Liquid Ejecting Apparatus Nozzle Maintenance via Mixed Fluid Droplets
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Solution Overview
Problem
The efficiency of maintenance for liquid ejecting apparatuses, such as printers, is poor due to the variability in nozzle states, leading to inconsistent ejection capacity and clogging issues, as the introduction of cleaning droplets can collapse the meniscus within nozzles and affect printing performance.
Innovation Solution
A liquid ejecting apparatus with a maintenance device that includes a fluid ejecting device capable of ejecting a mixed fluid of air and a second liquid, which is designed to resolve clogging by gently impacting hardened ink within nozzles without collapsing the meniscus, using small droplets with high kinetic energy to dislodge blockages while preventing fluid entry into the nozzle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If droplets of cleaning agent are vigorously introduced to resolve nozzle clogging, then clogging is removed, but the meniscus inside the nozzle collapses and ejection capacity is lowered
Solution Approach 1:
The cleaning process is segmented into two distinct phases: first, a gas stream (air or inert gas) is introduced to remove clogging without affecting the meniscus; second, if necessary, a small amount of cleaning liquid is applied. This segmentation allows the harmful effect (meniscus collapse) to be avoided by separating the clogging removal function from the cleaning function.
Solution Approach 2:
A gas stream is used as an intermediary substance to remove clogging from the nozzle. The gas acts as a mediator that can dislodge hardened ink and debris without directly contacting the meniscus in a way that would collapse it, thereby protecting the meniscus while still achieving clogging removal.
2Reliability
If cleaning maintenance is performed on nozzles, then clogging is resolved, but the results vary according to nozzle state leading to poor maintenance efficiency
Solution Approach 1:
The system incorporates sensors that automatically detect the state of each nozzle (clogged, partially clogged, or normal) and adjust the cleaning process accordingly. This self-service capability eliminates the need for manual assessment of nozzle states and applies the appropriate cleaning intensity automatically, ensuring consistent results across different nozzle conditions.
Solution Approach 2:
The cleaning parameters (gas flow rate, liquid cleaning agent application, duration) are dynamically changed based on the detected nozzle state. For lightly clogged nozzles, gentle cleaning is applied; for heavily clogged nozzles, more intensive cleaning is used. This parameter adaptation ensures optimal maintenance effectiveness while avoiding unnecessary aggressive cleaning that could damage the meniscus.
3Reliability
If cleaning liquid is applied to nozzles, then clogging is removed, but liquid enters the nozzle and disrupts the meniscus affecting printing performance
Solution Approach 1:
The system uses pneumatic pressure (gas flow) as the primary cleaning mechanism. A controlled stream of gas is directed into the nozzle to dislodge clogging. The gas flow rate and pressure are precisely controlled to be sufficient for clogging removal but insufficient to force liquid cleaning agents into the nozzle and disrupt the meniscus.
Solution Approach 2:
Instead of applying full-strength liquid cleaning agents directly to the nozzle, the system uses a partial action approach: a small amount of cleaning liquid is applied only if gas cleaning is insufficient, and even then, the liquid is applied in a controlled manner that prevents meniscus disruption. The gas cleaning provides the necessary cleaning action without the harmful effects of liquid intrusion.
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 apparatus effectively maintains nozzle performance by resolving clogging without disrupting the meniscus, ensuring consistent ink ejection and extending the lifespan of the nozzles, thereby improving printing efficiency and reliability.
Implementation Method 1
ejects small droplets of a cleaning liquid with a high kinetic energy
Implementation Method 2
small droplets with high kinetic energy to dislodge blockages
Implementation Method 3
capable of ejecting a mixed fluid of air and a second liquid
Data Source
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AI summary
A liquid ejecting apparatus includes a liquid ejecting unit having nozzles able to eject a first liquid to a medium; and a fluid ejecting device having ejection ports able to eject a fluid including a second liquid to the liquid ejecting unit, in which the fluid ejecting device performs, as a maintenance operation of the liquid ejecting unit, a first fluid ejection of ejecting a fluid including small droplets of the second liquid that are smaller than a nozzle opening to an opening region in which the nozzles of the liquid ejecting unit open, and a second fluid ejection of ejecting a fluid including droplets of the second liquid in which the smallest droplets are larger than the small droplets to the liquid ejecting unit.