Bookbinding device

A bookbinding device for bonding, with a hot-melt adhesive, one side of a sheet bundle to be bound and a back cover face of a cover sheet for covering the sheet bundle, comprising:

• a pair of holders capable of changing postures between a first posture of holding and restraining a lateral portion of the sheet bundle covered with the cover sheet, and a second posture of releasing the restraint;
• a tabular heating plate capable of generating heat for melting the hot-melt adhesive;
• a tabular cooling plate;
• a movable support plate which is arranged movably below the holders and supports the heating plate and the cooling plate;
• a first drive unit for changing the posture of the holders to the first posture or the second posture;
• a second drive unit for moving the movable support plate between a first position where the heating plate is positioned at a lower side of a holding space where the holders hold the sheet bundle, and a second position where the cooling plate is positioned at a lower side of the holding space;
• and
• a controller for controlling the operation of the first drive unit and the second drive unit;
• wherein
• the controller sequentially controls the first drive unit and the second drive unit as follows:
• in a preheating stage of preheating the heating plate, moving the movable support plate to the second position, and causing the holders to assume the first posture at least when the preheating is ended,
• in a heating stage of melting the hot-melt adhesive, moving the movable support plate to the first position, and thereafter causing the holders to assume the second posture, and
• in a cooling stage of solidifying the melted hot-melt adhesive, causing the holders to assume the first posture, and thereafter moving the movable support plate to the second position.