Inkjet Head Residual Vibration Inspection With Variable Filter Tuning

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Solution Overview

Problem

Existing liquid ejecting apparatuses, such as ink jet printers, face challenges in efficiently inspecting the ejection state of ejecting sections due to the need for long unit periods to accommodate both driving and detection of residual vibrations, which can lead to inefficiencies and potential ejection abnormalities.

Innovation Solution

A liquid ejecting apparatus with a drive signal generation section, a piezoelectric element, a pressure chamber, and a signal generation section that includes a filter circuit with a variable resistor to generate a pseudo residual vibration signal for determining the ejection state, allowing for more efficient inspection without prolonging unit periods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If both driving of the ejecting section and detection of residual vibration are executed in a unit period, then the ejection state can be inspected, but the unit period needs to be set to have a sufficiently long time length which reduces productivity

Engineering Contradiction:

Improveejection state inspection accuracyVSAvoidprinting efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent divides the inspection process into two separate time periods: a first time period for driving the ejecting section and a second time period for detecting residual vibration. This segmentation allows each process to be optimized independently, enabling accurate ejection state inspection without requiring excessively long unit periods, thus resolving the contradiction between inspection accuracy and printing efficiency.

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If the unit period is extended to accommodate both driving and detection, then accurate ejection state determination is possible, but the printing cycle time increases reducing productivity

Engineering Contradiction:

Improveejection state detection accuracyVSAvoidunit period duration

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent performs the driving action in a first time period before the detection action in a second time period. By separating these actions temporally, the system ensures that residual vibration can be detected without interference from the driving signal, improving measurement precision while avoiding excessive time loss through optimized period separation.

Inventive Principle:

Principle #10Preliminary action

3Ease of operation

If residual vibration detection is performed immediately after driving, then ejection state can be determined, but vibration from driving interferes with detection accuracy

Engineering Contradiction:

Improveinspection process simplicityVSAvoidresidual vibration signal clarity

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent employs periodic action by alternating between a first time period for driving and a second time period for detection. This periodic separation ensures that detection occurs when driving vibrations have subsided, improving signal clarity and measurement precision while maintaining operational simplicity through systematic alternation of functions.

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

This approach enables rapid and accurate determination of the ejection state of the ejecting sections, preventing ejection abnormalities and maintaining print quality by identifying and addressing issues like thickened ink, thus enhancing the efficiency and reliability of the printing process.

Implementation Method 1

a piezoelectric element driven by a drive signal, and a pressure chamber that ejects a liquid from the nozzle in response to driving of the piezoelectric element

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

a signal generation section to which a residual vibration signal generated by residual vibration in the ejecting section after the piezoelectric element is driven is input, and which generates a pseudo residual vibration signal according to the residual vibration signal

Methodology Applied

Scientific EffectElectrical filtering: Filter (electronic)

Data Source

PatentUS20260061746A1Liquid ejecting apparatus and liquid ejecting head

Publication Date: 2026.03.05 SEIKO EPSON CORP

AI summary

An ink jet printer includes: a drive signal generation unit that generates a drive signal, an ejecting section that includes a nozzle, a piezoelectric element driven by the drive signal, and a cavity that ejects an ink from the nozzle in response to driving of the piezoelectric element, a first inspection signal generation circuit to which a residual vibration signal generated by residual vibration in the ejecting section after the piezoelectric element is driven is input and which generates a pseudo residual vibration signal according to the residual vibration signal, and an inspection unit that determines a state of the ejecting section based on the pseudo residual vibration signal, in which the first inspection signal generation circuit includes a first filter circuit that generates the pseudo residual vibration signal, and the first filter circuit includes a variable resistor element having an adjustable resistance value.