Medium discharge device and image reading device

A medium discharge device comprising:

• a discharge drive roller that contacts a first surface of a medium to be discharged and that rotates by power from a drive source;
• a discharge driven roller that contacts a second surface opposite from the first surface of the medium to be discharged and that is drivenly rotated with the medium nipped between itself and the discharge drive roller;
• a first discharge aid member that contacts the second surface of the medium to be discharged, that has a larger diameter than the discharge driven roller, and that rotates by torque from the discharge driven roller;
• and
• a second discharge aid member that contacts the second surface of the medium to be discharged, that has a larger diameter than the discharge driven roller, and that rotates by torque from the discharge driven roller, wherein
• the second discharge aid member is positioned to the outside of the first discharge aid member in a width direction that intersects a medium discharge direction,
• the discharge driven roller and the first discharge aid member are displaceable in directions toward and away from the discharge drive roller, and
• the torque of the discharge driven roller is transmitted to the second discharge aid member via a shaft and a universal joint.