Ink Jet Head Power Reduction via Shared Waveform Generation

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Solution Overview

Problem

Existing ink jet heads with piezoelectric elements face high power consumption when attempting to achieve sufficient ejecting speed, as they require multiple switches for generating driving waveforms for each channel, leading to inefficiencies in power usage.

Innovation Solution

The ink jet head incorporates a capacitive-type actuator with a charging and discharging circuit and a waveform generation circuit that applies intermediate and driving voltages strategically to reduce power consumption while maintaining ejecting speed, by optimizing the timing of voltage application during ink ejection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If multiple switches are provided for each channel to generate driving waveforms, then sufficient ejecting speed is achieved, but power consumption becomes great

Engineering Contradiction:

Improveejecting speedVSAvoidpower consumption

Core Design Contradiction:

SpeedVSUse of energy by moving object

Solution Approach 1:

The patent merges the driving waveforms for multiple channels into a single shared waveform generation unit. Instead of having separate switches for each channel, the invention uses one waveform generation unit that sequentially drives multiple channels, thereby reducing the number of switches and power consumption while maintaining sufficient ejecting speed through optimized timing control.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent implements periodic action by using a single waveform generation unit that alternates between driving different channels in a sequential manner. The driving waveform is generated periodically and distributed to multiple channels through switching control, achieving both power savings and maintained ejection performance through time-multiplexed operation.

Inventive Principle:

Principle #19Periodic action

2Use of energy by moving object

If a single waveform generation unit is shared among multiple channels, then power consumption is reduced, but channel switching control becomes necessary

Engineering Contradiction:

Improvepower consumptionVSAvoidswitching control complexity

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent applies dynamics by implementing time-varyed switching control where the connection between the waveform generation unit and different channels changes dynamically over time. The switching mechanism adaptively connects the shared waveform unit to the appropriate channel based on the driving sequence, managing complexity through controlled temporal variation rather than static multi-channel architecture.

Inventive Principle:

Principle #15Dynamics

3Use of energy by moving object

If intermediate voltage is applied for a longer time, then power consumption is reduced, but ink ejection timing is delayed

Engineering Contradiction:

Improvepower consumptionVSAvoidejection timing delay

Core Design Contradiction:

Use of energy by moving objectVSLoss of time

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the voltage level and application time to different channels based on their specific requirements. The waveform generation unit modifies voltage parameters (amplitude and duration) for each channel sequentially, optimizing the balance between power consumption and ejection timing by tailoring voltage application characteristics to each channel's driving needs.

Inventive Principle:

Principle #35Parameter changes

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 power consumption while maintaining sufficient ink ejecting speed, allowing for stable and efficient ink ejection by adjusting the timing of voltage application in the capacitive-type actuator system.

Implementation Method 1

An ink jet head including a plurality of ejection channels includes a number of piezoelectric elements which are capacitive-type actuators, as actuators for ejecting ink from each channel

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

capacitive-type actuators... The actuators change volume of a pressure chamber by performing charging or discharging with a series of charging and discharging sequences

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS9289983B2Ink jet head

Publication Date: 2016.03.22 RISO TECH CORP

AI summary

When charging an actuator, first, the charging is performed by applying an intermediate voltage lower than a driving voltage which is a target voltage and then charging is performed by applying the driving voltage to the actuator. When discharging the actuator, the discharging is performed by applying the intermediate voltage and then the discharging is performed by applying a zero voltage to the actuator which is charged by the driving voltage. The time for applying the intermediate voltage at a timing of ejecting the ink from the nozzles is shorter than the time for applying the intermediate voltage to the actuator at other timings.