OLED Display Substrate Power Line Fractures for Color Uniformity
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Solution Overview
Problem
In organic light-emitting diode (OLED) displays, power signal lines near the light-emitting layer can cause color deviation due to overlapping with the light-emitting regions, leading to non-uniformity issues.
Innovation Solution
A display substrate design with a first power signal line and a second power signal sub-line featuring fractures to avoid overlaps with the light-emitting regions, ensuring the power signal lines do not penetrate through the effective light-emitting areas, thereby reducing color deviation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If power signal lines are disposed near the light-emitting layer to reduce voltage drop, then power supply efficiency is improved, but color deviation occurs due to overlapping with light-emitting regions
Solution Approach 1:
The second power signal sub-line is divided into multiple segments by introducing fractures, creating discontinuous segments that avoid overlapping with light-emitting regions while maintaining electrical connectivity through parallel alternative paths. This segmentation allows the power signal line to remain close to the light-emitting layer for efficient power supply while preventing color deviation by eliminating direct overlap with effective light-emitting areas.
Solution Approach 2:
The solution transitions from a continuous one-dimensional power signal line to a multi-dimensional structure with fractures creating spatial separation. The fractures introduce vertical and horizontal dimensional changes, allowing the power signal line to bypass light-emitting regions in the planar dimension while maintaining electrical continuity through alternative routing paths in the circuit dimension.
2Object-affected harmful factors
If power signal lines are moved away from light-emitting regions to avoid color deviation, then display uniformity is improved, but voltage drop increases
Solution Approach 1:
By segmenting the power signal line into discontinuous sections with fractures, the line can be positioned close to the light-emitting layer in most regions to minimize voltage drop, while strategically placing fractures at locations where overlap with light-emitting regions would cause color deviation. This segmented approach optimizes both power delivery and display uniformity.
Solution Approach 2:
The power signal line structure is optimized locally by introducing fractures only in specific regions where overlap with light-emitting regions occurs, rather than uniformly moving the entire line away. This local modification maintains excellent power supply in most areas while eliminating color deviation only where necessary, achieving optimal display uniformity without excessive voltage drop.
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
The design enhances the uniformity of the display by minimizing color deviation and maintaining consistent light emission across sub-pixels, improving the overall display quality.
Implementation Method 1
a first insulating layer formed over the pixel electrode and comprising a first material having a first dielectric constant and a first leakage current
Implementation Method 2
a first insulating layer formed over the pixel electrode and comprising a first material having a first dielectric constant and a first leakage current
Implementation Method 3
a second insulating layer formed over the first insulating layer and comprising a second material having a second dielectric constant and a second leakage current, wherein the second dielectric constant is higher than the first dielectric constant
Data Source
Figure 1A~1B
Figure 2~3A
Figure 3B~3C
AI summary
A display substrate and a display device are provided. The display substrate includes a first power signal line and a pixel defining layer. The first power signal line includes first power signal sub-lines extending along a first direction and second power signal sub-lines extending along a second direction. The pixel defining layer includes a plurality of openings to define effective light-emitting regions of a plurality of sub-pixels, the plurality of sub-pixels include a sub-pixel pair including two sub-pixels arranged along the second direction, and the sub-pixel pair includes two effective light-emitting sub-regions with an interval therebetween. In a plan view, the first power signal sub-line passes through the interval between the two effective light-emitting sub-regions, at least one second power signal sub-line includes a fracture, and the two effective light-emitting sub-regions are located at the fracture, so that a virtual straight line connecting two ends of a same fracture of the second power signal sub-line passes through the two effective light-emitting sub-regions. Providing the fracture in the second power signal sub-line can reduce the overlap between the two effective light-emitting sub-regions so as to reduce the color deviation of the sub-pixels.