Active pixel circuit and method for controlling the same, and active pixel sensing device

An active pixel circuit, comprising:

• a photosensitive device coupled to a first node, the photosensitive device being configured to generate a photocurrent under an irradiation of light rays, and transmit the photocurrent to the first node;
• a source follower transistor, a control electrode of the source follower transistor being coupled to a floating diffusion node;
• and
• a compensation circuit coupled to the first node, and further coupled to the floating diffusion node, a first control terminal, a second control terminal, a third control terminal, a first reference voltage terminal, a second reference voltage terminal, and a first power supply voltage terminal,
• wherein the compensation circuit is configured to:
• transmit a target threshold voltage to the first node under control of voltages of the first control terminal, the second control terminal, the third control terminal, the first reference voltage terminal, the second reference voltage terminal, and the first power supply voltage terminal, a voltage of the first node being associated with a voltage generated by the photocurrent and the target threshold voltage;
• store the voltage of the first node;
• obtain a compensation voltage according to the voltage of the first node;
• and output the compensation voltage to the floating diffusion node,
• wherein the target threshold voltage is the same as a threshold voltage of the source follower transistor;
• wherein the compensation circuit includes a threshold voltage acquisition sub-circuit, a control sub-circuit, and an energy storage sub-circuit;
• the threshold voltage acquisition sub-circuit is coupled to the first node and the first power supply voltage terminal;
• the control sub-circuit is coupled to the first node, a second node, the floating diffusion node, the first control terminal, the second control terminal, the third control terminal, the first reference voltage terminal, and the second reference voltage terminal;
• the energy storage sub-circuit is coupled between the second node and the floating diffusion node;
• the threshold voltage acquisition sub-circuit is configured to adjust a voltage of the first node to an associated voltage under control of a voltage of the first power supply voltage terminal, wherein the associated voltage is associated with the target threshold voltage and the voltage generated by the photocurrent;
• the control sub-circuit is configured to:
• output the associated voltage of the first node to the second node and a first reference voltage received at the first reference voltage terminal to the floating diffusion node under control of voltages of the first control terminal, the second control terminal, and the third control terminal;
• and charge the energy storage sub-circuit;
• the control sub-circuit is further configured to:
• adjust a voltage of the second node from the associated voltage to a second reference voltage received at the second reference voltage terminal under the control of the voltages of the first control terminal, the second control terminal, and the third control terminal;
• and adjust a voltage of the floating diffusion node from the first reference voltage to the compensation voltage through the energy storage sub-circuit.