Droplet Ejection Apparatus Ink Settling Control
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Solution Overview
Problem
Conventional droplet ejection apparatuses face challenges in shortening the time required for the recording process due to the difficulty in settling ink vibrations after flushing operations, leading to increased recording time and ink consumption.
Innovation Solution
A droplet ejection apparatus that performs a restoring operation by alternating between ejection drive pulses and non-ejection drive pulses, where the first operation involves continuous ejection pulses at a specific period and the second operation involves continuous non-ejection pulses with longer intervals, allowing the ink to settle quickly and reducing ink consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional flushing operation is performed to restore ink-droplet ejection performance, then the ink ejection performance is restored, but the recording time increases and ink consumption increases
Solution Approach 1:
The patent applies preliminary action by performing a restoring operation before the recording operation to prevent ink thickening. The restoring operation includes applying a first voltage to eject ink droplets and then applying a second voltage (lower than the first) to vibrate the meniscus without ejecting droplets, settling the ink quickly so recording can begin immediately without time loss
Solution Approach 2:
The patent changes voltage parameters by using two different voltage levels: a first voltage for ink ejection and a second voltage (lower than the first) for meniscus vibration without ejection. This parameter change allows the system to transition from a state that would require long settling time to one where ink is quickly settled, reducing recording time while maintaining ejection performance
2Reliability
If a conventional flushing operation is performed to restore ink-droplet ejection performance, then the ink ejection performance is restored, but ink consumption increases
Solution Approach 1:
The patent performs a restoring operation as a preliminary action before recording to prevent ink thickening. By using a second voltage that is lower than the first voltage, the system vibrates the meniscus without ejecting ink droplets during the settling phase, thereby restoring ejection performance while minimizing ink consumption compared to conventional flushing that continuously ejects droplets
Solution Approach 2:
The patent applies partial action by using a second voltage that is lower than the first voltage. This partial voltage application is sufficient to vibrate the meniscus and settle the ink without causing full droplet ejection, thus achieving the restoring effect with reduced ink consumption
3Reliability
If the first voltage is applied after the second voltage in a restoring operation, then the ink ejection performance is restored, but the ink vibration does not settle down quickly
Solution Approach 1:
The patent inverts the conventional sequence by applying the second voltage (lower voltage for vibration) after the first voltage (higher voltage for ejection). This inverted sequence allows the ink to be ejected first to clear thickening, then vibrated without ejection to settle quickly, reducing settling time while maintaining ejection performance
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 effectively shortens the interval between flushing and recording operations, reducing the total recording time and ink consumption by half compared to conventional methods.
Implementation Method 1
drive pulses are inputted into a piezoelectric actuator such that volumes of pressure chambers which are filled with the ink are changed
Implementation Method 2
a non-ejection drive pulse as the drive pulse by which the droplet can not be ejected and by which vibration can be applied to a meniscus of the liquid which is formed in the nozzle
Data Source
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AI summary
A droplet ejection apparatus comprises: (a) a recording head (30) including a nozzle (15) from which a droplet of a liquid is ejected, (b) a pressure chamber (16) which is filled with the liquid and whose volume is changeable for ejecting the droplet from the nozzle, and (c) an actuator (31) which changes the volume of the pressure chamber by a drive pulse inputted thereto; and an operating device which outputs the drive pulse to the actuator and which is capable of performing a restoring operation for restoring a droplet ejection performance of the recording head. The restoring operation includes: a first operation for outputting, a plurality of times, an ejection drive pulse as the drive pulse (50D) by which the droplet can be ejected; and a second operation for outputting, a plurality of times, a non-ejection drive pulse (50E) as the drive pulse by which the droplet can not be ejected, the second operation being performed following the first operation.