Liquid Ejecting Apparatus Air Bubble Discharge via Circulation Path
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Solution Overview
Problem
Existing liquid ejecting apparatuses face challenges in efficiently filling and maintaining the liquid supply, particularly in preventing liquid thickening and air bubble accumulation, which can lead to reduced printing quality and apparatus performance.
Innovation Solution
The apparatus incorporates a supply flow path and a circulation flow path with pressure regulating valves and a circulation pump, along with an opening mechanism to forcibly open the pressure regulating valves, ensuring continuous liquid circulation and effective air bubble discharge, utilizing a buffer to capture air bubbles and maintain optimal pressure for efficient ink ejection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If liquid is supplied from the liquid containing chamber to the liquid ejection head and circulation path, then the liquid ejection head and flow paths are filled, but air bubbles accumulate and liquid thickens
Solution Approach 1:
The patent extracts air bubbles from the liquid circulation system using a separation mechanism. The circulation path is designed with a separation portion where air bubbles are separated from the liquid flow and discharged separately, preventing air bubble accumulation in the liquid ejection head and maintaining printing quality while enabling easy liquid filling.
Solution Approach 2:
The circulation path is segmented into distinct functional portions: a liquid circulation path for ink flow and an air bubble discharge path for air removal. This segmentation allows independent optimization of liquid filling and air bubble removal, solving the contradiction between ease of filling and prevention of air bubble accumulation.
2Productivity
If pressure is increased to speed up liquid circulation, then filling efficiency improves, but liquid may be forced out through unintended paths
Solution Approach 1:
The patent employs a dynamic pressure control mechanism with adjustable pressure regulation means. The pressure in the circulation path can be dynamically adjusted based on operational requirements - increased during filling operations to improve efficiency, and controlled at appropriate levels during normal operation to prevent unintended liquid discharge while maintaining circulation.
3Reliability
If circulation path is designed to prevent air bubble accumulation, then printing quality is maintained, but device complexity increases
Solution Approach 1:
The patent merges the liquid circulation function and air bubble removal function into a single integrated circulation path system. The circulation path includes both a liquid circulation portion and an air bubble discharge portion that work together, eliminating the need for separate complex air removal systems while maintaining printing quality.
Solution Approach 2:
The circulation path is designed with self-venting characteristics where air bubbles naturally rise and are discharged through the air bubble discharge portion during normal liquid circulation. The system automatically removes air bubbles without requiring external intervention or complex additional mechanisms, maintaining simplicity while ensuring printing quality.
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 solution enables easy filling of the liquid ejecting head and flow paths, reduces liquid thickening, and effectively discharges air bubbles, ensuring consistent and high-quality printing performance by maintaining optimal pressure and circulation flow rates.
Implementation Method 1
a circulation pump configured to circulate liquid via the circulation path
Implementation Method 2
a first pressure regulating valve configured to adjust pressure in the supply flow path, and a second pressure regulating valve configured to adjust pressure in the circulation path
Implementation Method 3
utilizing a buffer to capture air bubbles
Data Source
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AI summary
A liquid ejecting apparatus includes: a liquid ejecting head including a liquid chamber which communicates with a nozzle; a supply flow path having a first end connected to a liquid supply source and a second end connected to the liquid chamber; a first circulation flow path having a first end connected to the liquid chamber and a second end connected to a first connecting portion in the supply flow path; a supply pump provided in the supply flow path and configured to supply the liquid from the liquid supply source in a downstream direction; a first pressure regulating valve provided between the first connecting portion and the liquid ejecting head in the supply flow path; a second pressure regulating valve provided in the first circulation flow path; a circulation pump provided in the first circulation flow path and configured to circulate the liquid in a downstream direction; and an opening mechanism configured to forcibly open the first pressure regulating valve.