Pixel-Defining Layer Grooves for Uniform High-PPI Inkjet Printing
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Solution Overview
Problem
Inkjet printing for display panel manufacturing faces challenges in controlling the process and achieving uniformity, especially for high PPI (pixels per inch) displays, due to the complexity of ink dripping and frequent nozzle movements, leading to non-uniform ink drops over time.
Innovation Solution
A display panel design featuring a pixel-defining layer with grooves and container portions of opposite polarity to the ink material, allowing for efficient ink flow and connection to multiple subpixel regions in a single nozzle pass, reducing the need for frequent ink dripping and enhancing printing accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If inkjet printing is used to deposit light-emitting layer in liquid form, then material utilization is improved, but printing accuracy deteriorates due to non-uniform ink drops
Solution Approach 1:
The pixel-defining layer is segmented into container portions and edge portions with gaps, creating a structured pathway system that guides ink flow. This segmentation allows the ink to be deposited in a controlled manner through multiple nozzles simultaneously filling different container portions, thereby maintaining printing accuracy while improving material utilization.
Solution Approach 2:
The container portions act as intermediary structures between the ink nozzles and the subpixel regions. The ink is first deposited into the container portions and then flows through the edge portions with gaps into the subpixel regions. This intermediary structure enables better control over ink distribution and reduces non-uniformity in the final deposition.
2Area of stationary object
If multiple nozzles perform ink-dripping multiple times while moving between subpixels, then coverage is improved, but process complexity increases
Solution Approach 1:
Multiple nozzles are combined to operate simultaneously on different container portions within the same subpixel row. This merging of operations allows all container portions to be filled in a single pass without requiring sequential movement and multiple dripping operations, thereby reducing process complexity while maintaining complete coverage.
Solution Approach 2:
The container portions are pre-formed in the pixel-defining layer before the inkjet printing process. This preliminary preparation creates ready-receive structures that guide the ink flow path, allowing nozzles to simply deposit ink into these pre-defined containers without complex positioning and movement control, thus simplifying the overall printing process.
3Productivity
If continuous inkjet printing is performed over extended periods, then production efficiency is improved, but ink uniformity deteriorates
Solution Approach 1:
The pixel-defining layer structure with container portions and connected edge portions enables continuous ink flow from the container through the gaps into the subpixel regions. This continuous action eliminates the need for repeated start-stop printing operations, allowing extended production runs while maintaining ink uniformity through consistent flow dynamics.
Solution Approach 2:
The container portions and edge portions with gaps create a self-regulating ink delivery system. The structure itself controls the ink flow from the container into the subpixel regions, reducing dependence on precise nozzle positioning and movement control. This self-service mechanism maintains ink uniformity even during extended printing operations.
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 simplifies the inkjet printing process, reduces nozzle movement complexity, and minimizes ink non-uniformity by allowing a single nozzle pass to fill multiple subpixel regions with the same color, improving material utilization and printing accuracy.
Implementation Method 1
The edge portion of each groove includes one or more gaps to allow the container portion to connect to one or more subpixel regions
Implementation Method 2
Each groove includes a container portion partially surrounded by an edge portion. The container portion is at a first height above the surface and the edge portion being at a second height greater than the first height relative to the surface
Implementation Method 3
The container portion is made of a material having opposite polarity to that of an ink material to be dripped into thereof
Data Source
AI summary
A display panel having a pixel defining layer defining subpixel apertures of subpixels is provided. The pixel defining layer is a unitary structure including column portions and row portions. A respective row portion is between two adjacent subpixel apertures that are in a same column and respectively from two adjacent rows. A respective column portion is in a space between two adjacent columns of subpixel apertures, spacing apart multiple pairs of adjacent row portions respectively in multiple rows. A respective row portion includes a depression part configured to allow fluid communication of an ink solution between the two adjacent subpixel apertures in the same column and respectively from the two adjacent rows. A minimum height of the depression part relative to a base substrate is less than a minimum height of a column portion adjacent to the respective row portion relative to the base substrate.