Patent ID: 8472858

Claim:
An image forming apparatus, comprising: an image forming unit performing a predetermined image forming process to form a toner image on a sheet; a fixing unit heat-fixing the toner image on the sheet to the sheet; and a sheet discharge unit discharging the sheet finished with the heat-fixing process to the outside, the sheet discharge unit including: a first path for discharging the sheet finished with the heat-fixing process to the outside, a second path for feeding the sheet again to the image forming unit in the case of performing a duplex image forming process for forming a toner image also on an underside of the sheet opposite to a top side where the toner image is formed; a sheet conveyor conveying the sheet from the first path to the outside, the sheet conveyor also temporarily discharging to the outside a part of the sheet except for a trailing end of the sheet with respect to a discharge direction of the sheet and then conveying the sheet back to the second path from the discharge direction trailing end; and a corrugating member corrugating the sheet in a width direction of the sheet orthogonal to a conveying direction of the sheet to give the sheet stiffness when the sheet conveyor conveys the sheet; wherein the second path includes a wall portion defining an upstream path section having a width that extends in a thickness direction of the sheet, the width being set to be narrow to such a degree that the corrugation of the sheet is reduced when the sheet passes the upstream path section, the wall portion having a flat part extending along the upstream path section and having a flat surface contacting a plane of the sheet, a facing member arranged at a position facing the flat part and narrowing the width of the upstream path section, the facing member including an elastic sheet member biased toward the flat part, the elastic sheet member including a base end portion and a leading end portion, the base end portion being positioned at an upstream side with respect to the conveying direction in which the sheet is conveyed to the image forming unit via the second path and being mounted on the facing member, and the leading end portion extending from the base end portion toward a downstream side with respect to the conveying direction and held in contact with the flat part.