Electroluminescent display device for minimizing a voltage drop and improving image quality and driving method thereof

1. An electroluminescence display device comprising:

a display panel having a display area where images are displayed and a non-display area where images are not displayed;

a subpixel located in the display area; and

a voltage transfer circuit that is in the non-display area and transfers a reference voltage to a voltage transfer node of the subpixel, in response to a signal applied from outside the display panel or a signal generated on the display panel,

wherein the subpixel comprises:

a driving transistor that has a gate connected to a gate node, a first electrode, and a second electrode;

a capacitor that has a first electrode connected to the voltage transfer node, and a second electrode connected to the gate of the driving transistor; and

an organic light-emitting diode that has an anode and a cathode connected to a second power supply line, and

wherein the subpixel further comprises:

a first transistor that has a gate connected to an nth scan line, a first electrode connected to a first data line, and a second electrode connected to the first electrode of the driving transistor;

a second transistor that has a gate connected to an nth emission control signal line, a first electrode connected to a second electrode of the first transistor, and a second electrode connected to a first power supply line;

a third transistor that has a gate connected to the nth scan line, a first electrode connected to a second electrode of the driving transistor, and a second electrode connected to the gate of the driving transistor;

a fourth transistor that has a gate connected to an (n−1)th scan line, a first electrode connected to an initial line, and a second electrode connected to the second electrode of the third transistor and the gate of the driving transistor, where n is an integer equal to or greater than 2;

a fifth transistor that has a gate connected to the nth emission control signal line, a first electrode connected to the second electrode of the driving transistor, and a second electrode connected to the anode of the organic light-emitting diode;

a sixth transistor that has a gate connected to the nth scan line, a first electrode connected to the initial line, and a second electrode connected to a second electrode of the fifth transistor; and

a seventh transistor that has a gate connected to the nth emission control signal line, a first electrode connected to the first power supply line, and a second electrode connected to the voltage transfer node.

2. The electroluminescence display device of claim 1 , wherein the display panel comprises a plurality of scan lines, to each of which a plurality of subpixels are connected, and the voltage transfer circuit is provided for each scan line in the non-display area.

3. The electroluminescence display device of claim 2 , wherein the voltage transfer circuit comprises at least one voltage transfer transistor that is turned on or off, in response to an (n−1)th scan signal for driving (n−1)th subpixels on an (n−1)th scan line or an nth scan signal for driving nth subpixels on an nth scan line.

4. The electroluminescence display device of claim 3 , wherein the voltage transfer circuit comprises:

a first voltage transfer transistor that has a gate connected to the (n−1)th scan line, a first electrode connected to a reference voltage line for transferring the reference voltage, and a second electrode connected to the voltage transfer node included in the subpixel; and

a second voltage transfer transistor that has a gate connected to the nth scan line, a first electrode connected to the reference voltage line, and a second electrode connected to the voltage transfer node.

5. The electroluminescence display device of claim 3 , wherein the voltage transfer circuit comprises a voltage transfer transistor that has a gate connected to the nth scan line, a first electrode connected to a reference voltage line for transferring the reference voltage, and a second electrode connected to the voltage transfer node.

6. The electroluminescence display device of claim 3 , wherein the voltage transfer circuit comprises a voltage transfer transistor that has a gate connected to the (n−1)th scan line, a first electrode connected to a reference voltage line for transferring the reference voltage, and a second electrode connected to the voltage transfer node.

7. The electroluminescence display device of claim 1 , wherein the voltage transfer circuit operates to output the reference voltage during an initial period and a sampling period for sampling the threshold voltage of a driving transistor of the subpixel, and

wherein the reference voltage is a fixed voltage during the initial period and the sampling period.

8. An electroluminescence display device comprising:

a display panel having a display area where images are displayed and a non-display area where images are not displayed;

a subpixel located in the display area;

a gate driver located in the non-display area; and

a voltage transfer transistor that is in the non-display area and transfers a reference voltage to the subpixel,

wherein a gate of the voltage transfer transistor is connected to the gate driver,

wherein the gate driver comprises:

a pull-up transistor; and

a first boosting capacitor connected to a gate of the pull-up transistor, and a drain of the pull-up transistor,

wherein the gate of the voltage transfer transistor is connected to the gate of the pull-up transistor, and

wherein the subpixel further comprises:

a first transistor that has a gate connected to an nth scan line, a first electrode connected to a first data line, and a second electrode connected to the first electrode of a driving transistor;

a second transistor that has a gate connected to an nth emission control signal line, a first electrode connected to a second electrode of the first transistor, and a second electrode connected to a first power supply line;

a third transistor that has a gate connected to the nth scan line, a first electrode connected to a second electrode of the driving transistor, and a second electrode connected to the gate of the driving transistor;

a fourth transistor that has a gate connected to an (n−1)th scan line, a first electrode connected to an initial line, and a second electrode connected to the second electrode of the third transistor and the gate of the driving transistor, where n is an integer equal to or greater than 2;

a fifth transistor that has a gate connected to the nth emission control signal line and a first electrode connected to the second electrode of the driving transistor;

a sixth transistor that has a gate connected to the nth scan line, a first electrode connected to the initial line, and a second electrode connected to a second electrode of the fifth transistor; and

a seventh transistor that has a gate connected to the nth emission control signal line, a first electrode connected to the first power supply line, and a second electrode connected to the voltage transfer node.

9. The electroluminescence display device of claim 8 , wherein the gate driver further comprises a first auxiliary transistor, and

wherein a gate of the first auxiliary transistor is connected to a line via which a logic-low voltage is applied, and a first electrode of the first auxiliary transistor is connected to the gate of the pull-up transistor.

10. The electroluminescence display device of claim 8 , wherein a first electrode of the voltage transfer transistor is connected to a line via which the reference voltage is applied, and a second electrode of the voltage transfer transistor is connected to a voltage transfer node included in the subpixel.

11. A driving method of an electroluminescence display device,

the electroluminescence display device including a display panel having a display area where images are displayed and a non-display area where images are not displayed; a subpixel located in the display area; and a gate driver and a voltage transfer circuit that are located in the non-display area, wherein the voltage transfer circuit transfers a reference voltage to the subpixel, the method comprising:

initializing the subpixel in an initial period; and

compensating for the threshold voltage of a driving transistor of the subpixel in a sampling period,

wherein, during the initializing period and the sampling period, the voltage transfer circuit operates in response to a signal applied from outside the display panel or a signal generated on the display panel,

wherein the reference voltage is a fixed voltage during the initializing period and the sampling period, and

wherein the subpixel further comprises:

a first transistor that has a gate connected to an nth scan line, a first electrode connected to a first data line, and a second electrode connected to the first electrode of the driving transistor;

a second transistor that has a gate connected to an nth emission control signal line, a first electrode connected to a second electrode of the first transistor, and a second electrode connected to a first power supply line;

a third transistor that has a gate connected to the nth scan line, a first electrode connected to a second electrode of the driving transistor, and a second electrode connected to the gate of the driving transistor;

a fourth transistor that has a gate connected to an (n−1)th scan line, a first electrode connected to an initial line, and a second electrode connected to the second electrode of the third transistor and the gate of the driving transistor, where n is an integer equal to or greater than 2;

a fifth transistor that has a gate connected to the nth emission control signal line, a first electrode connected to the second electrode of the driving transistor, and a second electrode connected to the anode of the organic light-emitting diode;

a sixth transistor that has a gate connected to the nth scan line, a first electrode connected to the initial line, and a second electrode connected to a second electrode of the fifth transistor; and

a seventh transistor that has a gate connected to the nth emission control signal line, a first electrode connected to the first power supply line, and a second electrode connected to the voltage transfer node.

12. The driving method of claim 11 , wherein the voltage transfer circuit is turned on for a first period based on an (n−1)th scan signal for driving (n−1)th subpixels on an (n−1)th scan line,

wherein the voltage transfer circuit is turned on during a second period subsequent to the first period based on an nth scan signal for driving nth subpixels on an nth scan line, and

wherein the reference voltage is transferred to the nth subpixels during the first and second periods.

13. The driving method of claim 11 , wherein, for the subpixels on the display panel, the initializing and the compensating are performed at different times based on an nth scan signal and an (n−1)th scan signal which overlap during at least 1 horizontal time.

14. The driving method of claim 13 , wherein the voltage transfer circuit is turned on based on the nth scan signal for driving the nth subpixels to transfer the reference voltage to the nth subpixels.

15. The driving method of claim 11 , wherein, for the nth subpixels on the display panel, the initializing and the compensating are performed simultaneously based on an nth scan signal and an (n−1)th scan signal which overlap during at least 1 horizontal time.

16. The driving method of claim 15 , wherein the voltage transfer circuit is turned on based on the (n−1)th scan signal for driving the (n−1)th subpixels to transfer the reference voltage to the nth subpixels.