Selective Kogation Removal in Liquid Ejection Heads
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for cleaning liquid ejection heads fail to selectively remove kogation from individual liquid chambers, leading to uneven ejection characteristics due to uniform electrochemical reactions across all chambers, despite varying conditions of kogation deposition.
Innovation Solution
A method involving a liquid ejection head with a coating layer that undergoes an electrochemical reaction, where a voltage is applied to selectively elute the coating layer into the liquid, allowing for controlled temperature changes in each chamber to remove kogation based on specific deposition conditions, thereby addressing the uneven kogation distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If uniform electrochemical reaction is applied to all liquid chambers, then cleaning process is simplified, but kogation removal effectiveness decreases due to uneven deposition conditions
Solution Approach 1:
The patent applies local quality by enabling independent temperature control for each liquid chamber. The temperature control unit adjusts temperatures selectively based on the specific kogation deposition conditions of each chamber, allowing tailored electrochemical reactions that match local requirements rather than applying uniform treatment to all chambers.
Solution Approach 2:
The patent segments the cleaning process by dividing the plurality of liquid chambers into groups or individuals that require different temperature conditions. The temperature control unit can independently adjust temperatures for different chambers or groups, enabling customized electrochemical reactions for each segment based on their specific kogation characteristics.
2Device complexity
If temperature is uniformly maintained across all liquid chambers, then system control is simplified, but ejection characteristics deteriorate due to varying kogation deposition
Solution Approach 1:
The patent implements local quality in temperature control by allowing each liquid chamber to operate at its optimal temperature based on kogation deposition levels. Chambers with heavier deposition can be maintained at higher temperatures to prevent further accumulation, while chambers with lighter deposition operate at lower temperatures, optimizing ejection characteristics for each local condition.
Solution Approach 2:
The patent applies dynamics by enabling real-time adjustment of temperatures in different liquid chambers based on their operational conditions and kogation deposition states. The temperature control unit dynamically modifies temperature settings to match changing requirements, ensuring optimal ejection performance under varying operating conditions.
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 approach enables selective and effective removal of kogation, stabilizing foaming and maintaining optimal ejection characteristics by controlling temperature and electrochemical reactions in each liquid chamber, improving print quality and ejection speed.
Implementation Method 1
applying a voltage to the coating layer to provoke an electrochemical reaction between the coating layer and the liquid
Implementation Method 2
the heat generating resistive element is made to generate heat, the liquid is heated suddenly and foams in a liquid contact area
Implementation Method 3
the liquid is heated suddenly and foams in a liquid contact area (i.e., a thermal action portion) located above the heat generating resistive element. Foaming produces pressure with which the liquid is ejected from ejection ports
Data Source
AI summary
A method for cleaning a liquid ejection head which includes applying a voltage to a coating layer of the liquid ejection head to cause the coating layer to be eluted in a liquid so that kogation deposited on a coating layer is removed. When removing kogation deposited on the coating layer, temperatures of the liquids in the liquid chambers are selectively changed among a plurality of liquid chambers.