Liquid Discharge Nozzle Meniscus Control for Droplet Accuracy
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Solution Overview
Problem
The uneven inner surface pattern of nozzles in liquid discharge devices causes liquid to remain in recesses, leading to increased viscosity and sedimentation, which deviates the flight direction of droplets, resulting in quality degradation of recorded images.
Innovation Solution
A liquid discharge device configuration where the meniscus is maintained closer to the initial position before discharge, reducing exposure to air and sediment generation, combined with a driving pulse generator that adjusts frequency based on environmental conditions to minimize sediment formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the etching rate is reduced to smooth the uneven pattern on the nozzle inner wall, then the manufacturing precision is improved, but the productivity deteriorates due to increased number and time of processes
Solution Approach 1:
The patent applies preliminary anti-action by controlling the meniscus position to prevent sediment formation before it occurs. By maintaining the meniscus closer to the initial position before discharge, the liquid in recesses is less exposed to air, preventing viscosity increase and sediment formation that would otherwise require additional smoothing processes
Solution Approach 2:
The patent changes operational parameters (meniscus position control through timing of discharge operations) to achieve the effect of smoothing the nozzle inner wall without actually modifying the physical structure. This parameter change allows maintaining productivity while achieving the beneficial effect of reduced sedimentation
2Ease of operation
If the meniscus is allowed to move freely in the nozzle, then the liquid discharge operation is simpler, but the liquid remains in recesses causing viscosity increase and sedimentation
Solution Approach 1:
The patent implements feedback control by monitoring the meniscus position and adjusting the timing of discharge operations accordingly. The control mechanism determines whether to perform discharge based on meniscus position relative to the center position between initial position and maximum draw-in position, ensuring reliable droplet flight while maintaining operational simplicity
Solution Approach 2:
The patent applies preliminary action by controlling the meniscus position before discharge occurs. By ensuring the meniscus is at an appropriate position before discharge, the system prevents sediment formation in advance, maintaining reliability without complicating the discharge operation itself
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 configuration reduces sediment generation and maintains droplet direction accuracy, enhancing image quality and throughput by minimizing the impact of viscosity increases and sedimentation.
Implementation Method 1
a driver element that causes a pressure vibration of liquid in the liquid channel and causes the liquid to be discharged from the nozzle
Implementation Method 2
liquid in the recesses is exposed to outside air when the meniscus is drawn into the nozzle so that the viscosity of liquid gradually increases and a sediment of a solid component of the liquid is attached
Data Source
AI summary
A liquid discharge device includes a liquid discharge head that includes a nozzle from which liquid is discharged and a liquid channel communicating with the nozzle, and that discharges liquid from the nozzle. The nozzle has an inner wall surface having an uneven pattern including a recess where the inner diameter of the nozzle is increased and a projection where the inner diameter of the nozzle is smaller than that in the recess. In a case where ink is continuously discharged from an identical nozzle, at a time when a meniscus in the nozzle after previous discharge is located closer to an initial position before discharge than a center position between the initial position and a position at which the meniscus is most greatly drawn toward the liquid channel, subsequent discharge is performed.