Backlight Control for Liquid Crystal Display Power and Color
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Solution Overview
Problem
Liquid crystal display devices using the RGBW system suffer from poor color rendering and increased power consumption due to the addition of white subpixels, leading to dark pure colors and inefficient backlight usage, especially under low gray levels where saturation analysis is less relevant.
Innovation Solution
A liquid crystal display device with an image data obtaining module, including a gray level analyzing module and a saturation analyzing module, generates specific backlight driving signals based on average pixel brightness and saturation information, using convolution operations and pulse width modulation to optimize backlight power consumption and image brightness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the RGBW system is used to replace the RGB system, then luminous efficiency is improved, but pure color saturation deteriorates due to white subpixels making background brightness greater than pure color brightness
Solution Approach 1:
The patent applies local quality by differentiating the treatment of different pixel types. Saturation analysis is performed specifically on subpixels that are not white subpixels (i.e., red, green, and blue subpixels), allowing pure color regions to maintain proper saturation while white subpixels continue to provide high luminous efficiency for background areas. This selective analysis preserves pure color saturation in critical regions while maintaining overall luminous efficiency.
Solution Approach 2:
The patent implements dynamic control by adjusting the backlight driving signal based on real-time analysis of image data characteristics. The system dynamically determines whether to perform saturation analysis based on the presence of pure color regions, and dynamically adjusts the backlight intensity accordingly. This dynamic approach allows the system to adapt between prioritizing luminous efficiency (when no pure color is present) and prioritizing color saturation (when pure color regions are detected).
2Manufacturing precision
If saturation analysis is performed on all image data, then pure color display quality is improved, but power consumption increases especially under low gray levels where saturation analysis is less relevant
Solution Approach 1:
The patent applies partial action by performing saturation analysis only when necessary - specifically, only when the image data contains regions requiring pure color display. The system analyzes image data to determine whether saturation analysis is needed, and only then performs the computationally intensive saturation analysis. This avoids the excessive action of performing saturation analysis on all image data unconditionally, thereby reducing power consumption while maintaining pure color display quality when needed.
Solution Approach 2:
The patent implements feedback by using the results of gray level analysis to control whether saturation analysis is performed. The system first analyzes the gray level characteristics of the image data, and based on this feedback, determines whether the image contains regions requiring pure color display. This feedback mechanism allows the system to intelligently activate saturation analysis only when the image characteristics indicate it is necessary, optimizing the balance between display quality and power consumption.
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 effectively reduces power consumption of the backlight module while improving the display of pure colors by adjusting backlight brightness, ensuring better image quality and reduced power usage.
Implementation Method 1
a liquid crystal panel 30
Implementation Method 2
the panel driving module 20 drives the liquid crystal panel 30 based on the image data
Implementation Method 3
a backlight module 50 and a backlight driving module 40
Implementation Method 4
the backlight driving module 40 includes a pulse width modulation module 41 configured to modulate the backlight driving signal
Implementation Method 5
the backlight driving module 40 includes a pulse width modulation module 41 configured to modulate the backlight driving signal during a display period to form a power supplier for being provided to the backlight module 50
Data Source
AI summary
A liquid crystal display device and a backlight control method thereof are provided. In response to that average pixel brightness of image data is less than a threshold, a first backlight driving signal is generated based on gray level information of the image data and a second backlight driving signal is generated based on saturation information of the image data. A convolution operation is performed on the first and the second backlight driving signal to output a backlight driving signal. The backlight driving signal is modulated and provided to a backlight module for producing backlight to a liquid crystal panel. Power consumption of the backlight module is lowered and meanwhile a dark effect caused in displaying images of a pure color is improved.