Pixel Driving Circuit Threshold Voltage Compensation
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Solution Overview
Problem
Active matrix organic light-emitting diode (AMOLED) displays face issues with threshold voltage drift over time, leading to poor picture quality due to changes in driving current, which existing technologies have not effectively addressed.
Innovation Solution
A pixel driving circuit comprising a reset module, a compensation module, and a light-emitting module, where the reset module transmits a reset voltage to the compensation and light-emitting modules, and the compensation module writes data signals to compensate for threshold voltage, allowing the light-emitting module to operate independently of threshold voltage, using specific thin film transistors and capacitors to manage control signals and voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a basic 2T1C driving circuit is used, then the device complexity is low, but the threshold voltage drift causes poor picture quality and affects display characteristics
Solution Approach 1:
The pixel circuit is divided into distinct functional modules: a reset module containing a second TFT and fourth TFT for resetting, a compensation module containing a first TFT, third TFT, and storage capacitor for threshold voltage compensation, and a light-emitting module containing a fifth TFT, sixth TFT, and light-emitting element. This segmentation allows each module to perform its specific function independently, resolving the threshold voltage drift issue while maintaining manageable complexity through modular design.
2Reliability
If threshold voltage compensation is implemented, then the display characteristics are improved, but the circuit complexity increases
Solution Approach 1:
The reset function and threshold voltage compensation function are merged into a single pixel circuit structure that shares common elements. The second TFT and fourth TFT in the reset module work together with the first TFT, third TFT, and storage capacitor in the compensation module to achieve both resetting and compensation functions simultaneously, reducing overall circuit complexity compared to implementing these functions separately.
Solution Approach 2:
The pixel circuit is designed with multi-functional transistors and capacitors that serve multiple purposes. For example, the storage capacitor serves both the compensation function by storing threshold voltage information and works in conjunction with the light-emitting module. This multi-functionality reduces the total number of components needed while maintaining comprehensive display characteristics.
Data Source
AI summary
The present disclosure provides a pixel driving circuit and a display apparatus. The circuit includes a reset module, a compensation module, and a light-emitting module. The reset module receives a first control signal and transmits a reset voltage to the compensation module and the light-emitting module according to the first control signal for resetting the compensation module and the light-emitting module. The compensation module receives a second control signal and write data signal according to the second control signal for compensating a threshold voltage. The light-emitting module receives a third control signal and a fourth control signal for emitting light according to the thud and fourth control signals.