Pixel Driving Circuit Coupling Module for OLED Brightness Consistency
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Solution Overview
Problem
OLED display panels face issues with inconsistent brightness due to leakage currents affecting the potential of the control terminal in the pixel driving circuit, leading to poor display quality.
Innovation Solution
A pixel driving circuit is designed with a data writing module connected to the first terminal of the driving module, and a coupling module that performs voltage division during the light-emitting stage to maintain the control terminal's potential within a preset threshold range, ensuring consistent light emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the data writing module is directly connected to the control terminal of the driving module, then data signals can be written efficiently, but leakage currents cause potential drift at the control terminal leading to brightness inconsistency
Solution Approach 1:
The patent introduces a coupling module as an intermediary between the data writing module and the driving module. This coupling module includes a coupling capacitor that transfers the data signal to the first terminal of the driving module without directly connecting to the control terminal, thereby preventing leakage current from affecting the control terminal potential while still achieving efficient data signal transmission.
2Device complexity
If the control terminal is directly driven by the data writing module, then the circuit structure is simple, but the potential of the control terminal cannot be maintained within a preset threshold range due to leakage currents
Solution Approach 1:
The coupling module acts as an intermediary that decouples the data writing path from the control terminal. The coupling capacitor transfers the data signal to the first terminal while isolating the control terminal from leakage current effects, enabling precise potential control without significantly increasing circuit complexity.
Solution Approach 2:
The patent segments the circuit into distinct functional modules: the data writing module, the coupling module with capacitor, and the driving module. This segmentation allows the control terminal to be isolated from the data writing path while maintaining functional connectivity through the coupling capacitor, thereby achieving precise potential control.
3Ease of operation
If leakage current affects the control terminal potential, then the circuit operation is simplified, but the light-emitting element produces inconsistent brightness
Solution Approach 1:
The coupling capacitor serves as a mediator that transfers the data signal to control the first terminal of the driving module without allowing leakage current to affect the control terminal. This maintains simple circuit operation while ensuring consistent light emission by stabilizing the control terminal potential.
Data Source
AI summary
A pixel driving circuit, a driving method, a display panel and a display device are provided. The pixel driving circuit include a driving module, configured to drive a light-emitting element to emit light, wherein a control terminal of the driving module is electrically connected to a first node, and a first terminal is electrically connected to a second node; a data writing module, configured to write data signals, wherein a control terminal of the data writing module is electrically connected with a first scan signal line, and a first terminal is electrically connected with a data signal terminal; and a coupling module, configured to couple the data signals to the first terminal of the driving module, wherein a first terminal of the coupling module is electrically connected to a second terminal of the data writing module, and a second terminal is electrically connected to the second node.