OLED Pixel Driving Circuit Threshold Voltage Drift Compensation
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Solution Overview
Problem
In organic light-emitting displays, the threshold voltage drift of driving transistors leads to inaccurate luminance of organic light-emitting diodes, resulting in non-uniform image display due to varying drift amounts across different diodes.
Innovation Solution
The organic light-emitting display panel incorporates a pixel driving circuit with a driving module, luminance control module, data write module, and potential collecting module, where the luminance control module sets the gate and first electrode of the driving transistor to the same potential, avoiding threshold voltage drift and extending the transistor's service life by controlling the light-emitting time of the organic light-emitting device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional pixel driving circuit with a driving transistor is used, then the organic light-emitting diode can be driven to emit light, but the threshold voltage of the driving transistor drifts over time due to process or aging factors, resulting in poor luminance accuracy and non-uniform display
Solution Approach 1:
The patent applies equipotentiality by setting the gate and first electrode of the driving transistor to the same potential through the luminance control module. This eliminates the potential difference that causes threshold voltage drift, thereby maintaining stable transistor characteristics over time and improving both luminance accuracy and service life.
Solution Approach 2:
The patent implements dynamic control of the driving transistor by using the luminance control module to adjust the potential of the gate and first electrode in real-time during operation. This dynamic adjustment compensates for threshold voltage drift and extends the transistor's service life while maintaining accurate luminance control.
2Device complexity
If the threshold voltage of the driving transistor is allowed to drift, then the device complexity is reduced, but the display uniformity deteriorates due to varying drift amounts across different sub-pixels
Solution Approach 1:
By setting the gate and first electrode to the same potential, the patent eliminates threshold voltage drift across all sub-pixels uniformly. This maintains display uniformity without requiring complex compensation circuits, as the equipotential condition applies consistently across the entire display panel.
3Measurement precision
If the luminance control module controls the light-emitting time of the organic light-emitting device, then the luminance accuracy is improved, but the device complexity increases due to additional control circuits
Solution Approach 1:
The luminance control module performs multiple functions: it sets the gate and first electrode to the same potential to prevent threshold drift, controls the light-emitting time of the organic light-emitting device for accurate luminance control, and extends the service life of the driving transistor. This multi-functionality reduces the need for separate circuits, thereby limiting the increase in device complexity.
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 solution maintains luminance accuracy and uniformity across sub-pixels, extends the service life of the driving transistor, and reduces the number of signal lines, enhancing the aperture ratio and resolution of the display panel.
Implementation Method 1
the driving module is configured to drive the organic light-emitting device to emit light under control of the control terminal and based on voltage provided by the first voltage terminal
Data Source
AI summary
The present application discloses an organic light-emitting display panel, and a driving method for the display. The organic light-emitting display panel comprises a plurality of pixel driving circuits, each of the pixel driving circuits comprises a first voltage terminal, a second voltage terminal, a scanning signal terminal, a data signal terminal, a first control signal terminal, a second control signal terminal, a potential collecting terminal, a driving module, an organic light-emitting device, a luminance control module, a data write module, and a potential collecting module. The driving module is configured to drive the organic light-emitting device to emit light under control of the control terminal based on voltage provided by the first voltage terminal. The method therefore mitigates a threshold voltage drift in advanced organic light-emitting display panel technology.