Backlight Brightness Calibration for Smooth Mini-LED Grayscale Transitions
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Solution Overview
Problem
Conventional AM-mini-LED display devices suffer from light leakage issues leading to discontinuous and jump-varying grayscale transitions, resulting in uneven brightness and posterization, which affect image quality.
Innovation Solution
A backlight module brightness calibration method that detects actual brightness values, re-sorts grayscale values based on these values, and generates a grayscale calibration table to map corrected grayscale values, ensuring consistent brightness across divisions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If light leakage is ignored in conventional AM-mini-LED backlight modules, then the structure remains simple and manufacturing is easier, but discontinuous grayscale transitions and posterization occur
Solution Approach 1:
The patent performs preliminary measurement of actual brightness values for each division before normal operation. By pre-characterizing the light leakage characteristics of each division and storing this information in a lookup table, the system prepares compensation data in advance. This preliminary action allows the system to account for light leakage effects without changing the physical structure, thus maintaining manufacturing simplicity while achieving continuous grayscale transitions.
Solution Approach 2:
The patent changes the control parameter from direct grayscale value input to compensated grayscale value lookup. By measuring actual brightness values and creating a mapping relationship between input grayscale values and actual brightness values, the system transforms the control approach. This parameter change allows the system to compensate for light leakage effects through software lookup tables rather than hardware modifications, maintaining manufacturing simplicity while improving grayscale transition continuity.
2Manufacturing precision
If light leakage compensation is implemented through software calibration, then grayscale transitions become continuous, but calibration time and measurement process complexity increase
Solution Approach 1:
The patent performs all brightness measurements and lookup table generation during the manufacturing process before the display device is delivered to the user. By completing the calibration and creating the compensated grayscale value lookup table in advance during factory production, the system eliminates the need for time-consuming calibration procedures during product usage. This preliminary action during manufacturing ensures continuous grayscale transitions while minimizing calibration time impact.
Solution Approach 2:
The patent enables the display device to self-calibrate during manufacturing by automatically measuring actual brightness values of each division and generating the compensated grayscale value lookup table without requiring manual intervention. The system performs self-measurement and self-compensation through automated testing equipment during production, reducing calibration time and complexity while achieving continuous grayscale transitions.
3Stability of the object's composition
If each division is calibrated individually to account for light leakage, then brightness uniformity improves, but device complexity and calibration process difficulty increase
Solution Approach 1:
The patent divides the backlight module into multiple independent divisions, each with its own light leakage characteristics. By measuring and characterizing each division separately and storing individual compensated grayscale value lookup tables for each division, the system accounts for division-specific variations. This segmentation approach enables brightness uniformity across divisions while managing complexity through modular, division-specific calibration data rather than a monolithic calibration system.
Solution Approach 2:
The patent changes the calibration approach from physical hardware modifications to parameter-based software lookup tables. By measuring actual brightness values and creating mapping relationships between input grayscale values and corrected values for each division, the system achieves brightness uniformity through parameter compensation. This parameter change reduces device complexity by avoiding complex hardware calibration mechanisms while achieving uniform brightness through software-based lookup table compensation.
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 method mitigates discontinuous grayscale transitions and posterization by aligning actual brightness values, providing consistent and even brightness transitions in display devices.
Implementation Method 1
a storage capacitor (Cst) connected between the MOSFET and the TFT
Implementation Method 2
light leakage exits (light irradiates TFT to excite charges to move)
Data Source
AI summary
The present application discloses a backlight module brightness calibration method. The method includes: a brightness detection step, a grayscale sorting step, a grayscale calibration table generation step, and a grayscale calibration table output step. The present application re-sorts first grayscale values of a grayscale range of backlight divisions of a display device according to actual brightness values to obtain a grayscale calibration table to further mitigate or avoid a technical issue of a discontinuous or jump-varying grayscale transition of a backlight module of a conventional display device.