Piezoelectric Liquid Ejecting Head Lamination for Stable Displacement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The configuration of piezoelectric elements in existing liquid ejecting heads, such as those in JP-A-2013-256137, can lead to a decrease in displacement characteristics and reliability, despite increasing displacement per unit voltage by laminating thin film piezoelectric bodies.
Innovation Solution
A liquid ejecting head design with a specific lamination order of pressure chamber substrate, diaphragm, common electrodes, and thin film piezoelectric bodies, including overlapping and non-overlapping regions, along with a voltage application circuit to apply reference and driving voltages, enhances displacement characteristics and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If two thin film piezoelectric bodies are laminated to increase displacement per unit voltage, then ejection characteristics are improved, but displacement characteristics and reliability may decrease
Solution Approach 1:
The piezoelectric element is segmented into two separate thin film piezoelectric bodies (first and second) with distinct functional regions. The first thin film piezoelectric body is positioned to overlap with the individual electrode for active actuation, while the second thin film piezoelectric body is positioned in a non-overlapping region that serves as a support structure. This segmentation allows each layer to perform its specific function optimally, preventing the reliability issues that arise from improper lamination configurations.
2Power
If two thin film piezoelectric bodies are laminated to increase displacement per unit voltage, then ejection characteristics are improved, but displacement characteristics may decrease
Solution Approach 1:
Different regions of the laminated piezoelectric structure are assigned different qualities and functions. The first thin film piezoelectric body in the overlapping region is optimized for generating displacement through electrical actuation, while the second thin film piezoelectric body in the non-overlapping region provides structural support and stability. This local differentiation ensures that the overall structure achieves both high displacement capability and maintained diaphragm performance.
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 improves displacement characteristics and reliability of the piezoelectric elements, maintaining ejection performance while potentially reducing component costs.
Implementation Method 1
a piezoelectric element that vibrates a diaphragm that constitutes a part of a wall surface of a pressure chamber is used. The diaphragm is vibrated by the piezoelectric element, and thus the liquid in the pressure chamber is ejected from a nozzle.
Data Source
AI summary
A liquid ejecting head includes: in which when a region in an arrangement direction where the second thin film piezoelectric body overlaps all of the individual electrode, the first common electrode, and the second common electrode when viewed in a lamination direction is defined as an overlapping region, and a region in the arrangement direction where the second thin film piezoelectric body overlaps the first common electrode and the second common electrode and does not overlap the individual electrode when viewed in the lamination direction is defined as a non-overlapping region, the first common electrode, the first thin film piezoelectric body, the second thin film piezoelectric body, and the second common electrode are laminated in the stated order from the lower side to the upper side in the non-overlapping region.