OLED Demura via Iterative Local Gamma Compensation
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Solution Overview
Problem
Current Demura algorithms are not suitable for OLED display panels due to differences in gamma curves between pixel dots, leading to inadequate brightness compensation and non-uniform display quality.
Innovation Solution
A method involving iterative calculations of local gamma values and compensation gray scales using a brightness capturing device, such as a CCD, to adjust pixel brightnesses to achieve target brightnesses, ensuring uniformity by repeatedly calculating compensation gray scales until a preset condition is met.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a unified gamma value or gamma curve is used for Demura compensation in OLED display panels, then the calculation process is simple, but the compensation result is inaccurate due to gamma curve differences between pixel dots
Solution Approach 1:
The patent divides the display panel into multiple local regions and calculates separate gamma values for each region based on captured brightness data. This local quality approach allows each region to be compensated according to its specific gamma characteristics, resolving the contradiction between simple calculation and accurate compensation by making the calculation complexity adaptive to local needs rather than uniformly simple or uniformly complex.
Solution Approach 2:
The patent segments the display panel into multiple measurement regions and performs separate gamma value calculations for each segment. This segmentation enables the system to handle gamma curve variations across different pixel dots by treating each region independently, thus achieving accurate compensation without requiring a single complex unified calculation model.
2Manufacturing precision
If iterative calculation is performed to achieve accurate brightness compensation, then the compensation accuracy is improved, but the calculation time increases
Solution Approach 1:
The patent implements iterative calculation with a preset maximum iteration count and early termination condition. When the compensation result meets the preset accuracy requirement, the iteration stops early, avoiding unnecessary additional calculations. This partial action approach ensures high compensation accuracy while minimizing calculation time by performing only the necessary iterations.
Solution Approach 2:
The patent uses feedback from captured brightness data to continuously adjust and refine the compensation gray scale values through iterative calculation. Each iteration uses the feedback from the previous iteration's results to improve accuracy, while the process is controlled to terminate when accuracy requirements are met, thus balancing accuracy improvement with time efficiency.
Data Source
AI summary
Disclosed is a method of eliminating OLED display panel Mura. The compensation gray scale which should be utilized is calculated according to the target brightnesses, the actual brightnesses at the 255 gray scale of the respective sub pixels, and the local gamma value at the present display gray scale, and then the OLED display panel is made to show the present compensation gray scale captured at present to determine whether the preset condition of ending the calculation of the compensation gray scale is achieved, and if it is not achieved, the actual brightness of the sub pixel at the compensation gray scale is captured to calculate again for obtaining the local gamma value at the present display gray scale and the compensation gray scale which should be utilized next time, and the iterative computation does not stop until the aforesaid preset condition is achieved.