Patent ID: 7823867

Claim:
A book binding apparatus comprising: a first conveying path configured to guide a sheet from a first device connected at an upstream side in a sheet conveying direction to a second device connected at the downstream side in the sheet conveying direction; a loading tray configured to receive a plurality of sheets from the first device and to load the sheets thereon to form a sheet bundle; a book binding device configured to convey the sheet bundle loaded on the loading tray and to bind the conveyed sheet bundle; a discharging device configured to discharge the sheet bundle bound by the book binding device therein; a storing device configured to store the sheet bundle discharged by the discharging device; a second conveying path configured to facilitate conveying the sheet bundle from the loading tray to the storing device, the second conveying path intersecting with the first conveying path; and a controller configured to switch between a first operation mode in which the sheet is conveyed along the first conveying path so as to transfer the sheet to the second device, and a second operation mode in which the sheet bundle is conveyed along the second conveying path so as to execute binding on the sheet bundle using the book binding device, wherein the controller permits a sheet conveying operation in the first operation mode when the number of sheet bundles that have not been discharged to the storing device by the discharging device is smaller than a predetermined number, whereas the controller prohibits the sheet conveying operation in the first operation mode when the number of sheet bundles that have not been discharged to the storing device by the discharging device is equal to or larger than the predetermined number.