Display Brightness Adjustment for Uneven Vcom and Pixel Voltages
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Solution Overview
Problem
Existing liquid crystal display technologies suffer from afterimages due to insufficient pixel and common voltages, leading to uneven brightness and image sticking, particularly when images are displayed over extended periods.
Innovation Solution
A brightness adjustment method that divides images into regions based on common and pixel voltage distributions, calculates voltage compensation values, and adjusts gamma voltages in overlapping regions to achieve even brightness across the display.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If gamma data is pre-stored and brightness adjustment is performed on a region basis using conventional methods, then the display can show different brightness levels, but brightness unevenness occurs due to insufficient Vpixel and uneven Vcom at some regions, causing afterimages
Solution Approach 1:
The display screen is divided into multiple first regions based on Vcom voltage distribution characteristics and multiple second regions based on Vpixel voltage distribution characteristics. These regions are then overlapped to form multiple adjustment regions, each requiring different gamma compensation. This segmentation allows precise regional brightness control to compensate for voltage unevenness and prevent afterimages.
Solution Approach 2:
Different gamma data is applied to different adjustment regions based on their specific voltage characteristics. Each region receives customized gamma compensation values calculated from its local Vcom and Vpixel voltage distributions, achieving local brightness optimization rather than uniform global adjustment.
2Device complexity
If the display device uses fixed gamma data for brightness adjustment, then the implementation is simple, but it cannot compensate for regional voltage differences, leading to brightness unevenness and afterimages
Solution Approach 1:
The system pre-calculates and stores multiple sets of gamma data corresponding to different adjustment regions before actual display operation. During display, the appropriate gamma data is selected and applied based on the current image content and regional voltage characteristics, avoiding complex real-time calculations while achieving precise regional compensation.
Solution Approach 2:
The gamma values are adjusted as a parameter to compensate for voltage distribution characteristics in different regions. By changing gamma parameters regionally, the system adapts the brightness characteristics to match the local voltage conditions, achieving uniform perceived brightness across the display.
3Ease of operation
If conventional region-based brightness adjustment is used, then implementation is straightforward, but it fails to address both Vcom and Vpixel voltage variations simultaneously, resulting in insufficient afterimage prevention
Solution Approach 1:
The screen is segmented into first regions based on Vcom characteristics and second regions based on Vpixel characteristics. The overlap of these segmentations creates adjustment regions that inherently account for both voltage types, maintaining methodological simplicity while improving effectiveness.
Solution Approach 2:
The adjustment regions formed by overlapping first and second regions serve as an intermediary concept that bridges Vcom and Vpixel compensation. Each adjustment region's gamma data is derived from both voltage characteristics, providing integrated compensation without requiring complex multi-step adjustment processes.
Data Source
AI summary
A brightness adjustment method, a brightness adjustment device and a display device are provided. The brightness adjustment method includes: dividing into M first regions in accordance with a distribution state of common voltages Vcom, a difference between the common voltages Vcom in different first regions being greater than a first threshold; dividing into N second regions in accordance with a distribution state of pixel voltages Vpixel, a difference between the pixel voltages Vpixel in different second regions being greater than a second threshold; calculating a voltage compensation value in each first region; calculating a voltage compensation value in each second region; overlapping the M first regions and the N second regions to obtain M*N adjustment regions; calculating gamma voltages at different grayscales in each adjustment region to obtain a set of gamma data about the M*N adjustment regions; driving a display module to display in accordance with the gamma data.