Liquid Ejection Head Vertical Flow Stabilization
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Solution Overview
Problem
Existing liquid ejection technologies face instability in ejection due to the lack of a detailed configuration for the confluence of bubbling and ejection media, leading to potential misalignment of the ejection medium with the ejection port, which can result in unstable ejection of the ejection medium.
Innovation Solution
The solution involves arranging the bubbling medium and the ejection medium to flow in a height direction within a pressure chamber, ensuring the pressure generating element, ejection port, and the ejection medium are aligned, with the ejection medium flowing below and the bubbling medium above, to stabilize the ejection process. This configuration includes a confluence wall and specific flow passage designs to maintain laminar flows and prevent interface disturbance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the bubbling medium and ejection medium flow side by side in a width direction, then the liquid flow passage configuration is simple, but the ejection medium may fail to contact the ejection port, resulting in unstable ejection
Solution Approach 1:
The patent transitions the liquid flow arrangement from a horizontal (width direction) configuration to a vertical (height direction) configuration. The bubbling medium and ejection medium are arranged to flow in the height direction with the ejection medium positioned below the bubbling medium, ensuring proper contact between the ejection medium and ejection port while maintaining flow stability.
2Ease of operation
If the ejection medium is positioned above the bubbling medium, then the ejection port can be easily accessed, but the interface between the two liquids becomes unstable, causing ejection instability
Solution Approach 1:
The patent inverts the conventional arrangement by positioning the ejection medium below the bubbling medium in the height direction. This inversion ensures that the ejection medium, which needs to be ejected, is in direct contact with the ejection port at the bottom, while the bubbling medium flows above it, creating a stable interface configuration that prevents mixing and ensures reliable ejection.
3Productivity
If thermal energy is applied to generate bubbles, then liquid ejection is achieved, but the interface between bubbling and ejection media may become unstable
Solution Approach 1:
The patent segments the liquid flow system into distinct regions: the bubbling medium flow passage and the ejection medium flow passage, separated by a partition wall. This segmentation allows thermal energy to be applied to generate bubbles in the bubbling medium without disrupting the ejection medium, as the partition wall prevents direct mixing while maintaining separate controlled environments for each liquid type.
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 configuration stabilizes the ejection of the ejection medium by ensuring consistent contact with the ejection port, reducing the risk of misalignment and enhancing the reliability of the ejection process, allowing for stable operation and improved ejection performance.
Implementation Method 1
imparting thermal energy
Implementation Method 2
growth of a bubble generated in the bubbling medium as a consequence of imparting thermal energy
Implementation Method 3
eject the ejection medium along with growth of a bubble
Data Source
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AI summary
In a liquid ejection head(1), a substrate(15) includes a first inflow port(20) which is located on an upstream side of a pressure chamber(18) in a flow direction of liquids in a liquid flow passage(13) and allows a first liquid(31) to flow into the liquid flow channel, a second inflow port(21) which is located on the upstream side of the first inflow port and allows a second liquid(32) to flow into the liquid flow passage, and a confluence wall(41) provided between the first inflow port and the second inflow port and having a portion at a higher position than a surface of the substrate on a downstream side of the first inflow port in the flow direction. In the pressure chamber, the first liquid flows in contact with a pressure generating element(12) and the second liquid flows closer to an ejection port(11) than the first liquid does.