Pixel circuit, driving method therefor, and display apparatus

1. A pixel circuit comprising:

an input sub-circuit;

a light emission control sub-circuit; and

an organic light-emitting transistor,

wherein the input sub-circuit is coupled to a gate line, a data line, and the light emission control sub-circuit, and is configured to write a data signal supplied via the data line into the light emission control sub-circuit under control of a gate scan signal supplied via the gate line, and

wherein the light emission control sub-circuit is coupled to a control electrode of the organic light-emitting transistor, and is configured to control a control electrode voltage of the organic light-emitting transistor according to the data signal to drive the organic light-emitting transistor to emit light;

wherein the light emission control sub-circuit comprises a first terminal coupled to a first voltage terminal and is configured to maintain the control electrode voltage corresponding to the data signal at the control electrode of the organic light-emitting transistor by utilizing a first voltage signal supplied via the first voltage terminal, and wherein the organic light-emitting transistor comprises a first electrode coupled to a second voltage terminal and is configured to emit the light responsive to a driving current corresponding to the data signal and a second voltage signal supplied via the second voltage terminal;

wherein the organic light-emitting transistor is a bipolar organic light-emitting transistor, and the second voltage terminal is configured to supply an AC voltage signal as the second voltage signal;

wherein the second voltage terminal is configured to, during every two consecutive frames, supply a positive polarity voltage signal and negative polarity voltage signal alternately on a per frame basis.

2. The pixel circuit of claim 1 , further comprising:

a light emission-off sub-circuit, wherein the light emission-off sub-circuit is coupled to a pulse width modulation signal line and the control electrode of the organic light-emitting transistor, and is configured to control the organic light-emitting transistor to stop emitting the light according to a pulse width modulation signal supplied via the pulse width modulation signal line,

wherein a duty cycle of the pulse width modulation signal is determined from a gray scale to be displayed by the pixel circuit.

3. The pixel circuit of claim 2 , wherein a voltage of the data signal is the control electrode voltage at which the organic light-emitting transistor is configured to emit the light at a maximum light emission intensity.

4. The pixel circuit of claim 2 , wherein the light emission-off sub-circuit comprises:

a first transistor comprising a first control electrode that is coupled to the pulse width modulation signal line, a first electrode that is coupled to a third voltage terminal, and a second electrode that is coupled to the control electrode of the organic light-emitting transistor,

wherein the first transistor is configured to be turned on in response to the pulse width modulation signal being at an active level, to control the organic light-emitting transistor to stop emitting the light by applying a third voltage signal supplied via the third voltage terminal to the control electrode of the organic light-emitting transistor.

5. The pixel circuit of claim 1 , wherein the first voltage terminal is coupled to the second voltage terminal.

6. The pixel circuit of claim 1 , wherein the input sub-circuit comprises:

a second transistor comprising a second control electrode that is coupled to the gate line, a first electrode that is coupled to the data line, and a second electrode that is coupled to the light emission control sub-circuit.

7. The pixel circuit of claim 1 , wherein the light emission control sub-circuit comprises:

a storage capacitor comprising a first terminal that is coupled to a first voltage terminal, and a second terminal that is coupled to the control electrode of the organic light-emitting transistor and an output terminal of the input sub-circuit.

8. The pixel circuit of claim 1 , wherein the second voltage terminal comprises a power supply voltage terminal, and a second electrode of the organic light-emitting transistor is coupled to a common voltage terminal.

9. A driving method for a pixel circuit, wherein the pixel circuit comprises an input sub-circuit, a light emission control sub-circuit, and an organic light-emitting transistor, the driving method comprising the following during a frame period of a frame to be displayed:

writing, by the input sub-circuit in a data writing phase, a data signal supplied via a data line into the light emission control sub-circuit under control of a gate scan signal supplied via a gate line; and

driving, by the light emission control sub-circuit in a light emission phase, the organic light-emitting transistor to emit light according to the data signal,

wherein the writing the data signal supplied via the data line into the light emission control sup-circuit comprises: maintaining, at a control electrode of the organic light-emitting transistor, a control electrode voltage corresponding to the data signal by supplying a first voltage signal to the light emission control sub-circuit,

wherein the driving the organic light-emitting transistor by the light emission control sub-circuit according to the data signal comprises supplying a second voltage signal to a first electrode of the organic light-emitting transistor, and driving the organic light-emitting transistor to emit the light through a driving current corresponding to the data signal and the second voltage signal;

wherein the organic light-emitting transistor is a bipolar organic light-emitting transistor, and the second voltage signal is an AC voltage signal;

wherein, during every two consecutive frames, a positive polarity voltage signal and a negative polarity voltage signal are alternately applied to the first electrode of the organic light-emitting transistor on a per frame basis.

10. The driving method of claim 9 , wherein a voltage of the data signal is determined from a gray scale to be displayed by the pixel circuit.

11. The driving method of claim 9 , wherein the frame period further comprises a light emission-off phase, and the driving method further comprises:

controlling, in the light emission-off phase, the organic light-emitting transistor to stop emitting the light by applying a third voltage signal to a control electrode of the organic light-emitting transistor,

wherein a duration of the light emission phase is determined from a gray scale of a pixel or a sub-pixel of the frame to be displayed.

12. The driving method of claim 11 , wherein a voltage of the data signal is a control electrode voltage of the organic light-emitting transistor at which the organic light-emitting transistor is configured to emit the light at a maximum light emission intensity.

13. A display apparatus comprising the pixel circuit of claim 1 .

14. A signal processor for use with the pixel circuit of claim 2 , wherein the signal processor is configured to calculate the duty cycle of the pulse width modulation signal from the gray scale to be displayed by the pixel circuit, and to generate and output a corresponding pulse width modulation signal to the light emission-off sub-circuit in the pixel circuit.