Liquid Ejection Head Drive Signal Control for Viscosity Adaptation
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Solution Overview
Problem
Liquid ejection heads face challenges in maintaining stable discharge characteristics due to varying viscosity of liquids, as existing drive waveforms fail to synchronize pressure generation and meniscus vibration effectively across a wide range of viscosities.
Innovation Solution
A control method and device that utilize multiple drive signals with specific pulse sections to adjust pressure generation in liquid ejection heads, including a prior pulse section for high viscosity liquids and a vibration control pulse section for low viscosity liquids, ensuring accurate discharge and vibration control by adjusting the drive signal based on viscosity thresholds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed waveform drive signal is used, then the device complexity is reduced, but the discharge characteristics deteriorate when viscosity varies over a wide range
Solution Approach 1:
The patent applies dynamics by making the drive signal adaptable rather than fixed. The control device dynamically selects between a first drive signal (with prior pulse section for high viscosity) and a second drive signal (with vibration control pulse section for low viscosity) based on the actual viscosity conditions, allowing the system to optimize performance across varying viscosity ranges while maintaining manageable complexity through conditional signal selection
2Manufacturing precision
If a prior pulse section is added to the drive signal, then the discharge accuracy for high viscosity liquid is improved, but the device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the drive signal into distinct functional sections: a prior pulse section (first contraction element and first expansion element) for meniscus preparation, a discharging pulse section (second contraction element) for droplet ejection, and optionally a vibration control pulse section. This segmentation allows each section to be optimized for its specific function, improving discharge accuracy while keeping the overall structure organized and manageable through clear functional division
3Reliability
If a vibration control pulse section is added to the drive signal, then the discharge stability for low viscosity liquid is improved, but the device complexity increases
Solution Approach 1:
The patent applies preliminary action by incorporating a vibration control pulse section that actively suppresses meniscus vibration before the discharging pulse section operates. This preliminary vibration control prepares the liquid interface for stable droplet ejection, improving discharge stability for low viscosity liquids. The vibration control is performed in advance of the actual droplet discharge, preventing vibration-related discharge errors before they occur
4Ease of operation
If the drive signal is simplified, then the ease of operation is improved, but the adaptability to different viscosity ranges deteriorates
Solution Approach 1:
The patent applies universality by designing a control device that can handle multiple viscosity ranges with a single unified system. The control device universally supports both high viscosity liquids (using the first drive signal with prior pulse section) and low viscosity liquids (using the second drive signal with vibration control pulse section), eliminating the need for separate specialized systems for different viscosity ranges while maintaining ease of operation through automated viscosity-based signal selection
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 stabilizes the discharge characteristics across a wide range of viscosities, improving the accuracy and quality of liquid ejection by synchronizing pressure generation and meniscus vibration, thereby enhancing printing or similar applications.
Implementation Method 1
a piezoelectric actuator is provided on one side of a flow channel formation substrate on which a pressure generation room communicating with the nozzle orifice is formed, and the droplet of ink is discharged from the nozzle orifice by applying pressure to ink in the pressure generation room by changing the form of this piezoelectric actuator
Implementation Method 2
A heater for drying and fixing ink is built into the ink jet recording head of this kind of ink jet recording device. In this case, the temperature of the ink within the ink jet recording head changes over a wide range from low to high, due to the influence of the heater
Data Source
AI summary
A drive signal includes a first drive signal and a second drive signal. The first drive signal includes a prior pulse section including a first contraction element and a discharging pulse section including a first expansion element pulling in a meniscus and the second contraction element discharging a droplet of liquid from the nozzle orifice. The second drive signal includes the discharging pulse section and a vibration control pulse section including a second expansion element controlling a residual vibration of the meniscus. A piezoelectric element is driven with the first drive signal when viscosity of the liquid is equal to or more than a first set value and is driven with the second drive signal when the viscosity is equal to or less than a second set value.