Shared Threshold Compensation for OLED Pixel Circuits
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Solution Overview
Problem
In organic light-emitting displays (OLEDs), the non-uniform threshold voltages of driving TFTs across pixel points lead to variations in current flowing through OLEDs, resulting in non-uniform display brightness, which is challenging to address without increasing the pixel area and reducing Pixels per Inch (PPI).
Innovation Solution
A pixel circuit design that includes multiple sub-pixel circuits with a shared threshold compensation module, where the compensation voltage is provided by one sub-pixel circuit and shared with others, reducing the need for individual compensation modules in each pixel circuit, thereby maintaining uniform current flow and reducing the overall pixel area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a threshold voltage compensation loop is arranged in each pixel circuit, then the threshold voltage of the driving TFT is compensated and current uniformity is improved, but the area of a single pixel increases and PPI is reduced
Solution Approach 1:
The patent merges the threshold voltage compensation function from individual pixel circuits into a shared compensation circuit that serves multiple pixel circuits. This consolidation eliminates the need for separate compensation loops in each pixel, thereby reducing pixel area while maintaining current uniformity through centralized threshold voltage compensation.
Solution Approach 2:
The shared compensation circuit is designed to provide threshold voltage compensation for multiple pixel circuits simultaneously. This multi-functional approach allows a single compensation module to serve multiple pixels, reducing the overall area required for compensation components while maintaining uniform current distribution across all pixels.
2Manufacturing precision
If a threshold voltage compensation loop is arranged in each pixel circuit, then the threshold voltage of the driving TFT is compensated, but the device complexity increases
Solution Approach 1:
The patent combines multiple threshold voltage compensation loops into a single shared compensation circuit. This merging reduces the total number of compensation components and simplifies the overall circuit architecture while maintaining the necessary threshold voltage compensation function for multiple pixel circuits.
Solution Approach 2:
The shared compensation circuit is designed to perform threshold voltage compensation for multiple pixel circuits through a universal compensation mechanism. This multi-functional design reduces device complexity by eliminating redundant compensation components while maintaining compensation effectiveness across all pixels.
Data Source
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AI summary
The embodiments of the present disclosure disclose a pixel circuit, a driving method and a display apparatus. The pixel circuit comprises multiple sub-pixel circuits, one of which is arranged with a threshold compensation module, and shares a voltage compensated by the threshold compensation module with other sub-pixel circuits. According to the embodiments of the present disclosure, only a threshold compensation module may be arranged for multiple pixels, so as to reduce an average area occupied by a single pixel and is beneficial for improving the PPI of the display apparatus.