Pixel and display device comprising same
A pixel comprising a light emitting unit comprising at least one light emitting element; a pixel circuit for supplying current to the light emitting in response to a data signal; a sensing transistor electrically connected between a data line and a first node that is a common node of the light emitting unit and the pixel circuit; and a control transistor electrically connected between a scanning line and a gate electrode of the sensing transistor.
1. A pixel comprising:
a light emitting unit configured of first light emitting elements disposed such that current flows through the first light emitting elements in a first direction and second light emitting elements disposed such that current flows through the second light emitting elements in a second direction opposite to the first direction;
a pixel circuit configured to supply current to the light emitting unit in response to a data signal;
a sensing transistor disposed in a controller and electrically connected between a data line and a first node that is a common node of the light emitting unit and the pixel circuit; and
a control transistor disposed in the controller and electrically connected between a scan line and a gate electrode of the sensing transistor, wherein the current flowing to the light emitting unit is determined based on an alignment direction and a number of the first light emitting elements and the second light emitting elements, wherein
the controller determines the number of the first light emitting elements aligned in the first direction based on the current, and
the controller determines the number of the second light emitting elements aligned in the second direction based on the current.
2. The pixel according to claim 1 , wherein, while an enable signal is supplied from an external device to the control transistor, the control transistor is turned on so that the scan line and the sensing transistor are electrically connected to each other.
3. The pixel according to claim 2 , wherein the sensing transistor is turned on by a scan signal supplied from the scan line so that the data line and the light emitting unit are electrically connected to each other.
4. A display device comprising:
a pixel comprising:
a light emitting unit configured of first light emitting elements disposed such that current flows through the first light emitting elements in a first direction and second light emitting elements disposed such that current flows through the second light emitting elements in a second direction opposite to the first direction;
a pixel circuit configured to supply current to the light emitting unit in response to a data signal; and
a sensing transistor electrically connected between a data line and a first node that is a common node of the light emitting unit and the pixel circuit;
a sensing unit electrically connected with the data line and configured to sense current flowing to the light emitting unit when the sensing transistor is turned on; and
a controller configured to determine an alignment direction and a number of the first light emitting elements and the second light emitting elements based on the current sensed by the sensing unit, wherein
the controller determines the number of the first light emitting elements aligned in the first direction based on the current sensed by the sensing unit, and
the controller determines the number of the second light emitting elements aligned in the second direction based in the current sensed by the sensing unit.
5. The display device according to claim 4 , wherein the pixel further comprises a control transistor electrically connected between a scan line and a gate electrode of the sensing transistor.
6. The display device according to claim 5 , wherein the controller supplies an enable signal to the control transistor of the pixel so that the control transistor is turned on.
7. The display device according to claim 6 , wherein, when the control transistor of the pixel is turned on, the sensing transistor is electrically connected with the scan line and is turned on in response to a scan signal supplied from the scan line so that the data line and the light emitting unit are electrically connected to each other.
8. The display device according to claim 7 , wherein, while the enable signal is supplied to the control transistor of the pixel, the pixel circuit is disabled.
9. The display device according to claim 7 , wherein the sensing unit comprises:
an amplifier including:
an input terminal electrically connected to the sensing transistor; and
an output terminal;
a variable resistor electrically connected between the input terminal of the amplifier and the controller; and
a control unit configured to determine current flowing to the light emitting unit based on an output voltage of the output terminal of the amplifier and a resistance value of the variable resistor.
10. The display device according to claim 9 , wherein, while the enable signal is supplied to the control transistor of the pixel, the controller supplies driving power to the variable resistor and supplies test power to a non-inverting input terminal of the amplifier.
11. The display device according to claim 10 , wherein the control unit controls the resistance value of the variable resistor such that the output voltage of the amplifier is equal to a voltage of the test power.
12. The display device according to claim 11 , wherein the control unit determines current flowing to the light emitting unit based on the driving power, the test power, and the controlled resistance value of the variable resistor.
13. The display device according to claim 12 , wherein the current flowing to the light emitting unit is determined based on the alignment direction and the number of the first light emitting elements and the second light emitting elements.
14. The display device according to claim 12 , wherein the light emitting unit is electrically connected between the first node and a power supply.
15. The display device according to claim 14 , wherein the first light emitting elements and the second light emitting elements are aligned in either the first direction in which current flows from the first node to the power supply or the second direction in which current flows from the power supply to the first node.
16. The display device according to claim 15 , wherein
the driving power is set to be higher than sensing power, and
the sensing power is set to be higher than power supplied by the power supply.
17. The display device according to claim 15 , wherein
the driving power is set to be lower than sensing power, and
the sensing power is set to be lower than power supplied by the power supply.