Electroluminescent Display Luminance Compensation via Digital Lookup Tables
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Solution Overview
Problem
Electroluminescent display devices face challenges in maintaining luminance uniformity due to changes in light emission ratios of color pixels and voltage drops across the display panel, leading to luminance deviations and gamma distortions.
Innovation Solution
A method and device that generate global and local compensation values based on input pixel values, global current values, and gamma distortion to produce compensated pixel values, enhancing luminance uniformity through a digital scheme that accounts for voltage drops and gamma distortions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a typical OLED display device supplies current corresponding to data signals using driving transistors to generate lights, then the display device achieves rapid response and low power consumption, but luminance uniformity is degraded due to changes in loading of the display panel
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing compensation values in lookup tables before actual display operation. The system pre-computes compensation data based on panel loading conditions and stores it in memory, so that during operation only table lookup and simple addition are needed. This eliminates the need for complex real-time calculations while maintaining luminance uniformity compensation effectiveness.
Solution Approach 2:
The patent replaces the mechanical/analog current control system with a digital signal processing system. Instead of using complex analog circuits to compensate for luminance variations, the system uses digital lookup tables and arithmetic operations to calculate compensation values. This substitution simplifies the system architecture and enables more precise compensation through software-based algorithms.
2Adaptability or versatility
If the loading of the display panel changes depending on light emission ratios of color pixels, then the display device can dynamically adjust output, but luminance uniformity is degraded due to voltage drops across the panel
Solution Approach 1:
The patent segments the compensation into multiple independent components: global compensation based on overall panel loading, local compensation based on position-specific voltage drops, and gamma compensation for signal non-linearity. Each component is calculated separately using dedicated lookup tables, then combined through simple addition. This segmentation allows the system to maintain dynamic output adjustment while compensating for luminance variations caused by loading changes.
Solution Approach 2:
The patent introduces compensation values as intermediary elements between the input signal and the final display output. These compensation values act as mediators that translate the effects of panel loading and voltage drops into correctable signal adjustments. By inserting this intermediary compensation layer, the system can maintain adaptability to different loading conditions while preserving luminance uniformity.
3Stability of the object's composition
If digital compensation methods are used to correct luminance deviations, then luminance uniformity is improved, but device complexity increases due to additional processing circuits
Solution Approach 1:
The patent reduces processing circuit complexity by performing all complex calculations in advance during system initialization or calibration. Lookup tables are pre-computed and stored in memory, eliminating the need for complex real-time calculation circuits. During normal operation, only simple table lookup and addition operations are required, significantly reducing the complexity of active processing circuits.
Solution Approach 2:
The patent uses lookup tables as pre-stored copies of compensation data. Instead of calculating compensation values in real-time through complex circuits, the system copies pre-computed compensation values from memory tables. This copying approach replaces complex computational hardware with simpler memory access and addition circuits, reducing overall device complexity while maintaining compensation effectiveness.
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
Significantly improves luminance uniformity by compensating for luminance deviations and gamma distortions, providing a more uniform image display compared to analog schemes, and effectively addressing voltage-related issues in electroluminescent display devices.
Implementation Method 1
electroluminescent displays have quick response speeds and reduced power consumption, using light-emitting diodes (LEDs) or organic light-emitting diodes (OLEDs) that emit light through recombination of electrons and holes
Data Source
AI summary
A method of compensating luminance in an electroluminescent display device including a display panel including pixels is provided. A global current value is generated based on input pixel values corresponding to the pixels where the global current value indicates a global current flowing through the display panel. With respect to each of the input pixel values, a global compensation value indicating a global luminance deviation according the global current is generated based on the input pixel value and the global current value. A gamma compensation value indicating a gamma distortion is generated based on the input pixel value where the gamma distortion is caused by compensating the input pixel value. A compensated pixel value is generated based on the input pixel value, the global compensation value and the gamma compensation value.