Pixel and display apparatus having the same
A pixel includes a capacitor including a first electrode and a second electrode, a first transistor which generates a driving current, a second transistor which applies a data voltage to the first electrode of the capacitor, a third transistor which applies an initialization voltage to the second electrode of the capacitor, a fourth transistor which generates a leakage current in response to a dimming signal, and a light emitting element which emits light based on a residual driving current, where the residual driving current is obtained by subtracting the leakage current from the driving current.
1. A pixel comprising:
a capacitor including a first electrode and a second electrode;
a first transistor which generates a driving current;
a second transistor which applies a data voltage to the first electrode of the capacitor;
a third transistor which applies an initialization voltage to the second electrode of the capacitor;
a fourth transistor which generates a leakage current in response to a dimming signal;
a light emitting element which emits light based on a residual driving current, wherein the residual driving current is obtained by subtracting the leakage current from the driving current; and
a resistance element connected to the fourth transistor and having a fixed resistance.
2. The pixel of claim 1 , wherein a sum of a turn-on resistance of the fourth transistor and the fixed resistance of the resistance element is greater than a saturation resistance of the light emitting element.
3. The pixel of claim 1 , wherein
the dimming signal is not activated in a basic frame period, and
the dimming signal is activated in a variable frame period.
4. The pixel of claim 3 , wherein the dimming signal in the variable frame period is activated at a same timing as an activation timing of a gate signal in the basic frame period.
5. The pixel of claim 4 , wherein an activation of the dimming signal is started in a blank period of the variable frame period.
6. The pixel of claim 1 , wherein a length of an activation period of the dimming signal is determined by a characteristic of the pixel.
7. The pixel of claim 1 , wherein a voltage level of the dimming signal is changed over a period of time during an activation period of the dimming signal.
8. The pixel of claim 7 , wherein the voltage level of the dimming signal is increased with time during the activation period of the dimming signal.
9. A display apparatus comprising:
a display panel including a plurality of pixels; and
a display panel driver which applies a gate signal and a dimming signal to the pixels,
wherein each of the pixels comprises:
a capacitor including a first electrode and a second electrode;
a first transistor which generates a driving current;
a second transistor which applies a data voltage to the first electrode of the capacitor;
a third transistor which applies an initialization voltage to the second electrode of the capacitor;
a fourth transistor which generates a leakage current in response to the dimming signal; and
a light emitting element which emit light based on a residual driving current, wherein the residual driving current is obtained by subtracting the leakage current from the driving current,
wherein each of the pixels further comprises a resistance element connected to the fourth transistor and having a fixed resistance.
10. The display apparatus of claim 9 , wherein a sum of a turn-on resistance of the fourth transistor and the fixed resistance of the resistance element is greater than a saturation resistance of the light emitting element.
11. The display apparatus of claim 9 , wherein
the dimming signal is not activated in a basic frame period, and
the dimming signal is activated in a variable frame period.
12. The display apparatus of claim 11 , wherein the dimming signal in the variable frame period is activated at a same timing as an activation timing of the gate signal in the basic frame period.
13. The display apparatus of claim 12 , wherein an activation of the dimming signal is started in a blank period of the variable frame period.
14. The display apparatus of claim 9 , wherein a length of an activation period of the dimming signal is determined by characteristic of the pixels.
15. The display apparatus of claim 9 , wherein a voltage level of the dimming signal is changed over a period of time during an activation period of the dimming signal.
16. The display apparatus of claim 15 , wherein the voltage level of the dimming signal is increased with time during the activation period of the dimming signal.
17. The display apparatus of claim 9 , wherein the display panel driver sequentially applies the dimming signal to the pixels on a row-by-row basis.
18. The display apparatus of claim 9 , wherein the display panel driver simultaneously applies the dimming signal to all of the pixels.