Patent ID: 7661673

Claim:
An image forming apparatus comprising: an image forming unit configured to form an image on a sheet; and a sheet conveyance unit configured to convey the sheet having a predetermined sheet passing width through the image forming unit; wherein the sheet conveyance unit includes: a sheet conveyance path designed so as to include nonlinear portions; a first conveyance roller pair which is provided at predetermined positions of the sheet conveyance path and which has a conveyance width therebetween capable of nipping and conveying a sheet having the minimum size sheet passing width among the sheets to be passed through the sheet conveying apparatus; a pair of resist rollers disposed in a downstream side of the first conveyance roller pair and in an upstream side of the image forming unit in the sheet conveyance path; a second conveyance roller pair which is provided in an upstream side of the first conveyance roller pair in the sheet conveyance path; a first guide plate which is placed between the first conveyance roller pair and the second conveyance roller pair, and has a first curved guide surface; a second guide plate which is placed between the first conveyance roller pair and the pair of resist rollers, and has a second curved guide surface; and a plurality of guide ribs which are extended on at least one of the first guide surface and the second guide surface in a sheet conveyance direction and are provided in a sheet passing width direction of the sheet in a region corresponding to the conveyance width of the first conveyance roller pair; wherein at least one of a first section of the sheet conveyance path between the second conveyance roller pair and the first conveyance roller pair, and a second section of the sheet conveyance path between the first conveyance roller pair and the pair of resist rollers is curved into a U-shape, and at least one of the first guide plate and the second guide plate forms one side wall of the section of the conveyance path curved into the U-shape.