Pixel circuit and display device
A pixel circuit includes: a driver transistor that supplies a current dependent on a voltage supplied via a signal line; a write transistor connected between the signal line and a gate electrode of the driver transistor; a first organic EL element connected to one electrode of the driver transistor, the one electrode being one of a drain electrode and a source electrode of the driver transistor; a switching transistor connected to the one electrode of the driver transistor; and a second organic EL element connected to the one electrode of the driver transistor via the switching transistor. The pixel circuit performs mobility correction that corrects a mobility of the driver transistor. The switching transistor turns ON after a write operation that writes the voltage supplied via the signal line and turns OFF before an operation that performs the mobility correction of the driver transistor begins.
1. A pixel circuit, comprising:
a driver transistor configured to supply a current dependent on a voltage supplied via a signal line;
a write transistor connected between the signal line and a gate electrode of the driver transistor;
a first light emitting element directly connected to one electrode of the driver transistor, the one electrode being one of a drain electrode and a source electrode of the driver transistor;
a switching transistor connected to the one electrode of the driver transistor; and
a second light emitting element connected to the one electrode of the driver transistor via the switching transistor,
wherein the pixel circuit is configured so that the first light emitting element and the second light emitting element emit light in a same direction,
wherein the pixel circuit is configured to perform mobility correction that corrects a mobility of the driver transistor, and
the switching transistor is configured to turn ON after a write operation that writes the voltage supplied via the signal line and turn OFF before an operation that performs the mobility correction of the driver transistor begins.
2. The pixel circuit according to claim 1 , further comprising:
a first subpixel circuit configured to emit light of a first color; and
a second subpixel circuit configured to emit light of a second color different from the first color,
wherein among the first subpixel circuit and the second subpixel circuit, only the first subpixel circuit includes the switching transistor and the second light emitting element.
3. The pixel circuit according to claim 2 ,
wherein the pixel circuit further includes a third subpixel circuit configured to emit light of a third color different from the first color and the second color,
among the first subpixel circuit, the second subpixel circuit, and the third subpixel circuit, only the first subpixel circuit includes the switching transistor and the second light emitting element,
the first color is blue,
the second color is red, and
the third color is green.
4. The pixel circuit according to claim 3 ,
wherein a capacitance of the first light emitting element included in the first subpixel circuit is equal to one of a capacitance of a light emitting element included in the second subpixel circuit and a capacitance of a light emitting element included in the third subpixel circuit.
5. The pixel circuit according to claim 1 ,
wherein an operation that applies a negative bias to the first light emitting element before the operation that performs the mobility correction of the driver transistor is present in the pixel circuit, and
the switching transistor is configured to turn OFF before the negative bias is applied to the first light emitting element.
6. The pixel circuit according to claim 1 ,
wherein a surface area of the second light emitting element is larger than a surface area of the first light emitting element.
7. The pixel circuit according to claim 1 ,
wherein the first light emitting element and the second light emitting element have a top-emission structure,
the first light emitting element includes a first light emitter configured to emit light, and a first contact part configured to connect an anode of the first light emitting element and a thin film transistor (TFT) layer,
the second light emitting element includes a second light emitter configured to emit light, and a second contact part configured to connect an anode of the second light emitting element and the TFT layer, and
in a plan view of the pixel circuit, the first contact part and the second contact part are disposed between the first light emitter and the second light emitter.
8. The pixel circuit according to claim 1 ,
wherein each of the first light emitting element and the second light emitting element is an organic electroluminescent (EL) element.
9. A display device, comprising:
the pixel circuit according to claim 1 ;
a horizontal selector configured to apply the voltage to the signal line;
a write scanner configured to control the write transistor;
a power supply scanner configured to apply a potential to the source electrode or the drain electrode of the driver transistor; and
a switch scanner configured to control the switching transistor.
10. The pixel circuit according to claim 1 ,
wherein the pixel circuit is configured to emit light from both the first light emitting element and the second light emitting element when the switching transistor is in an ON state and a positive voltage is applied to the drive transistor.