OLED Pixel Circuit with Dual-Capacitor Flicker Compensation
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Solution Overview
Problem
Organic light emitting display apparatuses suffer from flickering due to coupling phenomena between nodes in the pixel circuit, which degrades display quality.
Innovation Solution
A pixel circuit is designed with capacitors and transistors to compensate for luminance variations, reducing flicker by incorporating a driving transistor, first and second transistors, first and second capacitors, and a light-emitting diode to stabilize pixel performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional pixel circuit is used, then the device complexity is low, but flicker occurs due to coupling phenomena between nodes
Solution Approach 1:
The pixel circuit is divided into functionally independent modules: a driving transistor module for controlling current, a first compensation module with capacitor and transistor for compensating threshold voltage variations, and a second compensation module with additional capacitor and transistor for compensating mobility variations. This segmentation allows each module to address specific coupling phenomena independently, reducing overall flicker while maintaining manageable complexity.
Solution Approach 2:
Capacitors are introduced as intermediary elements to store and compensate for voltage variations caused by coupling phenomena. The first capacitor compensates for threshold voltage variations, while the second capacitor compensates for mobility variations. These intermediary components mediate between the driving transistor and the light-emitting diode, stabilizing the circuit operation and reducing flicker.
2Reliability
If additional capacitors and transistors are added to compensate for luminance variation, then flicker is reduced, but the device complexity increases
Solution Approach 1:
The compensation modules are designed to automatically compensate for variations in threshold voltage and mobility without external intervention. The capacitors and transistors in the compensation modules self-regulate the voltage and current to maintain stable luminance output, eliminating the need for complex external control systems and reducing overall device complexity.
Solution Approach 2:
The circuit compensates for coupling phenomena by dynamically changing electrical parameters such as voltage and current. The capacitors store and release charge to compensate for voltage variations, while the transistors adjust current flow to maintain stable luminance. These parameter changes occur automatically in response to coupling phenomena, reducing flicker without requiring complex structural modifications.
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
The solution effectively reduces flicker, thereby improving the display quality and stability of organic light emitting displays.
Implementation Method 1
a light emitting diode connected to the third transistor and a low potential power line
Data Source
AI summary
The present disclosure relates to a pixel circuit and a display apparatus comprising the pixel circuit. A pixel circuit according to an exemplary embodiment of the present disclosure may include a driving transistor including a gate electrode, a first electrode, and a second electrode, a first transistor connected to the gate electrode and the second electrode, a second transistor connected to the first transistor and the gate electrode, a third transistor connected to the second electrode and the first transistor, a first capacitor connected to the gate electrode, the first transistor, the second transistor, and a high potential power line, a second capacitor connected to the high potential power line, the first capacitor, and the second transistor, and a light emitting diode connected to the third transistor and the low potential power line.