OLED Sub-Pixel Degradation Compensation via Voltage Gain
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Solution Overview
Problem
Organic light emitting display devices experience decreased luminance and luminance deviation due to the degradation of organic light emitting diodes over time, leading to reduced performance and image quality.
Innovation Solution
The implementation of a degradation compensator within the panel driver that calculates and applies a degradation compensation gain value to each sub-pixel based on accumulated data, adjusting the data voltage to maintain initial luminance levels and compensate for non-linear degradation characteristics, thereby extending the lifespan of the organic light emitting diodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If organic light emitting diodes are driven continuously to maintain display operation, then luminance output is maintained, but degradation occurs leading to lowered luminance and luminance deviation
Solution Approach 1:
The patent implements a feedback mechanism by accumulating data on the driving history of each sub-pixel and using this accumulated data to calculate degradation compensation gain values. The panel driver continuously monitors and adjusts the data voltage based on accumulated degradation information, creating a closed-loop system that compensates for luminance degradation over time while maintaining display operation.
Solution Approach 2:
The patent changes the electrical parameters (data voltage) supplied to each sub-pixel based on accumulated degradation data. By calculating degradation compensation gain values from accumulated driving data and applying these as voltage adjustments, the system dynamically modifies operating parameters to compensate for degradation and maintain luminance output.
2Stability of the object's composition
If degradation compensation is applied to maintain luminance, then luminance stability is improved, but device complexity increases due to additional compensation circuitry
Solution Approach 1:
The patent makes the panel driver perform multiple functions: it not only drives the display pixels but also accumulates driving data, calculates degradation compensation values, and adjusts voltages accordingly. By integrating the degradation compensation functionality into the existing panel driver, the invention avoids adding separate complex compensation circuits while achieving luminance stability.
Solution Approach 2:
The system uses its own accumulated driving data to automatically calculate and apply degradation compensation. The panel driver monitors its own operation, accumulates relevant data, and self-adjusts the voltage output without requiring external intervention or additional sensing hardware, thereby maintaining stability while minimizing added complexity.
3Illumination intensity
If data voltage is increased to compensate for degradation, then luminance is maintained, but power consumption increases
Solution Approach 1:
The patent applies degradation compensation locally to each sub-pixel based on its specific accumulated driving data rather than uniformly increasing voltage across the entire display. By calculating individual degradation compensation gain values for each sub-pixel and applying targeted voltage adjustments only where needed, the system maintains luminance while minimizing overall power consumption increases.
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
This solution effectively maintains high luminance levels over time by compensating for degradation, reducing residual images and prolonging the lifespan of the organic light emitting diodes, while ensuring uniform luminance across sub-pixels.
Implementation Method 1
the organic light emitting diode (OLED) may emit light by the flow of data current (Ioled) supplied from the driving transistor (Tdr)
Data Source
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AI summary
An organic light emitting display device includes a display panel (100) having a plurality of sub-pixels; a memory (300) configured to accumulate and store data displayed by each sub-pixel; and a panel driver (200) configured to: calculate a degradation compensation gain value for increasing or decreasing a luminance of each sub-pixel based on accumulated data of each sub-pixel stored in the memory (300), generate modulated data of each sub-pixel by modulating input data to each sub-pixel according to the calculated degradation compensation gain value, convert the modulated data into a data voltage, and accumulate the modulated data from the accumulated data of the corresponding sub-pixel and then store the data in the memory (300).