Inkjet Head Auxiliary Pulse Stabilizes Ejection Speed
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Solution Overview
Problem
Inkjet heads with partition walls as actuators face challenges in simultaneously ejecting ink drops from adjacent nozzles due to residual pressure vibration, leading to slower ejection speeds and potential impact between drops, especially in multi-nozzle simultaneous driving states.
Innovation Solution
An inkjet head design that applies an auxiliary pulse signal with expansion and contraction pulses before the main drive pulse to stabilize the ejection speed of the first drop, using a shared wall configuration and a drive circuit that adjusts the pulse width of auxiliary pulses to match the resonance period of the pressure chamber, ensuring equal ejection speeds for subsequent drops.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a driving pulse signal is applied to the partition wall actuator to eject ink drops from adjacent nozzles simultaneously, then multi-nozzle simultaneous driving capability is improved, but the ejection speed of the second drop becomes slower than the first drop due to residual pressure vibration
Solution Approach 1:
An auxiliary pulse signal is applied before the main driving pulse signal to pre-vibrate the ink in the pressure chamber. This preliminary action prepares the ink by creating initial pressure vibration, ensuring that when the main pulse is applied, the ink is already in an optimal state for ejection, thus equalizing the ejection speeds of multiple drops.
Solution Approach 2:
The pulse width of the auxiliary pulse signal is specifically designed to match the resonance period of the pressure chamber. By changing the temporal parameter (pulse width) to align with the natural resonance characteristics of the system, the auxiliary pulse effectively prepares the ink for ejection without causing harmful residual vibrations that would slow down subsequent drops.
2Stability of the object's composition
If the ejection speed of the first drop is increased by applying an auxiliary pulse signal, then the ejection speed uniformity is improved, but the device complexity increases due to additional pulse signal control
Solution Approach 1:
The auxiliary pulse signal and the main driving pulse signal are merged into a single integrated pulse signal waveform. The auxiliary pulse is not a separate signal but is combined with the driving pulse, creating a unified control signal that performs both the pre-vibration and the main ejection functions, thereby reducing control complexity.
Solution Approach 2:
The auxiliary pulse signal serves multiple functions: it pre-vibrates the ink, synchronizes with the resonance period of the pressure chamber, and prepares the meniscus for optimal ejection. This multi-functional approach eliminates the need for separate control mechanisms, reducing overall device complexity while achieving ejection speed uniformity.
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 stabilizes the ejection speed of ink drops across various driving states, preventing separation and ensuring high-quality printing by compensating for residual pressure vibrations and hysteresis effects, thereby improving printing efficiency and quality.
Implementation Method 1
pressure vibration is generated in the pressure chamber due to the volume change, and ink drops are ejected from a nozzle communicating with the pressure chamber
Implementation Method 2
apply an auxiliary pulse signal (boost pulse) for amplifying the pressure vibration of the pressure chamber before the driving pulse signal for enabling the first drop to be ejected
Implementation Method 3
adjusts the pulse width of auxiliary pulses to match the resonance period of the pressure chamber
Data Source
AI summary
In accordance with an embodiment, an inkjet head comprises a pressure chamber configured to house ink; an actuator configured to be arranged corresponding to the pressure chamber; a plate configured to have a nozzle communicating with the pressure chamber; and a driving circuit configured to drive the actuator, wherein the drive circuit applies an auxiliary pulse signal which contains an expansion pulse for expanding the volume of the pressure chamber and a contraction pulse for contracting the volume of the pressure chamber in such a degree as not to eject an ink drop from the nozzle to the actuator before enabling the ink drop to be ejected from the nozzle communicating with the pressure chamber by applying the expansion pulse and the contraction pulse as a drive pulse signals.