Booklet finishing device

A booklet finishing device for flattening a spine portion of a booklet formed by folding a plurality of sheet materials, the booklet finishing device comprising:

• a frame;
• a first pressing unit and a second pressing unit which are configured to move relative to each other in a thickness direction of the booklet and configured to press a front surface and a back surface of the booklet respectively;
• a forming roller configured to press the spine portion in a direction perpendicular to the thickness direction;
• and
• a forming roller moving unit that moves the forming roller along the spine portion, wherein
• the first pressing unit includes:
• a first movable component supported by the frame and configured to move relative to the second pressing unit in the thickness direction;
• and
• a first guide component having a plate-shape and attached to a surface of the first movable component facing the second pressing unit, wherein a surface of the first guide component facing the second pressing unit includes:
• a first guide surface inclined to an insertion side of the booklet in a manner that the interval between the first guide surface and the second pressing unit is widened toward the insertion side of the booklet;
• a first contact surface extending along the moving direction of the forming roller and configured to contact the front surface of the booklet;
• and
• a first corner-forming end portion configured to form a corner portion of the spine portion of the booklet with the forming roller, the first corner-forming end portion being opposite to the insertion side of the booklet.