Liquid Ejection Head Side Shooter Meniscus Overshoot Control
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Solution Overview
Problem
Existing inkjet heads face challenges in achieving high-speed ink ejection and stable meniscus return due to overshooting phenomena, which affect the ejection characteristics and print quality.
Innovation Solution
The liquid ejection head incorporates a side shooter type design with pressure chambers, dummy chambers, and a pair of covers with apertures that increase fluid resistance, allowing for stable meniscus return and improved ejection stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the fluid resistance along the flow path from the common liquid chamber to the nozzle is reduced to enable faster ink replenishment, then the ink replenishment speed is improved, but the meniscus overshoot increases causing unstable ejection characteristics
Solution Approach 1:
The patent applies local quality by creating different fluid resistance characteristics in different sections of the flow path. Specifically, the communication path between the common liquid chamber and pressure chamber has higher fluid resistance than the pressure chamber-to-nozzle path, allowing localized control of fluid dynamics to balance replenishment speed and meniscus stability
Solution Approach 2:
The flow path is segmented into distinct sections with different resistance characteristics: the common liquid chamber to pressure chamber communication path is designed with higher fluid resistance (through narrower apertures or longer paths) compared to the pressure chamber to nozzle path, enabling independent optimization of each section's fluid dynamics
2Speed
If the ejection speed is increased to achieve high-speed inkjet operation, then the productivity is improved, but the meniscus return time is insufficient causing overshoot and unstable ejection
Solution Approach 1:
The patent applies preliminary anti-action by designing the fluid resistance distribution to preemptively counteract the meniscus overshoot phenomenon. The higher fluid resistance in the common liquid chamber to pressure chamber path acts as a preliminary restraint on meniscus movement, preventing excessive overshoot before it occurs and ensuring stable ejection at high speeds
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 solution enhances the ejection speed and stability by reducing meniscus overshoot and promoting faster meniscus return, thereby improving the overall print quality and enabling high-speed operation.
Implementation Method 1
a plurality of pressure chambers each communicating with a corresponding one of the nozzles, a plurality of dummy chambers each disposed between two of the pressure chambers that are adjacent to each other, and a plurality of sidewalls separating the pressure and dummy chambers along the first direction and deformable to change a volume of each of the pressure chambers according to a drive signal
Implementation Method 2
a pair of covers having a plurality of apertures and partly covering both ends of each of the pressure chambers in a second direction intersecting the first direction such that the pressure chambers communicate with a common chamber at both ends thereof through the apertures
Data Source
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AI summary
A liquid ejection head of a side shooter type includes a plate including nozzles arranged along a first direction and through which liquid is ejected, an actuator including pressure chambers communicating with the nozzles, dummy chambers each disposed between two adjacent pressure chambers, and sidewalls separating the chambers along the first direction and deformable to change a volume of each pressure chamber according to a signal, and covers having apertures and partly covering both ends of each pressure chamber in a second direction intersecting the first direction such that the pressure chambers communicate with a common chamber at both ends thereof through the apertures. Each cover includes a first portion on and between the sidewalls and a second portion other than the first portion, and a first length of the first portion is equal to or greater than a second length of the second portion in the second direction.