Image forming apparatus with reversely-rotatable roller of differential velocities

An image forming apparatus comprising:

• an image forming portion;
• a conveying roller which is provided upstream of the image forming portion in a sheet conveying direction, and which conveys a sheet to the image forming portion;
• a re-conveying path which guides, to the image forming portion, a sheet having an image formed on its one side by the image forming portion;
• a reversely-rotatable roller which is provided downstream of the image forming portion in the sheet conveying direction, which normally rotates and conveys the sheet having the image formed on its one side at a first velocity that is faster than a sheet conveying velocity of the conveying roller and then, which reversely rotates and conveys the same sheet to the re-conveying path at a second velocity that is slower than the first velocity;
• and
• a re-conveying roller which is provided on the re-conveying path, and which conveys the sheet reversely-conveyed by the reversely-rotated roller to the conveying roller,
• wherein a sheet conveying velocity of the re-conveying roller is faster than the second velocity of the reversely-rotatable roller when the reversely-rotatable roller and the re-conveying roller convey the same sheet, and the sheet conveying velocity of the conveying roller is faster than the sheet conveying velocity of the re-conveying roller when the re-conveying roller and the conveying roller convey the same sheet.