OLED Pixel Circuit Voltage Regulator for Leakage Uniformity
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Solution Overview
Problem
In OLED display panels, node leakage in pixel circuits leads to deviations in light emitting luminance, causing uneven luminance across sub-pixels, particularly due to differences in leakage times between rows, resulting in interlaced bright and dark lines.
Innovation Solution
The introduction of a pixel circuit design that includes a voltage regulator module connected to a target node between switch modules, maintaining the potential of this node to reduce leakage current by minimizing voltage differences, thereby stabilizing luminance and uniformity across the display panel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional pixel circuit design is used, then device complexity is low, but node leakage causes luminance deviation and uneven luminance
Solution Approach 1:
The pixel circuit is divided into multiple functional modules: driving module, threshold compensation module, first switch module, second switch module, and voltage regulator module. Each module performs a specific function to control different aspects of the driving current, allowing precise management of node potentials and leakage currents while maintaining overall circuit reliability
Solution Approach 2:
The voltage regulator module acts as an intermediary component that maintains the potential of the target node between the first and second switch modules. This intermediary element stabilizes the voltage level and reduces leakage current without requiring complete redesign of the entire pixel circuit architecture
2Reliability
If more switch modules are added to control leakage, then luminance uniformity improves, but device complexity increases
Solution Approach 1:
The first and second switch modules serve multiple functions: they control the flow of driving current to the light emitting element, regulate node potentials, and minimize leakage currents. This multi-functionality reduces the need for additional dedicated components while achieving luminance stability
Solution Approach 2:
The voltage regulator module maintains equipotential conditions at the target node by stabilizing its potential level. This equipotential approach minimizes voltage differences that drive leakage currents, thereby improving luminance stability without requiring excessive switching components
Data Source
AI summary
The present application provide a pixel circuit and a driving method thereof, and a display panel. The pixel circuit includes: a driving module, a control end of the driving module being electrically connected to a first node; a threshold compensation module, electrically connected to a first scan signal line, the first node, and a first end of the driving module; a first switch module, electrically connected to a first light emitting control signal line and the first end of the driving module; a second switch module, electrically connected to a second light emitting control signal line, a second end of the first switch module, and a first electrode of a light emitting element; and a voltage regulator module, electrically connected to a constant voltage signal line and a target node.