Liquid Ejecting Apparatus Pulse Timing for Stable Droplet Placement
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Solution Overview
Problem
Existing liquid ejecting apparatuses face challenges in stabilizing ink ejection at high speeds due to insufficient time for damping nozzle vibrations, leading to unstable ink droplet placement when reducing the time interval between ejection pulses.
Innovation Solution
A drive signal generator produces a first common drive signal with specific ejection pulses that include filling, ejection, and damping elements, ensuring a sufficient time period for pressure chamber stabilization, allowing for stable ink droplet formation and reduced residual vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the time interval between ejection pulses is reduced to increase ejection speed, then productivity is improved, but the remaining vibration of ink in the nozzle cannot be sufficiently damped, leading to deterioration of ejection stability
Solution Approach 1:
The drive signal uses periodic ejection pulses with specifically controlled intervals. By setting the time interval between pulses to appropriate values, the system achieves stable ink ejection at high speeds while allowing sufficient time for vibration damping between pulses, thus resolving the contradiction between productivity and reliability
Solution Approach 2:
The invention optimizes the time interval parameter between ejection pulses to balance speed and stability. By carefully selecting this parameter, the system can operate at high ejection speeds while ensuring that residual vibrations are sufficiently damped before the next ejection, thereby maintaining ejection stability
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 solution enables stable and efficient ink droplet placement even at high speeds by effectively managing pressure fluctuations in the pressure chamber, reducing instability and ensuring consistent ink ejection.
Implementation Method 1
a drive element such as a piezoelectric element that causes pressure applied to the liquid in the pressure chamber to fluctuate in accordance with a drive signal
Implementation Method 2
The last ejection pulse includes a damping element that reduces a fluctuation in the pressure in the pressure chamber by changing in electrical potential after the ejection element of the last ejection pulse
Data Source
AI summary
In a liquid ejecting apparatus, a drive signal includes a plurality of ejection pulses corresponding to a plurality of droplets that are combined before landing on a medium. The plurality of ejection pulses has filling elements and ejection elements. The ejection element of a first ejection pulse changes in electrical potential from a first electrical potential to a reference electrical potential. The ejection element of the last ejection pulse changes in electrical potential from a second electrical potential to a third electrical potential. The reference electrical potential is between the first electrical potential and the third electrical potential and between the second electrical potential and the third electrical potential. A time period from the start of the filling element of the last ejection pulse to the start of the ejection element of the last ejection pulse is greater than or equal to 0.5 TC and less than 0.7 TC.