Patent ID: 7492471

Claim:
An image forming apparatus which prints images on print sheets and inserts tab-index sheets between the printed print sheets, the image forming apparatus comprising: an orientation detecting unit which detects an orientation of a print sheet being supplied based on a tray from which the print sheet is supplied; a rotation-angle selecting unit which selects, automatically, without user intervention, a rotation angle of an image in order to match the orientation of the image to the detected orientation of the print sheet and a predetermined positional relationship with a tab of the tab-index sheets, the predetermined positional relationship indicating a position of the tab as being either at a top edge, at a bottom edge, at a left edge, or at a right edge of a tab-index sheet with respect to the image in an upright position; and a printing unit which prints the image being rotated by the selected rotation angle such that the tab comes at the position indicated by the predetermined positional relationship relative to the printed image.