Ink-jet Head Meniscus Stability via Dynamic Non-ejection Pulses
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Solution Overview
Problem
Conventional ink-jet devices face instability in ejecting large droplets due to meniscus position and vibration changes during non-ejection periods, leading to potential ejection errors and droplet bending, which existing solutions fail to fully address.
Innovation Solution
The ink-jet recording device employs a dynamic non-ejection drive pulse voltage that maintains meniscus stability by applying a series of non-ejection drive pulses with specific voltage and pulse width conditions, ensuring the meniscus behavior mimics the ejection period, thus preventing instability and ensuring consistent droplet ejection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a non-ejection drive voltage is applied to move the meniscus outside the non-ejection nozzle, then foreign matter adhesion is prevented, but the meniscus becomes static and unstable during subsequent ejection
Solution Approach 1:
The patent applies a dynamic non-ejection drive voltage that varies over time during the non-ejection period, rather than a static voltage. This dynamic voltage profile maintains the meniscus in a stable, movable state that prevents foreign matter adhesion while ensuring the meniscus is properly positioned and stable for the next ejection event. The voltage changes in a controlled manner to balance meniscus stability with ejection readiness.
Solution Approach 2:
The patent employs periodic non-ejection drive pulses during the non-ejection period to maintain meniscus stability. These periodic actions prevent the meniscus from becoming static and ensure it remains in a controlled state that prevents foreign matter adhesion while preparing for the next ejection. The periodic voltage application creates a rhythm that stabilizes the meniscus without causing instability during subsequent ejection.
2Quantity of substance
If multi-drive signals with multiple drive pulses are used to eject large droplets, then droplet size is increased, but meniscus instability causes non-ejection and flying bending
Solution Approach 1:
The patent applies a non-ejection drive voltage during the non-ejection period to preliminarily position and stabilize the meniscus before the ejection event. This preliminary action ensures that when multiple drive pulses are applied for large droplet ejection, the meniscus is already in an optimal, stable state, preventing non-ejection and flying bending issues. The meniscus is prepared in advance to handle the demands of large droplet ejection.
Solution Approach 2:
The patent changes the voltage parameters during the non-ejection period to optimize meniscus stability. By adjusting the non-ejection drive voltage parameters (amplitude, duration, waveform), the meniscus is maintained in a state that supports stable ejection of large droplets. The parameter changes ensure the meniscus can accommodate the multiple drive pulses required for large droplet ejection without becoming unstable.
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 allows for stable ejection of large droplets by maintaining meniscus stability during non-ejection periods, preventing droplet bending and ensuring consistent ink deposition, as demonstrated by increased droplet velocity and reduced non-ejection occurrences.
Implementation Method 1
a piezoelectric element that deforms an ink channel (pressure chamber) supplying ink to the nozzle and generates pressure fluctuation to propel the ink
Implementation Method 2
vibrates the ink meniscus to eject the ink droplet
Data Source
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AI summary
Provided is an ink-jet recording device in which a head driving unit for driving a recording operation of an ink-jet head is configured to be able to apply a discharge driving pulse Pa for causing an ink to be discharged from a nozzle, and a non-discharge driving pulse Pb for moving a meniscus formed in the nozzle without causing the ink to be discharged from the nozzle. Furthermore, the head driving unit carries out: during an ink discharge period for forming one dot during the recording operation, discharge driving in which the discharge driving pulse is applied a number of times up to a number n of gradations with respect to one dot to be landed on a recording medium, wherein the dot diameter is changed according to the number of times; and, during an ink non-discharge period during the recording operation, non-discharge driving in which the non-discharge driving pulse is applied m times which is equal to or greater than the number n of gradations for a period equal to the ink discharge period for forming the one dot, to move the meniscus.