Inkjet Actuator Refresh Control for Nozzle Clogging

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Solution Overview

Problem

Inkjet printing systems face issues with nozzle clogging due to ink drying, leading to reduced print quality and increased maintenance needs, as existing refresh measures are not always effective in preventing drying and may disrupt print operations or consume excessive ink.

Innovation Solution

Implementing a method where the actuator is controlled to perform intensified refresh measures when a defective nozzle is detected, including increased vibration cycles and ejection of ink droplets with higher volumes to specific points on the print image, allowing for nozzle revival during operation without interrupting print production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If standard refresh measures are implemented during dead times, then ink drying is prevented to some extent, but nozzle defects still occur and print operations are disrupted

Engineering Contradiction:

Improvenozzle functionalityVSAvoidprint operation continuity

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The system performs preliminary detection of nozzle defects using sensor units before they become critical failures. By detecting defects early during operation, the system can switch to error operating mode and implement intensified refresh measures proactively, preventing complete nozzle failure and maintaining print operation continuity.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The control system dynamically adjusts the refresh measure intensity based on real-time nozzle status. In normal operating mode, standard refresh measures are applied. Upon detecting a nozzle defect, the system transitions to error operating mode with intensified refresh measures, creating a dynamic adaptation that maintains productivity while ensuring nozzle reliability.

Inventive Principle:

Principle #15Dynamics

2Reliability

If intensified refresh measures are implemented continuously, then nozzle reliability is improved, but ink consumption increases

Engineering Contradiction:

Improvenozzle functionalityVSAvoidink consumption

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

Instead of continuously applying intensified refresh measures to all nozzles, the system applies partial action only to defective nozzles detected by sensor units. The intensified refresh measures are targeted specifically at nozzles showing defects, while other nozzles continue with standard operation, thereby maintaining reliability where needed while minimizing unnecessary ink consumption.

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The system uses sensor units to provide real-time feedback on nozzle status. This feedback enables the control system to make informed decisions about when and where to apply intensified refresh measures. The feedback mechanism ensures that ink is consumed only when necessary for defective nozzles, optimizing the balance between reliability and ink consumption.

Inventive Principle:

Principle #23Feedback

3Reliability

If multiple vibration cycles are inserted during dead times, then ink viscosity is reduced and clogging is prevented, but print quality may be affected by random dot placement

Engineering Contradiction:

Improvenozzle patencyVSAvoidprint image quality

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The system performs preliminary detection of nozzle defects using sensor units before they affect print quality. By identifying and addressing defective nozzles proactively through intensified refresh measures, the system prevents the need for random dot placement that would compromise print image quality, while still maintaining nozzle patency.

Inventive Principle:

Principle #10Preliminary 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 extends the operational time of nozzles by allowing for nozzle defect remediation during printing, reducing maintenance interruptions and enhancing productivity by maintaining print quality and minimizing ink consumption.

Implementation Method 1

During a vibration cycle, the actuator is controlled with a predetermined waveform such that the ink meniscus at the output of the nozzle is set into vibration without an ink droplet being ejected. The ink at the end of the nozzle channel is intermixed due to the vibration

Methodology Applied

Scientific EffectVibration: Vibration

Implementation Method 2

the actuator is controlled to output an ink droplet from a nozzle of the printing element

Methodology Applied

Scientific EffectPressure-driven ejection:

Data Source

PatentUS11207882B2Method and device for controlling an actuator of an inkjet printing system

Publication Date: 2021.12.28 CANON PRODN PRINTING HLDG BV

AI summary

In an inkjet printing system, an actuator that is associated with a nozzle of a printing element is controlled in a normal operating mode, given a non-defective nozzle, to implement at least one standard refresh measure if the time period in which the actuator is not activated to output an ink droplet exceeds a preset limit value. After detection of a defective nozzle, the actuator is controlled in an error operating mode to implement at least one intensified refresh measure.