OLED Display Threshold Voltage Ripple Correction
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Solution Overview
Problem
Organic light emitting display devices face luminance deviations due to non-uniform electrical characteristics of driving transistors, leading to errors in image quality compensation caused by ripples in the driving voltage during threshold voltage sensing.
Innovation Solution
An organic light emitting display device with a determiner to detect voltage ripples, a detector to identify affected horizontal lines, a corrector to adjust characteristic data based on adjacent lines, and a data processor to compensate input data, ensuring accurate image quality correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If direct voltage application method is used for sensing threshold voltage, then sensing speed is improved, but measurement precision deteriorates due to voltage ripple errors
Solution Approach 1:
The patent introduces a sensing transistor as an intermediary component between the driving transistor and the voltage source. This sensing transistor isolates the driving transistor from direct voltage application, preventing voltage ripple from directly affecting the threshold voltage measurement. The sensing transistor acts as a buffer that enables accurate sensing without the harmful direct voltage connection.
2Stability of the object's composition
If image quality compensation is performed using sensed threshold voltage, then luminance uniformity is improved, but reliability deteriorates due to horizontal line defects from voltage ripple errors
Solution Approach 1:
The sensing transistor serves as a protective intermediary that prevents voltage ripple from corrupting the threshold voltage measurement. By inserting this intermediate component, the system maintains reliable measurements even in the presence of voltage fluctuations, ensuring that image quality compensation can be performed accurately without introducing horizontal line defects.
Solution Approach 2:
The patent performs threshold voltage sensing through the sensing transistor before applying compensation based on the measured values. By obtaining accurate threshold voltage data through the intermediary sensing transistor in advance, the system can perform reliable image quality compensation without the risk of voltage ripple-induced errors affecting the final display output.
Data Source
AI summary
Disclosed is an organic light emitting display device. In a sensing mode of sensing a threshold voltage of a driving transistor, when ripple occurs in a driving voltage applied to a drain of the driving transistor, an error may occur in the sensed threshold voltage. Therefore, when sensing a threshold voltage of a driving transistor, the display device corrects a threshold voltage of a driving transistor of each pixel included in a horizontal line having an error caused by a ripple of a driving voltage, to a threshold voltage of each pixel included in another horizontal line.