Gamma Voltage Correction for Display Luminance Uniformity
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Solution Overview
Problem
Display devices face deviations in image quality characteristics due to manufacturing process variability, leading to suboptimal gamma voltage settings that affect luminance and color coordinates, resulting in defective products and reduced yield.
Innovation Solution
A gamma voltage correction method and device that measures light characteristics in specific areas of a display device, adjusts gamma voltages for sub-pixels in multiple gray levels, and interpolates corrections for non-reference levels to ensure differences in luminance and color coordinates are within a reference range, improving image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If gamma voltage correction is performed using manufacturing process data only, then correction speed is improved, but correction precision deteriorates due to inability to account for actual light characteristics variations
Solution Approach 1:
The patent merges two correction approaches: (1) manufacturing process data-based correction for rapid initial adjustment, and (2) light characteristic measurement-based correction for precise optimization. The system first performs correction using manufacturing data, then refines it by measuring actual light characteristics and calculating additional correction values, combining both methods to achieve both speed and precision.
Solution Approach 2:
The patent performs preliminary correction using manufacturing process data before final light characteristic measurement. This preliminary action provides a baseline correction that reduces the magnitude of subsequent adjustments needed, optimizing the overall correction process efficiency while maintaining accuracy.
2Device complexity
If gamma voltage is corrected uniformly across all display areas, then device complexity is reduced, but image quality deteriorates due to manufacturing variability in different regions
Solution Approach 1:
The patent applies local quality correction by dividing the display into multiple measurement areas and calculating separate gamma voltage correction values for each area based on local light characteristics. This allows each region to be corrected according to its specific manufacturing variations, achieving uniform image quality across the entire display while maintaining manageable system complexity through automated measurements.
3Measurement precision
If light characteristics are measured across the entire display area, then correction precision is improved, but measurement time and complexity increase
Solution Approach 1:
The patent segments the display area into multiple measurement regions and performs light characteristic measurements on selected areas rather than the entire display. Correction values are calculated for each segment and then applied across corresponding regions, achieving comprehensive correction coverage while significantly reducing measurement time and complexity compared to measuring every pixel.
Data Source
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AI summary
In a gamma voltage correction method for a display device including a first display area and a second display area, the gamma voltage correction method includes: correcting a gamma voltage for each sub-pixel of the first display area based on measured light characteristics of a first area of the first display area in a plurality of gray levels (S304); and correcting a gamma voltage for each sub-pixel of the second display area based on measured light characteristics of a second area of the first display area around the second display area and measured light characteristics of the second display area in the plurality of gray levels (S406).