Head Chip Independent Common Electrodes for Heat and Size Reduction

Solution Overview

Problem

In liquid ejecting apparatuses with multiple pressure chambers for a common nozzle, existing technologies face challenges in reducing the size of the head chip and suppressing heat generation while maintaining the ability to inspect the performance of each pressure chamber.

Innovation Solution

A head chip configuration is introduced, featuring a first and second nozzle, each with corresponding pressure chambers, piezoelectric bodies, and electrodes. This configuration includes independent common electrodes for each pair of piezoelectric elements, allowing for individual signal supply and reducing the number of switching elements, thus minimizing the size of the wiring substrate and suppressing heat generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If separate driving signals are sent to piezoelectric elements corresponding to two pressure chambers with a common nozzle, then the performance of each pressure chamber can be inspected separately, but the number of switching elements increases, causing the wiring substrate to become large and the switch circuit to overheat

Engineering Contradiction:

Improveinspection capabilityVSAvoidwiring substrate size

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the common electrode into two independent common electrodes (first common electrode and second common electrode), each corresponding to a different pressure chamber. This segmentation allows separate inspection of each pressure chamber while reducing the number of switching elements needed, as each piezoelectric element now has its own dedicated common electrode rather than sharing a single common electrode across multiple pressure chambers.

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If separate driving signals are sent to piezoelectric elements corresponding to two pressure chambers with a common nozzle, then the performance of each pressure chamber can be inspected separately, but the switch circuit becomes overheated due to increased number of switching elements

Engineering Contradiction:

Improveinspection capabilityVSAvoidheat generation

Core Design Contradiction:

Measurement precisionVSTemperature

Solution Approach 1:

The patent divides the common electrode into two independent common electrodes (first common electrode and second common electrode), each corresponding to a different pressure chamber. This segmentation allows separate inspection of each pressure chamber while reducing the number of switching elements needed, as each piezoelectric element now has its own dedicated common electrode rather than sharing a single common electrode across multiple pressure chambers.

Inventive Principle:

Principle #1Segmentation

3Device complexity

If a common driving signal is sent to individual electrodes of two piezoelectric elements corresponding to a common nozzle, then the size of the wiring substrate is reduced and heat generation is suppressed, but the natural frequencies of the two vibration sections cannot be measured separately

Engineering Contradiction:

Improvewiring substrate sizeVSAvoidnatural frequency measurement

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent divides the common electrode into two independent common electrodes (first common electrode and second common electrode), each corresponding to a different pressure chamber. This segmentation allows separate inspection of each pressure chamber while reducing the number of switching elements needed, as each piezoelectric element now has its own dedicated common electrode rather than sharing a single common electrode across multiple pressure chambers.

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

The proposed configuration reduces the size of the head chip, suppresses heat generation, and enables individual inspection of each pressure chamber's performance, improving the overall efficiency and reliability of the liquid ejecting apparatus.

Implementation Method 1

a first piezoelectric body that generates a pressure in the first pressure chamber; a second piezoelectric body that generates a pressure in the second pressure chamber

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentUS12208617B2Head chip, liquid ejecting head, and liquid ejecting apparatus

Publication Date: 2025.01.28 SEIKO EPSON CORP

AI summary

There is provided a head chip including: a first-nozzle; a second-nozzle; a first-pressure-chamber communicating with the first-nozzle; a second-pressure-chamber communicating with the first-nozzle; a third-pressure-chamber communicating with the second-nozzle; a fourth-pressure-chamber communicating with the second-nozzle; a first-piezoelectric-body generating a pressure in the first-pressure-chamber; a second-piezoelectric-body generating a pressure in the second-pressure-chamber; a third-piezoelectric-body generating a pressure in the third-pressure-chamber; a fourth-piezoelectric-body generating a pressure in the fourth-pressure-chamber; a first-individual-electrode coupled to the first-piezoelectric-body; a second-individual-electrode coupled to the second-piezoelectric-body; a third-individual electrode coupled to the third-piezoelectric-body; a fourth-individual-electrode coupled to the fourth-piezoelectric-body; a first-common-electrode commonly coupled to the first-piezoelectric-body and the third-piezoelectric-body; and a second-common-electrode that is independent of the first-common-electrode and is commonly coupled to the second-piezoelectric-body and the fourth-piezoelectric-body.