Piezoelectric Inkjet Actuator With Nested Descender
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Solution Overview
Problem
Ink jet printing systems face limitations in fluid ejection rate and efficiency due to single fluid flow pathways, which restrict the resonance frequency and maximum flow rate of printheads, especially when lower voltages are applied.
Innovation Solution
The design incorporates a pumping chamber with multiple fluid flow pathways, including a recirculation pathway, and a piezoelectric actuator to increase resonance frequency, allowing for higher fluid ejection rates and efficient operation at lower voltages by reducing fluid travel distance and impedance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single fluid flow pathway is used in the printhead, then the device complexity is reduced, but the resonance frequency and maximum flow rate are restricted
Solution Approach 1:
The fluid delivery system is segmented into multiple parallel flow pathways (first fluid flow pathway and second fluid flow pathway) that transport fluid from different reservoirs to the pumping chamber. This segmentation allows independent optimization of each pathway and enables higher overall flow rates by processing multiple fluid streams simultaneously, directly resolving the contradiction between productivity and device complexity.
Solution Approach 2:
The invention transitions from a single-dimensional fluid flow path to a multi-dimensional configuration by introducing parallel pathways and a recirculation loop. The descender structure creates vertical separation between the pumping chamber and nozzle, while multiple horizontal pathways provide additional flow dimensions. This dimensional expansion increases the resonance frequency and maximum flow rate without proportionally increasing complexity.
2Productivity
If the fluid travel distance is reduced to increase resonance frequency, then the productivity is improved, but the device complexity increases due to multiple pathways
Solution Approach 1:
The descender structure is positioned within the pumping chamber, creating a nested configuration where the descender (containing the nozzle) is embedded in the pumping chamber volume. This nesting reduces the fluid travel distance from the pumping chamber to the nozzle by placing the nozzle directly within the chamber's fluid flow zone, thereby increasing resonance frequency while minimizing the added structural complexity.
3Productivity
If multiple reservoirs are connected to increase fluid supply, then the productivity is improved, but the device complexity increases
Solution Approach 1:
Multiple reservoirs (first reservoir and second reservoir) are merged through parallel fluid flow pathways that converge at the pumping chamber. This merging allows simultaneous fluid supply from multiple sources, increasing the overall fluid supply rate and productivity. The parallel pathway design enables independent reservoir management while achieving combined flow output, resolving the contradiction between productivity improvement and device complexity.
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 enhances the frequency at which fluid can be ejected from the printhead, achieving a higher maximum flow rate and enabling efficient operation with lower voltage inputs, thereby improving the overall performance of ink jet printing systems.
Implementation Method 1
a piezoelectric actuator operable to pump fluid through the pumping chamber toward a nozzle
Implementation Method 2
a configuration of the flow pathways can increase a resonance frequency of the flow pathways in the printhead, thereby increasing the frequency at which the pumping chamber can be actuated to eject fluid from the printhead
Data Source
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AI summary
An apparatus includes a pumping chamber and a descender having a first end and a second end. The first end of the descender is centered relative to the pumping chamber and defines a first fluid flow pathway between the pumping chamber and a nozzle disposed at the second end of the descender. One or more second fluid flow pathways are defined at the second end of the descender.