Backlight Dimming Controller Block Segmentation for LCD Blooming
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Solution Overview
Problem
The blooming phenomenon occurs during local dimming in liquid crystal display devices, causing image brightness to be reduced and clarity to be compromised due to strong light leakage from light sources in dark areas to adjacent bright areas.
Innovation Solution
The display device minimizes blooming by dividing each block into a greater number of unit blocks than the number of light sources, allowing for precise adjustment of dimming values and transmittance, and further adjusts dimming values based on the surrounding environment's brightness to prevent brightness reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If local dimming is applied to improve contrast, then image contrast is improved, but blooming phenomenon occurs causing image clarity to deteriorate
Solution Approach 1:
The patent divides each block into multiple unit blocks (e.g., 2x2 or 3x3 grid) to create finer granularity in dimming control. This segmentation allows independent dimming value calculation for each unit block, preventing light leakage between adjacent regions with different brightness requirements, thereby resolving the blooming phenomenon while maintaining contrast improvement.
Solution Approach 2:
The patent applies different dimming values to different unit blocks based on their specific image content characteristics. By calculating representative values for each unit block and applying localized dimming adjustments, the system maintains high contrast in dark regions while preventing blooming in bright regions, achieving spatially optimized light control.
2Use of energy by moving object
If local dimming is applied to reduce power consumption, then power consumption is reduced, but image brightness is reduced due to blooming
Solution Approach 1:
By segmenting blocks into unit blocks, the patent enables precise power management where only necessary regions are dimmed. Unit blocks with dark content receive reduced power, while bright unit blocks maintain full brightness, preventing the overall brightness reduction that would result from blanket dimming approaches.
Solution Approach 2:
The patent applies dimming selectively to specific unit blocks based on their content characteristics. This localized approach ensures that power consumption is reduced only in regions where it is necessary, while maintaining image brightness in regions where high luminance is required, thus resolving the contradiction between power savings and brightness maintenance.
3Object-affected harmful factors
If the number of light sources is increased to reduce blooming, then blooming is reduced, but manufacturing cost increases
Solution Approach 1:
The patent achieves blooming reduction through software-based block segmentation and differential dimming control rather than hardware multiplication. By dividing existing blocks into unit blocks and applying independent dimming values, the system eliminates blooming without requiring additional light sources, thus maintaining cost-effectiveness.
Solution Approach 2:
The patent controls blooming by changing the dimming parameter values assigned to different unit blocks rather than changing the physical light source configuration. This parameter-based control approach achieves the same effect as having more light sources but without the associated manufacturing cost increase.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances image contrast and reduces the blooming phenomenon while maintaining image brightness, without increasing manufacturing costs by using more light sources.
Implementation Method 1
A transmissive liquid crystal display device that occupies most of liquid crystal display devices displays an image by modulating light from a backlight unit by controlling an electric field that is applied to a liquid crystal layer
Data Source
Figure 1~2
Figure 3
Figure 4A~4A(c)
AI summary
Provided are a display device and an operating method thereof. The display device includes a liquid crystal display panel, a backlight unit including a plurality of light sources for supplying light to the liquid crystal display panel and driven in a state of being divided into a plurality of blocks corresponding to the number of the light sources, and a backlight dimming controller configured to calculate dimming values of the plurality of blocks. The backlight dimming controller is configured to divide each of the plurality of blocks into a plurality of unit blocks and control brightness of an output image differently for each of the unit blocks.