Dummy Pixel Repair Lines for OLED Luminance Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In organic light-emitting display devices, defective pixels can cause bright or dark spots due to improper light emission, leading to visibility issues, and existing methods to repair these defects often result in luminance differences between repaired and adjacent pixels, affecting image quality.
Innovation Solution
The use of a dummy pixel circuit with repair lines that transfer driving current and power voltage to a defective pixel, minimizing luminance differences by isolating and reconnecting electrical components using laser-induced breakdown of insulating films, allowing the dummy pixel to mimic the behavior of adjacent pixels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dummy pixel is used to repair a defective pixel, then the defective pixel can be replaced to eliminate bright spots, but luminance differences occur between repaired and adjacent pixels
Solution Approach 1:
The patent applies equipotentiality by connecting the power node of the dummy pixel circuit to the same power voltage as adjacent pixel circuits through repair lines. This ensures that the dummy pixel operates at the same electrical potential as surrounding pixels, eliminating luminance differences caused by voltage variations and achieving uniform brightness across the display panel.
Solution Approach 2:
The patent utilizes parameter changes by adjusting the power voltage applied to the dummy pixel circuit through controlled connection to adjacent pixel power nodes. By matching the power voltage parameter to that of surrounding pixels, the luminance output of the repaired pixel is tuned to match adjacent pixels, resolving the luminance uniformity issue.
2Reliability
If multiple repair lines are used to connect dummy pixel circuits to power nodes, then power voltage can be supplied to repaired pixels, but the number of repair lines increases device complexity
Solution Approach 1:
The patent applies universality by designing repair lines that serve multiple functions: they connect dummy pixel circuits to power nodes for voltage supply, and simultaneously serve as signal transmission paths. This multi-functionality reduces the need for separate dedicated power supply lines, thereby decreasing overall device complexity while maintaining reliable power delivery to repaired pixels.
3Reliability
If more repair lines are added to improve power supply, then repaired pixels can be better powered, but aperture ratio decreases and parasitic capacitance increases
Solution Approach 1:
The patent applies merging by combining the power supply function and signal transmission function into the same repair line structure. By integrating these functions, the patent reduces the total number of separate conductive elements needed, thereby minimizing the area occupied by repair infrastructure and preventing aperture ratio reduction while maintaining stable power supply to repaired pixels.
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 approach effectively reduces luminance differences between repaired and adjacent pixels, maintaining image quality by ensuring consistent brightness and reducing the number of repair lines required, thus increasing the aperture ratio and minimizing parasitic capacitance.
Implementation Method 1
electrical components using laser-induced breakdown of insulating films
Data Source
AI summary
An organic light-emitting display apparatus includes: a plurality of dummy pixels including a dummy pixel circuit; a plurality of pixels including a first pixel including: a light-emitting element configured to emit light in response to a driving current supplied from the dummy pixel circuit; and a pixel circuit separated from the light-emitting element; a plurality of voltage lines configured to apply a power voltage to a power node of a second pixel; and a plurality of repair lines including: a first repair line coupling the dummy pixel circuit and the light-emitting element and configured to transfer to the light-emitting element the driving current supplied from the dummy pixel circuit; and a second repair line coupling the dummy pixel circuit and the power node of the second pixel and configured to apply to the dummy pixel circuit the power voltage that is applied to the power node.