Backlight Mura Removal via Partitioned Compensation
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Solution Overview
Problem
Existing methods for resolving direct-lit backlight mura in LCD devices require excessive memory space and logic resources, making them inefficient for high-definition and ultra-high-definition displays.
Innovation Solution
A method that divides the backlight into multiple partitions and units, calculates brightness compensation values, and applies linear interpolation to reduce data requirements and logic resource consumption, allowing for thinner and cost-effective direct-lit backlight modules.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If brightness compensation is applied to each partition in existing direct-lit backlight modules, then backlight mura is resolved, but memory space and logic resources are excessively consumed
Solution Approach 1:
The patent divides the backlight into multiple partitions and further divides each partition into multiple units. By segmenting the compensation data storage into a first storage area (for reference partition compensation values) and a second storage area (for difference values of other partitions), the system reduces overall memory requirements while maintaining comprehensive brightness compensation across all partitions
Solution Approach 2:
The patent extracts the reference partition compensation values from the complete set of all partition compensation values and stores them separately in the first storage area. Only the difference values for other partitions are stored in the second storage area, thereby reducing total data storage requirements while preserving the ability to reconstruct full compensation data
2Reliability
If brightness compensation is applied to each partition in existing direct-lit backlight modules, then backlight mura is resolved, but logic resources are excessively consumed
Solution Approach 1:
The patent segments the compensation process into two distinct stages: first, retrieving reference partition compensation values from the first storage area; second, retrieving difference values from the second storage area and combining them with the reference values. This segmented approach simplifies the logic required in each stage compared to managing complete compensation data for all partitions simultaneously
Solution Approach 2:
The patent extracts only the essential reference partition compensation values and the differential information for other partitions, removing the need to process and store complete compensation datasets for all partitions. This extraction reduces computational complexity and logic resource consumption while maintaining compensation effectiveness
3Ease of manufacture
If the diffusion sheet is made thinner for cost reduction, then manufacturing cost is reduced, but backlight mura occurs
Solution Approach 1:
The patent implements a feedback mechanism where brightness values are measured for each partition, compensation values are calculated based on these measurements, and then applied to correct non-uniformities. This closed-loop feedback system enables the use of thinner, lower-cost diffusion sheets while maintaining backlight uniformity through active compensation
Solution Approach 2:
The patent changes the parameters of the backlight system by introducing dynamic compensation values that adjust the effective brightness output of different partitions. This allows the physical diffusion sheet to be thinner while the optical uniformity is maintained through parameter adjustment in the control system
Data Source
AI summary
The present invention teaches a method for removing backlight mura. The method divides backlight into partitions, and divides each partition into units. The method then selects one of the partitions as a reference partition and selects the compensation values of the reference partition from all partitions. The method further calculates brightness difference values for all partitions other than the reference partition relative to the brightness of the reference partition. Finally, the method conduct brightness compensation to the other partitions based on the reference partition's compensation values, and the brightness difference values of the other partitions. The method may not only effectively eliminate backlight mura, but also allow the direct-lit backlight module to be thinner or of lower cost, and significant reduce storage requirement and logic resource.