Piezoelectric Actuator Re-polarization After Polishing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Piezoelectric elements in inkjet recording apparatuses experience degradation in displacement properties over time, leading to fluctuations in ink ejection properties and image quality, particularly during the manufacturing process of inkjet heads involving polishing and heat treatment.
Innovation Solution
A method of manufacturing a piezoelectric actuator that includes a polishing step followed by a first heating step where the piezoelectric body is heated to a temperature not lower than its Curie point for re-polarization, and optionally a second heating step at a temperature between 100°C and the Curie point, to improve durability and initial characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the piezoelectric body is subjected to polishing and heat treatment during manufacturing, then the manufacturing precision and surface quality are improved, but the displacement properties of the piezoelectric element deteriorate due to marked decline
Solution Approach 1:
The patent applies preliminary action by performing re-polarization heating treatment at the Curie point or higher temperature immediately after polishing the piezoelectric body, before the element is assembled into the final actuator. This preliminary restoration action counteracts the polarization damage caused by polishing, ensuring the piezoelectric element maintains its displacement properties from the outset rather than degrading during operation.
2Reliability
If annealing is performed after the piezoelectric element has been driven for a long period of time, then the displacement properties are restored, but the element operates in a degraded state for an extended period
Solution Approach 1:
The patent performs re-polarization heating treatment at the Curie point or higher temperature during the manufacturing process, before the piezoelectric element is put into service. This preliminary action restores the polarization state in advance, preventing the element from operating in a degraded polarization state and eliminating the need for future annealing treatments to restore displacement properties.
3Reliability
If the piezoelectric body is heated to a temperature not lower than the Curie point for re-polarization, then the durability and initial characteristics are improved, but the manufacturing process complexity increases
Solution Approach 1:
The patent merges the re-polarization heating step with the existing manufacturing process sequence, integrating it between the polishing step and the subsequent assembly steps. By combining this necessary thermal treatment into the standard manufacturing flow rather than treating it as a separate additional process, the patent minimizes the increase in manufacturing complexity while ensuring the piezoelectric element achieves proper polarization restoration.
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 prevents decline in displacement properties over long periods of use, enhancing the durability and initial characteristics of the piezoelectric element, thereby improving ejection stability and image quality in inkjet recording apparatuses.
Implementation Method 1
a first heating step of heating the piezoelectric body to a temperature which is not lower than a Curie point of the piezoelectric body and performing re-polarization of the piezoelectric body having been polished in the polishing step
Implementation Method 2
Japanese Patent Application Publication No. 06-342946, for instance, proposes a method whereby the piezoelectric element is subjected to an annealing process at a temperature not lower than the Curie point of the piezoelectric material
Data Source
AI summary
A method of manufacturing a piezoelectric actuator includes a first polarization of a piezoelectric body; polishing the piezoelectric body; first heating step of heating the piezoelectric body to a temperature which is not lower than a Curie point of the piezoelectric body and performing a re-polarization of the piezoelectric body in a second polarization of the piezoelectric body having been heated in the first heating step.