Backlight Partition Brightness Control for LCD Detail Preservation
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Solution Overview
Problem
Liquid crystal display (LCD) devices with mini-LED backlights face challenges in maintaining adequate backlight brightness, especially when displaying dark images with small, scattered bright areas, leading to loss of display details and insufficient detail display capabilities.
Innovation Solution
The liquid crystal display device incorporates a backlight module with a light-emitting unit, a calculation unit, a comparison unit, and a control unit. The calculation unit calculates a first preset backlight brightness value for each backlight partition based on the partition's average and maximum brightness values. The comparison unit compares this value with a second preset value from the previous frame, and the control unit outputs a brightness driving value to adjust the backlight emission accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the LD algorithm uses average brightness value to determine backlight brightness, then the backlight brightness is reduced for dark images, but the backlight brightness becomes too low or zero, resulting in loss of display details
Solution Approach 1:
The patent changes the parameter used for backlight brightness calculation from average brightness value to maximum brightness value. By using the maximum brightness value of the display image to determine the backlight brightness, the system ensures that the backlight provides sufficient illumination for the brightest areas while maintaining appropriate dimming for darker areas, thus avoiding the problem of zero or near-zero backlight brightness that occurs with average-based calculation.
2Loss of energy
If the backlight brightness is reduced for dark images, then energy consumption is reduced, but display detail capability is lost
Solution Approach 1:
The patent changes the calculation parameter from average brightness to maximum brightness, which allows the backlight to maintain higher brightness levels than average-based methods would permit. This ensures that even in dark images with small bright areas, the backlight provides sufficient illumination to preserve display details, while still achieving energy savings compared to full brightness operation.
3Illumination intensity
If the backlight brightness is set to zero for dark areas, then local dimming effect is achieved, but detail display capability in dark areas is insufficient
Solution Approach 1:
The patent changes the brightness calculation parameter from average to maximum, which prevents the backlight from being set to zero even for dark areas. By using the maximum brightness value of the entire display image, the system ensures that the backlight maintains sufficient illumination to preserve details in dark areas while still achieving the desired local dimming effect through spatial variation in brightness values.
Data Source
AI summary
Liquid crystal display devices and backlight driving methods thereof are provided. A backlight module of the liquid crystal display device includes a light-emitting unit, a calculation unit, a comparison unit, and a control unit. The calculation unit calculates a first preset backlight brightness value of a backlight partition according to a partition average brightness value and a partition maximum brightness value of a corresponding display partition under a current frame display image. The comparison unit compares a second preset backlight brightness value of the backlight partition under a previous frame display image and the first preset backlight brightness value, and outputs a comparison result. The control unit outputs a first brightness driving value of the backlight partition under the current frame display image according to the comparison result. The light-emitting unit emits light in the backlight partition according to first brightness driving value.