Inkjet Ejection Head Layout for Compact Ink Circulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid ejection heads face challenges in maintaining circulation efficiency and flow amount while minimizing the size of the substrate and circulation flow path, as well as preventing ink evaporation and concentration at the ejection ports, which can lead to instability and increased viscosity.
Innovation Solution
The liquid ejection head incorporates second energy generation elements in individual flow paths to circulate ink, utilizing electrothermal conversion elements to form circulation flows that reduce ink concentration and evaporation, thereby stabilizing ejection and maintaining circulation efficiency with a shortened flow path and reduced substrate size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the circulation flow path is extended to optimize circulation efficiency, then the circulation flow amount increases, but the substrate size and head size increase
Solution Approach 1:
The circulation flow path is configured to extend in the width direction (perpendicular to the ejection port array direction) rather than only in the length direction. This dimensional change allows the flow path to achieve sufficient circulation efficiency while keeping the overall substrate area compact, resolving the contradiction between circulation flow amount and substrate size.
2Area of stationary object
If the circulation flow path is shortened to reduce substrate size, then the substrate size decreases, but the circulation efficiency of the flowing energy generation element degrades
Solution Approach 1:
By extending the circulation flow path in the width direction (perpendicular to the ejection port array), the patent achieves sufficient circulation path length for efficient energy generation element operation without increasing the overall substrate area, thus maintaining circulation efficiency while reducing substrate size.
Solution Approach 2:
The circulation flow path is specifically configured to have different characteristics in different regions: it extends in the width direction where space is available, while maintaining compact dimensions in the length direction. This localized optimization allows efficient circulation without excessive substrate size.
3Productivity
If the circulation flow path is extended to maintain circulation efficiency, then the circulation flow amount increases, but the ink evaporation and concentration at ejection ports worsen
Solution Approach 1:
The circulation flow path extends in the width direction to achieve sufficient circulation flow amount for preventing ink evaporation and concentration at the ejection ports, while maintaining a compact overall substrate area. This dimensional configuration ensures adequate ink flow to keep ejection ports湿润 without requiring excessive substrate area.
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 maintains stable ink ejection by reducing ink concentration and evaporation, ensuring efficient circulation flow and minimizing substrate size, while also minimizing ink discarding and improving throughput.
Implementation Method 1
second energy generation elements (circulation heaters) different from a first energy generation element (ejection heater) for ejecting the liquid to the circulation flow path
Data Source
Figure 1A~1B
Figure 2A~2D
Figure 3A~3D
AI summary
A liquid ejection head (1) including: individual ejection units that include ejection ports (11), pressure chambers (12), first energy generation elements (14) that are provided in the pressure chambers (12) and generate heat energy, and second energy generation elements (24) that are provided in individual flow paths and generate heat energy; and a common flow path (38) that supplies a liquid to the individual flow paths, a direction in which the ejection ports are aligned perpendicularly intersecting an extending direction of the individual flow paths, the liquid ejection head (1) being provided with a structure in which a flow resistance between the first energy generation elements (14) and the second energy generation elements (24) is increased is used.