Light emitting device
View Patent ↗Provided is a light emitting device. Particularly, the light emitting device comprises a threshold voltage compensator. The threshold voltage compensator is connected between a gate and a drain of the driving TFT and has a gate connected to a second scan line to temporarily store at the storage capacitor a gate voltage reflecting a threshold voltage of the driving TFT in response to a second scan signal supplied by a second scan line and to transmit the data signal regardless of variations in the threshold voltage of the driving TFT when the output current is supplied to the light emitting diode.
1. A light emitting device comprising:
a light emitting diode emitting light due to an output current;
a storage capacitor storing a data signal supplied by a data line;
a driving thin film transistor (TFT) connected between a supply voltage and the light emitting diode and having a gate connected to one end of the storage capacitor to supply the output current to the light emitting diode using the data signal stored in the storage capacitor;
an input switch connected between the one end of the storage capacitor and the data line and having a gate connected to a first scan line to transmit the data signal supplied by the data line in response to a first scan signal supplied by the first scan line; and
a threshold voltage compensator connected between the gate and a drain of the driving TFT and having a gate connected to a second scan line to temporarily store at the storage capacitor a gate voltage reflecting a threshold voltage of the driving TFT in response to a second scan signal supplied by the second scan line and to transmit the data signal regardless of variations in the threshold voltage of the driving TFT when the output current is supplied to the light emitting diode.
2. A light emitting device comprising:
a light emitting diode emitting light due to an output current;
a storage capacitor storing a data signal supplied by a data line;
a driving thin film transistor (TFT) connected between a ground voltage and the light emitting diode and having a gate connected to one end of the storage capacitor to supply the output current to the light emitting diode using the data signal stored in the storage capacitor;
an input switch connected between the gate of the driving TFT and the data line and having a gate connected to a first scan line to transmit the data signal supplied by the data line in response to a first scan signal supplied by the first scan line; and
a threshold voltage compensator connected between the gate and a drain of the driving TFT and having a gate connected to a second scan line to temporarily store at the storage capacitor a gate voltage reflecting a threshold voltage of the driving TFT in response to a second scan signal supplied by the second scan line and to transmit the data signal regardless of variations in the threshold voltage of the driving TFT when the output current is supplied to the light emitting diode.
3. The light emitting device of claim 1 , wherein the driving TFT, the input switch and the threshold voltage compensator are P-channel metal oxide semiconductor (PMOS) transistors.
4. The light emitting device of claim 2 , wherein the driving TFT, the input switch and the threshold voltage compensator are N-channel metal oxide semiconductor (NMOS) transistors.
5. The light emitting device of claim 1 , wherein the first scan line and the second scan line are substantially the same line, and the first scan signal and the second scan signal are substantially the same signal.
6. The light emitting device of claim 2 , wherein the first scan line and the second scan line are substantially the same line, and the first scan signal and the second scan signal are substantially the same signal.
7. The light emitting device of claim 1 , wherein the data signal supplied by the data line is a static current, and when the first scan signal and the second scan signal are in an ‘on’ state, the data signal drives the driving TFT.
8. The light emitting device of claim 7 , wherein the static current is supplied to the driving TFT when the first scan signal and the second scan signal are in an ‘on’ state.
9. The light emitting device of claim 2 , wherein the data signal supplied by the data line is a static current, and when the first scan signal and the second scan signal are in an ‘on’ state, the data signal drives the driving TFT.
10. The light emitting device of claim 9 , wherein the static current is supplied to the driving TFT when the first scan signal and the second scan signal are in an ‘on’ state.
11. The light emitting device of claim 6 , further comprising:
a threshold voltage restorer connected to the gate of the driving TFT and supplying a gate voltage that is lower than the ground voltage.
12. The light emitting device of claim 11 , wherein the threshold voltage restorer is connected between the gate of the driving TFT and a supporting data line and has a gate connected to a supporting scan line.
13. The light emitting device of claim 11 , wherein the threshold voltage restorer is connected between the gate of the driving TFT and a ground voltage of a previous terminal and has a gate connected to a first scan line of the previous terminal.
14. The light emitting device of claim 11 , wherein the threshold voltage restorer is connected between the gate of the driving TFT and the first scan line and has a gate connected to the first scan line of the previous terminal.
15. The light emitting device of claim 12 , wherein the threshold voltage restorer is an NMOS transistor.
16. The light emitting device of claim 13 , wherein the threshold voltage restorer is an NMOS transistor.
17. The light emitting device of claim 14 , wherein the threshold voltage restorer is an NMOS transistor.
18. The light emitting device of claim 1 , wherein the light emitting device comprises an organic emissive layer.
19. The light emitting device of claim 2 , wherein the electroluminescence device comprises an organic emissive layer.