Backlight Control for LED Displays via Frame Segmentation
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Solution Overview
Problem
Existing backlight control methods for LED displays, which adjust intensity only once per frame, result in undesired visual artifacts, especially when transitioning from bright to dark images or when ambient lighting affects color perception, limiting contrast and color accuracy.
Innovation Solution
The solution involves adjusting the backlight intensity multiple times within a frame, dividing the display into sections for independent control, and adapting to ambient lighting conditions to enable smooth transitions and enhanced contrast, allowing for flexible luminosity adjustments and color emphasis/de-emphasis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If backlight intensity is adjusted only once per frame, then the control method is simple, but visual artifacts occur during transitions from bright to dark images
Solution Approach 1:
The patent segments the backlight control process by dividing each frame into multiple intervals (first interval, second interval, third interval) with different brightness levels. Instead of a single per-frame adjustment, the backlight intensity is segmented into multiple adjustment points within each frame, allowing smooth transitions between bright and dark images and eliminating visual artifacts.
2Object-affected harmful factors
If backlight intensity is adjusted multiple times within a frame, then visual artifacts are reduced, but the control system becomes more complex
Solution Approach 1:
The patent implements periodic backlight intensity adjustments within each frame by establishing a control cycle that divides the frame into multiple intervals. The backlight controller periodically adjusts intensity at predetermined timing points (first, second, and third intervals) rather than continuously, achieving smooth transitions while maintaining manageable system complexity through structured periodic control.
3Illumination intensity
If the display is divided into sections for independent backlight control, then contrast ratio is improved, but device complexity increases
Solution Approach 1:
The patent segments the display into multiple sections (first section, second section, third section) with independently controllable backlight units. Each section can be adjusted independently based on the content being displayed in that region, enabling local contrast optimization and enhancing overall image quality while maintaining a modular control architecture.
4Device complexity
If backlight intensity is adjusted independently of displayed images, then control is simple, but color accuracy and contrast are compromised
Solution Approach 1:
The patent implements feedback control by having the backlight controller receive image data from the display controller and adjust backlight intensity based on the actual content being displayed. The system analyzes the brightness characteristics of incoming image data and dynamically adjusts backlight intensity in real-time, ensuring optimal color accuracy and contrast while maintaining manageable control complexity through algorithmic processing.
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
This approach reduces visual artifacts, improves contrast ratio, and optimizes color representation by allowing gradual luminosity transitions and adaptive control based on ambient lighting, enhancing the overall display performance.
Implementation Method 1
the light source for the backlight includes one or more cold cathode fluorescent lamps (CCFLs)... The light source for the backlight can also be an incandescent light bulb, an electroluminescent panel (ELP), or one or more hot cathode fluorescent lamps (HCFLs)... LEDs generally have a higher ratio of light generated to power consumed
Implementation Method 2
PWM of a signal or power source involves the modulation of its duty cycle, to control the amount of power sent to a load. PWM uses a square wave whose duty cycle is modulated resulting in the variation of the average value of the waveform. PWM alternates between a high voltage that causes the emission of bright light and a low voltage that does not cause the emission of light
Data Source
AI summary
The present invention discloses apparatus and techniques relating to the intelligent control of a display's backlight LED strings. The present invention provides for controlling the display intensity on a region-by-region basis and for adjusting the intensity multiple times within the duration of a frame. The present invention also provides backlight adjustment in a manner that emphasizes certain colors and deemphasizes certain colors. The present invention also provides for adjustment of the backlight based on the ambient temperature.