Patent ID: 6937829

Claim:
An image forming apparatus capable of feeding tab sheets of a predetermined tab sheet bundle or other sheets than the tab sheets, comprising: a first sheet feed device that feeds each of the tab sheets of the predetermined tab sheet bundle or the other sheets to an image transfer position via a first conveying path with the sheet being inverted; a second sheet feed device that feeds each of the tab sheets of the predetermined tab sheet bundle or the other sheets to the image transfer position via a second conveying path without each sheet being inverted; a first sheet discharge device that discharges each of the tab sheets of the predetermined tab sheet bundle or the other sheets in a face-up state; a second sheet discharge device that discharges each of the tab sheets of the predetermined tab sheet bundle or the other sheets in a face-down state; a designating device that designates a type of sequence of tabs of each of tab sheet bundles set in said first sheet feed device and said second sheet feed device; and a determining device responsive to a user's instruction for feeding tab sheets and selection of a combination of one of said first sheet feed device and said second sheet feed device and one of said first sheet discharge device and said second sheet discharge device, for determining whether a combination of the selected one of said first sheet feed device and said second sheet feed device, the selected one of said first sheet discharge device and said second sheet discharge device, and the type of sequence of tabs of the tab sheet bundle set in the selected one of said first sheet feed device and said second sheet feed device is valid or not.