Edge-Type Backlight Brightness Uniformity Compensation
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Solution Overview
Problem
Existing LCD apparatuses with edge-type backlight assemblies face issues in maintaining uniform brightness due to variations in LED luminosity, liquid crystal transmittance, and electronic component deviations, leading to poor product yield and image quality.
Innovation Solution
A system comprising an edge-type backlight assembly, a display panel with local dimming regions, a brightness sensor, and a local dimming controller that calculates and applies brightness compensation values to each region to ensure uniformity, using a light guide plate and alternating LED light source groups to guide light and adjust driving currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If an edge-type backlight assembly is used to reduce thickness, then the thickness of the LCD apparatus is reduced, but brightness uniformity deteriorates due to variations in LED luminosity and liquid crystal transmittance
Solution Approach 1:
The backlight assembly is divided into multiple independently controllable light emitting regions corresponding to different zones of the display panel. Each region can be adjusted separately to compensate for brightness non-uniformity, allowing local brightness correction while maintaining the thin edge-type structure.
Solution Approach 2:
Different regions of the backlight assembly are assigned different driving currents to achieve local brightness adjustment. Regions with lower brightness receive higher driving currents while regions with higher brightness receive lower currents, thereby achieving overall brightness uniformity across the display panel.
2Illumination intensity
If LED driving currents are increased to compensate for brightness variations, then brightness uniformity improves, but energy consumption increases
Solution Approach 1:
The driving currents for different LED groups are dynamically adjusted based on measured brightness values. By changing the current parameters selectively in different regions, the system achieves brightness uniformity while minimizing overall energy consumption compared to uniformly increasing all currents.
Solution Approach 2:
A feedback mechanism measures the actual brightness output of each region and uses this information to adjust the driving currents accordingly. This closed-loop control ensures that energy is consumed only where necessary to achieve the desired brightness uniformity, avoiding unnecessary energy waste.
3Adaptability or versatility
If multiple electronic components are used for brightness control, then brightness adjustment capability improves, but manufacturing precision deteriorates due to component deviations and inconsistent driving currents
Solution Approach 1:
The system performs self-calibration by measuring its own brightness output and automatically adjusting its driving currents to compensate for component variations. This self-service approach eliminates the need for high-precision manual calibration and reduces the impact of manufacturing tolerances on final performance.
Solution Approach 2:
The system performs preliminary brightness measurement and compensation during the manufacturing or initialization phase. By pre-adjusting the driving currents based on measured brightness characteristics, the system compensates for component deviations before actual use, ensuring consistent performance despite manufacturing variations.
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
The system effectively compensates for brightness inconsistencies, optimizing maximum brightness and contrast, improving product yield and image quality by ensuring uniform brightness distribution across the LCD panel.
Implementation Method 1
a light guide plate and alternating LED light source groups to guide light
Implementation Method 2
a brightness sensor, configured to measure whether the brightness distribution of the display panel is uniform
Implementation Method 3
a local dimming controller that calculates and applies brightness compensation values to each region to ensure uniformity, using a light guide plate and alternating LED light source groups to guide light and adjust driving currents
Data Source
AI summary
A system and a method for compensating uniformity of brightness are provided. The system includes an edge-type backlight assembly, a display panel, a brightness sensor, a compensating calculator, and a local dimming controller. The display panel is disposed above the edge-type backlight assembly. The display panel includes plural regions for local dimming. The brightness sensor is configured to measure whether the brightness distribution of the display panel is uniform. When the brightness distribution of the display panel is not uniform, the compensating calculator calculates a brightness compensation value corresponding to each of the regions of the display panel. The local dimming controller is configured to drive the edge-type backlight assembly according to the brightness compensation value corresponding to each of the regions of the display panel.