Backlight Brightness Control for LCD Lifespan and Power
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Solution Overview
Problem
Existing LCD technologies face challenges in simultaneously achieving high brightness and long lifespan for backlight CCFLs, leading to inefficient power consumption and image quality issues due to the need for additional circuits and potential brightness saturation.
Innovation Solution
An intelligent display device with a brightness calculating unit and a brightness controlling unit that compares the brightness average values of current and previous image data to adjust backlight brightness and contrast control values, preventing brightness saturation by controlling the backlight driving signal and contrast level, thereby optimizing power consumption and image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a high current is applied to the backlight CCFL to increase brightness, then the brightness is improved, but the lifespan of the CCFL is reduced
Solution Approach 1:
The patent implements dynamic backlight brightness control by continuously monitoring the average brightness of displayed images and adjusting the backlight current accordingly. When images are predominantly dark, the backlight current is reduced to extend lifespan; when bright images are detected, the current is increased to maintain image quality, thus dynamically balancing brightness and lifespan
Solution Approach 2:
The system changes the operating parameters of the backlight by adjusting the current level based on image content analysis. The controller modifies the backlight driving parameters in real-time according to the calculated average brightness values, allowing the system to operate at optimal current levels for different display scenarios
2Adaptability or versatility
If an additional circuit is added to control brightness according to image data, then the brightness control capability is improved, but the device complexity increases
Solution Approach 1:
The controller is designed to perform multiple functions: it processes image data to calculate average brightness, generates appropriate backlight driving signals, and controls the inverter circuit. This multi-functional approach eliminates the need for separate dedicated brightness control circuits, reducing overall system complexity while maintaining full brightness control capability
Solution Approach 2:
The patent combines the brightness control function with the existing backlight driving circuitry by integrating the brightness calculation and control logic into the controller that already manages the inverter. This merging of functions avoids adding independent control circuits and simplifies the overall system architecture
3Stability of the object's composition
If the backlight brightness is controlled uniformly across all screens, then the brightness consistency is improved, but the power consumption increases
Solution Approach 1:
The patent applies local quality control by adjusting the backlight brightness according to the specific content being displayed on different screens. Rather than uniform brightness control, the system analyzes the image data of each screen and applies appropriate brightness levels locally, reducing power consumption when dark images are displayed while maintaining brightness consistency when needed
4Ease of operation
If the brightness control is applied without considering image content, then the control simplicity is improved, but the image quality deteriorates due to brightness saturation
Solution Approach 1:
The system implements feedback control by continuously monitoring the image data, calculating the average brightness, and using this information to adjust the backlight driving signals. This closed-loop approach prevents brightness saturation by reducing backlight intensity when images are already bright, thereby maintaining image quality while keeping the control mechanism relatively simple
Data Source
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AI summary
Disclosed is an intelligent display device which has an adaptive backlight brightness control function of controlling the brightness of a backlight according to the gray scale level of an image data displayed by frame unit, and a method for controlling brightness of image in the display device. The display device includes a display panel having a pixel array and a backlight, a gate driving unit, a data driving unit, a brightness calculating unit, a brightness controlling unit, a backlight driving unit, and a contrast controlling unit.