LCD Dynamic Contrast Control With Histogram-Based Backlight and Gamma
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Solution Overview
Problem
TFT liquid crystal display apparatus face issues of lower brightness and contrast, particularly in displaying dark pictures, leading to increased power consumption and flicker due to existing Dynamic Gamma Control solutions.
Innovation Solution
A processing device and method that adjusts the backlight source brightness and liquid crystal panel transmissivity through histogram statistical processing, generating a pulse wide modulation dimming control signal and Gamma reference voltage to enhance dynamic contrast while maintaining brightness, thereby reducing power consumption and eliminating flicker.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If Dynamic Gamma Control solution is used to increase contrast by changing Gamma voltage, then the contrast of picture is improved, but the brightness is increased which leads to higher power consumption
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the Gamma voltage based on histogram statistics of the displayed image. When dark pictures are detected, the system modifies the Gamma reference voltage to enhance contrast in the dark region while maintaining overall brightness control through backlight dimming, thus improving contrast without proportionally increasing power consumption
Solution Approach 2:
The system implements dynamic contrast enhancement by continuously monitoring the histogram distribution of displayed images and adjusting Gamma voltage in real-time. This dynamic adaptation allows the system to optimize contrast only when needed (dark pictures) rather than maintaining high contrast settings continuously, thereby reducing unnecessary power consumption
2Manufacturing precision
If Dynamic Gamma Control solution is used to increase contrast, then the dynamic range of gray scale voltage is improved, but flicker is perceived when pictures become bright or dark suddenly
Solution Approach 1:
The system performs preliminary histogram analysis on the incoming image data before display, allowing it to predict and prepare appropriate Gamma voltage adjustments. This preliminary action enables smooth transitions by pre-calculating the required voltage changes, preventing sudden shifts that would cause flicker perception
Solution Approach 2:
The patent implements a feedback mechanism where the histogram statistics of displayed images are continuously monitored and used to adjust Gamma voltage settings. This closed-loop control ensures that contrast enhancement is applied smoothly and adaptively, preventing abrupt changes that would manifest as flicker while maintaining optimal dynamic range
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 solution increases dynamic contrast and picture quality, reduces power consumption by over 40% by adjusting backlight source brightness and liquid crystal panel transmissivity, and eliminates flicker by maintaining constant brightness, thus improving the overall performance of TFT liquid crystal display apparatus.
Implementation Method 1
generating a pulse wide modulation dimming control signal... receiving the pulse wide modulation dimming control signal from said central processing module, and driving the backlight source
Implementation Method 2
TFT liquid crystal display apparatus... driving a liquid crystal panel... changing the transmissivity of the liquid crystal panel
Data Source
AI summary
This invention relates to a processing device and processing method of high dynamic contrast for liquid crystal display apparatus, the processing device comprises a receiver, an inverter, and a source driving IC connected with a central processing module. The processing method includes: performing a histogram statistical process on received low voltage Differential Signaling data; obtaining a backlight source dimming coefficient and a Gamma reference voltage parameter of the same frame of picture according to the result of the histogram statistical process. controlling the brightness of the backlight source according to said backlight source dimming coefficient; controlling the voltage of the pixel capacitor on the liquid crystal panel according to said Gamma reference voltage parameter. This invention respectively adjusts the brightness of the backlight source and the voltage of the pixel capacitor of the liquid crystal panel simultaneously, and hence the dynamic contrast of the picture is increased, the problems of lower contrast and flicker of TFT liquid crystal display apparatus are ameliorated, and the power consumption of the backlight source is saved.