OLED Data Voltage Compensation for Sub-Pixel Degradation
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Solution Overview
Problem
Display devices utilizing self-emitting organic light-emitting diodes (OLEDs) face issues of image quality degradation and image retention due to insufficient compensation of target data voltage caused by circuit component degradation.
Innovation Solution
A display device with a sensing circuitry to detect sub-pixel characteristics and a timing controller to determine and apply compensation values to correct the data voltage, ensuring accurate output to the sub-pixels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If compensation value is applied to video data based on sensed sub-pixel characteristics, then image quality degradation and image retention are reduced, but the system complexity increases due to additional sensing circuitry and correction mechanisms
Solution Approach 1:
The sensing circuitry measures sub-pixel characteristics (such as threshold voltage and mobility) in advance before normal display operation. Based on these preliminary measurements, compensation values are calculated and stored. During subsequent video data processing, these pre-calculated compensation values are applied to correct for component degradation, eliminating the need for real-time complex calculations and reducing operational system complexity.
Solution Approach 2:
A timing controller is introduced as an intermediary component that receives sensed sub-pixel characteristics, calculates appropriate compensation values, and applies these corrections to video data before it reaches the display driver. This intermediary handles the complex compensation logic centrally, simplifying the overall system architecture while maintaining reliable image quality through systematic correction of degradation effects.
2Measurement precision
If sensing circuitry is added to detect sub-pixel characteristics, then compensation accuracy is improved, but the device complexity and manufacturing cost increase
Solution Approach 1:
The sensing circuitry is designed to perform multiple functions: it measures sub-pixel characteristics for compensation purposes, and can also be used for initial panel characterization and quality control during manufacturing. This multi-functionality justifies the added circuit complexity by providing measurement precision benefits across multiple operational phases, from production to runtime compensation.
Solution Approach 2:
The display system performs self-diagnosis and self-correction by using the sensing circuitry to automatically detect sub-pixel characteristic variations and generate compensation values without external intervention. This self-service capability improves measurement precision while minimizing the need for additional external testing equipment or manual calibration procedures, thereby offsetting the internal circuit complexity with operational simplicity.
3Manufacturing precision
If compensation values are corrected based on sensed output data voltage, then target data voltage accuracy is achieved, but processing time and power consumption increase
Solution Approach 1:
Compensation values are pre-calculated and stored based on sensed sub-pixel characteristics and expected voltage requirements. When video data is processed, these pre-computed compensation values are retrieved and applied directly, avoiding time-consuming real-time calculations. This preliminary preparation achieves target data voltage accuracy while minimizing processing time during actual display operation.
Solution Approach 2:
The system implements a feedback mechanism where the sensed output data voltage is compared against target voltage levels, and compensation values are adjusted accordingly. This feedback loop refines voltage accuracy over time while maintaining efficient processing by using simple comparison and adjustment logic rather than complex iterative calculations, thus balancing precision with processing speed.
Data Source
AI summary
Embodiments relate to a display device and driving method thereof. A display device includes a display panel including a sub-pixel, a data driver including a driving circuitry configured to output data voltage to the sub-pixel and a sensing circuitry configured to sense a characteristic of the sub-pixel, and a timing controller configured to determine a compensation value of video data based on the sensed characteristic and corrects the compensation value based on sensing of an output data voltage of the driving circuitry.