Liquid Ejecting Head Drive Circuit Signal Isolation

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Solution Overview

Problem

In liquid ejecting apparatuses like inkjet printers, increasing the number of drive signals for improved printing speed leads to reduced accuracy due to signal interference and noise, as seen in existing technologies.

Innovation Solution

A liquid ejecting apparatus with a piezoelectric element driven by multiple drive signal output circuits, including one for ejecting ink and another for not ejecting ink, using conductive components to manage signal propagation and reduce interference, with specific wiring and coupling configurations to isolate signals with different voltage amplitudes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple drive signals with different waveforms are simultaneously transferred to improve printing speed, then the ejection speed is improved, but the accuracy of signal transfer is reduced due to mutual interference and noise

Engineering Contradiction:
Improveprinting speedVSAvoidsignal transfer accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent segments the signal transfer process by separating drive signals with different voltage amplitudes into different transmission lines. The first drive signal output circuit uses a first transmission line, while the second drive signal output circuit uses a second transmission line, preventing mutual interference between signals and maintaining transfer accuracy while enabling simultaneous operation for improved printing speed

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a third conductive component as an intermediary that electrically couples the liquid ejecting head to both the first and second drive signal output circuits. This intermediary component allows the head to receive multiple drive signals while maintaining signal isolation through its specific positioning between the first and second conductive components, reducing mutual interference

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the number of drive signal types is increased to improve ejection speed, then productivity is improved, but device complexity increases due to multiple signal lines and circuits

Engineering Contradiction:
Improveejection speedVSAvoidsignal line configuration
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The liquid ejecting head is designed with multi-functionality to handle multiple drive signals simultaneously. The head includes multiple piezoelectric elements that can be driven by different drive signals (first drive signals for ejection, second drive signals for vibration) through different conductive components, allowing one head to perform multiple functions and improving ejection speed without proportionally increasing overall device complexity

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

Solution Approach 2:

The patent applies local quality by providing different conductive component configurations for different drive signals. The first conductive component is positioned between the second and third conductive components, creating localized signal isolation zones. This allows specific regions of the signal transmission system to have optimized properties for reducing interference while maintaining overall system functionality

Inventive Principle:
Principle #3Local quality

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

This configuration enhances printing speed by minimizing signal interference, thereby improving the accuracy and efficiency of ink ejection in the liquid ejecting apparatus.

Implementation Method 1

a liquid ejecting head that includes a piezoelectric element and ejects a liquid

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP3960468B1Liquid ejecting apparatus and head driving circuit
Publication Date: 2023.12.27 SEIKO EPSON CORP
  • EP3960468B1 patent drawingFigure 1
  • EP3960468B1 patent drawingFigure 2A
  • EP3960468B1 patent drawingFigure 2B

AI summary

A liquid ejecting apparatus includes a liquid ejecting head that includes a piezoelectric element and ejects a liquid, a first drive signal output circuit that outputs a first drive signal to drive the piezoelectric element so as to eject the liquid from the liquid ejecting head, a second drive signal output circuit that outputs a second drive signal to drive the piezoelectric element so as to eject the liquid from the liquid ejecting head, a third drive signal output circuit that outputs a third drive signal, having a smaller voltage amplitude than voltage amplitudes of the first and second drive signals, to drive the piezoelectric element so as not to eject the liquid from the liquid ejecting head, and a first conductive component including a first conductive section that electrically couples the liquid ejecting head to the first drive signal output circuit, a second conductive section that electrically couples the liquid ejecting head to the second drive signal output circuit, and a third conductive section that electrically couples the liquid ejecting head to the third drive signal output circuit. The first conductive section is positioned between the second conductive section and the third conductive section.