Display device and method of driving the same
According to the disclosure, a display device includes a pixel including a light emitting element, a pixel circuit for controlling a current flowing from a first power line to a second power line via the light emitting element, and an initialization transistor connected between an anode electrode of the light emitting element and a third power line to which a voltage of initialization power is supplied, and a power supply for supplying the initialization power. The power supply includes an initialization power supply for supplying the initialization power, and a virtual load unit connected to the third power line and for providing an additional load to the third power line.
1 . A display device comprising:
a pixel including a light emitting element, a pixel circuit for controlling a current flowing from a first power line to a second power line via the light emitting element, and an initialization transistor connected between an anode electrode of the light emitting element and a third power line to which a voltage of initialization power is supplied; and
a power supply for supplying the initialization power,
wherein the power supply comprises:
an initialization power supply for supplying the initialization power;
a virtual load unit connected to the third power line and providing an additional load to the third power line, the virtual load unit including a first switch and a first resistor connected in series between the third power line and a ground potential; and
a sensing unit for sensing at least one of a voltage and a current of the third power line and controlling the virtual load unit in response to at least one of the sensed voltage and current.
2 . The display device according to claim 1 , further comprising:
a timing controller for controlling the virtual load unit.
3 . The display device according to claim 2 , wherein the timing controller maintains a constant load on the third power line by controlling the first switch.
4 . The display device according to claim 2 , wherein the virtual load unit includes at least one additional switch and an additional resistor connected in parallel with the first switch and the first resistor, and
each of the first switch and the additional switch is turned on or turned off under control of the timing controller.
5 . The display device according to claim 1 , wherein the sensing unit maintains a constant voltage on the third power line by controlling the first switch.
6 . The display device according to claim 1 , wherein the virtual load unit includes at least one additional switch and an additional resistor connected in parallel with the first switch and the first resistor, and
the sensing unit maintains a constant voltage on the third power line by controlling the turn-on and turn-off of the first switch and the additional switch.
7 . The display device according to claim 1 , wherein the first resistor is a digital resistor.
8 . The display device according to claim 7 , wherein the sensing unit controls the first switch and a resistance value of the first resistor, and maintains a constant voltage on the third power line.
9 . The display device according to claim 1 , wherein the initialization transistor is turned on in response to a first scan signal being supplied to a first scan line, and
the first scan signal is supplied at least twice during one frame period.
10 . The display device according to claim 1 , wherein the power supply further comprises:
a first power supply for supplying first driving power to the first power line; and
a second power supply for supplying second driving power having a voltage lower than that of the first driving power to the second power line.
11 . The display device according to claim 1 , wherein a resistance value of the first resistor is predetermined.
12 . The display device according to claim 11 , the pixel further comprising:
a plurality of scan lines connected to and supplying a first scan signal to the pixel circuit,
wherein the resistance value of the first resistor corresponds to the load applied to the third power line by one scan line of the plurality of scan lines that is supplying the first scan signal.
13 . A display device comprising:
a pixel including a light emitting element, a pixel circuit for controlling a current flowing from a first power line to a second power line via the light emitting element, and an initialization transistor connected between an anode electrode of the light emitting element and a third power line to which a voltage of initialization power is supplied;
a power supply for supplying the initialization power,
wherein the power supply comprises:
an initialization power supply for supplying the initialization power; and
a virtual load unit connected to the third power line and providing an additional load to the third power line, the virtual load unit including a first switch and a first resistor connected in series between the third power line and a ground potential, the first resistor being a digital resistor; and
a timing controller for controlling the virtual load unit and controlling the turn-on and turn-off of the first switch and a resistance value of the first resistor so that a load on the third power line is constant.
14 . The display device according to claim 13 , wherein the virtual load unit includes at least one additional switch and an additional resistor connected in parallel with the first switch and the first resistor, and
each of the first switch and the additional switch is turned on or turned off under control of the timing controller.
15 . The display device according to claim 13 , wherein the power supply further comprises:
a first power supply for supplying first driving power to the first power line; and
a second power supply for supplying second driving power having a voltage lower than that of the first driving power to the second power line.
16 . The display device according to claim 13 , wherein the initialization transistor is turned on in response to a first scan signal being supplied to a first scan line, and
the first scan signal is supplied at least twice during one frame period.