Drop Ejection Waveform Straightening Pulse

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Solution Overview

Problem

Drop ejection devices often produce drops with trajectory errors due to nozzle misalignment and transient or permanent jet straightness issues, leading to degraded image quality in printing applications.

Innovation Solution

A method and apparatus for driving a drop ejection device using a multi-pulse waveform with a straightening pulse to ensure drops are ejected with a straight trajectory, reducing drop trajectory errors by bulging the meniscus position of fluid past the nozzle and minimizing asymmetric wetting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a single drive pulse is used to eject drops, then the device operation is simple, but drop trajectory errors occur due to nozzle misalignment and transient jet straightness issues

Engineering Contradiction:
Improvedevice operation simplicityVSAvoiddrop placement accuracy
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The single drive pulse waveform is segmented into multiple pulses: a first drive pulse for building the drop and a second drive pulse for ejecting the drop. This segmentation allows independent optimization of drop formation and ejection phases, enabling straighter trajectories and improved placement accuracy while maintaining operational simplicity through automated multi-pulse control.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first drive pulse performs preliminary action by building and preparing the drop before the second drive pulse ejects it. This preliminary drop formation phase ensures the drop is properly formed and positioned, reducing trajectory errors and improving placement accuracy without requiring manual intervention.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If multi-pulse waveform with straightening pulse is used to reduce trajectory errors, then drop placement accuracy improves, but device complexity increases

Engineering Contradiction:
Improvedrop placement accuracyVSAvoidwaveform control complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The multi-pulse waveform system performs self-service by automatically executing the sequence of drop building and ejection pulses without external intervention. The controller autonomously manages the complex multi-pulse waveform generation, allowing the system to achieve high placement accuracy while keeping the user interface simple and the operation straightforward.

Inventive Principle:
Principle #25Self-service

3Productivity

If drop ejection is performed without straightening pulse, then the ejection process is fast, but jet trajectory errors occur causing image quality degradation

Engineering Contradiction:
Improveejection speedVSAvoidjet trajectory straightness
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The periodic multi-pulse waveform alternates between drop building phase (first drive pulse) and ejection phase (second drive pulse), creating a rhythmic cycle that maintains high ejection speed. The periodic nature of this action ensures consistent drop formation and trajectory control, preventing trajectory errors and maintaining image quality while sustaining productivity.

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

The solution effectively reduces drop placement errors, improving image quality by ensuring drops are ejected straightly, thereby enhancing the accuracy and consistency of drop placement in printing processes.

Implementation Method 1

Drop ejection is controlled by pressurizing fluid in the fluid path with an actuator

Methodology Applied
Scientific EffectPressurization: Pressurisation

Implementation Method 2

an actuator, which may be, for example, a piezoelectric deflector

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP2490897B1Method and apparatus to eject drops having straight trajectories
Publication Date: 2016.09.21 FUJIFILM DIMATIX INC
  • EP2490897B1 patent drawingFigure 1
  • EP2490897B1 patent drawingFigure 2
  • EP2490897B1 patent drawingFigure 3

AI summary

Described herein is a method and apparatus for driving a drop ejection device to produce drops having straight trajectories. In one embodiment, a method for driving a drop ejection device having an actuator includes building a drop of a fluid with at least one drive pulse by applying a multi- pulse waveform having the at least one drive pulse and a straightening pulse to the actuator. Next, the method includes causing the drop ejection device to eject the drop with a straight trajectory in response to the pulses of the multi-pulse waveform. The straightening pulse is designed to ensure that the drop is ejected without a drop trajectory error.