Micro Nozzle Ink Supply Control for OLED Pattern Coating
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Solution Overview
Problem
Inkjet printing devices often experience nozzle clogging due to uncontinuous ink supply, leading to inefficient and costly manufacturing processes in pattern coating for light-emitting devices, particularly in OLED and QLED production.
Innovation Solution
A method and device where the ink supply to a micro nozzle is controlled based on preset distances to maintain continuous ink flow during pattern coating, using laser positioning and ink outlet pressure detection to manage ink droplet size and prevent nozzle clogging, ensuring precise and efficient coating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If inkjet printing is used for precise pattern coating, then coating precision is improved, but nozzle clogging occurs due to uncontinuous ink supply
Solution Approach 1:
The patent implements continuous ink supply to the nozzle during the entire coating process. The ink supply device maintains constant ink flow to the micro nozzle, preventing the nozzle from being empty and avoiding clogging caused by uncontinuous supply. This resolves the contradiction by ensuring the nozzle remains functional throughout precise pattern coating operations.
Solution Approach 2:
The patent employs a feedback mechanism where the position of the nozzle and substrate is continuously monitored, and ink supply is adjusted accordingly. When the nozzle approaches the substrate or during retraction, the system receives feedback signals and automatically adjusts ink supply to maintain continuity, preventing clogging while maintaining coating precision.
2Manufacturing precision
If inkjet printing device is used for pattern coating, then coating accuracy is improved, but device cost increases
Solution Approach 1:
The patent integrates multiple functions into a unified coating system. The ink supply device serves both precise pattern coating and continuous supply functions, while the control system manages both positioning and ink flow. This multi-functionality reduces the need for separate specialized components, thereby lowering overall device cost while maintaining coating accuracy.
Solution Approach 2:
The patent optimizes ink supply parameters such as flow rate, pressure, and viscosity to match the specific requirements of pattern coating. By adjusting these parameters, the system achieves high coating accuracy without requiring expensive specialized equipment, as the same basic inkjet infrastructure can be tuned for precise operation.
3Reliability
If continuous ink supply is maintained, then nozzle clogging is prevented, but ink waste increases
Solution Approach 1:
The patent implements controlled continuous ink supply rather than full continuous supply. Ink is supplied at a rate that maintains nozzle functionality without excessive accumulation. The system provides just enough ink to prevent clogging during idle periods and positioning movements, minimizing waste while ensuring reliability.
Solution Approach 2:
The patent recovers and recycles excess ink that would otherwise be wasted. The system collects ink that drips or is expelled during continuous supply, filters it, and returns it to the ink reservoir. This recovery process reduces overall ink consumption while maintaining continuous supply to prevent nozzle clogging.
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 reduces the likelihood of nozzle clogging and enables continuous, stable ink supply during coating, improving the accuracy and efficiency of pattern formation on substrates, thereby enhancing the manufacturing process for light-emitting devices.
Implementation Method 1
a position of the end of the micro nozzle or the lowest end of the ink droplet is detected through at least one of the followings: a laser
Data Source
AI summary
A coating method, a coating device and a light-emitting device, the coating method comprises: controlling an ink supply device to stop supplying ink to a micro nozzle when it is determined that the lowest end of an ink droplet from the micro nozzle reaches a first position; determining that the distance between the end of the micro nozzle and a substrate reaches a second distance, the second distance being preset; controlling the ink supply device to continue to supply ink, and controlling the micro nozzle to move relative to the substrate for a pattern coating. The disclosure provides a good pattern forming solution, thereby avoiding the technical problem in the prior art of inkjet printing apparatuses easily causing nozzle clogging.