Liquid Ejection Head With Segmented Energy Elements
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Solution Overview
Problem
Liquid ejection heads face reliability issues due to increased viscosity of liquids at and near the ejection orifices, which obstruct proper liquid ejection and lead to decreased performance over time.
Innovation Solution
A liquid ejection head design featuring a bubble generation chamber with a circulation energy generation element and an ejection energy generation element, where the elements are spaced differently to maintain reliable operation over long periods by minimizing viscosity increase through controlled energy generation and circulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a circulation energy generation element is driven continuously to maintain liquid viscosity, then liquid ejection performance is maintained, but the reliability of the liquid ejection head decreases
Solution Approach 1:
The circulation energy generation element operates intermittently rather than continuously. It is activated periodically to circulate liquid and reduce viscosity, then deactivated to conserve energy and extend operational duration, achieving a balance between maintaining performance and ensuring long-term reliability
Solution Approach 2:
The system changes the operational parameters of the circulation energy generation element by adjusting its activation timing and duration based on liquid viscosity conditions, allowing it to operate only when necessary rather than continuously, thereby extending its service life
2Reliability
If the circulation energy generation element is positioned close to the ejection orifice for effective circulation, then liquid viscosity is reduced, but the risk of flow path wall detachment increases
Solution Approach 1:
The circulation energy generation element is positioned to act locally on the liquid in the circulation flow path without directly adjacent to the ejection orifice. This localized energy generation circulates liquid effectively while maintaining adequate distance from the ejection orifice to prevent flow path wall detachment
Solution Approach 2:
The liquid itself acts as an intermediary medium. The circulation energy generation element energizes the liquid in the circulation path, and this energized liquid then flows to reduce viscosity at the ejection orifice, achieving the desired effect without direct proximity between the energy generation element and the ejection orifice
3Productivity
If the ejection energy generation element is positioned close to the ejection orifice for efficient ejection, then ejection efficiency is improved, but heat accumulation increases
Solution Approach 1:
The energy generation functions are segmented into two separate elements: an ejection energy generation element positioned near the ejection orifice for efficient liquid ejection, and a circulation energy generation element positioned in the circulation flow path for viscosity control. This segmentation allows the ejection element to operate close to the orifice without excessive heat accumulation affecting the circulation system
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 design enhances the reliability and efficiency of liquid ejection heads by reducing the risk of flow path wall detachment, improving ejection efficiency, and minimizing heat accumulation, thus maintaining high performance over extended use.
Implementation Method 1
a circulation energy generation element which is arranged at a position, different from the position of the bubble generation chamber, to face the liquid circulation flow path and generates energy for circulating liquid in the liquid circulation flow path
Implementation Method 2
the substrate has an ejection energy generation element which is arranged to face the bubble generation chamber and generates energy for ejecting liquid, in the bubble generation chamber, from the liquid ejection orifice
Implementation Method 3
a liquid circulation flow path which is disposed between the ejection orifice forming member and the substrate, the liquid circulation flow path includes a bubble generation chamber facing the liquid ejection orifice
Data Source
AI summary
A liquid ejection head includes an ejection orifice forming member having a liquid ejection orifice and a substrate having a liquid flow path such that a liquid circulation flow path is formed between the ejection orifice forming member and the substrate. The liquid circulation flow path includes a bubble generation chamber facing the liquid ejection orifice and is branched from the liquid flow path so as to pass through the bubble generation chamber and join the liquid flow path. The substrate has an ejection energy generation element arranged to face the bubble generation chamber and a circulation energy generation element arranged at a different position to face the liquid circulation flow path. The gap between the ejection energy generation element and the ejection orifice forming member is different from the gap between the circulation energy generation element and the ejection orifice forming member.