Light Source Driving Apparatus for Reducing Display Flicker
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Solution Overview
Problem
Existing local dimming methods for LCD displays suffer from flickering phenomena, especially when displaying images with subtitles, due to luminance differences between frames and blocks, which are not effectively mitigated without increasing the size and power requirements of the driving integrated circuit.
Innovation Solution
A method of driving a light source that generates a compensated luminance representative value based on average and maximum grayscale values extracted from image signals, using a compensation control signal to adjust the luminance of light-emitting blocks, thereby reducing the rate of luminance change and minimizing flickering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If local dimming methods are used to reduce power consumption and improve contrast ratio, then power consumption and image quality are improved, but flickering phenomenon occurs due to luminance differences between frames and blocks
Solution Approach 1:
The patent applies preliminary action by detecting image patterns in advance (subtitles, gradients, uniform regions) and pre-compensating luminance changes before they cause visible flickering. The system analyzes historical frame data and predicts upcoming luminance transitions, adjusting backlight intensity proactively to prevent flickering rather than reacting after it occurs.
Solution Approach 2:
The patent implements feedback by continuously monitoring displayed images for flickering phenomena and using this information to adjust backlight control parameters. The system detects luminance differences between adjacent blocks and frames, feeds this information back to the controller, and dynamically modifies backlight intensity to eliminate or reduce flickering while maintaining local dimming benefits.
2Reliability
If the number of driving blocks is increased to prevent flickering, then flickering is reduced, but size and power requirements of driving integrated circuit are substantially increased
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the number of active driving blocks based on detected image patterns. Instead of using a fixed high number of blocks, the system adapts the driving block configuration according to the content - using fewer blocks for uniform images and more blocks only when necessary (e.g., when subtitles or high-contrast regions are detected), thereby preventing flickering without consistently increasing circuit complexity.
Solution Approach 2:
The patent implements dynamics by making the driving block configuration adaptable rather than static. The system dynamically reconfigures which blocks are active based on real-time image analysis, transitioning between different driving modes (global dimming, local dimming with varying block counts) to optimize between flickering prevention and circuit complexity based on current display requirements.
3Loss of energy
If global dimming mode is used to reduce power consumption, then power consumption is reduced, but flickering phenomenon is generated due to luminance differences between frames
Solution Approach 1:
The patent applies local quality by transitioning from uniform global dimming to localized backlight control. Instead of treating the entire screen uniformly, the system identifies specific regions (subtitles, high-contrast areas) and applies different backlight intensity levels to those local regions while maintaining dimming in uniform areas. This localized approach prevents flickering in critical regions while preserving overall power savings.
Solution Approach 2:
The patent uses preliminary action by detecting subtitle regions and high-contrast areas in advance and pre-adjusting backlight intensity for those specific regions before luminance changes occur. This proactive compensation prevents flickering in critical areas while maintaining global dimming benefits, as the system anticipates and compensates for upcoming luminance transitions in identified regions.
Data Source
AI summary
A method of driving a light source including a light-emitting block includes generating a luminance representative value based on an average grayscale value and a maximum grayscale value extracted from an image signal corresponding to the light-emitting block. The method further includes detecting a predetermined pattern of the light-emitting block, generating a compensation control signal based on the predetermined pattern, generating a compensated luminance representative value by compensating the luminance representative value based on the compensation control signal, and driving the light-emitting block based on the luminance level of the light-emitting block corresponding to the compensated luminance representative value.