Image forming apparatus

An image forming apparatus capable of correcting a lateral deviation and/or a skew of a sheet, comprising:

• a pair of conveying rollers which convey the sheet to a transfer position of an image;
• an image sensor which reads the sheet on an upstream side of the transfer position in a sheet conveying direction;
• a control device which processes an output signal of the image sensor;
• and
• a cleanup device which cleans a reading surface of the image sensor, wherein
• the image sensor includes a plurality of light-receiving elements arranged along a main scanning direction,
• the cleanup device includes a cleanup body movable in the main scanning direction,
• the cleanup device causes the cleanup body to reciprocate, to clean the reading surface of the image sensor,
• the control device senses a position of a foreign substance on the reading surface of the image sensor as well as calculates a lateral deviation amount and/or a skew amount of the sheet based on the output signal of the image sensor,
• the control device identifies a first position and a second position that are respective ends of a partial region including the position in the main scanning direction where the foreign substance was detected of an entire region of the reading surface of the imaging sensor, and
• the control device causes the cleanup device to reciprocate between the first position and the second position.