Patent ID: 7889362

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, wherein said rotation-angle selecting unit checks whether the image is a first image, said rotation-angle selecting unit arranging the image in an orientation matching an orientation of the print sheet upon finding that the image is the first image, and said rotation-angle selecting unit arranging the image in an orientation matching an orientation of a sheet on which the first image is printed upon finding that the image is not the first image.