Liquid Ejection Drive Signals for Residual Vibration Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-frequency discharge of low-viscosity liquid droplets in liquid ejecting apparatuses, such as inkjet printers, becomes unstable due to intense residual vibrations in the pressure chamber, necessitating wider discharge pulse intervals or slower potential changes, which hinders efficient operation.
Innovation Solution
A drive signal with multiple discharge pulses is employed, including a first contraction element, a maintaining element, and a re-contraction element for each pulse, with specific potential differences and durations to stabilize the pressure chamber volume, reducing residual vibrations and enabling high-frequency discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the interval between discharge pulses is narrowed to achieve high-frequency discharge, then productivity is improved, but discharge stability deteriorates due to intense residual vibrations in the pressure chamber
Solution Approach 1:
The drive signal is segmented into multiple discrete discharge pulses within one unit period, each pulse being carefully controlled to manage residual vibrations. By dividing the discharge process into separate pulses with specific timing and potential characteristics, the system achieves high-frequency discharge while maintaining stability through controlled vibration management between pulses
Solution Approach 2:
The drive signal employs periodic discharge pulses within a defined unit period, creating a rhythmic discharge pattern. This periodic action allows the system to operate at high frequencies while the regular timing and structure of the pulses help manage and control residual vibrations, ensuring stable discharge throughout the periodic cycle
2Reliability
If the rate of potential change is reduced to suppress residual vibration, then discharge stability is improved, but the efficiency of high-frequency discharge is hindered
Solution Approach 1:
The drive signal dynamically adjusts the potential characteristics of each discharge pulse, including the potential differences and timing, to optimize both stability and frequency. By making the drive signal adaptive and dynamic rather than static, the system can suppress residual vibrations while maintaining high discharge frequencies through optimized pulse characteristics
3Reliability
If wider intervals between discharge pulses are used to suppress residual vibration, then discharge stability is improved, but the interval for discharging droplets that combine during flight is lost
Solution Approach 1:
The system changes multiple parameters of the drive signal simultaneously, including pulse timing, potential differences, and duration, to achieve a balance where residual vibrations are suppressed while droplet combination remains effective. By coordinating changes in these parameters, the system maintains both stability and the ability to discharge droplets at intervals that allow for flight combination
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 drive signal stabilizes droplet discharge by minimizing residual vibrations, allowing for efficient and stable operation even with low-viscosity liquids, facilitating high-frequency ejection.
Implementation Method 1
a drive element that causes a pressure fluctuation in the liquid in the pressure chamber when a drive signal is supplied to the drive element
Data Source
AI summary
A liquid ejecting apparatus includes a discharge portion having a drive element that is drove with a drive signal. The drive signal includes a plurality of discharge pulses corresponding to a plurality of droplets that combine before landing on a medium. A first discharge pulse of the plurality of discharge pulses includes a first contraction element that changes a potential from a first potential to a second potential to contract a volume of a pressure chamber, a first contraction maintaining element, and a first re-contraction element that changes a potential from the second potential to a third potential to further contract the volume of the pressure chamber. A first potential difference from the first potential to the second potential of the first discharge pulse is equal to or greater than 20% and less than 50% of a second potential difference from the first potential to the third potential.