Medium transport device and medium processing apparatus including the same

A medium transport device comprising:

• first transport units including a first transport unit on a front side and a first transport unit on a rear side that are respectively disposed in a front part and a rear part of a region having a length in a transport direction of a medium having a transportable minimum size and that transport the medium while nipping the medium;
• a second transport unit that is disposed between the first transport units and that transports the medium while nipping the medium and pulling the nipped medium outward in a width direction intersecting the transport direction;
• and
• a controller that performs control to:
• when the medium is a thin medium, cause the medium transport device to transport the medium while nipping the medium by using only the second transport unit,
• wherein the thin medium is a medium having a thickness less than or equal to a predetermined thickness;
• and
• when the medium is a medium other than the thin medium, cause the medium transport device to transport the medium while nipping the medium by using the first transport units and the second transport unit.