LCD White Balance Calibration With Luminance Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional white balance calibration methods in LCD modules result in significant luminance loss and color inconsistency, necessitating additional brightness calibration, which prolongs the calibration process and increases costs.
Innovation Solution
An advanced white balance calibration process that simultaneously performs white balance and brightness calibration by using tristimulus conversion, predicting color coordinate variations, and adjusting R/G/B gain values to minimize deviations and achieve homogeneity across LCD modules.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional white balance calibration adjusts R and G channel gains based on CIE 1931 chromaticity diagram, then color temperature accuracy is improved, but luminance loss increases significantly
Solution Approach 1:
The patent changes the calibration parameters from traditional CIE 1931 chromaticity coordinates to CIE 2015 UCS (Uniform Chromaticity Scale) coordinates, which provide a more uniform color space. This parameter change allows for more accurate color temperature adjustment while minimizing luminance loss, as the UCS space better represents human perception of color differences.
Solution Approach 2:
The patent performs preliminary measurement of the LCD module's actual color coordinates and luminance characteristics before calibration. By measuring the specific properties of each module and pre-calculating the optimal gain adjustments in CIE 2015 UCS space, the system可以避免subsequent luminance loss that would require additional brightness calibration steps.
2Measurement precision
If conventional white balance calibration is performed separately from brightness calibration, then color accuracy is improved, but calibration process time increases
Solution Approach 1:
The patent merges white balance calibration and brightness calibration into a single integrated process. By using CIE 2015 UCS color space and simultaneously optimizing both color coordinates and luminance based on measured module characteristics, the system achieves accurate color calibration without requiring a separate brightness calibration step, thereby reducing total calibration time.
Solution Approach 2:
The calibration algorithm is designed to perform multiple functions simultaneously: it adjusts color temperature, corrects color coordinates, and optimizes luminance all in one process. This multi-functional calibration approach eliminates the need for sequential calibration steps while maintaining high color accuracy across different LCD modules.
3Measurement precision
If R and G channel gains are adjusted to correct color coordinates, then white balance accuracy is improved, but color consistency among products deteriorates
Solution Approach 1:
The patent transitions from using CIE 1931 xy color space to CIE 2015 UCS color space for calibration. This parameter change provides a more uniform color space that better correlates with human perception, allowing for more consistent color adjustments across different LCD modules while maintaining accurate white balance.
Solution Approach 2:
The patent performs individualized calibration for each LCD module by measuring its specific color coordinates and luminance characteristics. By tailoring the calibration parameters to each module's actual properties rather than applying uniform gain adjustments, the system achieves both accurate white balance and consistent color performance across product batches.
Data Source
AI summary
A method and apparatus for displaying an image using advanced white balance calibration. an image display method includes receiving target color coordinates and target luminance, receiving actual color coordinates and actual luminance measured from an LCD module, performing tristimulus conversion, the actual color coordinates, and the actual luminance, outputting R/G/B gain values, calculating an estimated luminance value of the LCD module, comparing the estimated luminance value with the target luminance value to estimate a BLU LED current required to output the target luminance value, predicting an amount of color coordinate variation caused by the estimated BLU LED current fluctuation, compensating for the target color coordinates and calculating final R/G/B gain values and applying the final R/G/B gain values to the LCD module.