Liquid Ejection Head With Dual Chambers for Bubble Discharge
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Solution Overview
Problem
Bubbles entering liquid ejection heads during replacement or maintenance can cause insufficient pressure for liquid ejection and potential leakage due to expansion, affecting the performance and stability of the apparatus.
Innovation Solution
A liquid ejection head design featuring a first and second depressurization chamber with gas-permeable membranes, allowing for controlled pressure adjustment and bubble discharge through a depressurization operation, including a unidirectional pump and on-off valves to manage pressure and gas flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a filter chamber with a non-permeable filter is used to trap bubbles, then bubbles in the liquid supply channel can be trapped, but bubbles formed in the pressure chambers cannot be collected
Solution Approach 1:
The patent divides the bubble collection function into two separate chambers: a first depressurization chamber for collecting bubbles from the liquid supply channel (using a non-permeable filter), and a second depressurization chamber for collecting bubbles from the pressure chambers (using a permeable membrane). This segmentation allows each chamber to specialize in collecting bubbles from different locations, solving the limitation of the single-chamber design.
Solution Approach 2:
The patent introduces a permeable membrane as an intermediary between the pressure chamber and the second depressurization chamber. This membrane allows bubbles to pass through while maintaining pressure separation, enabling bubble collection from the pressure chamber without compromising the pressure needed for liquid ejection.
2Ease of operation
If the filter chamber is located vertically above the pressure chambers, then liquid can be supplied to the pressure chambers, but bubbles formed in the pressure chambers cannot be effectively collected
Solution Approach 1:
The patent transitions from a vertical arrangement (filter chamber above pressure chambers) to a horizontal arrangement where the first and second depressurization chambers are positioned adjacent to different parts of the pressure chamber system. This dimensional change allows bubbles to be collected from multiple locations simultaneously without interfering with liquid supply.
Solution Approach 2:
The patent embeds the depressurization chambers within the existing pressure chamber structure, positioning them adjacent to the pressure chambers rather than separate. This nested configuration allows the bubble collection system to be integrated into the liquid supply pathway without disrupting the vertical liquid flow from the liquid supply channel.
3Device complexity
If a single depressurization chamber is used, then the structure is simple, but bubbles from different locations cannot be effectively collected and discharged
Solution Approach 1:
The patent segments the single depressurization chamber into two separate chambers with different functions: the first depressurization chamber handles bubbles from the liquid supply channel, while the second depressurization chamber handles bubbles from the pressure chambers. Each chamber has its own permeable membrane and discharge pathway, enabling effective bubble removal from multiple sources.
Solution Approach 2:
The patent applies different properties to different parts of the depressurization system: the first depressurization chamber uses a non-permeable filter for bubble trapping from the liquid supply channel, while the second depressurization chamber uses a permeable membrane for bubble collection from the pressure chambers. This local differentiation optimizes bubble collection effectiveness for each specific location.
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
Effectively suppresses bubble effects by reliably discharging them, ensuring stable liquid ejection performance and preventing leakage, even under varying environmental conditions.
Implementation Method 1
a first depressurization chamber adjoining the first liquid reservoir part with a first gas permeable membrane therebetween
Implementation Method 2
a unidirectional pump configured to generate a pressure difference between the liquid reservoir part and the pressure chamber
Implementation Method 3
an ejection port for ejecting a liquid; a pressure chamber provided with an energy generation element which generates an energy for ejecting the liquid from the ejection port
Data Source
AI summary
A liquid ejection head includes: an ejection port for ejecting the liquid; a pressure chamber provided with an energy generation element which generates an energy for ejecting the liquid from the ejection port; a first liquid reservoir part communicating with one end of the pressure chamber and capable of holding the liquid to be supplied to the pressure chamber; a first depressurization chamber adjoining the first liquid reservoir part with a first gas permeable membrane therebetween and configured such that an inside of the first depressurization chamber is depressurizable; a second liquid reservoir part communicating with another end of the pressure chamber and capable of holding the liquid collected from the pressure chamber; and a second depressurization chamber adjoining the second liquid reservoir part with a second gas permeable membrane therebetween and configured such that an inside of the second depressurization chamber is depressurizable.