Pixel ciruit, active matrix organic light emitting diode display panel, display apparatus, and method of compensating threshold voltage of driving transistor

An active matrix organic light emitting diode (AMOLED) display panel comprising a matrix of pixel circuits, each pixel circuit in the matrix comprising:

• a first transistor comprising a bottom gate and a top gate, a drain supplied with a high-level power-supply voltage, and a source coupled to a light emitting diode (LED), the bottom gate being provided with a first voltage signal and the source being provided with a second voltage signal in a compensation period during which a present value of a threshold voltage of the first transistor is sensed at the source and a third voltage signal is determined based on the present value of the threshold voltage, and the top gate being configured to be provided with the third voltage signal in an emission period to reduce the present value of the threshold voltage,
• wherein the LED is an organic light-emitting diode comprising an anode coupled to the source of the first transistor and a cathode being supplied with a low-level power-supply voltage, the LED being configured in the emission period to emit light induced by a driving current provided by the first transistor that is a turn-on current substantially independent of the threshold voltage.

(canceled)

(canceled)

(canceled)

(canceled)