Waveform Generating Device Inkjet Printer Power Reduction

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Solution Overview

Problem

Inkjet printers using piezoelectric elements face challenges in reducing power consumption, as existing driving signals require higher voltages to effectively discharge ink, which is inefficient and increases energy usage.

Innovation Solution

A waveform generating device applies a driving signal with a first portion reducing ink pressure and a second portion increasing it, where the second portion's potential is increased after half the natural vibration period, and reduced after 1.3 to 1.6 times this period, with a zero potential interval, optimizing ink discharge efficiency while minimizing voltage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a conventional driving signal is applied to the piezoelectric element, then ink can be discharged from the nozzle, but the required driving voltage is high which increases power consumption

Engineering Contradiction:
Improvepower consumptionVSAvoiddriving voltage
Core Design Contradiction:
Use of energy by moving objectVSPower

Solution Approach 1:

The patent applies periodic driving signals with specific timing intervals to the piezoelectric element. The first driving signal reduces ink pressure and the second driving signal increases it, with timing coordinated to resonate with the ink's natural vibration period. This periodic action enables effective ink discharge at lower voltages by utilizing resonant amplification of the ink's natural oscillations.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent changes the timing parameters of the driving signals to match the natural vibration period of the ink (specifically setting the interval between the first and second driving signals to correspond to 1.3-1.6 times the half-time of the natural vibration period). This parameter optimization allows the system to achieve effective ink discharge with reduced driving voltage, thereby lowering power consumption.

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If the driving voltage is reduced to lower power consumption, then energy efficiency improves, but ink discharge effectiveness may be compromised

Engineering Contradiction:
Improvepower consumptionVSAvoidink discharge effectiveness
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent utilizes mechanical vibration principles by timing the driving signals to coincide with the natural vibration period of the ink column in the pressure chamber. The first driving signal creates a pressure reduction that initiates ink movement, and the second driving signal, applied at the optimal time interval, amplifies this movement through resonant vibration, ensuring reliable ink discharge even at lower voltages.

Inventive Principle:
Principle #18Mechanical vibration

Solution Approach 2:

The patent employs feedback by coordinating the timing of the second driving signal with the natural vibration response of the ink. The interval between the first and second driving signals is specifically set to 1.3-1.6 times the half-time of the natural vibration period, creating a feedback loop where the ink's own vibration response triggers the next phase of driving, ensuring effective discharge while maintaining low power consumption.

Inventive Principle:
Principle #23Feedback

3Device complexity

If a single-stage pressure change is applied to the ink, then the driving signal can be simplified, but residual vibration in the ink chamber increases reducing printing quality

Engineering Contradiction:
Improvedriving signal structureVSAvoidprinting quality
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent segments the pressure change process into two distinct stages: a first driving signal that reduces ink pressure and a second driving signal that increases it. This segmentation allows each stage to be optimized independently for its specific function, with timing coordinated to minimize residual vibration. The multi-stage approach eliminates the need for complex single-stage signals while significantly improving printing quality by reducing ink chamber vibrations.

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

This approach reduces residual vibration and improves printing quality by using lower driving voltages, achieving efficient ink discharge with reduced energy consumption.

Implementation Method 1

An ink jet head using a piezoelectric element discharges ink when a driving signal is applied to the piezoelectric element so as to deform the piezoelectric element

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

a waveform generating device that applies a driving signal to an actuator to discharge ink from a pressure chamber connected to a nozzle, the driving signal including a first portion for reducing an ink pressure in the pressure chamber and a second portion for increasing the ink pressure in the pressure chamber

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP3459741B1Waveform generating device and ink jet recording apparatus
Publication Date: 2020.08.12 TOSHIBA TEC KK
  • EP3459741B1 patent drawingFigure 1
  • EP3459741B1 patent drawingFigure 2
  • EP3459741B1 patent drawingFigure 3

AI summary

According to one embodiment, a waveform generating device includes a head driver (100) configured to apply a driving signal to an actuator (18) to discharge ink from a pressure chamber connected to a nozzle (23), the driving signal including a first portion (D) for reducing an ink pressure in the pressure chamber and a second portion (P) for increasing the ink pressure in the pressure chamber. The second portion is increased in potential by a first potential (f) increase when ink pressure in the pressure chamber is at a maxima and the second portion (g) is further increased in potential by a second potential increase when the ink pressure of the pressure chamber is at a negative value after the first potential increase.