OLED Pixel Circuit Pre-Compensation for Fast Transistor Discharge
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As the resolution of OLED displays improves, the driving transistor in OLED pixel circuits may not be sufficiently discharged within a short period, leading to incomplete discharge and a preset display brightness not being achieved.
Innovation Solution
A pixel circuit comprising a reset module, compensation module, energy storage module, drive module, drive control module, power supply module, and light emitting module, where the input voltage of the third power supply signal terminal is larger than the difference between the input voltage of the data signal terminal and the threshold voltage of the drive module, and less than the input voltage of the second power supply signal terminal, utilizing a voltage pre-compensation principle to speed up the discharging of the drive module to the potential Vth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the driving transistor is discharged within a short period, then the display response time is improved, but the discharge completeness deteriorates
Solution Approach 1:
The patent applies preliminary action by introducing a pre-compensation phase before the main discharge phase. In this pre-compensation phase, the driving transistor is partially discharged to a predetermined intermediate voltage level, which is closer to the final target voltage than the initial state. This preliminary discharge reduces the voltage gap that needs to be bridged in the subsequent main discharge phase, enabling complete discharge within a short time window. The pre-compensation voltage is specifically set to be larger than the difference between the data signal terminal voltage and the threshold voltage, ensuring the transistor reaches the required discharge state before the main discharge occurs.
2Productivity
If the discharge time is shortened, then the display refresh rate is improved, but the discharge completeness deteriorates
Solution Approach 1:
The patent implements preliminary action by performing a pre-compensation discharge operation before the main discharge phase. This pre-compensation step partially discharges the driving transistor to an intermediate voltage state, reducing the remaining discharge distance. By preparing the transistor in this intermediate state beforehand, the main discharge phase can complete the discharge process quickly and completely within the shortened time window required for high refresh rate operation.
Solution Approach 2:
The patent applies parameter changes by dynamically adjusting the discharge voltage levels and timing parameters. Specifically, the pre-compensation voltage is set to a specific range (larger than the difference between data signal terminal voltage and threshold voltage, but less than the second power supply voltage). This parameter optimization ensures that the transistor reaches the correct discharge state at the right time, enabling both high refresh rate and complete discharge.
3Stability of the object's composition
If the driving transistor is discharged to Vth, then the display brightness consistency is improved, but the discharge time increases
Solution Approach 1:
The patent uses preliminary action by performing a pre-compensation discharge to an intermediate voltage state before the final discharge to Vth. This intermediate state is strategically chosen to be closer to Vth than the initial voltage, reducing the remaining discharge distance. As a result, the final discharge phase reaches Vth quickly and consistently, ensuring display brightness consistency without requiring excessive discharge time.
Solution Approach 2:
The patent optimizes parameter changes by setting the pre-compensation voltage within a specific range: larger than the difference between the data signal terminal voltage and the threshold voltage, but less than the second power supply voltage. This parameter optimization creates an efficient discharge trajectory that balances discharge speed and accuracy, achieving consistent Vth discharge without unnecessary time loss.
Data Source
AI summary
The present invention provides a pixel circuit, a driving method thereof and a display device which are related to the field of display technology. The pixel circuit comprises a reset module, a compensation module, an energy storage module, a drive module, a drive control module, a power supply module and a light emitting module, the input voltage of the third power supply signal terminal is larger than the difference between the input voltage of the data signal terminal and the threshold voltage of the drive module, and is less than the input voltage of the second power supply signal terminal. The present invention is capable of discharging the driving transistor to a potential Vth within a short period, ensuring the driving transistor to be discharged completely in a short time.