External Compensation GOA Circuit for AMOLED Display Threshold Voltage Shift
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional AMOLED display technologies face challenges in simultaneously achieving normal driving and blanking time random detection waveforms, which are necessary for effective external real-time compensation of threshold voltage shifts in thin film transistors, affecting the uniformity and accuracy of screen image display.
Innovation Solution
The proposed external compensation gate driver on array (GOA) circuit incorporates a scan signal output branch and a random detection signal output branch, allowing the circuit to switch between working and non-working statuses using a blank signal, enabling the output of both normal driving and random detection waveforms during blanking time to detect threshold voltage shifts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the GOA circuit uses a single output branch for normal driving, then the circuit structure is simple, but it cannot perform random detection during blanking time to compensate for threshold voltage shifts
Solution Approach 1:
The GOA circuit is divided into two independent output branches: a scan signal output branch for normal driving and a random detection signal output branch for threshold voltage detection. This segmentation allows each branch to perform its specific function independently, enabling both normal display operation and compensation detection without interference, thereby resolving the contradiction between compensation accuracy and circuit complexity.
Solution Approach 2:
The GOA circuit is designed with multi-functionality by incorporating both scan signal output and random detection signal output capabilities within the same circuit structure. The circuit can switch between normal driving mode and detection mode using the same input signals (scan signal, clock signal, and blank signal), achieving universal functionality that addresses both display driving and threshold voltage compensation needs.
2Measurement precision
If the circuit outputs normal driving waveforms continuously, then the display operation is stable, but it cannot detect threshold voltage shifts during blanking time
Solution Approach 1:
The circuit utilizes the periodic blanking time intervals in the display refresh cycle to periodically switch to detection mode. During each blanking period, the random detection signal output branch is activated to detect threshold voltage shifts, while the scan signal output branch remains active for normal driving. This periodic action enables precise threshold voltage detection without compromising overall display refresh efficiency.
Solution Approach 2:
The blank signal serves as an intermediary control signal that mediates between the scan signal output branch and the random detection signal output branch. It enables the circuit to switch between normal driving and detection modes during blanking time, allowing threshold voltage detection to occur without disrupting the continuous display operation, thus maintaining both detection precision and productivity.
Data Source
AI summary
The present invention discloses an external compensation GOA circuit and a display panel. By adding a random detection signal output branch, a first output waveform of a scan signal line fulfilling normal driving is outputted in a normal time, and a second output waveform of the scan signal line fulfilling blanking time random detection is outputted in a blanking time, such that randomly detecting a threshold voltage of the drive transistor by using the blanking time of the scan signal can be achieved to further achieve external real time compensation of the threshold voltage shift, enhance uniformity of screen image display, and improve a lifespan of the display panel.