Image forming apparatus

An image forming apparatus comprising:

• an image forming unit configured to form an image on a sheet;
• a first guide configured to guide the sheet having the image formed by the image forming unit;
• a switchback roller configured to rotate in a forward direction in which the sheet is ejected in a sheet ejection direction and in a backward direction in which the sheet is fed in a switchback direction;
• a second guide configured to guide the sheet guided by the first guide toward the switchback roller in the sheet ejection direction, the second guide being further configured to guide the sheet being fed in the switchback direction from the switchback roller toward a re-feed path for re-feeding the sheet toward the image forming unit;
• and
• a corrugation member including a nip portion configured to contact the switchback roller and a protruding portion protruding toward the switchback roller relative to the nip portion, the corrugation member having a shape for producing, in the sheet being fed, a recessed portion and a ridge portion as viewed from a downstream side of the switchback roller in the sheet ejection direction along a tangent to the switchback roller at a nip position where the nip portion of the corrugation member and the switchback roller nip the sheet therebetween,
• wherein the second guide has:
• a first guide surface disposed to contact the recessed portion of the sheet fed in the switchback direction;
• and
• a second guide surface spaced apart from the first guide surface at least in an axial direction of the switchback roller, the second guide surface being disposed to contact the ridge portion of the sheet fed in the switchback direction,
• wherein, as viewed from the downstream side of the switchback roller in the sheet ejection direction along the tangent to the switchback roller at the nip position, a distance between an end of the first guide closest to the switchback roller and an end of the second guide surface closest to the switchback roller is greater than a distance between the end of the first guide closest to the switchback roller and an end of the first guide surface closest to the switchback roller,
• wherein a curvature radius of the second guide surface is greater than a curvature radius of the first guide surface, and
• wherein, when projected in the axial direction of the switchback roller, the first guide surface and the second guide surface overlap each other on a downstream side, in the switchback direction, of an intersection point of the second guide and the tangent to the switchback roller at the nip position.