IMAGE FORMING APPARATUS

Disclosed is an image forming apparatus that forms an image on one side of a sheet and then forms an image on the other side of the sheet. A single-sided sheet passing path transports a sheet housed in a sheet-feeding tray to the image forming section, and a double-sided sheet passing path reverses a sheet with an image formed on one side and causes the sheet to join the single-sided sheet passing path. The single-sided sheet passing path is formed so as to include a second interval which includes a registration sensor placed near a joining position of the single-sided and double-sided sheet passing paths in the double-sided sheet passing path as one end point and in which a sheet draws a moving trajectory substantially identical to a moving trajectory of a sheet in a first interval extending toward an upstream side in the transport direction of the sheet.