Patent ID: 7722306

Claim:
An image forming system, comprising: a binding section that generates a stack of sheets by accumulating a plurality of sheets and binds the stack of sheets by wrapping the stack of sheets with a cover sheet in a shape of a horizontal U; an input section for inputting a value of a spine cover width; a measurement section for measuring a thickness of the stack of sheets; a spine cover width determining section for determining the spine cover width in the cover sheet by operating in either an input mode in which the spine cover width in the cover sheet is based on the value of the spine cover width inputted by said input section, or in a measurement mode in which the spine cover width in the cover sheet is based on the thickness of the stack of sheets measured by said measurement section; an image forming section for forming a front cover image and a back cover image on the cover sheet, the front and back cover images separated by a spacing equal to the spine cover width; and a central processing unit including a control section for switching between the input mode and the measurement mode of said measurement section when a plurality of books are bound, wherein said control section judges whether or not it is the output of the first book of the plurality of books bound and controls spine cover determining operation by said spine cover width determining section by operating in the input mode when said control section judges it is the output of the first book, and operating in the measurement mode when the control section judges it is not the output of the first book.