PURPOSE: An image sensor using a charging characteristic of a data readout line and an operation method thereof are provided to exactly display a sensor image regardless of an on-current property of a TFT(Thin Film Transistor) using the charging characteristic of a data readout line. CONSTITUTION: A sensor pixel is defined by crossing scanning lines and dada readout lines. A switching transistor is connected to the scanning lines and the dada readout lines to switch the sensor pixel. A readout operation unit(140) operates the data readout lines and detects a change of resistance according to an image pattern through the data readout line. An active switch(172) obtains a detailed signal using voltage charged in a parasitic capacitor.
