Patent ID: 7878495

Claim:
An image forming apparatus which uses a plurality of sheet processing apparatuses serially connected and equipped with the same or different sheet processing functions, the image forming apparatus comprising: a conveyance device which conveys sheets; a transmitting device which transmits timing information for use to determine a discharge timing of a sheet, the timing information including arrival time information indicating an arrival time at which the sheet arrives at a first sheet processing apparatus and a feeding interval of sheets to the first sheet processing apparatus; a receiving device which receives edited timing information, which is the timing information that has been edited and relayed from the first sheet processing apparatus to a second sheet processing apparatus as a target sheet processing apparatus to which the sheet is loaded; and a controller which (a) compares extension time information included in the edited timing information with delay time information included in the edited timing information, the extension time information indicating an extension time necessary to postpone the arrival time of the sheet such that the second sheet processing apparatus finishes a preparation operation before the arrival of the sheet, and the delay time information indicating a delay time necessary to postpone an arrival time of a next sheet such that the second sheet processing apparatus finishes a sheet process of the sheet before the arrival of the next sheet, (b) determines the discharging timing of the sheet based on the arrival time information and the longer one of the extension time and the delay time, and (c) controls said conveyance device so that the sheet will be discharged at the determined discharging timing, wherein the arrival time information is edited by adding time consumed to pass through other sheet processing apparatuses connected between the first and second sheet processing apparatuses.