Piezoelectric Actuator Electrode Potential Synchronization
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Solution Overview
Problem
The existing piezoelectric actuator in ink-jet heads has limitations in increasing the deformation of piezoelectric elements, which restricts the volume change of pressure chambers and consequently the discharge energy applied to the ink.
Innovation Solution
A liquid discharge apparatus and method that includes a piezoelectric actuator with individual and common electrodes, where a driving device outputs individual and common driving signals to synchronize the electric potential changes of both, allowing greater deformation of the piezoelectric elements and increased discharge energy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If only the electric potential of the individual electrode is changed by the driver IC, then the device complexity is reduced, but the deformation amount of the piezoelectric element is limited
Solution Approach 1:
The patent applies dynamics by making the common electrode potential variable rather than fixed. The driver IC dynamically adjusts the common electrode potential in response to individual electrode potential changes, enabling the piezoelectric element to achieve greater deformation amplitude while maintaining manageable control complexity through coordinated potential switching.
Solution Approach 2:
The patent changes the parameter of common electrode potential from a constant ground potential to a variable potential that responds to individual electrode signals. This parameter change allows the electric field across the piezoelectric element to be optimized, increasing deformation amount without requiring excessive complexity in the driving circuitry.
2Shape
If the deformation amount of piezoelectric elements is increased, then the volume change of pressure chamber is increased, but the discharge energy is limited by the existing driving method
Solution Approach 1:
The patent uses dynamics by implementing a dynamic driving method where the common electrode potential is adjusted in response to individual electrode potential changes. This dynamic coordination creates a synergistic effect that amplifies the piezoelectric deformation, enabling larger volume changes in the pressure chamber and consequently higher discharge energy without requiring a single overly complex driving signal.
Solution Approach 2:
The patent employs periodic action through the coordinated switching of individual and common electrode potentials. The driver IC generates periodic potential changes that work together to maximize piezoelectric deformation, creating a rhythmic expansion and contraction cycle that enhances both deformation amount and discharge energy efficiency.
3Shape
If the electric potential difference between individual electrode and common electrode is increased, then the piezoelectric deformation is enhanced, but the control precision is reduced
Solution Approach 1:
The patent implements feedback by having the common electrode potential respond to the individual electrode potential changes. The driver IC monitors the individual electrode signal and adjusts the common electrode potential accordingly, creating a closed-loop control system that enhances piezoelectric deformation while maintaining precise control through coordinated potential switching based on real-time signal feedback.
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 enables greater deformation of piezoelectric elements, resulting in increased discharge energy and improved ink discharge efficiency, allowing for larger ink droplets and more precise control over ink discharge amounts for applications like gradation printing.
Implementation Method 1
The piezoelectric actuator has a piezoelectric layer, a plurality of individual electrodes, and a common electrode. The plurality of individual electrodes are connected to a driver IC for driving the piezoelectric actuator via a wiring member. Further, the common electrode is always retained at the ground electric potential. The driver IC outputs the driving signal to the individual electrode corresponding to the nozzle from which the ink is to be discharged so that the electric potential of the individual electrode is switched between the driving electric potential and the ground electric potential. Accordingly, the voltage, which is applied to the portion of the piezoelectric layer interposed between the individual electrode and the common electrode (hereinafter referred to as 'piezoelectric element' as well), is changed. In this situation, the contraction occurs in the piezoelectric element, and the piezoelectric actuator is deformed so that the piezoelectric actuator is warped or bent.
Data Source
AI summary
A liquid discharge apparatus is provided, comprising a channel structure; a piezoelectric actuator which has a plurality of individual electrodes, a common electrode, and a piezoelectric layer sandwiched between the individual electrodes and the common electrode; and a driving device which drives the piezoelectric actuator. The driving device outputs an individual driving signal which causes a change of an electric potential of the individual electrode, to the individual electrode corresponding to the nozzle for discharging the liquid. Further, the driving device outputs a common driving signal which causes a change of an electric potential of the common electrode in synchronization with the change of the electric potential of the individual electrode into which the individual driving signal is inputted, to the common electrode.