Sheet transport device including two types of corrugation members, sheet postprocessing apparatus, and sheet postprocessing system

A sheet transport device comprising:

• a delivery roller that delivers a sheet;
• and
• a transport route provided upstream of the delivery roller in a delivery direction of the sheet, and including an upper guide member and a lower guide member opposed to each other, and configured to guide the sheet toward the delivery roller,
• wherein the lower guide member includes:
• a plurality of first guide ribs aligned on a surface of the lower guide member in a width direction orthogonal to the delivery direction, and each extending in the delivery direction, to support the sheet;
• a first corrugation member having a belt-like and thin plate shape, extending in the delivery direction along the first guide rib;
• and
• a first elastic member supporting an end portion of the first corrugation member, on a side of the delivery roller in the delivery direction, such that the end portion protrudes ahead of the first guide rib toward the upper guide member, with respect to the other end portion, and
• the upper guide member includes:
• a plurality of second guide ribs aligned on a surface of the upper guide member in the width direction orthogonal to the delivery direction, and each extending in the delivery direction, to support the sheet;
• a second corrugation member having a belt-like and thin plate shape, extending in the delivery direction of the sheet, along the second guide rib;
• and
• a second elastic member supporting an end portion of the second corrugation member, on the side of the delivery roller in the delivery direction, such that the end portion protrudes ahead of the second guide rib toward the lower guide member, with respect to the other end portion.