Liquid Ejection Head Drive Waveform for Droplet Rectilinearity
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Solution Overview
Problem
Conventional image forming apparatuses face challenges in suppressing droplet ejection bending while maintaining high frequency driving, as the inclusion of waveform components to prevent bending increases the drive waveform length, making it difficult to achieve desired maximum drive frequencies.
Innovation Solution
The apparatus employs a drive waveform with a first pulse that does not include a waveform component to suppress ejection bending, followed by a second pulse that includes this component, where the droplet amount and speed of the second pulse are greater than those of the first pulse, to eject droplets effectively while minimizing bending.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a waveform component that suppresses ejection bending is included in all pulses, then ejection bending is suppressed, but the drive waveform length increases and high frequency driving becomes difficult
Solution Approach 1:
The drive waveform is segmented into multiple pulses with different characteristics. The first pulse excludes the bending suppression waveform component to maintain short duration, while the second pulse includes it to ensure droplet rectilinearity. This segmentation allows selective application of the waveform component only where necessary.
Solution Approach 2:
The bending suppression waveform component is applied partially - only in the second pulse rather than all pulses. This partial action maintains the essential function of suppressing ejection bending while minimizing the increase in overall waveform length, thereby preserving high frequency driving capability.
2Productivity
If a drive pulse without waveform component that suppresses ejection bending is used, then the drive waveform length is shortened and high frequency driving is enabled, but the ejected droplet is subject to influence of remaining oscillation and bends
Solution Approach 1:
The drive waveform is divided into multiple pulses where only specific pulses (the second pulse) include the bending suppression waveform component. This segmentation ensures that the waveform length is minimized overall while still providing bending suppression where it matters most for droplet quality.
Solution Approach 2:
The first pulse performs preliminary droplet ejection without the bending suppression component, and the second pulse follows with the suppression component to correct any bending. This preliminary action approach allows the system to maintain high drive frequency while still achieving droplet rectilinearity through the subsequent corrective pulse.
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 allows for the suppression of ejection bending while maintaining high frequency driving capabilities, ensuring improved image quality by reducing the influence of preceding pulse oscillations and enhancing droplet rectilinearity.
Implementation Method 1
a pressure generation unit configured to generate a pressure for pressurizing a liquid in the individual liquid chamber
Data Source
AI summary
An image forming apparatus includes a liquid ejection head including a pressure generation unit configured to generate a pressure for pressurizing a liquid in an individual liquid chamber communicating nozzles; and a head drive control unit configured to generate a drive waveform including pulses in time series, select one or more pulses from the drive waveform according to a droplet size, and provide the selected drive pulses to the pressure generation unit. The drive waveform includes a first pulse not including a waveform component that suppresses ejection bending, and allowing a droplet to be ejected, and a second pulse including the waveform component that suppresses ejection bending, and allowing a droplet to be ejected. An amount of the droplet ejected in the second pulse is larger than in the first pulse, and a speed of the droplet ejected in the second pulse is higher than that in the first pulse.