Pixel sensing circuit and driving method thereof, image sensor and electronic device

A pixel sensing circuit, comprising:

• a photoelectric conversion sub-circuit electrically coupled to a signal collection point and configured to collect an incident light, and generate an electrical signal based on the incident light collected, so as to charge the signal collection point;
• a resetting sub-circuit electrically coupled to a first controlling signal line and a first power supply terminal and configured to write a first power supply voltage from the first power supply terminal to the signal collection point, under a control of a first controlling signal from the first controlling signal line;
• a conversion transistor having a control electrode electrically coupled to the signal collection point, a first electrode electrically coupled to a second power supply terminal, and a second electrode, wherein the conversion transistor is configured to output a current signal according to a voltage at the signal collection point;
• a compensation and pulling-up sub-circuit electrically coupled to the second electrode of the conversion transistor, a second controlling signal line, a third controlling signal line, a fourth controlling signal line, a second power supply terminal, and a third power supply terminal, wherein the compensation and pulling-up sub-circuit is configured to:
• obtain a threshold voltage of the conversion transistor under a control of a second controlling signal from the second controlling signal line;
• generate a compensation voltage according to the threshold voltage;
• write the compensation voltage to the signal collection point, wherein the compensation voltage V0 is given by V0=VSS+Vth, VSS refers to a second power supply voltage, and Vth refers to the threshold voltage;
• and
• pull up the voltage at the signal collection point, under a control of a third controlling signal from the third controlling signal line and a fourth controlling signal from the fourth controlling signal line, so as to enable the conversion transistor to operate in a saturated state;
• and
• a selection sub-circuit electrically coupled to the second electrode of the conversion transistor and the third controlling signal line, and configured to output the current signal from the second electrode of the conversion transistor under the control of the third controlling signal.