X-ray detector and driving method therefor

An X-ray detector comprising:

• a first electrode formed on a substrate;
• a photoconductive layer formed on the first electrode;
• a second electrode formed on the photoconductive layer and configured to be in a voltage applied state with a bias voltage or a floating state;
• a power supply circuit configured to control an output of the bias voltage to be on/off;
• and
• wherein the power supply circuit selects any bias voltage ranging from a first-level bias voltage to an N-th-level bias voltage, and controls an output of the selected bias voltage to be on/off, wherein the N is 2 or greater.