Medium-transporting device and image reading apparatus

A medium-transporting device comprising:

• a first unit that forms an inner side of an inverting path on which a medium is inverted while being curved;
• a second unit that forms an outer side of the inverting path and retreats from the first unit to perform an exposing operation of exposing a portion of the inverting path in a transport direction of the medium;
• a third unit that forms the outer side of the inverting path in a portion downstream of the second unit in the transport direction and is provided so as to be rotatable about a first rotational shaft such that the third unit is configured to be reciprocated with respect to the first unit;
• an inner roller rotatably provided in the first unit;
• at least one outer roller located outside the inverting path and configured to transport the medium by rotating with the inner roller;
• and
• at least one supporting unit that supports the outer roller so as to be rotatable, that is provided so as to be rotatable about a second rotational shaft, and that forms the outer side of the inverting path, wherein
• the second unit is configured to apply a pressing force to the supporting unit in accordance with the exposing operation,
• the supporting unit is configured to rotate, by receiving a force from the second unit, in a direction in which the outer roller moves away from the inner roller, and
• the third unit is configured to rotate, by receiving a force from the supporting unit, in a direction in which the third unit retreats from the first unit.