Skew correction device, image forming system, and skew correction method

An image forming system comprising a skew correction device, wherein the skew correction device includes:

• a conveying path through which a booklet formed by folding a sheet bundle is conveyed in a conveying direction;
• a positioning unit on which a leading-end portion of the booklet in the conveying direction is to abut, the positioning unit being arranged to be able to protrude into and retreat from the conveying path;
• an abutting unit that pushes a trailing-end portion of the booklet in the conveying direction, thereby moving the booklet toward the positioning unit and causing the leading-end portion of the booklet to abut on the positioning unit;
• and
• a pushing force changing unit that changes a pushing force applied by the abutting unit to the booklet to push the booklet against the positioning unit based on a pushing amount of the abutting unit to the booklet.

A skew correction method comprising:

• conveying a booklet formed by folding a sheet bundle along a conveying path;
• causing a leading-end portion of the booklet in the conveying direction to abut on a positioning unit arranged to be able to protrude into and retreat from the conveying path;
• performing skew correction on the booklet by pushing a trailing-end portion of the booklet in the conveying direction, which has abutted on the positioning unit, against the positioning unit;
• and
• changing a pushing force, with which the booklet is to be pushed by the abutting unit, based on a pushing amount of the abutting unit to the booklet by setting the pushing amount based on information relating to the pushing amount.