AMOLED pixel unit, method for driving the same, and display device

1. An AMOLED pixel unit comprising a compensating unit, a light emitting control unit, a driving transistor, a storage capacitor and an organic light emitting diode, wherein:

the compensating unit is switched on under a control of a signal on a scan line, transmits a signal on a data line to a gate and a first electrode of the driving transistor, and meanwhile transmits a reference power supply signal to a first terminal of the storage capacitor;

the light emitting control unit is switched on under a control of a signal on a light emitting control line, transmits a first power supply signal to the first electrode of the driving transistor, and meanwhile connects the first terminal of the storage capacitor to the gate of the driving transistor to drive the organic light emitting diode to emit light; and

an anode of the organic light emitting diode is connected to a second terminal of the storage capacitor, and a cathode of the organic light emitting diode receives a second power supply signal.

2. The AMOLED pixel unit according to claim 1 , wherein

the compensating unit comprises: a first switching transistor, a third switching transistor, and a fifth switching transistor; wherein

a gate of the first switching transistor receives the signal on the scan line, a first electrode of the first switching transistor receives the signal on the data line, and a second electrode of the first switching transistor is connected to a first electrode the third switching transistor and the first electrode of the driving transistor;

a gate of the third switching transistor receives the signal on the scan line, and a second electrode of the third switching transistor is connected to the gate of the driving transistor and the light emitting control unit;

a gate of the fifth switching transistor receives the signal on the scan line, a first electrode of the fifth switching transistor is connected to the reference power supply, and a second electrode of the fifth switching transistor is connected to the first terminal of the storage capacitor and the light emitting control unit.

3. The AMOLED pixel unit according to claim 2 , wherein

the light emitting control unit comprises a second switching transistor and a fourth switching transistor; wherein

a first electrode of the second switching transistor receives the first power supply signal, a gate of the second switching transistor receives the signal on the light emitting control line, and a second electrode of the second switching transistor is connected to the first electrode of the driving transistor;

a first electrode of the fourth switching transistor is connected to the second electrode of the third switching transistor and the gate of the driving transistor, a gate of the fourth switching transistor receives the signal on the light emitting control line, and a second electrode of the fourth switching transistor is connected to the first terminal of the storage capacitor and the second electrode of the fifth switching transistor.

4. The AMOLED pixel unit according to claim 3 , wherein the first power supply signal is an operating voltage for light emitting ELVDD, the second power supply signal is an earth voltage for light emitting ELVSS, and a high level of ELVSS is higher than a driving voltage corresponding to a highest gray scale of OLED.

5. The AMOLED pixel unit according to claim 3 , wherein the first switching transistor, the second switching transistor, the third switching transistor, the fourth switching transistor, the fifth switching transistor and the driving transistor are selected individually from any one of a poly silicon TFT, amorphous silicon TFT, Oxide TFT and Organic TFT.

6. The AMOLED pixel unit according to claim 3 , wherein the first switching transistor, the second switching transistor, the third switching transistor, the fourth switching transistor, the fifth switching transistor and the driving transistor are N type TFTs, wherein the first electrode is a drain and the second electrode is a source.

7. A display device, including the AMOLED pixel unit according to claim 1 .

8. The display device according to claim 7 , wherein

the compensating unit comprises: a first switching transistor, a third switching transistor, and a fifth switching transistor; wherein

a gate of the first switching transistor receives the signal on the scan line, a first electrode of the first switching transistor receives the signal on the data line, and a second electrode of the first switching transistor is connected to a first electrode the third switching transistor and the first electrode of the driving transistor;

a gate of the third switching transistor receives the signal on the scan line, and a second electrode of the third switching transistor is connected to the gate of the driving transistor and the light emitting control unit;

a gate of the fifth switching transistor receives the signal on the scan line, a first electrode of the fifth switching transistor is connected to the reference power supply, and a second electrode of the fifth switching transistor is connected to the first terminal of the storage capacitor and the light emitting control unit.

9. The display device according to claim 8 , wherein

the light emitting control unit comprises a second switching transistor and a fourth switching transistor; wherein

a first electrode of the second switching transistor receives the first power supply signal, a gate of the second switching transistor receives the signal on the light emitting control line, and a second electrode of the second switching transistor is connected to the first electrode of the driving transistor;

a first electrode of the fourth switching transistor is connected to the second electrode of the third switching transistor and the gate of the driving transistor, a gate of the fourth switching transistor receives the signal on the light emitting control line, and a second electrode of the fourth switching transistor is connected to the first terminal of the storage capacitor and the second electrode of the fifth switching transistor.

10. The display device according to claim 9 , wherein the first power supply signal is an operating voltage for light emitting ELVDD, the second power supply signal is an earth voltage for light emitting ELVSS, and a high level of ELVSS is higher than a driving voltage corresponding to a highest gray scale of OLED.

11. The display device according to claim 9 , wherein the first switching transistor, the second switching transistor, the third switching transistor, the fourth switching transistor, the fifth switching transistor and the driving transistor are selected individually from any one of a poly silicon TFT, amorphous silicon TFT, Oxide TFT and Organic TFT.

12. The display device according to claim 9 , wherein the first switching transistor, the second switching transistor, the third switching transistor, the fourth switching transistor, the fifth switching transistor and the driving transistor are N type TFTs, wherein the first electrode is a drain and the second electrode is a source.

13. A method for driving an AMOLED pixel unit comprising a compensating unit, a light emitting control unit, a driving transistor, a storage capacitor and an organic light emitting diode, wherein, the method comprises steps of:

during a compensating phase, activating a signal on a scan line to switch on the compensating unit, such that a signal on a data line is transmitted to a gate and a first electrode of the driving transistor and a reference power supply signal is transmitted to a first terminal of the storage capacitor at the same time; and

during a light emitting phase, activating a signal on a light emitting control line and deactivating the signal on the scan line to switch on the light emitting control unit, such that a first power supply signal is transmitted to the first electrode of the driving transistor and the first terminal of the storage capacitor is connected to the gate of the driving transistor, and the organic light emitting diode is driven to emit light.

14. The method according to claim 13 , wherein

the compensating unit comprises: a first switching transistor, a third switching transistor, and a fifth switching transistor; wherein a gate of the first switching transistor receives the signal on the scan line, a first electrode of the first switching transistor receives the signal on the data line, and a second electrode of the first switching transistor is connected to a first electrode the third switching transistor and the first electrode of the driving transistor; a gate of the third switching transistor receives the signal on the scan line, and a second electrode of the third switching transistor is connected to the gate of the driving transistor and the light emitting control unit; a gate of the fifth switching transistor receives the signal on the scan line, a first electrode of the fifth switching transistor is connected to the reference power supply, and a second electrode of the fifth switching transistor is connected to the first terminal of the storage capacitor and the light emitting control unit

the light emitting control unit comprises a second switching transistor and a fourth switching transistor; wherein a first electrode of the second switching transistor receives the first power supply signal, a gate of the second switching transistor receives the signal on the light emitting control line, and a second electrode of the second switching transistor is connected to the first electrode of the driving transistor; a first electrode of the fourth switching transistor is connected to the second electrode of the third switching transistor and the gate of the driving transistor, a gate of the fourth switching transistor receives the signal on the light emitting control line, and a second electrode of the fourth switching transistor is connected to the first terminal of the storage capacitor and the second electrode of the fifth switching transistor;

an anode of the organic light emitting diode is connected to a second terminal of the storage capacitor, and a cathode of the organic light emitting diode receives a second power supply signal;

wherein, in a case in which the first switching transistor, the second switching transistor, the third switching transistor, the fourth switching transistor, the fifth switching transistor and the driving transistor are N type TFTs, the first electrode is a drain and the second electrode is a source; and the method further comprises:

during the compensating phase, the signal on the scan line being at a high level to turn on the first switching transistor, the third switching transistor and the fifth switching transistor, such that the driving transistor is charged by the signal on the data line, and a voltage of the first terminal of the storage capacitor is set to a voltage of the reference power supply signal by the reference power supply;

during the light emitting phase, the signal on the light emitting control line being at a high level to turn on the second switching transistor and the fourth switching transistor, and the scan line being at a low level, such that the storage capacitor keeps its stored electric charges unchanged and the driving transistor drives the organic light emitting diode to emit light.

15. The method according to claim 14 , wherein the first power supply signal is an operating voltage for light emitting ELVDD, the second power supply signal is an earth voltage for light emitting ELVSS, and a high level of ELVSS is higher than a driving voltage corresponding to a highest gray scale of OLED.