Ink Ejection Head Manifold Port Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In liquid ejection heads, pressure distribution in manifolds due to the length and orientation of pressure chambers leads to variations in liquid ejection characteristics among nozzle openings, affecting the amount of ejected liquid.
Innovation Solution
A liquid ejection head design where the nozzle row forms an angle with the horizontal direction, featuring a manifold with an ink introducing port positioned between the center of pressure chamber rows and the upstream end, reducing pressure variations by minimizing the influence of gravity-induced pressure changes and flow path resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the liquid ejection head is disposed with nozzle rows inclined or perpendicular to the horizontal direction, then the ejection surface can be oriented for specific printing applications, but pressure distribution in the manifolds causes variations in liquid ejection characteristics among nozzle openings
Solution Approach 1:
The patent positions the liquid introducing port at a specific location in the manifold (between the center of pressure chamber rows and the upstream end) to create equipotential conditions for liquid pressure distribution. This strategic positioning compensates for gravity-induced pressure variations, ensuring that all nozzle openings receive liquid at substantially equal pressure regardless of the ejection surface orientation, thereby resolving the contradiction between orientation adaptability and ejection consistency.
2Quantity of substance
If the manifolds are made long to supply liquid to multiple pressure chambers, then more nozzle openings can be served, but pressure changes are distributed unevenly among pressure chambers
Solution Approach 1:
The patent applies local quality by strategically positioning the liquid introducing port at a specific location within the manifold rather than uniformly distributing liquid introduction along the entire manifold length. This localized positioning at a critical point (between center and upstream end) creates optimal pressure distribution characteristics that compensate for the long manifold geometry, allowing multiple nozzle openings to be served while maintaining pressure uniformity.
3Stability of the object's composition
If the liquid introducing port is positioned at the center of the manifold, then liquid distribution may be symmetric, but gravity-induced pressure changes still cause variations in ejection characteristics
Solution Approach 1:
The patent deliberately introduces asymmetry by positioning the liquid introducing port off-center in the manifold, specifically between the center of pressure chamber rows and the upstream end. This asymmetric positioning counterbalances the symmetric gravity-induced pressure distribution, creating an overall uniform pressure field that compensates for gravitational effects and ensures consistent ejection characteristics across all nozzle openings.
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 reduces pressure variations in pressure chambers and nozzle openings, resulting in consistent ink ejection characteristics and minimizing variations in the amount of ejected ink.
Implementation Method 1
the liquid introducing port being provided at a position between the center of a row of the pressure chambers and a first end located on the upstream side in the direction of gravity
Implementation Method 2
pressure generating members that change the pressures in the pressure chambers
Data Source
AI summary
An ink introducing port is provided on the upstream side of the center of a row of pressure chambers in the direction of gravity g, the pressure due to ink introduction is applied to a region where the influence by the head is small.