A media sheet router moves sheets from a digital printer through the router and selectively to a plurality of finishers at full process speed. A router inlet path is aligned with the printer outlet path. Two router outlet paths are disposed at ninety degrees to the left and right of the router inlet path. The router outlet paths are each aligned with a finisher inlet path or another router. First and second turning elements are each mounted at forty-five degrees to the router inlet path and at ninety degrees to each other. Each turning element directs the sheets in a helical path to the router outlet paths. Transfer belts hold the sheets against each turning element. A bypass transfer moves the sheet to a bypass outlet path aligned with a bypass finisher inlet path. Diverters selectively direct the sheets onto the turning elements or the bypass transfer.

A paper feed roller of the present invention comprises a roller body 2 integrally formed of elastic material in a cylindrical shape in which a plurality of protruding lines 6 are disposed on a peripheral surface 5 at even intervals, wherein the roller body 2 is formed so that crest portions 6a and trough portions 6b are continuously provided in a circumferential direction, an opening angle is equal to or more than 2 and is equal to or less than 8, a radial height h of the protruding line is equal to or more than 0.051 mm and is equal to or less than 0.1 mm, and a curvature radius r1 at a shoulder is equal to or more than 0.55 mm.

A sheet conveying device includes a sheet stacker, an air blower, and a guide. The sheet stacker stacks a plurality of sheets. The air blower blows air onto the plurality of sheets. The guide faces an uppermost sheet of the plurality of sheets on the sheet stacker and contacts the uppermost sheet at a plurality of positions of the guide spaced apart from each other in a sheet conveyance direction.