Multi-Inlet Inkjet Printhead Resolves Refill Speed and Backflow Trade-off
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional inkjet printheads face challenges with impedance matching between ink chamber inlets and nozzles, leading to poor print quality, nozzle starvation, and hydraulic cross-talk due to limited design flexibility and contamination risks, especially at higher ejection frequencies.
Innovation Solution
The implementation of multiple small ink inlets within the ink chamber, allowing for varied shapes and orientations, which enhances fluid flow, reduces backflow, and improves impedance matching, enabling higher ejection frequencies and better print quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a large ink inlet opening is used, then the refill speed of the ink chamber is improved, but the back flow of ink into the ink supply channel increases
Solution Approach 1:
The single large ink inlet is divided into multiple smaller inlets. This segmentation allows the chamber to refill effectively through collective flow from multiple small openings while each individual small inlet maintains high impedance to prevent backflow during ejection, thus resolving the contradiction between refill speed and energy loss.
2Speed
If a large ink inlet opening is used, then the refill speed of the ink chamber is improved, but hydraulic cross-talk in adjacent ink chambers increases
Solution Approach 1:
Dividing the inlet into multiple small openings isolates the flow paths between adjacent chambers. Each small inlet acts as an independent flow channel with high impedance, preventing pressure oscillations from propagating to neighboring chambers while collectively maintaining adequate refill performance.
3Reliability
If the ink inlet radius is matched to the nozzle radius, then the impedance match is improved, but the design flexibility of the chamber shape is reduced
Solution Approach 1:
The inlet structure is segmented into multiple small inlets that can be strategically positioned around the chamber. This allows the chamber to maintain optimal impedance matching characteristics while enabling greater design flexibility in chamber geometry, as the inlets can be placed at various locations without requiring a single large opening that constrains shape design.
Solution Approach 2:
Different regions of the chamber can have different inlet configurations tailored to local requirements. Each small inlet can be positioned and sized optimally for its specific location, allowing the overall chamber shape to be more flexible while maintaining good impedance matching at each inlet-nozzle pair.
4Loss of energy
If multiple small ink inlets are used, then the back flow and cross-talk are reduced, but the manufacturing complexity increases
Solution Approach 1:
The mechanical fabrication of multiple small inlets is replaced by direct laser writing or laser drilling methods. This substitution simplifies manufacturing by enabling precise creation of multiple small inlet openings directly in the printhead structure without requiring complex multi-step mechanical machining or assembly processes.
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 multi-inlet design improves inkjet printhead performance by reducing backflow and cross-talk, allowing for increased ejection frequency and maintaining drop ejection energy, resulting in improved print quality and flexibility in chamber shapes.
Implementation Method 1
A piezoelectric inkjet printer uses a piezoelectric material actuator on a wall of an ink-filled chamber to generate a pressure pulse that forces a drop of ink out of the nozzle
Implementation Method 2
A thermal bubble inkjet printer uses a heating element actuator in an ink-filled chamber to vaporize ink and create a bubble that forces an ink drop out of a nozzle
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A fluid ejection device includes a chamber, at least one fluid supply channel, and more than two fluid inlets disposed between the fluid channel and the chamber. An inkjet printing system includes a fluid ejection device having a chamber disposed along fluid supply channels within the fluid ejection device, where a first channel is disposed along a first side of the chamber and a second channel is disposed along a second side of the chamber. The chamber includes multiple fluid inlets, where a first plurality of fluid inlets is disposed between the chamber and the first channel and a second plurality of fluid inlets is disposed between the chamber and the second channel.