Droplet Ejection Waveform Compensation for Print Head Uniformity
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Solution Overview
Problem
Droplet ejection devices, such as inkjet printers, face challenges in achieving uniform drop velocity and mass distribution due to manufacturing variations, cross-talk, and natural frequency response, leading to non-uniformities in output pattern quality, which existing approaches like tightening manufacturing tolerances or additional electronics cannot effectively address without increased costs and complexity.
Innovation Solution
A method involving multi-level image mapping and waveforms with compensating edges or pulses is applied to droplet ejection devices to compensate for cross-talk and systematic variations, adjusting drop velocity and mass by processing buffer data and shifting affected pixels, thereby improving drop formation and uniformity across the print head.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If additional electronics such as amplifiers and switches are added to drive various nozzles using separate waveforms to compensate for variations, then drop velocity uniformity and mass distribution improve, but device complexity and cost increase
Solution Approach 1:
The patent applies parameter changes by modifying the electrical waveform parameters (amplitude, duration, shape) of the single drive signal to compensate for nozzle variations. Different portions of the multi-pulse waveform are selectively activated to adjust drop velocity and mass, eliminating the need for additional electronics while achieving uniform drop ejection across all nozzles
2Manufacturing precision
If separate waveforms are used to drive various nozzles to compensate for manufacturing variations, then drop mass uniformity improves, but the time required for waveform generation and application increases
Solution Approach 1:
The patent merges multiple compensation functions into a single multi-pulse waveform that can be applied to all nozzles simultaneously. The waveform includes multiple sections with different pulse patterns that are selectively activated to compensate for variations across different nozzle groups, reducing the time required compared to applying separate waveforms to each nozzle
3Manufacturing precision
If tightening manufacturing tolerances is implemented to reduce non-uniformities, then drop velocity and mass distribution improve, but manufacturing cost and complexity increase
Solution Approach 1:
The patent enables the droplet ejection device to self-compensate for manufacturing variations through software-controlled waveform adjustment. The system characterizes individual nozzle performance and automatically applies compensating pulse patterns to balance drop ejection, eliminating the need for expensive manufacturing tolerance tightening while achieving uniform drop distribution
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 enhances drop velocity and mass uniformity, reduces frequency response variations, and improves print head sustainability by dynamically addressing systematic and cross-talk-related issues without the need for additional expensive electronics, resulting in improved output quality and reduced operational complexities.
Implementation Method 1
Droplet ejection devices are used for a variety of purposes, most commonly for printing images on various media. Drop-on-demand droplet ejection devices are used in many applications because of their flexibility and economy.
Data Source
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AI summary
Methods and systems are described herein for driving droplet ejection devices with multi-level waveforms. A method for driving droplet ejection devices includes determining image data for the droplet ejection devices, converting the image data into converted data to be stored in an image buffer having first and second levels, processing the converted data to determine cross-talk affected data, and applying the multi-level waveform to the droplet ejection devices. The multi-level waveform includes a first section having at least one compensating edge and a second section having at least one drive pulse. The at least one compensating edge has a compensating effect to compensate for cross-talk variation across the droplet ejection devices.