Dual-Head Droplet Ejection Speed Control for Mist Suppression
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Solution Overview
Problem
Existing droplet ejection apparatuses face issues with mist generation and reduced landing accuracy due to the adhesion of one liquid to the nozzles of another head, leading to ejection failures and increased apparatus size and cost.
Innovation Solution
The apparatus includes a first head for ejecting a first liquid and a second head for aggregating the first liquid, with the ejection speed of the second head controlled to be lower than that of the first head, reducing mist generation and maintaining landing accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the ejection speed of the second head is reduced to suppress mist generation, then mist generation is suppressed, but the landing accuracy of the first liquid is reduced
Solution Approach 1:
The patent applies parameter changes by differentiating the ejection speeds of the two heads. The second head (aggregation liquid) operates at a lower ejection speed to minimize mist generation, while the first head (target liquid) maintains a higher ejection speed to ensure accurate landing. This differential parameter setting resolves the contradiction by optimizing each head's performance for its specific function.
2Object-generated harmful factors
If an airflow generating section is provided between the first head and second head, then mist adhesion to nozzles is prevented, but the apparatus size and cost are increased
Solution Approach 1:
The patent extracts the airflow generating section from the system, replacing it with a velocity-based control approach. By removing this additional component and instead using differential ejection speed control, the patent prevents mist adhesion without increasing apparatus complexity, size, or cost.
Solution Approach 2:
The system uses the ejection velocities themselves to prevent mist adhesion, rather than requiring an external airflow generation system. The controlled ejection process inherently manages mist suppression through proper velocity management of the aggregation liquid.
3Object-generated harmful factors
If the ejection speed of the second head is reduced, then mist generation is suppressed, but the influence of air resistance increases
Solution Approach 1:
The patent manages the air resistance effect through parameter optimization. By setting the second head's ejection speed to a specific lower range (0.5-5.0 m/s), the system balances mist suppression with acceptable air resistance influence. The differential velocity approach allows the first head to compensate for any positioning adjustments needed.
Data Source
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AI summary
Provided is a droplet ejection apparatus that includes a droplet ejection section which ejects droplets from nozzles. The droplet ejection section includes a first head for ejecting a first liquid and a second head for ejecting a second liquid for aggregation of the first liquid. An ejection speed of the second head is lower than an ejection speed of the first head.