Inkjet Head Chip Electrode Geometry for Uniform Channel Ejection
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Solution Overview
Problem
Existing inkjet head designs experience variations in ink ejection speed due to differences in electrode dimensions across channels, leading to inconsistent ink landing times and deteriorated ejection performance, which can be exacerbated by changes in electrode thickness to compensate for these variations.
Innovation Solution
The design incorporates electrodes on the actuator plate with dimensions that decrease gradually from the channel ends towards the central portion, ensuring consistent effective areas across channels without altering channel shapes, using oblique evaporation to form electrodes with matching dimensions and low-dielectric films to stabilize the electrode regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If oblique evaporation is used to form electrodes, then electrodes can be deposited on inner surfaces of channels, but the evaporation depth varies with distance from the evaporation source causing inconsistent electrode dimensions
Solution Approach 1:
The patent applies local quality by making the electrode width vary along the channel length. Specifically, the electrode width is smaller at the ejection channel end and larger at the non-ejection channel end, compensating for the varying evaporation depth caused by oblique evaporation. This local variation in electrode geometry ensures uniform electrode cross-sectional area and consistent ejection performance across all channels.
2Manufacturing precision
If electrode dimensions are increased to compensate for area variation, then opposed region area increases, but drive wall strength and durability are compromised
Solution Approach 1:
The patent resolves this contradiction by locally adjusting only the electrode width (dimension in channel extension direction) while keeping the electrode thickness (dimension in channel depth direction) constant. This localized geometric modification achieves uniform opposed region area without reducing drive wall thickness, thereby maintaining drive wall strength and durability while ensuring consistent ejection performance.
3Manufacturing precision
If drive wall thickness is changed to control volume variation, then ejection performance variation is reduced, but drive wall strength and durability are affected
Solution Approach 1:
The patent avoids changing drive wall thickness by instead varying the electrode width along the channel. This alternative approach achieves uniform ejection performance through electrode geometry optimization rather than drive wall thickness modification, thereby maintaining drive wall strength and durability while ensuring consistent ink ejection across all channels.
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 homogenizes ejection performance across channels, reducing variations in ink ejection speed and ensuring consistent ink landing, thereby enhancing the reliability and precision of the inkjet head.
Implementation Method 1
a voltage is applied between electrodes provided to the drive wall to cause the drive wall to make a thickness-shear deformation
Implementation Method 2
The electrodes described above are deposited on inner surfaces (the drive walls) of each of the channels by performing oblique evaporation from an oblique direction
Data Source
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AI summary
A head chip, a liquid jet head, a liquid jet recording device, and a method of manufacturing a head chip each capable of suppressing the variation in ejection performance between the ejection channels without changing the shape of a channel (a drive wall) are provided. In the head chip according to an aspect of the present disclosure, when a region in which the first common electrode part and a second common electrode part are opposed in an X direction to each other across the drive wall, and which is configured to generate an electrical field in the drive wall is defined as an opposed region, a dimension in a Z direction in a first upside common part is formed so as to decrease in a direction from the drive wall located at the first side in the X direction toward the drive wall located at the second side in the X direction among the plurality of drive walls, a dimension in the Z direction in a second upside common part is formed so as to decrease in a direction from the drive wall located at the second side in the X direction toward the drive wall located at the first side in the X direction among the plurality of drive walls, and a dimension in a Y direction in the opposed region decreases in directions from the drive walls located at both end sides in the X direction toward the drive wall located in a central portion in the X direction.