Inkjet Head Electrode Segmentation for Waveform Stability

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Solution Overview

Problem

Inkjet heads with piezoelectric members experience voltage drops in common electrodes, leading to variations in driving waveforms, which can impair print reliability due to differences in impedance and the number of piezoelectric members driven simultaneously, causing unintended ink ejection from adjacent grooves.

Innovation Solution

The inkjet head employs separate drivers for each first and second electrode, allowing independent control of electric potentials to each channel, eliminating common impedance issues and ensuring consistent driving waveforms, thereby stabilizing print quality and reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a common electrode is used to drive multiple piezoelectric members, then device complexity is reduced, but voltage drops vary depending on the number of piezoelectric members driven simultaneously, causing differences in driving waveforms and impairing print reliability

Engineering Contradiction:
Improveelectrode structure complexityVSAvoidprint reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The common electrode is divided into multiple independent electrodes, with each electrode corresponding to a specific piezoelectric member. This segmentation allows independent voltage control for each piezoelectric member, eliminating voltage drops caused by common impedance and ensuring consistent driving waveforms regardless of how many piezoelectric members are driven simultaneously.

Inventive Principle:
Principle #1Segmentation

2Reliability

If separate drivers are used for each electrode, then driving waveform consistency is improved, but device complexity increases

Engineering Contradiction:
Improvedriving waveform consistencyVSAvoiddriver circuit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The electrode structure is segmented into multiple independent electrodes, each connected to its own driver circuit. This segmentation enables independent control of each piezoelectric member, ensuring that driving waveforms remain consistent regardless of the number of simultaneously driven members, thereby improving print reliability.

Inventive Principle:
Principle #1Segmentation

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 solution stabilizes print quality by preventing voltage drops and ensuring consistent ink ejection, improving reliability and reducing manufacturing costs by eliminating the need for complex wiring of common electrodes.

Implementation Method 1

If a voltage is applied to a pair of electrodes that sandwich the piezoelectric member, the piezoelectric member is deformed. The inkjet head deforms the piezoelectric member to change pressure in the grooves to thereby eject the ink.

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP3173234B8Inkjet head and inkjet recording apparatus
Publication Date: 2019.11.13 TOSHIBA TEC KK

AI summary

An inkjet head contains a piezoelectric member which alternately includes plural first grooves and plural second grooves respectively constituted by a pair of side surfaces and a bottom surface; a first electrode on at least one of a pair of the side surfaces of each first groove; a second electrode on the side surface to face the first electrode across the piezoelectric member of each second groove; and a driving circuit including plural first drivers for each first electrode and inputting a common first driving waveform to each first electrode, and plural second drivers for each second electrode and inputting a second driving waveform of each second electrode corresponding to print data to each second electrode.