Touch display device and method of driving the same

1. A touch display device comprising:

a display panel configured to display an image;

a touch sensor including a first touch electrode and a second touch electrode arranged to cross each other, and a dummy touch electrode disposed adjacent to the first touch electrode and the second touch electrode, on the display panel; and

a touch driver configured to drive the first touch electrode and the second touch electrode and apply a signal or a voltage to the dummy touch electrode,

wherein during an uplink signal generation period of a first mode of the touch display device, the touch driver is configured to apply a same uplink signal to the dummy touch electrode and at least one of the first touch electrode or the second touch electrode, and the same uplink signal is obtained by an active pen from the dummy touch electrode and the at least one of the first touch electrode or the second touch electrode during the uplink signal generation period,

wherein during a downlink pulse sensing period during which a pen signal generated by the active pen is sensed, the touch driver is configured to apply a logic low signal or a low voltage to the dummy touch electrode, the downlink pulse sensing period after the uplink signal generation period.

2. The touch display device according to claim 1 , wherein during a second mode of the touch display device, the touch driver applies the logic low signal or the low voltage to the dummy touch electrode during the uplink signal generation period of the second mode during which a signal to be transmitted to an active pen placed on the touch sensor is generated and during the downlink pulse sensing period of the second mode during which the pen signal generated from the active pen placed on the touch sensor is sensed.

3. The touch display device according to claim 1 , wherein the touch sensor further comprises a ring guard disposed to surround an active area in which the first touch electrode, the second touch electrode, and the dummy touch electrode are located, and

wherein the touch driver applies the signal or the voltage to the ring guard.

4. The touch display device according to claim 1 , wherein the dummy touch electrode comprises:

a first dummy touch electrode configured to execute the same function as the first touch electrode; and

a second dummy touch electrode configured to execute the same function as the second touch electrode.

5. The touch display device according to claim 4 , wherein when a first dummy transistor located between the first touch electrode and a first channel of the touch driver is turned on, the first dummy touch electrode executes the same function as the first touch electrode, and

wherein when a second dummy transistor located between the second touch electrode and a second channel of the touch driver is turned on, the second dummy touch electrode executes the same function as the second touch electrode.

6. The touch display device according to claim 5 , wherein the first dummy transistor and the second dummy transistor are simultaneously tuned on or tuned off in response to a dummy control signal output from a third channel of the touch driver.

7. The touch display device according to claim 6 , wherein the touch driver comprises:

switches configured to control input and output of the first channel, the second channel, and the third channel;

a circuit configured to output or sense the signal, when the circuit is connected to one or more of the first, second, and third channels through one or more of the switches; and

a controller configured to control the switches and the circuit.

8. The touch display device according to claim 1 , wherein the dummy touch electrode is located between portions of the first touch electrode and between portions of the second touch electrode, on the same layer as the first touch electrode and the second touch electrode.

9. A method of driving a touch display device including a display panel configured to display an image, a touch sensor including a first touch electrode and a second touch electrode arranged to cross each other, and a dummy touch electrode disposed adjacent to the first touch electrode and the second touch electrode, on the display panel, and a touch driver configured to drive the first touch electrode and the second touch electrode and apply a signal or a voltage to the dummy touch electrode, the method comprising:

during an uplink signal generation period of a first mode of the touch display device, applying a same uplink signal to the dummy touch electrode and at least one of the first touch electrode or the second touch electrode, the same uplink signal obtained by an active pen placed on the touch sensor from the dummy touch electrode and the at least one of the first touch electrode or the second touch electrode during the uplink signal generation period; and

during a downlink pulse sensing period that is after the uplink signal generation period, applying a logic low signal or a low voltage to the dummy touch electrode and sensing a downlink pulse generated from the active pen placed on the touch sensory.

10. A touch display device comprising:

a display panel configured to display an image;

a touch sensor on the display panel, the touch sensor including a first touch electrode, a second touch electrode arranged to cross the first touch electrode, and a dummy touch electrode disposed around the first touch electrode and the second touch electrode, and

a touch driver configured to drive the first touch electrode and the second touch electrode and apply a signal or a voltage to the dummy touch electrode,

wherein during an uplink signal generation period of a first mode of the touch display device, the touch driver is configured to apply a same uplink signal to the dummy touch electrode and at least one of the first touch electrode or the second touch electrode, and the same uplink signal is obtained by an active pen from the dummy touch electrode and the at least one of the first touch electrode or the second touch electrode during the uplink signal generation period,

wherein during a downlink pulse sensing period during which a pen signal generated by the active pen is sensed, the touch driver is configured to apply a logic low signal or a low voltage to the dummy touch electrode, the downlink pulse sensing period after the uplink signal generation period,

wherein the dummy touch electrode is electrically connected to the first touch electrode or the second touch electrode in response to a dummy control signal being in a first state, and

wherein the dummy touch electrode is electrically disconnected from the first touch electrode and the second touch electrode in response to the dummy control signal being in a second state.

11. The touch display device according to claim 10 , wherein during the uplink signal generation period the dummy touch electrode is electrically connected to the first touch electrode or the second touch electrode in response to the dummy control signal being in the first state.

12. The touch display device according to claim 10 , wherein during the uplink signal generation period of a second mode in which a signal to be transmitted to the active pen placed on the touch sensor is generated and during the downlink pulse sensing period of the second mode in which the pen signal generated from the active pen placed on the touch sensor is sensed:

the dummy touch electrode is electrically disconnected from the first touch electrode and the second touch electrode in response to the dummy control signal being in a second state, and the logic low signal or the low voltage is applied to the dummy touch electrode during the second mode.

13. The touch display device according to claim 10 , wherein the touch sensor further comprises a ring guard disposed to surround an active area in which the first touch electrode, the second touch electrode, and the dummy touch electrode are located, and

wherein a signal or a voltage is applied to the ring guard.

14. The touch display device according to claim 10 , wherein the dummy touch electrode comprises:

a first dummy touch electrode configured to be electrically connected to or disconnected from the first touch electrode in response to the dummy control signal; and

a second dummy touch electrode configured to be electrically connected to or disconnected from the second touch electrode in response to the dummy control signal, and

wherein the first dummy electrode and the second dummy electrode are electrically disconnected from each other.

15. The touch display device according to claim 14 , further comprising:

a first dummy transistor electrically connecting the first dummy electrode to, or disconnecting the first dummy electrode from, the first touch electrode in response to the dummy control signal, and

a second dummy transistor electrically connecting the second dummy electrode to, or disconnecting the second dummy electrode from, the second touch electrode in response to the dummy control signal.

16. The touch display device according to claim 15 , wherein the first dummy transistor and the second dummy transistor are simultaneously turned on or off in response to the dummy control signal.