Liquid Ejection Head Pressure Stabilization via Flow Path Merging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid ejection heads face challenges in maintaining consistent flow velocity of liquid into ejection ports, leading to variations in image quality due to pressure differences and flow rate variations, which are difficult to control with existing pressure adjusting mechanisms.
Innovation Solution
A liquid ejection head design incorporating a supply flow path, a collection flow path, and two pressure adjusting mechanisms, with a filter storage chamber and upstream flow paths that communicate downstream of the filter to stabilize pressure adjustments and reduce pressure losses, thereby maintaining a consistent flow velocity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If two pressure adjusting mechanisms are provided to independently control liquid pressure, then pressure control precision is improved, but device complexity increases and pressure loss variation occurs due to different flow rates through filters
Solution Approach 1:
The patent merges the filter functions into a single common filter unit that serves both pressure adjusting mechanisms. The first and second upstream flow paths both pass through the same filter, eliminating the need for separate filters for each pressure adjusting mechanism. This reduces device complexity while maintaining pressure control precision through the shared filter system.
2Speed
If pressure difference between supply and collection flow paths is increased to maintain liquid flow, then flow velocity is improved, but flow velocity variation increases due to pressure loss differences in separate flow paths
Solution Approach 1:
The patent combines the flow paths of the first and second upstream flow paths after the pressure adjusting mechanisms, causing them to communicate at a downstream position. This merging equalizes the pressure conditions and reduces pressure loss differences, thereby stabilizing flow velocity while maintaining adequate flow rates through the element substrates.
Solution Approach 2:
The patent introduces a communication path between the first and second upstream flow paths at a downstream position, acting as an intermediary that equalizes pressure conditions. This communication path allows pressure equilibrium to be established, reducing flow velocity variation caused by asymmetric pressure losses in the separate flow paths.
3Reliability
If separate filters are provided for each pressure adjusting mechanism, then filtration is improved, but pressure loss variation occurs due to different flow rates, making pressure control unstable
Solution Approach 1:
The patent merges the filtration function into a single common filter that serves both upstream flow paths. By providing one filter instead of two separate filters, the system eliminates pressure loss variation that would occur with different flow rates through separate filters, thereby stabilizing pressure control while maintaining reliable filtration of the liquid.
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 design stabilizes pressure adjustments and reduces flow velocity variations, enhancing image quality by maintaining a consistent flow velocity and reducing pressure losses, thus improving the reliability of the liquid ejection process.
Implementation Method 1
a filter storage chamber (222) including therein a filter (221) that captures a foreign matter included in a liquid
Implementation Method 2
the connection section (235) causes the first upstream flow path (233) and the second upstream flow path (234) to communicate with each other, wherein the connection section is provided at a downstream side from the filter
Data Source
AI summary
A liquid ejection head includes a pressure adjusting mechanism that communicates with a supply flow path that supplies a liquid to an element substrate including an ejection port ejecting a liquid, and adjusts a pressure of the liquid flowing in the supply flow path, a pressure adjusting mechanism that communicates with a collection flow path that collects a liquid from the element substrate, and adjusts a pressure of the liquid flowing in the collection flow path, and a filter storage chamber including therein a filter that captures foreign matter in the liquid. Further, the liquid ejection head includes upstream flow paths and a connection section that causes the upstream flow paths to communicate with each other, and is provided downstream of the filter.