Liquid Ejection Head Protrusion Water Repellency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ink adhesion to ejection orifices with protrusions in liquid ejection heads leads to satellite formation and printing failures, as existing liquid-repellent treatments are ineffective in preventing ink adhesion and maintaining high-definition image quality.
Innovation Solution
A liquid ejection head with ejection orifices featuring protrusions and a highly water-repellent region at the protrusion edges, formed through a method involving a photocationic polymerizable resin layer and a water-repellent layer with fluorine-containing groups, where the water-repellent layer is selectively exposed to create regions of varying water repellency to prevent ink adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a liquid-repellent treatment is performed on the whole ejection orifice face, then water repellency is improved, but ink adhesion increases and satellite formation occurs
Solution Approach 1:
The invention applies different surface properties to different regions of the ejection orifice face. Specifically, the protrusion edges are treated with a liquid-repellent coating while the central ejection region maintains different surface characteristics. This local differentiation allows the protrusion edges to prevent satellite formation through capillary action while the central region facilitates clean ink ejection and prevents adhesion.
2Manufacturing precision
If protrusions are added to ejection orifices to shorten tailing, then satellite formation is reduced, but ink adhesion increases leading to printing failures
Solution Approach 1:
The invention treats only specific regions (protrusion edges) with liquid-repellent coating rather than the entire surface. This localized treatment maintains the geometric benefits of protrusions for satellite suppression while preventing the harmful ink adhesion that occurs on untreated protrusion surfaces.
Solution Approach 2:
Instead of treating the entire ejection orifice face with liquid-repellent coating, the invention applies the treatment only to specific regions (the protrusion edges). This partial action achieves the necessary capillary effect for satellite suppression without the excessive ink adhesion that would result from complete surface treatment.
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 effectively prevents ink adhesion on the ejection orifice surfaces, reducing satellite formation and ensuring high printing quality by creating a pinning effect that directs ink away from the orifice, thereby improving ejection precision and reducing print deflection.
Implementation Method 1
a first exposure step of partly exposing the water-repellent layer and the photocationic polymerizable resin layer to form an ejection orifice pattern
Implementation Method 2
a second exposure step of exposing the water-repellent layer where an outer surface including at least a protrusion edge in a portion to be the protrusion of the ejection orifice is an unexposed portion, thereby eliminating the fluorine-containing group in an exposed portion
Implementation Method 3
the protrusion includes, on an outer surface including at least a protrusion edge, a highly water-repellent region having a higher water repellency than that of an outer surface of a periphery of the ejection orifice
Data Source
AI summary
A liquid ejection head includes an ejection orifice configured to eject a liquid, the ejection orifice has at least one protrusion protruding from the peripheral portion of the ejection orifice toward the center of the ejection orifice, and the protrusion includes, on the outer surface including at least the protrusion edge, a highly water-repellent region having a higher water repellency than that of the outer surface of the periphery of the ejection orifice.