Gate-In-Panel Circuit Q Node Voltage Compensation

The patent applies preliminary action by pre-charging the Q node voltage before the touch sensing period begins. The compensation transistor is activated during the touch sensing period to maintain the Q node voltage at a high level, preventing the voltage decay that would otherwise occur during the extended touch sensing interval. This preliminary maintenance of voltage ensures that when the next pixel driving period begins, the gate driver is ready to output proper gate pulses without degradation, thus preventing dim lines while enabling touch sensing functionality.

The patent implements feedback through the compensation transistor that monitors and responds to the Q node voltage level. During the touch sensing period, the compensation transistor detects when the Q node voltage would naturally decay and actively compensates by maintaining it at a high level. This feedback mechanism ensures that the gate driver's internal state remains reliable regardless of the touch sensing period duration, allowing extended sensing periods for improved accuracy without compromising gate driver output characteristics.

The patent converts the harmful effect of leakage current during the touch sensing period into a beneficial outcome. Instead of allowing the leakage current to cause Q node voltage decay and waveform degradation, the compensation transistor is specifically designed to counteract this leakage effect. The compensation transistor activates during the touch sensing period to replenish the charge lost to leakage, thereby converting the harmful leakage current into an opportunity to demonstrate the compensation mechanism's effectiveness, ensuring clean waveforms and proper gate driver operation throughout the time-divided frame period.