Medium transport device and recording device

A medium transport device comprising:

• a medium mounting portion at which a first medium and a second medium are mounted;
• a feeding roller configured to send the first medium in a transport direction;
• a separation roller configured to nip the first medium between the feeding roller and the separation roller, and separate the first medium and the second medium;
• a transport roller pair configured to transport the first medium sent from the feeding roller;
• and
• a driving mechanism configured to drive the separation roller, wherein
• the separation roller is rotatable in a first rotational direction in which the first medium is sent in the transport direction, and also in a second rotational direction that is opposite from the first rotational direction,
• the driving mechanism causes the separation roller to rotate in the second rotational direction,
• the driving mechanism applies a rotational load having a first load value to rotation of the separation roller in the first rotational direction, and
• switches, after a leading edge of the first medium passes through the transport roller pair and before a trailing edge of the first medium passes through between the feeding roller and the separation roller, a rotational load applied to the separation roller from the first load value to a second load value that is lower than the first load value.