Display Pixel Circuit Feedback to Stabilize Driving Transistor Voltage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Display devices experience blotch defects such as the Mura phenomenon due to unstable source electrode voltages caused by parasitic capacitors affecting the driving transistors, leading to poor image quality.
Innovation Solution
The display device incorporates a novel pixel circuit design with transistors and capacitors that stabilize the voltage of the driving transistor by applying power during specific periods, compensating for threshold voltage fluctuations and preventing voltage changes at the transistor's electrode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a parasitic capacitor is formed between the data line and the source electrode of the driving transistor, then data voltage transmission is enabled, but the source electrode voltage becomes unstable causing Mura phenomenon
Solution Approach 1:
The patent applies preliminary action by performing compensation for the parasitic capacitor's coupling effect before the data voltage is applied to the source electrode. The compensation transistor adjusts the gate voltage of the driving transistor in advance to counteract the expected voltage change caused by the parasitic capacitor, thereby preventing Mura phenomenon while maintaining data voltage transmission capability
Solution Approach 2:
The patent implements feedback by using the storage capacitor to store the gate voltage of the driving transistor and comparing it with reference voltages. The compensation transistor adjusts the gate voltage based on the feedback from the storage capacitor to counteract the coupling effect of the parasitic capacitor, stabilizing the source electrode voltage while maintaining data transmission
2Productivity
If the source electrode voltage changes due to parasitic capacitor coupling, then data voltage is transmitted, but blotch defects occur in the display
Solution Approach 1:
The storage capacitor stores the gate voltage of the driving transistor and provides feedback to the compensation transistor. The compensation transistor uses this feedback to adjust the gate voltage and counteract the coupling effect of the parasitic capacitor, ensuring stable source electrode voltage and preventing blotch defects while maintaining data transmission
Solution Approach 2:
The patent changes the gate voltage parameter of the driving transistor dynamically to compensate for the coupling effect. By adjusting the gate voltage based on the stored voltage and reference voltages, the system maintains stable source electrode voltage despite data voltage transmission through the parasitic capacitor
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 design stabilizes the voltage of the driving transistor, preventing blotch defects and improving image quality by maintaining consistent electrode voltages, thus enhancing display performance.
Implementation Method 1
a storage capacitor connected between the third node and the first power line
Implementation Method 2
a parasitic capacitor formed between a data line configured to transmit a data voltage to the pixels and the source electrode of the driving transistor
Data Source
AI summary
A display device includes a plurality of pixels where each pixel includes a first transistor connected between a first node and a second node, and including a gate electrode connected to a third node, a second transistor connected between a data line and the first node, and including a gate electrode, a third transistor connected between the second node and the third node, and including a gate electrode, a fourth transistor connected between a first initialization voltage line and the third node, and including a gate electrode, a fifth transistor connected between a first power line and the first node, and including a gate electrode, a sixth transistor connected between the second node and a fourth node, and including a gate electrode, a storage capacitor connected between the third node and the first power line, and a light emitting element connected between the fourth node and a second power line.