Sheet processing apparatus and sheet processing method

A sheet processing apparatus comprising:

• a sheet conveying path that brings in sheets discharged from an image forming apparatus and guides the sheets to a standby tray;
• a processing tray that is provided below the standby tray and is capable of receiving the sheets supplied from the standby tray and placing the sheets thereon;
• a post-processing unit configured to apply post-processing to the sheets placed on the processing tray;
• a sheet discharging unit configured to have a conveying tool that discharges the sheets subjected to the post-processing by the post processing mechanism;
• a paddle that is attached to a rotating shaft arranged in a direction orthogonal to a conveying direction of the sheets and for guiding the sheets supplied from the standby tray to the processing tray, the paddle including a receiving unit that receives an end of a sheet supplied from the standby tray and a sending unit that is arranged at a predetermined angle with respect to the receiving unit and sends the sheets on the processing tray to the post-processing mechanism;
• a sheet discharge tray that receives the sheets discharged from the discharge port;
• a tray control unit that controls a height position of the sheet discharge tray such that a sheet on an uppermost surface of the sheets stacked on the sheet discharge tray is in a predetermined height position;
• a discharge control unit that controls an operation of the sheet discharging unit and stops discharge of new sheets, when a quantity of the sheets stacked on the sheet discharge tray reaches a full state set in advance;
• and
• a paddle control unit that rotates the paddle a predetermined angle and temporarily presses the sheet on the conveying tool with the pressing unit, when a sheet is present on the conveying tool in the full state.

A sheet processing method comprising:

• sending sheets supplied from an image forming apparatus to a post-processing unit with a paddle having a rotatable sending unit;
• discharging the sheets subjected to post-processing by the post-processing unit from a discharge port using a conveying tool;
• receiving the sheet discharged from the discharge port with a sheet discharge tray;
• controlling a height position of the sheet discharge tray such that a sheet on an uppermost surface of the sheets stacked on the sheet discharge tray is at a predetermined height position;
• stopping an operation of the conveying tool when a quantity of the sheets stacked on the sheet discharge tray reaches a full state set in advance;
• and
• rotating the paddle a predetermined angle when a sheet is present on the conveying tool in the full state and temporarily pressing the sheet on the conveying tool with the sending unit.