Ink Jet Drive Circuit Voltage Segmentation for Droplet Control
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Solution Overview
Problem
Existing ink jet recording apparatuses face challenges in efficiently adjusting the droplet ejection process to achieve precise control over the number of droplets and their ejection speed, leading to variations in droplet volume and printing quality, particularly due to limitations in drive circuit voltage and pulse width management.
Innovation Solution
The apparatus incorporates a drive circuit that outputs a drive waveform with a first and second pulse group, where the second pulse group has a lower voltage amplitude than the first, allowing for consistent ejection speed and adjustable droplet volume by varying pulse widths based on the number of consecutively ejected droplets, and includes a negative pulse to manage residual pressure vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single voltage amplitude is used for all ejection pulses, then the circuit design is simple, but the droplet ejection speed becomes unstable when ejecting multiple consecutive droplets
Solution Approach 1:
The drive waveform is segmented into two distinct pulse groups: a first pulse group with a first voltage amplitude for initial droplet ejection, and a second pulse group with a second voltage amplitude for subsequent droplet ejection. This segmentation allows independent optimization of voltage parameters for different ejection phases, ensuring stable droplet speed while maintaining controllable circuit complexity.
Solution Approach 2:
The drive circuit dynamically switches between different voltage amplitudes based on the ejection sequence. The control unit activates the first voltage amplitude for the first pulse group and switches to the second voltage amplitude for the second pulse group, creating a dynamic voltage control system that adapts to the ejection phase to maintain consistent droplet ejection speed.
2Speed
If high voltage amplitude is applied to all ejection pulses, then droplet ejection speed is maintained, but power consumption and temperature rise increase
Solution Approach 1:
The invention changes the voltage amplitude parameter between different pulse groups. The first pulse group uses a first voltage amplitude sufficient for initial droplet ejection, while the second pulse group uses a reduced second voltage amplitude. This parameter change maintains adequate droplet ejection speed for subsequent droplets while significantly reducing power consumption and heat generation in the drive circuit.
3Quantity of substance
If pulse width is increased to eject more droplets, then the number of droplets increases, but droplet volume becomes inconsistent
Solution Approach 1:
The drive circuit employs periodic pulse groups with distinct characteristics. The first pulse group contains a first number of ejection pulses with the first voltage amplitude, and the second pulse group contains a second number of ejection pulses with the second voltage amplitude. This periodic structure with varying parameters enables precise control over the total number of droplets ejected while maintaining consistent droplet volume through optimized pulse timing and voltage sequencing.
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 solution enhances printing speed and quality by ensuring consistent ejection speed and droplet volume, reducing power consumption and temperature rise in the drive circuit, thereby improving the overall performance of the ink jet recording apparatus.
Implementation Method 1
an actuator configured to change a pressure on the liquid in the pressure chamber by changing a volume of the pressure chamber in response to a drive signal
Implementation Method 2
a nozzle connected to the pressure chamber and through which the liquid contained in the pressure chamber can be ejected when an ejection pulse is supplied to the actuator
Data Source
Figure 1~2
Figure 3
Figure 4A~4B
AI summary
An ink jet head drive device includes a pressure chamber in which a liquid can be contained, an actuator configured to change a pressure on the liquid in the pressure chamber by changing a volume of the pressure chamber in response to a drive signal, a nozzle through which the liquid contained in the pressure chamber can be ejected when an ejection pulse is supplied to the actuator, and a drive circuit configured to output the drive signal to the actuator as a drive waveform having a first pulse group and a second pulse group following the first pulse group when at least three consecutive ejection pulses are included in the drive waveform. All ejection pulses in the first pulse group have a first voltage amplitude, and all ejection pulses in the second pulse group have a second voltage amplitude that is smaller than the first voltage amplitude.