Image forming apparatus

An image forming apparatus comprising:

• a transfer unit configured to transfer a toner image onto a sheet;
• a fixing unit configured to fix the toner image onto the sheet, wherein the fixing unit includes a roller for conveying the sheet;
• a first detection unit configured to detect the sheet between the transfer unit and the fixing unit;
• a second detection unit configured to detect the sheet between the transfer unit and the fixing unit, wherein the second detection unit is located at a position different from a position of the first detection unit in a width direction orthogonal to a sheet conveyance direction;
• a third detection unit configured to detect the sheet between the transfer unit and the fixing unit, wherein the third detection unit is located at a position on an opposite side in relation to a side at which the second detection unit is provided with respect to the position of the first detection unit in the width direction;
• and
• a control unit configured to control a rotational speed of the roller,
• wherein, in a first case where a signal from the second detection unit and a signal from the third detection unit are the same, the control unit switches the rotational speed of the roller for controlling a loop amount of the sheet between the transfer unit and the fixing unit, and
• wherein, in a second case where the signal from the second detection unit and the signal from the third detection unit are different from each other, the control unit sets the rotational speed of the roller into a predetermined speed without switching the rotational speed of the roller.

An image forming apparatus comprising:

• a transfer unit configured to transfer a toner image onto a sheet;
• a fixing unit configured to fix the toner image onto the sheet, wherein the fixing unit includes a roller for conveying the sheet;
• a lopsided loop detection unit configured to detect a lopsided loop of the sheet between the transfer unit and the fixing unit;
• and
• a control unit configured to control a rotational speed of the roller,
• wherein, in a first case where the lopsided loop is not detected by the lopsided loop detection unit, the control unit switches a rotational speed of the roller for controlling a loop amount of the sheet between the transfer unit and the fixing unit, and
• wherein, in a second case where the lopsided loop is detected by the lopsided loop detection unit, the control unit sets the rotational speed of the roller into a predetermined speed without switching the rotational speed of the roller.