chamber.