OLED Pixel Electrode Openings Reduce Parasitic Capacitance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Organic light-emitting display apparatuses face image quality deterioration due to parasitic capacitors formed between conductive layers and pixel electrodes, which affect the driving current and result in errors in image display.
Innovation Solution
Incorporating a pixel electrode with openings that overlap conductive layers in the driving circuit, minimizing parasitic capacitance by strategically placing openings in regions with the greatest influence on current, thereby reducing the impact on image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the pixel electrode is made as a continuous reflective layer to improve light extraction efficiency, then the light emission intensity is improved, but parasitic capacitance increases between the pixel electrode and driving circuit conductive layers
Solution Approach 1:
The pixel electrode is segmented by forming openings (through-holes or recesses) in the reflective layer, dividing it into multiple regions. This segmentation reduces the overlapping area between the pixel electrode and driving circuit conductive layers, thereby reducing parasitic capacitance while maintaining light extraction efficiency in the exposed regions.
Solution Approach 2:
Different regions of the pixel electrode are designed with different properties: regions with openings have reduced capacitance influence, while surrounding reflective regions maintain high light extraction efficiency. The openings are strategically positioned to optimize the balance between light emission and parasitic capacitance reduction.
2Area of stationary object
If the pixel electrode overlaps with driving circuit conductive layers to reduce device area, then the device footprint is reduced, but parasitic capacitance increases affecting image quality
Solution Approach 1:
By segmenting the pixel electrode through openings, the patent maintains the overlapping layout for compact device footprint while reducing the effective overlapping area that generates parasitic capacitance. This allows the device to remain compact without sacrificing image quality.
3Object-generated harmful factors
If openings are added to the pixel electrode to reduce parasitic capacitance, then parasitic capacitance influence is reduced, but the manufacturing process complexity increases
Solution Approach 1:
The openings in the pixel electrode can be formed using standard semiconductor manufacturing techniques such as photolithography and etching, which are already part of the OLED fabrication process. This approach integrates the parasitic capacitance reduction into existing manufacturing workflows without requiring entirely new processes.
Data Source
AI summary
An organic light-emitting display apparatus includes a pixel electrode with at least one opening; an intermediate layer disposed on the pixel electrode that includes an organic emission layer; an opposite electrode disposed on the intermediate layer; and a driving circuit that includes an upper conductive layer that overlaps the at least one opening of the pixel electrode in a plan view, and that is electrically connected to the pixel electrode.