Multiple-Path Printhead Design for Pressure-Wave Cancellation
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Solution Overview
Problem
Pressure waves escaping from jetting channels in printheads propagate along the manifold, causing jetting instability in individual channels.
Innovation Solution
Design printheads with multiple fluid paths between the manifold and jetting channels, ensuring a difference in path lengths to create a threshold time difference in pressure wave arrival at the manifold, leading to destructive interference and improved jetting consistency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a common fluid path (manifold) is used to convey print fluid to multiple jetting channels, then the device complexity is reduced and ease of manufacture is improved, but pressure waves escape along the manifold causing jetting instability
Solution Approach 1:
The patent divides the single common fluid path into multiple separate fluid paths, with each path containing isolation structures (such as isolation walls or isolation channels) that segment the flow paths. This segmentation prevents pressure waves from propagating along the manifold to affect other jetting channels, thereby resolving the jetting instability issue while maintaining a manufacturable design through systematic division of the fluid delivery system.
Solution Approach 2:
The patent introduces intermediary structures (isolation walls, isolation channels, or damping elements) within the fluid paths that act as mediators to absorb or block pressure wave propagation. These intermediary elements are positioned between the jetting channels and the manifold to prevent harmful pressure wave transmission, thus improving jetting stability without requiring complete redesign of the manifold system.
2Reliability
If multiple fluid paths with different lengths are designed to create threshold time difference for pressure wave arrival, then jetting consistency is improved through destructive interference, but the device complexity increases
Solution Approach 1:
The patent deliberately introduces asymmetric design elements into the fluid paths, such as varying the lengths of different fluid paths or creating asymmetric isolation structures. This asymmetry creates threshold time differences in pressure wave arrival at the manifold, enabling destructive interference that cancels pressure waves and improves jetting consistency. The asymmetric design is implemented in a controlled manner to achieve the desired wave interference effect while managing overall 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
The design results in improved jetting consistency and performance by canceling out pressure waves through out-of-phase interference, enhancing the stability of droplet ejection.
Implementation Method 1
pressure waves may escape from the jetting channels, and propagate along the manifold
Implementation Method 2
the pressure waves arriving at different times can at least partially cancel each other out within the manifold apparatus
Data Source
AI summary
Printheads and design of printheads. In one embodiment, a printhead comprises a plurality of jetting channels, and a manifold apparatus fluidly coupled to the jetting channels. For each jetting channel, the printhead includes a first fluid path between the jetting channel and the manifold apparatus, and a second fluid path between the jetting channel and the manifold apparatus. The jetting channel is configured to jet a print fluid via pressure waves generated in a pressure chamber of the jetting channel. Lengths of the first fluid path and the second fluid path are different by a threshold length so that an arrival time of the pressure waves at the manifold apparatus are different by a threshold time.