Sheet bundle discharging apparatus and bookbinding apparatus

A bookbinding apparatus comprising:

• a binding unit configured to bind a sheet bundle;
• and
• a sheet bundle discharging apparatus including:
• (1) a conveyance belt configured to convey and discharge a sheet bundle in a predetermined conveyance direction;
• (2) an attitude changing unit configured to change an attitude of the sheet bundle from a first attitude in which the sheet bundle is apart from the conveyance belt to a second attitude in which the sheet bundle is placed on the conveyance belt;
• and (3) a receiving member configured to receive an end portion of the sheet bundle in a case where the attitude changing unit changes the attitude of the sheet bundle from the first attitude to the second attitude,
• wherein, by changing the attitude of the sheet bundle from the first attitude to the second attitude by the attitude changing unit, the end portion of the sheet bundle can reach the receiving member after the end portion of the sheet bundle passes through a region above the conveyance belt with a component of movement that is parallel to a conveyance surface of the conveyance belt, the component of movement being in a belt width direction perpendicular to the predetermined conveyance direction,
• wherein a friction coefficient between the sheet bundle and the receiving member is smaller than a friction coefficient between the sheet bundle and the conveyance belt,
• wherein the attitude changing unit changes the attitude of the sheet bundle bound by the binding unit from the first attitude to the second attitude, and
• wherein the conveyance belt discharges the sheet bundle in the second attitude in the predetermined conveyance direction.