Liquid Ejection Head Stepped Supply Paths
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid ejection heads face challenges in achieving high-speed printing while reducing the number of recovering operations, as they struggle to configure liquid chambers that are narrow in the scanning direction and large in the height direction due to limitations in the draft angle and capillary force of the groove structure.
Innovation Solution
The liquid ejection head incorporates a liquid chamber with multiple supply paths of varying widths, where the path at a higher vertical position has a stronger capillary force, allowing for efficient ink supply and air bubble retention, and is formed by molding with strategically placed draft angles to accommodate increased height without narrowing the ejection port side groove excessively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the liquid chamber is made large in the height direction to increase capacity, then the number of recovering operations is reduced, but the manufacturing precision deteriorates due to draft angle requirements in molded structures
Solution Approach 1:
The liquid chamber groove structure transitions from a two-dimensional planar groove to a three-dimensional stepped structure with multiple levels. This dimensional change allows the groove to accommodate draft angles while maintaining sufficient width at the ejection port side, resolving the conflict between increasing chamber height and maintaining groove precision.
Solution Approach 2:
The liquid chamber groove structure is segmented into multiple stepped levels rather than being a single continuous groove. This segmentation allows different portions of the groove to have different widths, with the upper steps providing sufficient width for capillary action while the lower steps accommodate the draft angle requirements for molding.
2Productivity
If the groove width is narrowed to increase capillary force, then ink supply efficiency is improved, but the manufacturing precision deteriorates due to difficulty in providing draft angles
Solution Approach 1:
Different portions of the groove structure have different widths tailored to their specific functions. The upper portion near the ejection port has a narrower width to provide strong capillary force for ink supply, while the lower portion has a wider width to accommodate draft angles for molding, thus resolving the contradiction between ink supply efficiency and manufacturability.
3Area of stationary object
If the number of ejection ports is increased to achieve large size printing, then printing coverage is improved, but the amount of ink to be discharged in recovering operation increases
Solution Approach 1:
The liquid chamber is designed with sufficient capacity to accumulate air bubbles generated during printing operations before recovering operations are performed. This preliminary accumulation capability allows the system to handle multiple ejection ports and their associated air bubble generation without proportionally increasing ink discharge during recovery, as bubbles can be stored in the chamber.
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 enables high-speed printing and reduces the number of recovering operations by allowing for a larger liquid chamber capacity in the height direction, thereby minimizing ink discharge and air bubble accumulation, while maintaining efficient ink supply and printing performance.
Implementation Method 1
the supply path which is located at a higher position in a vertical direction in a posture taken in use has a stronger capillary force
Data Source
AI summary
Provided are a liquid ejection head, a liquid ejection apparatus and a manufacturing method for the liquid ejection head which make it possible to achieve both of high-speed printing and a reduction in number of recovering operations. A liquid chamber which is formed in a part of a flow passage that guides liquid to an ejection element substrate includes plural supply paths which are able to supply the liquid by capillarity, are connected together and are different from one another in width.