Image forming apparatus and method of controlling the same

A method of controlling an image forming apparatus configured to form images on both sides of a sheet, the image forming apparatus comprising (a) an image forming unit configured to form an image on an image bearing member, (b) a first conveyer configured to convey the sheet on a conveyance path, and to move the sheet being conveyed toward a width direction, which is orthogonal to a conveyance direction, (c) a second converter configured to invert and convey, after the formed image is transferred onto a first surface of the sheet, the sheet to transfer an image onto a second surface of the sheet, and (d) a detector configured to detect a side edge position of the sheet in the width direction during conveyance for the transferring onto the first surface of the sheet, and during conveyance for the transferring onto the second surface of the sheet, respectively, the method comprising:

• determining, based on a first detection result of the detector for the first surface of a previous sheet which precedes a first sheet, a first forming position of an image to be transferred on the first surface of the first sheet on the image bearing member in the width direction;
• controlling, based on the first forming position and a second detection result of the detector for the first surface of the first sheet, the first conveyer to move the first sheet;
• determining a second forming position of the image to be transferred on the second surface of the first sheet based on a third detection result of the detector for the second surface of the previous sheet;
• and
• controlling the first conveyer to move the first sheet based on the second forming position and a fourth detection result of the detector for the second surface of the first sheet.