OLED Storage Electrode Integration for Brightness Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing organic light emitting diode (OLED) display devices face challenges in achieving high resolution and uniform brightness, especially in large-sized panels, due to voltage drops and instability in electric connections, which are exacerbated by the limited area of pixel regions and the need for additional semiconductor processes.
Innovation Solution
The solution involves a modified OLED display device structure with a substrate, semiconductor layer, insulating layers, and metal layers that form storage electrodes and connect the drain electrode to an anode, along with a mesh structure for voltage compensation, reducing the step height of contact holes and eliminating the need for additional doping processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the number of storage electrodes is increased to achieve sufficient capacitance, then the capacitance is sufficient to operate the organic light emitting layer, but the occupied area of the storage electrodes increases, making high resolution difficult to achieve in the limited pixel region
Solution Approach 1:
The patent combines the storage electrode function with the pixel electrode structure by forming the storage electrode as an integrated part of the pixel electrode assembly. This merging allows the storage electrode to provide sufficient capacitance while occupying minimal additional area within the pixel region, thereby resolving the contradiction between capacitance sufficiency and area limitation.
Solution Approach 2:
The patent utilizes the vertical dimension by forming the storage electrode in a stacked configuration with the pixel electrode, rather than expanding horizontally. This dimensional transition allows the storage electrode to be positioned above or below the pixel electrode, providing sufficient capacitance without increasing the planar area of the pixel region.
2Manufacturing precision
If the height of the fourth insulating layer is increased for planarization, then the planarization is improved, but the step of the third contact hole formed in the fourth insulating layer becomes greater, causing uneven thickness or partial cutting of the anode
Solution Approach 1:
The patent optimizes the thickness parameter of the fourth insulating layer to achieve an optimal balance between planarization quality and contact hole step height. By carefully controlling the layer thickness within a specific range, the patent ensures sufficient planarization while maintaining acceptable step heights that prevent anode deformation and connection failures.
3Productivity
If the pixel regions have the same limited area, then the integration density is high, but the voltage drop occurs as a pixel is farther from a power supply terminal, causing disuniformity of brightness
Solution Approach 1:
The patent segments the power supply network by introducing multiple power supply terminals distributed across the display panel. This segmentation divides the large panel into multiple zones, each with its own power terminal, thereby reducing the maximum distance from any pixel to a power terminal and minimizing voltage drops that cause brightness non-uniformity.
Solution Approach 2:
The patent introduces additional power supply terminals at different spatial locations across the panel, effectively utilizing the two-dimensional space to distribute power more evenly. This approach maintains high integration density while ensuring that no pixel is too far from a power supply point, thereby preserving brightness uniformity.
Data Source
AI summary
An organic light emitting diode display device includes: a semiconductor layer on a substrate and including source and drain regions; a first insulating layer on the semiconductor layer; a gate electrode and a first storage electrode on the first insulating layer; a second insulating layer on the gate electrode and the first storage electrode; source and drain electrodes connected with the source and drain regions, respectively; a second storage electrode on the second insulating layer at a location corresponding to the first storage electrode; a third insulating layer on the source and drain electrodes and the second storage electrode; a first metal layer on the third insulating layer and connecting the drain electrode to an anode; and a second metal layer on the third insulating layer at a location corresponding to the second storage electrode.