LED Matrix Scan-Line Switching for Fast, Low-Ghosting Row Control

The patent divides the LED matrix into multiple scan lines (M scan lines) and uses M separate power switches to control each scan line independently. The monolithic integrated circuit switch device segments the control function across multiple scan terminals, enabling row-by-row scanning where only one scan line is active at a time. This segmentation allows efficient sequential control while maintaining manageable device complexity through integrated circuit design.

The patent implements periodic scanning by successively activating each scan line in a cyclic manner. The micro controller unit transmits switch control codes in sequential order, turning on each power switch for its designated scan line in turn, then repeating the cycle. This periodic row-by-row scanning achieves fast display refresh while keeping the control system organized and efficient.

The patent converts the harmful parasitic capacitance effects into beneficial functionality by implementing discharge circuits that actively manage the stored charge. Instead of allowing parasitic capacitance to cause ghosting and grayscale spikes, the discharge circuits provide controlled discharge paths that eliminate these artifacts. The clamp circuits similarly convert potential voltage transition problems into stable operating conditions by clamping voltages to appropriate levels during switching transitions.

The patent applies preliminary anti-action by implementing discharge and clamp circuits that counteract the harmful effects of parasitic capacitance before they can manifest as ghosting or grayscale spikes. These circuits are designed to neutralize voltage transitions and charge accumulation in advance, ensuring clean switching behavior even at high switching speeds.