Inkjet Driving Waveform Control for Satellite Droplet Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inkjet image forming apparatuses face challenges in reducing satellite droplet length and occurrence, which affects print speed, image quality, and accuracy, especially when multiple recording heads are used, as satellite droplets can vary in color tone and position, leading to blurred images and reduced accuracy in reading bar codes.
Innovation Solution
The image forming apparatus employs a driving waveform generator that produces a specific driving waveform with multiple pulses per cycle, including a first expansion, first contraction, second retaining, second contraction, and third retaining waveform elements, with the second contraction waveform element having a longer time period and higher potential difference than the first contraction waveform element, to efficiently eject droplets and minimize satellite formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional driving waveforms are used to eject droplets, then droplet ejection is achieved, but satellite droplets are formed with longer length and higher occurrence rate
Solution Approach 1:
The patent applies periodic action by using a driving waveform with multiple pulses (first pulse, second pulse, and third pulse) within one driving cycle. Each pulse has specific waveform elements (expansion, retaining, contraction) that periodically act on the liquid chamber to control droplet ejection. This periodic multi-pulse approach allows precise control of the ejection process to minimize satellite droplet formation while maintaining effective droplet delivery.
Solution Approach 2:
The driving waveform is segmented into multiple distinct pulses, each with specific waveform elements. The first pulse includes first expansion, first retaining, and first contraction waveform elements. The second pulse includes second expansion, second retaining, and second contraction waveform elements. The third pulse includes third expansion, third retaining, and third contraction waveform elements. This segmentation allows independent optimization of each pulse's function to control droplet formation and minimize satellites.
2Productivity
If print speed is increased, then productivity is improved, but satellite droplet length increases and occurrence increases
Solution Approach 1:
The patent applies preliminary action by using the first pulse with expansion, retaining, and contraction waveform elements before the main ejection pulse. The first contraction waveform element creates a preliminary contracted state that prepares the liquid for optimal ejection in subsequent pulses. This preliminary preparation reduces satellite droplet formation and allows faster printing speeds without compromising droplet quality.
Solution Approach 2:
The patent changes multiple parameters of the driving waveform including the number of pulses per cycle, the timing of each pulse, the potential difference of each waveform element, and the time period of contraction elements. By optimizing these parameters, the system achieves high print speed while minimizing satellite droplet length and occurrence through precise control of liquid chamber dynamics.
3Productivity
If multiple recording heads are used, then productivity is improved, but image quality deteriorates due to varying satellite droplet states
Solution Approach 1:
The patent applies universality by designing a common driving waveform structure that can be applied to multiple recording heads simultaneously. Each head receives the same standardized driving waveform with three pulses and seven waveform elements, ensuring consistent droplet ejection characteristics across all heads. This universal approach eliminates variations in satellite droplet formation between different heads, maintaining uniform image quality while enabling multi-head parallel printing for high productivity.
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 effectively shortens satellite droplet length, ensures accurate droplet merging, and enhances image quality by reducing satellite droplet occurrences, maintaining consistency in color tone and improving print accuracy across multiple recording heads.
Implementation Method 1
a pressure generator to generate a pressure to pressurize the liquid in the liquid chamber
Implementation Method 2
a driving pulse of a conventional driving waveform contracts the liquid chamber from an expanded state to eject liquid droplets
Data Source
AI summary
An image forming apparatus includes a recording head and a driving waveform generator. The recording head has a nozzle, a liquid chamber, and a pressure generator. The driving waveform generator is connected to the pressure generator to generate and output a driving waveform including a plurality of driving pulses per driving cycle to eject a droplet from the nozzle. A last one of the driving pulses includes a first expansion waveform element, a first retaining waveform element, a first contraction waveform element, a second retaining waveform element, a second contraction waveform element, a third retaining waveform element, and a second expansion waveform element. The first contraction waveform element has a potential difference greater than a potential difference of the first expansion waveform element. The second contraction waveform element has a time period longer than a time period of the first contraction waveform element.