Hybrid Backlight Control for Display Devices
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Solution Overview
Problem
Existing Dynamic Backlight Control (DBLC) methods, such as the peak-value method, rely heavily on individual pixels, leading to unnecessary high backlight levels and flicker, and fail to optimize power savings without compromising image quality.
Innovation Solution
A hybrid method combining histogram-based statistical analysis with peak-value methods to determine the optimal backlight level on a frame-by-frame basis, balancing power savings and image quality by surveying all pixels and using a hybrid approach to select the best method for each frame.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the peak-value method is used to determine backlight level based on the most demanding pixel, then power consumption is reduced for dark images, but the backlight level becomes unnecessarily high due to reliance on single pixels and causes flicker
Solution Approach 1:
The patent segments the pixel population into different groups (e.g., first group and second group) based on their backlight requirements. Instead of relying on a single peak pixel, the system analyzes multiple segments of pixels to determine the backlight level, thereby reducing the impact of stray pixels while maintaining power savings.
Solution Approach 2:
The patent merges the analysis of multiple pixel groups together to determine the final backlight level. By combining the requirements from different pixel segments rather than focusing on a single peak pixel, the system achieves more stable backlight control that reduces both power consumption and flicker.
2Reliability
If the backlight level is set high to maintain image quality, then visual artifacts are avoided, but power consumption increases significantly
Solution Approach 1:
The patent applies partial action by setting the backlight level based on only a portion of the pixel requirements rather than meeting the maximum demand of all pixels. By analyzing multiple pixel groups and using thresholds, the system provides sufficient backlight for most pixels while avoiding excessive backlight for rare peak pixels, thus saving power while maintaining acceptable image quality.
3Loss of energy
If dynamic backlight control adjusts backlight level frame-by-frame, then power savings are achieved, but flicker is caused due to drastic changes from stray pixels
Solution Approach 1:
The patent applies beforehand cushioning by establishing thresholds and minimum/maximum backlight levels before processing each frame. These pre-set parameters cushion against drastic backlight changes by limiting the range of adjustment and filtering out the impact of stray pixels, thereby reducing flicker while maintaining power savings through frame-by-frame optimization.
Data Source
AI summary
Display systems and methods for adjusting backlight illumination are disclosed for selecting a backlight illumination level that is low enough to reduce backlight power consumption while maintaining a desired level of image quality. The method 1) determines the peak illumination level requested by a frame to satisfy all pixels in a frame, 2) determines a histogram-based statistical illumination value for the frame, and 3) selects the lower of the two values. The histogram-based statistical illumination value is calculated using an error function for different ranges of illumination levels, wherein the error function correlates with luminance error introduced by selecting next lower range of illumination levels.