Backlight Brightness Adjustment via Stepwise PWM Control

The patent implements dynamic brightness adjustment by continuously monitoring ambient luminance through a light sensor and dynamically updating PWM duty cycles in real-time. The system transitions from static periodic adjustment to dynamic continuous adaptation, allowing the backlight brightness to respond immediately to ambient light changes without delayed periodic updates, thereby eliminating visible flickering while maintaining energy efficiency.

The patent employs feedback control by using a light sensor to continuously detect ambient luminance and feeding this information back to the control processor. The processor calculates the appropriate PWM duty cycle based on the feedback signal and adjusts the backlight brightness accordingly. This closed-loop feedback mechanism ensures real-time tracking of ambient light changes and eliminates the delayed response and flickering observed in open-loop periodic adjustment methods.

The patent applies partial action by using only the necessary most significant bits of the PWM signal for brightness adjustment, rather than utilizing the full 8-bit precision. By focusing on the most significant bits that have the greatest impact on perceived brightness, the system achieves smooth transitions without flickering while keeping the device complexity low. This selective use of signal precision eliminates sudden backlight changes caused by minor variations in less significant bits.

The patent changes the parameter of PWM signal precision by effectively using only the most significant bits for brightness control. This parameter change smooths out sudden backlight variations by ignoring minor fluctuations in less significant bits, thereby reducing visible flickering while maintaining adequate brightness control precision. The system transforms the approach from using full precision to using selective precision optimized for human visual perception.