PWM Signal Generator for Smooth Backlight Brightness Control

The patent changes the control parameter from discrete LED element selection or current value adjustment to continuous duty ratio modulation. By varying the duty ratio of PWM signals, the system achieves fine-grained brightness control with high resolution while maintaining simple control logic.

The patent replaces mechanical/discrete control methods (controlling number of LED elements or current values) with electrical signal-based continuous control through PWM duty ratio adjustment, enabling smoother and more precise brightness transitions.

The patent pre-divides the duty ratio adjustment range into multiple discrete levels and stores corresponding PWM signals in advance. When brightness adjustment is needed, the system simply selects from pre-prepared signals rather than calculating and generating PWM signals in real-time, significantly reducing the setting period.

Instead of adjusting the duty ratio continuously or at every possible level, the patent uses a limited number of pre-defined duty ratio levels that are sufficient for practical brightness adjustment requirements. This partial action approach reduces computational overhead and time consumption while maintaining adequate brightness control precision.

The patent introduces dynamic brightness adjustment by continuously or near-continuously varying the duty ratio of PWM signals. This dynamic control enables smooth brightness transitions without abrupt changes, improving both the smoothness of brightness variation and the precision of luminance adjustment.

The patent maintains continuous PWM signal generation with varying duty ratios, ensuring that brightness adjustment is a continuous process rather than discrete steps. This continuous action eliminates gaps and interruptions in brightness change, achieving smooth transitions while maintaining high adjustment precision.