Image forming apparatus

An image forming apparatus comprising:

• a printing device configured to form an image on a sheet conveyed along a conveying path;
• a plurality of line sensors disposed downstream of the printing device in a sheet conveying direction along a width direction intersecting the sheet conveying direction, with respective positions in the width direction partially overlapping with each other, and configured to read images of a plurality of partial areas from the sheet, each of the partial areas including a non-overlapping area which does not overlap with an adjacent area and an overlapping area which overlaps with the adjacent area, each of which is a part of a sheet passing area in the width direction;
• an image judgment portion configured to judge whether or not data of each of a plurality of read images obtained by the plurality of line sensors satisfies a tolerance condition based on a corresponding one of a plurality of reference image data items representing the images of the plurality of partial areas;
• and
• an error processing portion configured to execute predetermined error processing when it is judged that the data of any of the plurality of read images does not satisfy the tolerance condition.