Touch display device and driver circuit
A touch display device is provided. The touch display device includes a touch display panel and a driver circuit. The touch display panel includes a control transistor coupled to a common electrode through a liquid crystal capacitor. The driver circuit is coupled to the touch display panel, and outputs a first driving signal to a first terminal of the control transistor. When the touch display panel switches from a first operational cycle to a first transition interval, the driver circuit adjusts the first driving signal to change a voltage of the first terminal of the transistor from a first voltage to a second voltage different from the first voltage to adjust a voltage of the common electrode.
1 . A touch display device, comprising:
a touch display panel comprising a control transistor that is coupled to a common electrode through a liquid crystal capacitor; and
a driver circuit, coupled with the touch display panel, to output a first driving signal to a first terminal of the control transistor,
when the touch display panel switches from a first operating cycle to a first transition interval, the driver circuit adjusts the first driving signal to change a voltage of the first terminal of the control transistor from a first voltage to a second voltage smaller than the first voltage to adjust a voltage of the common electrode, wherein the first operating cycle is display cycle,
wherein the driver circuit further adjusts a voltage of the first driving signal before a touch panel synchronization signal changes.
2 . The touch display device of claim 1 , wherein the first driving signal is a source driving signal and the first terminal of the control transistor is a source terminal,
wherein the driver circuit comprises:
a source control circuit to output the source driving signal, and to adjust the source driving to change the voltage of the source terminal from the second voltage to a third voltage when the touch display panel switches from a second operating cycle to a second transition interval, wherein the second operating cycle is after the first transition interval.
3 . The touch display device of claim 2 , wherein a drive power of the source control circuit in the first operating cycle is greater than the drive power in the first transition interval.
4 . The touch display device of claim 2 , wherein the third voltage has a gamma reference voltage,
wherein the source control circuit further adjusts the source driving signal to change the voltage of the source terminal from the third voltage to a fourth voltage higher than the gamma reference voltage when the touch display panel switches from the second transition interval to a third operating cycle, and
a drive power of the source control circuit in the second transition interval is less than the drive power in the third operating cycle.
5 . The touch display device of claim 2 , wherein the first transition interval comprises a first sub-interval and a second sub-interval,
wherein the source control circuit further adjusts the source driving signal in the first sub-interval to change the voltage of the source terminal from the first voltage to a fourth voltage less than the first voltage, and
in the second sub-interval pulls up the source driving signal to pull up the voltage of the source terminal from the fourth voltage to the second voltage.
6 . The touch display device of claim 5 , wherein a drive power of the source control circuit in the first sub-interval is less than the drive power in the second sub-interval.
7 . The touch display device of claim 5 , wherein the second transition interval comprises a third sub-interval and a fourth sub-interval,
wherein the source control circuit further pulls up the source driving signal in the third sub-interval to pull up the voltage of the source terminal from the second voltage to the third voltage greater than the second voltage, and
in the fourth sub-interval pulls down the source driving signal to pulls down the voltage of the source terminal from the third voltage to a fifth voltage.
8 . The touch display device of claim 1 , wherein the driver circuit comprises:
a source control circuit to output a source driving signal as the first driving signal and to adjust the source driving signal in a first sub-interval of the first transition interval to change the voltage of the first terminal of the control transistor from the first voltage to a third voltage less than the first voltage, and
to adjust the source driving signal in a second sub-interval of the first transition interval to change the voltage of the first terminal of the control transistor from the third voltage to the second voltage greater than the third voltage; and
a gate control circuit to output a second driving signal to a second terminal of the control transistor and to pull up the second driving signal to pull up the second terminal of the control transistor to a fourth voltage in the first transition interval.
9 . The touch display device of claim 8 , wherein the gate control circuit further controls the second terminal of the control transistor to be in a high impedance state in the first sub-interval,
pulls up the second driving signal in the second sub-interval to pull up the voltage of the second terminal of the control transistor to a fifth voltage less than the fourth voltage, and
pulls up the second driving signal to pull up the voltage of the second terminal to the fourth voltage in a third sub-interval, after the second sub-interval, of the first transition interval.
10 . The touch display device of claim 1 , wherein a drive power of the driver circuit in the first operating cycle is greater than the drive power in the first transition interval.
11 . The touch display device of claim 1 , wherein the driver circuit further switches from a first drive mode to a second drive mode different from the first drive mode before the touch panel synchronization signal changes.
12 . A driver circuit for driving a touch display panel, comprising:
a control circuit to generate a control signal based on a display data voltage for a display cycle and a preset voltage for a touch sensing cycle; and
a first driver circuit coupled to the control circuit and to output, in response to the control signal, a first driving signal, wherein in a first transition interval from the display cycle to the touch sensing cycle the first driving signal has a voltage decreasing to a first voltage from a second voltage,
wherein the first voltage is different from the second voltage of the first driving signal in the display cycle,
wherein the driver circuit further adjusts the voltage of the first driving signal before a touch panel synchronization signal changes.
13 . The driver circuit of claim 12 , wherein the first driver circuit further pulls up, in response to the control signal, the first driving signal from the first voltage to the preset voltage in a second transition interval between the display cycle and the touch sensing cycle,
wherein the second transition interval is after the first transition interval.
14 . The driver circuit of claim 13 , wherein the first driver circuit comprises a source control circuit to output the first driving signal;
wherein the driver circuit further comprises:
a gate control circuit to pull up a second driving signal to a third voltage in the second transition interval.
15 . The driver circuit of claim 12 , wherein the first driver circuit further has, in response to the control signal, different drive power in the display cycle, the first transition interval and the touch sensing cycle.
16 . The driver circuit of claim 15 , wherein a drive power of the first driver circuit in the first transition interval is greater than the drive power in the display cycle.
17 . The driver circuit of claim 12 , wherein the preset voltage is between the display data voltage and the first voltage.