Liquid-Ejecting Head Bubble Discharge via Sub-Chamber Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inkjet printing systems face issues with bubbles remaining in the common liquid chamber, leading to turbulent ink flow and inadequate bubble discharge, especially when nozzle lengths are increased for higher printing speeds.
Innovation Solution
A liquid-ejecting head design featuring a recording element substrate with energy generating elements, supported by a first and second supply port system where the second supply port is smaller and positioned at the end of the common liquid chamber, allowing for improved ink flow and reduced bubble retention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the length of the nozzle row is increased to increase printing speed, then productivity is improved, but the ink flow becomes turbulent and bubble discharge is prevented
Solution Approach 1:
The common liquid chamber is divided into multiple sub-chambers, each supplying ink to a specific portion of the nozzle row. This segmentation allows independent control of ink flow to different nozzle sections, preventing turbulence while maintaining high printing speed. Each sub-chamber can be optimized for its specific function without affecting the entire system.
Solution Approach 2:
Different portions of the nozzle row are supplied with ink from separate sub-chambers with locally optimized flow characteristics. The liquid chamber shape and flow passage dimensions are customized for each sub-chamber to ensure laminar flow and effective bubble discharge in that specific region, rather than using a uniform structure for the entire nozzle row.
2Reliability
If a common liquid chamber is formed to prevent bubbles from staying, then bubble discharge is improved, but flow velocity difference between nozzles increases
Solution Approach 1:
By dividing the common liquid chamber into multiple sub-chambers, each sub-chamber can be shaped to optimize bubble discharge for its specific nozzle portion while maintaining uniform flow velocities. The segmentation allows independent optimization of flow characteristics for each section without compromising overall velocity uniformity.
Solution Approach 2:
Each sub-chamber is designed with locally optimized geometry to ensure uniform flow velocity to its corresponding nozzle portion while effectively discharging bubbles. The liquid chamber shape, flow passage dimensions, and positioning are customized for each sub-chamber to achieve both bubble discharge and velocity uniformity in that specific region.
3Reliability
If the liquid chamber cross-section is increased to improve bubble discharge, then bubble discharge is improved, but device complexity increases
Solution Approach 1:
Instead of increasing the cross-section of a single large liquid chamber, the system uses multiple smaller sub-chambers. Each sub-chamber has a manageable cross-section that facilitates bubble discharge while the overall system capacity is maintained through the collective volume of multiple chambers. This segmentation reduces structural complexity compared to a single large chamber design.
Solution Approach 2:
The invention transitions from a single large liquid chamber to multiple smaller chambers arranged in a distributed pattern. This dimensional redistribution allows bubble discharge to be improved through multiple pathways without requiring a single chamber with excessively large cross-section, thereby reducing structural complexity while maintaining functionality.
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 enhances bubble discharge and recovery properties, ensuring efficient ink ejection and preventing bubble accumulation, even at increased printing speeds.
Implementation Method 1
a recording element substrate provided with an energy generating element that generates energy used to eject a liquid from a discharge port
Data Source
AI summary
A liquid-ejecting head includes a recording element substrate that includes an energy generating element generating energy for ejecting a liquid from a discharge port, a supporting member that supports the recording element substrate and has a liquid chamber supplying the liquid to the recording element substrate, a first supply port formed in one surface thereof, communicating with the liquid chamber, and having fluid communication with the recording element substrate, a second supply port being smaller than the first supply port, formed in a surface opposite the one surface at a position corresponding to a longitudinal end side of the first supply port, and communicating with the liquid chamber, and a flow passage forming member that supplies the liquid to the second supply port. The cross-section of the liquid chamber in a direction extending from the opposite toward one surfaces gradually increases in part of the extending direction.