Ink Jet Head Driving Method for Droplet Count Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ink jet printing faces issues with unstable ejection and degraded print quality due to low ejection speed of the first droplet and high speed of subsequent droplets, leading to increased power consumption and extended drive cycle times, especially when printing with a small number of droplets.
Innovation Solution
An ink jet head driving method that applies a boost pulse to amplify pressure vibration before the drive pulse for the first droplet when the number of droplets is small, and disables the boost pulse when the number of droplets is greater than or equal to a predetermined number, optimizing ejection speed and reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the number of droplets is small and a boost pulse is applied to increase first droplet ejection speed, then ejection stability and print quality improve, but power consumption increases and drive cycle time extends
Solution Approach 1:
The patent applies a boost pulse only dynamically when the number of droplets to be ejected is less than a predetermined threshold. The control device adjusts the driving waveform based on the droplet count, applying an enhanced voltage profile (boost pulse followed by drive pulses) only when necessary for small droplet counts, and using standard drive pulses alone when droplet counts are sufficient. This dynamic adaptation resolves the contradiction by enabling stable ejection only when needed while minimizing power consumption in other cases.
2Manufacturing precision
If the number of droplets is small and a boost pulse is applied to increase first droplet ejection speed, then print quality improves, but drive cycle time extends
Solution Approach 1:
The control device dynamically selects the driving waveform based on the number of droplets to be ejected. When the droplet count is below the threshold, the boost pulse waveform is applied to ensure high print quality through stable ejection. When the droplet count meets or exceeds the threshold, the system switches to standard drive pulses only, eliminating the extended pause time and achieving high-speed printing. This conditional dynamic control resolves the time-quality tradeoff.
3Productivity
If standard drive pulses are used without boost pulse for high-speed printing, then productivity improves, but ejection stability degrades for small droplet counts
Solution Approach 1:
The system dynamically adapts the driving waveform based on real-time droplet count information. For small droplet counts where ejection stability is critical, the boost pulse waveform is activated to ensure reliable first droplet ejection. For larger droplet counts where high-speed printing is the priority, the system uses standard drive pulses only, achieving maximum productivity. This conditional dynamic control resolves the contradiction between speed and reliability.
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 method improves ejection stability and print quality by adjusting ejection speed based on the number of droplets, allowing for high-speed printing without degrading quality, and reduces power consumption by optimizing voltage usage.
Implementation Method 1
a piezoelectric actuator 14 provided in correspondence with each of the pressure generating chambers 17 to apply vibration to the pressure generating chambers 17 via a vibration plate 13
Implementation Method 2
apply a boost pulse to amplify a pressure vibration of the pressure chamber prior to a drive pulse for ejecting a first liquid droplet
Data Source
AI summary
There is provided an ink jet head driving method for applying a drive pulse to an actuator to change capacities of a plurality of pressure chambers in which ink has been filled, ejecting an ink droplet from a nozzle formed in communication with the pressure chamber to print onto a printing medium, and moreover, continuously ejecting a plurality of liquid droplets to carry out gradation printing according to the number of liquid droplets, the method including making control so as to, in the case where the number of the liquid droplets is smaller than a predetermined number, apply a boost pulse to amplify a pressure vibration of the pressure chamber prior to a drive pulse for ejecting a first liquid droplet, and in the case where the number of liquid droplets is equal to or greater than the predetermined number, disable applying of the boost pulse.