Pixel Driving Circuit With Threshold Compensation for Mura Reduction
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Solution Overview
Problem
Current display panels suffer from non-uniformity in thin film transistor electrical parameters, leading to the Mura phenomenon due to variations in threshold voltage and mobility, which affects brightness and chromaticity.
Innovation Solution
A pixel driving circuit with a threshold compensation circuit and a storage circuit that adjusts the potential of the control terminal in response to the light-emitting element's potential, maintaining consistency in potential patterns to eliminate the influence of threshold voltage on the driving current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If thin film transistors are used in display panels, then the display can be manufactured with current processes, but non-uniformity in electrical parameters occurs leading to Mura phenomenon
Solution Approach 1:
The patent applies preliminary action by introducing a threshold compensation circuit that performs compensation before the display output stage. The circuit pre-adjusts the gate-source voltage of the driving transistor to account for threshold voltage variations, ensuring uniform display performance despite manufacturing non-uniformities in TFT electrical parameters
Solution Approach 2:
The patent implements parameter changes by dynamically adjusting the gate-source voltage (Vgs) of the driving transistor through the threshold compensation circuit. The circuit modifies the voltage parameter to compensate for threshold voltage shifts, thereby maintaining consistent driving current and eliminating Mura phenomenon while preserving the manufacturability of standard TFT processes
2Manufacturing precision
If threshold voltage compensation is implemented, then display uniformity is improved, but circuit complexity increases
Solution Approach 1:
The patent applies merging by integrating the threshold compensation function into the existing pixel circuit structure. The compensation circuit shares nodes and transistors with the driving circuit, combining multiple functions (data writing, threshold compensation, and driving) into a unified circuit architecture that reduces overall complexity compared to separate compensation circuits
Solution Approach 2:
The patent implements universality by designing the compensation circuit to serve multiple functions: it performs threshold voltage compensation, maintains data signal integrity, and works across different display modes. The same circuit structure handles both compensation and normal driving operations, reducing the need for additional dedicated compensation components
Data Source
AI summary
An array substrate includes a first direct voltage signal line extending along a first direction; and a second direct voltage signal line extending along a second direction, the first direction intersecting the second direction. Pixel driving circuits are arranged in an array along the first direction and the second direction, and are respectively electrically connected to the first direct voltage signal line and the second direct voltage signal line. A pixel driving circuit includes a first transistor having a gate electrically connected to a first node. The first transistor is configured to provide a driving current for a light-emitting element. A first storage capacitor includes a first plate electrically connected to the first node, and a second plate electrically connected to a first electrode of the light-emitting element through a first connection part.