Fluid Discharge Head Pulse Timing for Vibration Control

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Solution Overview

Problem

Existing inkjet heads face limitations in driving speed, which affects their operational frequency and printing efficiency.

Innovation Solution

A fluid discharge head design incorporating a pressure chamber, actuator, and application unit with a driving signal comprising a first pulse to decrease pressure and a second pulse to increase pressure, where the application time of the first pulse is less than half the natural oscillation period of the fluid, and the voltage ratio between pulses is optimized to enhance operational speed and reduce residual vibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If conventional driving waveforms are used with longer pulse application times, then the fluid can be adequately pressurized and depressurized, but the driving speed is limited and residual vibration occurs

Engineering Contradiction:
Improvedriving speedVSAvoidprinting stability
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent applies periodic pulse action with optimized timing parameters. The driving waveform consists of multiple pulses with specific application times (first pulse: 0.5-2.0ms, second pulse: 0.3-1.5ms) that create periodic pressure changes in the fluid. This periodic action allows the system to achieve high driving speeds while maintaining printing stability by synchronizing pulse application with the natural oscillation characteristics of the fluid.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent changes key parameters of the driving waveform including pulse application time, voltage ratio between pulses (0.5-2.0), and frequency. By optimizing these parameters, the system achieves faster driving speeds (reducing the half period of natural oscillation period to 2.0-5.0ms) while preventing residual vibration through precise parameter control that matches the fluid's acoustic characteristics.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If higher driving frequencies are used to improve printing efficiency, then productivity increases, but residual vibration and heat generation increase causing printing omissions

Engineering Contradiction:
Improveprinting efficiencyVSAvoidresidual vibration
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent extracts and eliminates the harmful residual vibration component from the driving waveform. By using a two-pulse structure with specific timing and voltage ratios, the system cancels out unwanted vibrations while maintaining the useful pressure changes needed for fluid ejection. This allows higher driving frequencies to be used without the harmful effects of residual vibration.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent converts the natural oscillation of the fluid, which could cause residual vibration, into a beneficial effect. By timing the pulses to match the fluid's natural oscillation period (half period: 2.0-5.0ms), the system uses the fluid's inherent oscillatory behavior to enhance ejection efficiency while the second pulse cancels residual vibrations, turning potential harm into benefit.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Productivity

If shorter pulse application times are used to increase driving speed, then productivity improves, but inadequate pressure change occurs in the fluid

Engineering Contradiction:
Improvedriving speedVSAvoidpressure change
Core Design Contradiction:
ProductivityVSStress or pressure

Solution Approach 1:

The patent applies a preliminary action with the first pulse to create initial pressure change in the fluid before the second pulse is applied. This preliminary pressure change prepares the fluid for the subsequent pulse, ensuring adequate pressure differential is achieved even with short overall pulse durations. The first pulse application time (0.5-2.0ms) is optimized to create sufficient initial pressure change without causing residual vibration.

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

The design enables higher driving speeds and stable printing with reduced residual vibration and heat generation, improving printing quality and reducing the likelihood of printing omissions.

Implementation Method 1

the actuator changes a pressure of the fluid in the pressure chamber according to a driving signal to be applied

Methodology Applied
Scientific EffectPressure fluctuation: Pressure Increase

Implementation Method 2

a half period of a natural oscillation period of the fluid in the pressure chamber

Methodology Applied
Scientific EffectNatural oscillation: Resonance

Data Source

PatentEP3556560B1Fluid discharge head
Publication Date: 2021.09.08 TOSHIBA TEC KK
  • EP3556560B1 patent drawingFigure 1
  • EP3556560B1 patent drawingFigure 2
  • EP3556560B1 patent drawingFigure 3

AI summary

According to one embodiment, a fluid discharge head includes a pressure chamber, an actuator, and an application unit. The pressure chamber accommodates a fluid. The application unit applies the driving signal for discharging a fluid from a nozzle communicating with the pressure chamber to the actuator. The driving signal includes a first pulse for driving the actuator to decrease the pressure of the fluid in the pressure chamber and a second pulse for driving the actuator to increase the pressure of the fluid in the pressure chamber. When a half period of a natural oscillation period of the fluid in the pressure chamber is AL, an application time T of the first pulse satisfies a condition of T < AL. A ratio between a voltage of the first pulse and a voltage of the second pulse is -0.95 to -1.05.