Photo sensor device

A photo sensor device comprising:

• a gate line,
• a signal line, and
• a photo sensor circuit disposed on a substrate, the photo sensor circuit including
• a first switching transistor,
• a second switching transistor,
• a photo transistor, and
• a capacitance element,
• wherein
• the first switching transistor includes
• a first semiconductor layer,
• a first gate electrode,
• a first source electrode, and
• a first drain electrode,
• the second switching transistor includes
• a second semiconductor layer,
• a second gate electrode, and
• a second source electrode,
• the photo transistor includes
• a fourth semiconductor layer,
• a fourth gate electrode,
• a fourth source electrode, and
• a fourth drain electrode,
• the capacitance element includes
• a first terminal and
• a second terminal,
• the first semiconductor layer of the first switching transistor and the fourth semiconductor layer of the photo transistor are formed of an oxide semiconductor material in a same layer,
• the first gate electrode of the first switching transistor, the fourth gate electrode of the photo transistor and the first terminal of the capacitance element are formed in a same layer, and
• the first drain electrode of the first switching transistor and the fourth drain electrode of the photo transistor are formed in a same layer.