LED Display Circuit with Variable Duty Cycle Driving

The patent applies periodic action by using pulse-width modulation (PWM) to drive the LED with alternating current pulses at different duty cycles. Instead of continuously supplying high current, the circuit delivers periodic pulses where the LED is on for a specific duration and off for the remainder of the period. This achieves average luminance control while maintaining peak current stability during the on-period, reducing overall energy consumption while preserving luminance stability when needed.

The patent implements dynamics by making the driving current adjustable and adaptive. The circuit dynamically changes the duty cycle of the driving current based on the required gray level, allowing the system to optimize between luminance stability and energy consumption in real-time. The driving current is not fixed but varies according to display requirements, enabling the system to use higher current only when luminance stability is critical and lower current when energy savings are prioritized.

By using periodic PWM driving, the circuit achieves effective luminance control without requiring continuously high current pathways. The periodic on-off switching allows the use of smaller current-carrying components since the average current is reduced, even though peak currents during the on-period remain sufficient for stability. This reduces the size of traces, transistors, and other current-handling elements in the circuit.

The patent applies multi-functionality by designing a single primary driving circuit that serves multiple sub-pixels. Instead of having separate driving circuits for each sub-pixel (which would require significant area), one driving circuit is shared among multiple sub-pixels through time-division multiplexing. The circuit alternates between driving different sub-pixels within a frame period, achieving the function of multiple drivers with a single physical circuit, thereby reducing overall circuit area.

The patent implements multi-functionality by designing a single primary driving circuit that can drive multiple sub-pixels through time-division multiplexing. Within each frame period, the driving circuit sequentially activates different sub-pixels (e.g., red, green, blue sub-pixels for different pixels) at different time slots. This allows one physical circuit to perform the function of multiple dedicated circuits, enabling high-resolution displays without proportionally increasing the total circuit area.

The patent uses periodic action through frame-based scanning and time-division multiplexing. The driving circuit operates in periodic frames, with each frame containing multiple time slots for activating different sub-pixels. This periodic scanning approach allows the circuit to service many sub-pixels over time, achieving high-resolution display capability while keeping the instantaneous current requirements and circuit complexity manageable, thus reducing the area needed compared to simultaneous driving of all sub-pixels.

The patent applies parameter changes by dynamically adjusting the duty cycle based on the gray level range. For low gray levels, a higher duty cycle is used to improve luminous efficiency and reduce noise. For high gray levels, a lower duty cycle is used to prevent saturation and maintain color accuracy. The system also adjusts the peak current amplitude in conjunction with duty cycle changes, creating a coordinated parameter adjustment strategy that optimizes both efficiency and color fidelity across different brightness ranges.

The patent implements local quality by applying different driving parameters (duty cycle and current amplitude) to different gray level ranges. Instead of using a uniform driving approach for all gray levels, the circuit selectively applies optimized parameters specific to each range. Low gray levels receive higher duty cycles and lower amplitudes, while high gray levels receive lower duty cycles and higher amplitudes, allowing each operating region to have locally optimized characteristics for its specific requirements.