An image forming apparatus in that a sheet having an image formed on a first
side
thereof by an image forming portion is again transported to the image forming portion
so that an image may be formed on an opposite or second side of the sheet, the
image forming apparatus including a sheet feeding portion, a re-transport path,
a pair of registration rollers provided upstream of the image forming portion,
and a loop forming space provided upstream of the pair of registration rollers
so as to form the loop, wherein an entrance to the loop forming space for the sheet
having passed along the re-transport path is formed downstream of an entrance to
the loop forming space for the sheet fed from the sheet feeding portion.
