OLED Driving Element Segmentation for High Aperture Ratio
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Active matrix organic electroluminescent devices (OLEDs) face challenges in achieving high aperture ratio and resolution due to the large size of the driving element, which occupies significant area in the pixel region, making it difficult to manufacture OLEDs with high aperture ratio and high resolution.
Innovation Solution
The solution involves reducing the width of the driving element by forming a driving source electrode and drain electrode with a first electrode along a direction and multiple second electrodes extending from it, alternating with each other, and a driving gate electrode connected to the switching drain electrode, allowing for a reduced overall size while maintaining the same width-to-length ratio, and utilizing an overlap portion for storage capacitance without additional components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If a conventional driving element structure is used, then the device can provide sufficient driving current, but the driving element occupies large area reducing aperture ratio
Solution Approach 1:
The driving source electrode and driving drain electrode are segmented into multiple parallel electrodes (first driving source electrode, second driving source electrode, first driving drain electrode, second driving drain electrode) arranged in the second direction. This segmentation allows the driving element to provide sufficient total current through multiple parallel conduction paths while reducing the overall area by optimizing the spatial distribution of current flow paths.
Solution Approach 2:
The patent extends the electrode structure from a single-direction linear arrangement to a two-dimensional grid-like configuration by introducing electrodes extending in the second direction (crossing the first direction). This dimensional expansion allows current to flow through multiple parallel paths, increasing driving capability without proportionally increasing the area occupied by the driving element.
2Area of moving object
If the driving element size is reduced to increase aperture ratio, then high resolution can be achieved, but additional storage capacitance components are needed increasing device complexity
Solution Approach 1:
The patent merges the storage capacitance function with the existing driving gate electrode structure. The driving gate electrode serves dual purposes: controlling the driving transistor and providing storage capacitance through its overlap regions with the source and drain electrodes. This eliminates the need for separate storage capacitance components, reducing device complexity while maintaining high aperture ratio.
Solution Approach 2:
The driving gate electrode is designed to perform multiple functions simultaneously: it acts as the control electrode for the driving transistor and also serves as the storage capacitance element. This multi-functionality reduces the total number of components needed in the pixel structure, simplifying the device while achieving high aperture ratio.
3Reliability
If the driving element occupies large area, then sufficient storage capacitance can be provided, but the aperture ratio and resolution are reduced
Solution Approach 1:
The patent creates local overlap regions between the driving gate electrode and the source/drain electrodes where storage capacitance is concentrated. Instead of requiring uniform large-area structures, the capacitance is localized to specific overlap regions, allowing sufficient storage capacitance to be achieved within a compact driving element footprint, thereby preserving high aperture ratio.
Data Source
AI summary
An organic electroluminescent device including a driving element having a driving gate electrode connected to the switching element, the driving gate electrode formed uniformly on the substrate, a driving source electrode having a first driving source electrode along a first direction and a plurality of second driving source electrodes extending from the first driving source electrode along a second direction crossing the first direction, a driving drain electrode spaced apart from the driving source electrode, the driving drain electrode having a first driving drain electrode along the first direction and a plurality of second driving drain electrodes extending from the first driving drain electrode along the second direction, wherein the plurality of second driving source electrodes alternate with the plurality of second driving drain electrodes, wherein the driving source electrode and the driving drain electrode including an interval therebetween are facing the driving gate electrode.