OLED Pixel Circuit With Voltage-Stabilizing Capacitor for Flicker Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In OLED display substrates, the variation in gate electrode voltage due to leakage current causes brightness fluctuations, leading to a flicker phenomenon that affects display quality.
Innovation Solution
A pixel circuit design incorporating a voltage stabilizing capacitor connected to the second electrode of a first transistor, which maintains a constant voltage at this electrode, balancing the 'pulling up' and 'pulling down' effects of leakage currents, thereby stabilizing the driving voltage and reducing brightness variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a driving voltage is applied to the gate electrode of the driving transistor during the light emitting stage, then the OLED emits light with corresponding brightness, but leakage current causes voltage variation at the gate electrode leading to brightness variation and flicker
Solution Approach 1:
A voltage stabilizing capacitor is introduced as an intermediary component connected between the gate electrode and a constant voltage signal source. This capacitor acts as a mediator that supplies compensating current to counteract the leakage current effect, thereby stabilizing the gate electrode voltage and preventing brightness variation during the light emitting stage
Solution Approach 2:
The voltage stabilizing capacitor forms a feedback mechanism by being connected to both the gate electrode and a constant voltage source. The capacitor automatically adjusts its voltage contribution based on the leakage current conditions, providing negative feedback that maintains stable gate voltage and eliminates flicker phenomenon
2Stability of the object's composition
If the voltage stabilizing capacitor is connected to the second electrode of the first transistor, then the voltage stability is enhanced and flicker is reduced, but the device complexity increases
Solution Approach 1:
The voltage stabilizing capacitor serves multiple functions: it stabilizes the gate electrode voltage, compensates for leakage current effects, and maintains constant voltage reference. By making this single component multi-functional, the circuit achieves improved voltage stability without proportionally increasing overall device complexity
Solution Approach 2:
The patent optimizes the capacitance value and connection parameters of the voltage stabilizing capacitor to achieve effective voltage stabilization with minimal additional complexity. By carefully selecting the capacitor's electrical parameters and connection configuration, the solution achieves the desired stability improvement while keeping the circuit structure as simple as possible
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 stabilizes the driving voltage, reducing flicker phenomena and enhancing display quality by maintaining consistent light emission.
Implementation Method 1
a voltage stabilizing capacitor, a first electrode of the voltage stabilizing capacitor being connected to the second electrode of the first transistor, and a second electrode of the voltage stabilizing capacitor being connected to a constant voltage signal source
Data Source
AI summary
The pixel circuit includes: a light emitting module configured to emit light; a driving module configured to drive the light emitting module to emit light according to a driving voltage during a light emitting stage; a storage module configured to maintain the driving voltage and to provide the driving voltage to the driving module during the light emitting stage; a first transistor, a first electrode of the first transistor being connected to a position where the driving module receives the driving voltage, and a second electrode of the first transistor being not directly connected to a signal source; a second transistor, a first electrode of the second transistor being connected to the first electrode of the first transistor, wherein a structure to which a second electrode of the second transistor is connected is different from a structure to which the second electrode of the first transistor is connected.