OLED Pixel Circuit Threshold Voltage Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
OLED display apparatuses experience significant brightness differences between phases due to varying bias states of driving transistors, leading to display issues like flickering at low-frequency and low-grayscale states, which affect the display effect.
Innovation Solution
Incorporating a threshold detection module to detect the threshold voltage of driving transistors and adjusting the voltage accordingly during the adjusting phase to minimize bias state differences between phases, ensuring consistent brightness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the driving transistor operates in different phases without threshold voltage compensation, then the pixel circuit can complete data writing and light emission, but the brightness difference between phases becomes significant
Solution Approach 1:
The threshold detection module detects the threshold voltage of the driving transistor before the data writing phase and light emission phase. Based on the detected threshold voltage, an adjusting voltage is generated and applied to compensate for the bias state differences that would otherwise occur during phase transitions, thereby preventing brightness inconsistency before it manifests
Solution Approach 2:
The patent dynamically adjusts the voltage parameter applied to the driving transistor by generating an adjusting voltage based on the detected threshold voltage. This parameter change compensates for the bias state variations between phases, maintaining consistent brightness while allowing the display to operate at different refresh frequencies and grayscale levels
2Use of energy by moving object
If the pixel circuit operates at low-frequency and low-grayscale states, then power consumption is reduced, but brightness difference between phases becomes more obvious
Solution Approach 1:
The threshold detection module continuously monitors the threshold voltage of the driving transistor and provides feedback information. Based on this feedback, the adjusting voltage is dynamically generated to compensate for bias state differences, ensuring that brightness consistency is maintained even when the display operates at low-frequency and low-grayscale states with reduced power consumption
3Illumination intensity
If a threshold detection module is added to detect threshold voltage, then brightness consistency is improved, but device complexity increases
Solution Approach 1:
The threshold detection module is integrated into the existing pixel circuit structure, sharing circuit elements and signal pathways with other pixel circuit components. The detection and compensation functions are merged into the phase transition process, adding minimal structural complexity while achieving brightness consistency across different operating conditions
Data Source
AI summary
A display apparatus and a method for driving the same are provided. The display apparatus includes pixel circuits and a threshold detection module. The pixel circuit includes a driving transistor and a data voltage writing module including an output terminal electrically connected to the driving transistor. The threshold detection module is configured to detect a threshold voltage of the driving transistor. An operating process of the pixel circuit includes a first phase and a second phase. The first phase includes a data writing phase and a light-emitting phase. The second phase includes an adjusting phase and a light-emitting phase. The driving transistor receives a data voltage during the data writing phase. During the adjusting phase, the driving transistor receives an adjusting voltage corresponding to the threshold voltage of the driving transistor that is detected by the threshold detection module.