Local Dimming Backlight Voltage Control for Faster Current Stabilization
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Solution Overview
Problem
Conventional display devices with local dimming functions face slow response rates in adjusting backlight module voltages and currents, leading to longer stabilization times and higher power loss, especially during rapid screen changes.
Innovation Solution
A backlight control circuit with a power supply circuit, local dimming circuit, and supply voltage adjustment circuit that generates adjustment signals based on image data and LED characteristics to pre-adjust and dynamically fine-tune the power supply voltage, ensuring rapid stabilization and reduced power loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If feedback mechanism is used to adjust operating voltage and driving current, then brightness stability is improved, but response time increases and power loss increases
Solution Approach 1:
The patent applies preliminary action by using a feed-forward mechanism that predicts the required operating voltage based on incoming image data characteristics (such as average luminance, contrast, and histogram analysis) before the actual display frame is rendered. This allows the power supply voltage to be adjusted in advance, so when the frame is displayed, the voltage is already optimized, eliminating the delay inherent in feedback-only systems.
Solution Approach 2:
The patent combines feedback mechanism with feed-forward prediction. The feedback circuit monitors actual brightness and provides correction signals, while the feed-forward module pre-adjusts voltage based on predicted image characteristics. This hybrid approach maintains brightness stability while significantly reducing response time compared to feedback-only systems.
2Reliability
If feedback mechanism is used to adjust operating voltage and driving current, then brightness stability is improved, but power loss increases
Solution Approach 1:
By predicting the required voltage level based on image data characteristics before the frame is displayed, the system pre-adjusts the power supply voltage to the optimal value. This eliminates the need for large voltage adjustments during frame display, reducing power loss that would otherwise occur during feedback-based voltage stabilization.
Solution Approach 2:
The patent changes the operating voltage parameter in advance based on predicted image characteristics (such as average luminance level, contrast ratio, and histogram distribution). By adjusting voltage proactively rather than reactively, the system avoids the energy dissipation that occurs when voltage must be rapidly adjusted during frame display to maintain brightness stability.
3Adaptability or versatility
If operating voltage is dynamically adjusted during rapid screen changes, then brightness tracking is improved, but voltage response delay occurs
Solution Approach 1:
The feed-forward module analyzes incoming image data characteristics (such as luminance histograms, contrast levels, and scene complexity) and predicts the optimal operating voltage before the frame is displayed. This pre-adjustment ensures that voltage tracking keeps pace with rapid screen changes without the inherent delay of feedback-based adjustment.
Solution Approach 2:
The patent implements dynamic voltage adjustment by continuously monitoring image data characteristics and adjusting the operating voltage in real-time based on predicted requirements. The system adapts voltage levels dynamically for different scene conditions (such as dark scenes, bright scenes, high-contrast content) while maintaining fast response through the feed-forward prediction mechanism.
Data Source
AI summary
A backlight control circuit includes a power supply circuit, a local dimming circuit, a backlight driving circuit, and a supply voltage adjustment circuit. The power supply circuit is used to output the power supply voltage to a backlight module. The backlight module has multiple dimming zones, and each dimming zone has light emitting diodes (LEDs). The local dimming circuit is used to generate a local dimming signal according to image data and a configuration of the dimming zones. The backlight driving circuit is used to generate backlight driving signals to the dimming zones of the backlight module according to the local dimming signal. The supply voltage adjustment circuit is used to generate a first supply voltage adjustment signal to the power supply circuit for adjusting the power supply voltage based on the local dimming signal and a characteristic data of each LED in the dimming zones.