OLED Display Luminance Uniformity via Sensor Compensation
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Solution Overview
Problem
Organic light emitting displays face challenges in maintaining uniform luminance due to degradation of organic light emitting diodes and non-uniformity in the threshold voltage and mobility of driving transistors, leading to inefficient image display.
Innovation Solution
Incorporating a sensor and converter system that extracts degradation and mobility information of organic light emitting diodes and driving transistors, respectively, to adjust data signals and ensure uniform luminance by compensating for these variations within the pixel structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional pixel circuits without compensation mechanisms are used, then device complexity is reduced, but luminance uniformity deteriorates due to OLED degradation and transistor parameter variations
Solution Approach 1:
The patent extracts degradation information and mobility information in advance during non-display periods, stores them in memory, and uses this pre-acquired data to compensate for OLED degradation and transistor parameter variations during subsequent display operations. This preliminary measurement and storage approach enables uniform luminance without adding complex real-time compensation circuits.
Solution Approach 2:
The patent introduces a sensor as an intermediary component that measures OLED degradation information and transistor mobility information. This sensor acts as a mediator between the OLED/transistor and the control system, providing quantitative data that enables compensation without requiring complex direct interaction between the display elements and control circuits.
2Illumination intensity
If real-time compensation for OLED degradation is implemented, then luminance uniformity is improved, but response speed deteriorates due to additional measurement and calculation time
Solution Approach 1:
The patent performs degradation information extraction and mobility information extraction during non-display periods, storing results in advance. This preliminary action eliminates the need for real-time measurements during display operation, maintaining fast response speed while achieving luminance uniformity through pre-computed compensation values.
Solution Approach 2:
The patent implements periodic extraction of degradation information and mobility information at specific intervals (e.g., after predetermined time periods or at predetermined frame counts), rather than continuous real-time measurement. This periodic approach maintains luminance uniformity while minimizing impact on response speed by limiting measurement overhead to discrete time points.
3Measurement precision
If degradation information extraction and mobility information extraction are performed continuously, then measurement precision is improved, but energy consumption increases
Solution Approach 1:
The patent extracts degradation information and mobility information periodically based on predetermined conditions (time intervals or frame counts), rather than continuously. This periodic measurement approach maintains sufficient measurement precision for compensation purposes while significantly reducing power consumption compared to continuous monitoring.
Solution Approach 2:
The patent performs degradation information extraction and mobility information extraction selectively during non-display periods or at specific intervals, using partial measurements rather than exhaustive continuous monitoring. This partial action approach provides sufficient information for effective compensation while minimizing energy consumption.
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
The system effectively maintains uniform luminance across the display, reducing the impact of diode degradation and transistor mobility variations, thereby enhancing image quality and consistency.
Implementation Method 1
An organic light emitting display among the flat panel display devices displays an image using organic light emitting diodes (OLEDs) that generate light using the recombination of electrons and holes
Data Source
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AI summary
An organic light emitting display device includes: a plurality of pixels at crossing portions of data lines, scan lines, and emission control lines; a sensor for sensing degradation information of organic light emitting diodes and mobility information of driving transistors, which are included in each pixel; a converter for storing the degradation information of organic light emitting diodes and the mobility information of driving transistors, which are sensed utilizing the sensor and converting input data to corrected data by utilizing the stored information; and a data driver receiving the corrected data and generating data signals to be supplied.