Display assembly, display apparatus, and driving method

A display apparatus, comprising a display assembly, wherein the display assembly comprises a display panel and a function module located on a light-emitting surface of the display panel, and wherein:

• the function module comprises a plurality of function units, and each function unit comprises at least one phototransistor and one switch transistor;
• the phototransistor comprises a first active layer, a first gate, a first source, and a first drain, a material for making the first active layer comprises an organic semiconductor material, the first active layer is located on a side of the first gate away from the display panel, and the first drain and the first gate partially overlap in a direction perpendicular to the display assembly to form a first capacitor;
• the switch transistor comprises a second active layer, a second gate, a second source, and a second drain, and the second source is connected to the first drain;
• and
• each function unit comprises a transparent electrode, the transparent electrode is located on a side of the first active layer away from the first gate, the transparent electrode overlaps the first active layer in the direction perpendicular to the display assembly, and a dielectric layer is disposed between the transparent electrode and the first active layer.

A driving method for a display assembly, wherein the display assembly comprises a display panel and a function module located on a light-emitting surface of the display panel, and wherein:

• the function module comprises a plurality of function units, and each function unit comprises at least one phototransistor and one switch transistor;
• the phototransistor comprises a first active layer, a first gate, a first source, and a first drain, a material for making the first active layer comprises an organic semiconductor material, the first active layer is located on a side of the first gate away from the display panel, and the first drain and the first gate partially overlap in a direction perpendicular to the display assembly to form a first capacitor;
• the switch transistor comprises a second active layer, a second gate, a second source, and a second drain, and the second source is connected to the first drain;
• and
• each function unit comprises a transparent electrode, the transparent electrode is located on a side of the first active layer away from the first gate, the transparent electrode overlaps the first active layer in the direction perpendicular to the display assembly, and a dielectric layer is disposed between the transparent electrode and the first active layer;
• and
• wherein the driving method comprises:
• controlling both the switch transistor and the phototransistor to be turned off, and charging the first capacitor to accumulate an amount of initial charge under an action of a leakage current of the phototransistor;
• controlling the switch transistor to be turned on, discharging the first capacitor, and controlling the switch transistor to be turned off after reading the amount of initial charge through the second drain;
• in response to a touch of a finger, changing an electric field between the transparent electrode and the first active layer, and charging the first capacitor to accumulate an amount of touch charge;
• and
• controlling the switch transistor to be turned on, discharging the first capacitor, reading the amount of touch charge through the second drain, and determining a touch position of the finger based on the amount of touch charge.