Organic light emitting display having longer life span
View Patent ↗An organic light emitting display, including a driving transistor electrically coupled to a first power line, a first switch electrically coupled to the driving transistor and an emission line, a second switch electrically coupled to the driving transistor and a previous scan line, a third switch electrically coupled to the first switch and a data line, a fourth switch electrically coupled to the data line and the third switch, a fifth switch electrically coupled to the driving transistor and a scan line, a first capacitor electrically coupled to the second switch and the third switch, a second capacitor electrically coupled to the third switch and the fifth switch, and an organic light emitting diode electrically coupled to the driving transistor and a second power line.
1. An organic light emitting display, comprising:
a driving transistor electrically coupled to a first power line;
a first switch electrically coupled to the driving transistor and an emission line;
a second switch electrically coupled to the driving transistor and a previous scan line;
a third switch electrically coupled to the first switch and a data line;
a fourth switch electrically coupled to the data line and the third switch;
a fifth switch electrically coupled to the driving transistor and a scan line;
a sixth switch electrically coupled to the fifth switch;
a first capacitor electrically coupled to the second switch and the third switch;
a second capacitor electrically coupled to the third switch and the fifth switch; and
an organic light emitting diode electrically coupled to the driving transistor and a second power line, the organic light emitting diode being directly coupled to the driving transistor, wherein the first switch, the second switch, the third switch, the fourth switch, and the fifth switch are P-channel field effect thin-film transistors, and the sixth switch is a N-channel field effect thin-film transistor, wherein:
the second switch and the sixth switch are electrically coupled to the third power line, and
when the previous scan line has a low level, the scan line has a high level, the emission line has a low level, a first electrode of the first capacitor, a first electrode of the second capacitor and a control electrode of the driving transistor are electrically coupled to a third power line, such that the first electrode of the first capacitor, the first electrode of the second capacitor and the control electrode of the driving transistor are initialized to a voltage level of the third power line.
2. The organic light emitting display as claimed in claim 1 , wherein the driving transistor includes a control electrode electrically coupled to the second switch, a first electrode electrically coupled to the first switch and the third switch, and a second electrode electrically coupled to the fifth switch and the organic light emitting diode.
3. The organic light emitting display as claimed in claim 1 , wherein the first switch includes a control electrode electrically coupled to the emission line, a first electrode electrically coupled to the first power line, and a second electrode electrically coupled to the driving transistor.
4. The organic light emitting display as claimed in claim 1 , wherein the second switch includes a control electrode electrically coupled to the previous scan line, a first electrode electrically coupled to a third power line, and a second electrode electrically coupled to the driving transistor.
5. The organic light emitting display as claimed in claim 4 , wherein a voltage of the first power line is higher than a voltage of the third power line.
6. The organic light emitting display as claimed in claim 1 , wherein the fourth switch includes a control electrode electrically coupled to the scan line, a first electrode electrically coupled to the data line, and a second electrode electrically coupled to the first capacitor, the second capacitor, and the third switch.
7. The organic light emitting display as claimed in claim 1 , wherein the fifth switch includes a control electrode electrically coupled to the scan line, a first electrode electrically coupled to a node between the driving transistor and the organic light emitting diode.
8. The organic light emitting display as claimed in claim 1 , wherein the sixth switch includes a control electrode electrically coupled to the scan line, a first electrode electrically coupled to a third power line, and a second electrode electrically coupled to the fifth switch.
9. The organic light emitting display as claimed in claim 1 , wherein the first capacitor includes a first electrode electrically coupled to the second capacitor, the third switch, and the fourth switch, and a second electrode electrically coupled to the driving transistor and the second switch.
10. The organic light emitting display as claimed in claim 1 , wherein the second capacitor includes a first electrode electrically coupled to the first capacitor, the third switch, and the fourth switch, and a second electrode electrically coupled to the fifth switch.
11. The organic light emitting display as claimed in claim 1 , wherein the organic light emitting diode includes an anode electrode electrically coupled to the driving transistor and the fifth switch, and a cathode electrode electrically coupled to the second power line.
12. The organic light emitting display as claimed in claim 1 , wherein a third capacitor is further electrically coupled to a node between the first power line and the first capacitor.
13. The organic light emitting display as claimed in claim 12 , wherein the third capacitor includes a first electrode electrically coupled to the first power line and a second electrode electrically coupled to a node between the first capacitor, the second capacitor, the third switch, and the fourth switch.
14. The organic light emitting display as claimed in claim 1 , wherein a voltage of the first power line is higher than a voltage of the second power line.
15. The organic light emitting display as claimed in claim 1 , wherein the third switch includes a control electrode electrically coupled to the previous scan line, a first electrode electrically coupled to a data line, the first capacitor, and the second capacitor, and a second electrode electrically coupled to a node between the first switch and the driving transistor.
16. The organic light emitting display as claimed in claim 1 , wherein when the previous scan line is maintained at a low level, the scan line is maintained at a high level, and the emission line changes to a high level, a threshold voltage of the driving transistor is reflected in the first and second capacitor, such that a voltage of the control electrode of the driving transistor has the voltage the level of the third power line, and the threshold voltage of the driving transistor is compensated.
17. The organic light emitting display as claimed in claim 16 , wherein when the previous scan line changes to a high level, the scan line changes to a low level, and the emission line changes to a low level, a data voltage of the data line is stored in the first and second capacitors and simultaneously, a threshold voltage of the organic light emitting diode is reflected.
18. The organic light emitting display as claimed in claim 17 , wherein when the previous scan line is maintained at a high level, the scan line changes to a high level and the emission line is maintained at a low level, current provided to the organic light emitting diode through the driving transistor increases due to the data voltage and the threshold voltage of the organic light emitting diode reflected in the first and second capacitor.
19. The organic light emitting display as claimed in claim 18 , wherein the current provided to the organic light emitting diode increases in proportion to the threshold voltage of the organic light emitting diode.